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ARK CLS Seismic Coloured Inversion V2.94

1. 3 2 Selecting Data SciQt integrates with various third party data repositories This should be transparent to you and is dependent on how the software was launched To use the Coloured Inversion application to design an operator it is first necessary to analyse the seismic and well data spectra This is achieved by loading some seismic trace data and well log impedance data in time Pop up the Select Input Data dialog by either clicking the Input Seismic and Well data menu item under the Tools menu bar or by clicking the Icon The table below shows both tabs of the Select Input Data dialog with an example of data selected for Coloured Inversion operator design Seismic Coloured Inversion is data driven which means that the complete analysis and design of the operator or as far as possible are performed as soon as the data is selected loaded or updated 3 2 1 Input Seismic With the Select Input Data Dialog displayed click the Input Seismic tab default to select the input seismic data to be used The SciQt will connect with various data repositories depending on the environment in which the Coloured Inversion software is being run It attempts to do this in such a manner that the Geoscientist need know only minimal information to be able to connect seamlessly with the seismic database However as data repositories from third party vendors use different techniques to store data there will inevitably be some differences wi
2. Auto Calc The top checkbox controls whether the Low Cut and High Cut i e design operator bandwidth values are automatically calculated 1 Top Auto Calc checkbox checked default on the distributed template In this mode the design operator bandwidth is automatically calculated 2 Top Auto Calc checkbox unchecked In this mode you can manually set the Low Cut and High Cut spinboxes Low Cut this control will be sensitised allowing you to adjust the low cut to optimise the Coloured Inversion operator Using the Residual Operator QC chart will help The objective here is that the residual operator should be essentially flat and centred around 0 dB within the bandwidth High Cut this control will be sensitised allowing you to adjust the high cut to optimise the Coloured Inversion operator Using the Residual Operator QC chart will help As with the Low Cut the objective is that the residual operator should be essentially flat and centred around 0 dB within the bandwidth Auto Calc The middle checkbox allows you to control the slopes on the derived operator This checkbox is only sensitised if you are manually setting the design operator Low Cut and High Cut i e the top Auto Calc checkbox is unchecked 1 Middle Auto Calc checkbox checked default on the distributed template In this mode the 60 dB down point is at 0 Hz on the low size with the 60 dB down point 30 Hz above the High Cut value on the hi
3. 4 1 Interfacing with the SciQt Application This section describes how you interface with the SciQt Main Window and the SciQt Main Window ancillary tools The primary tools allowing you to load data analyse design and apply the Coloured Inversion operator are described in greater detail in later sections 4 1 1 SciQt Main Window The Coloured Inversion main window GUI consists of from top to bottom a menubar area a toolbar area a chart area and a status area see figure below The chart area which occupies the large central area of the main window is used to display various charts of spectra and time data providing instant feedback to the Interpretation Geoscientist in his her quest to design a Coloured Inversion operator The four sub sections which follow will provide you with a description of each of these areas We will pay particular attention to the central chart area Figure 4 1 SciQt main window w Seismic Coloured Inversion testdata sci test l O3Apr2008 se5s File View Tools Help s u ic RE jt oce Raw Seismic Seismic Mean nid V Y if zu zt p S AN a 9 a 107 q 4 ff AM SLT Ji j J i 50 100 50 Frag Hz Freq iHz Log Input time domain Log Input Detrend time domain 10000 30000 n 25000 M Ina PERDATA ys anya aT IAN http opendtect org rel doc arkcls sci ch04s01 html 1 of 13 21 10 2009 15 30 04 X 4 1 Interfacing
4. Freg Hz The images in the figure above show how data on an individual chart can be identified To identify data on a given chart point to a vertex on one of the data curves and press MB1 you need to be near to a vertex If you are close to a vertex when you click MB1 the curve name and the coordinates of the vertex will be displayed This is useful since it gives you a mechanism for identifying anomalous curves so that they can be removed In the LH image there is a spike on the red curve around 43Hz Clicking on the tip of the spike identifies it as TRACE 005 Now in this case you can go to the Input Seismic tab on the Select Input Data Dialog and deselect it The RH image shows the result of deselecting TRACE 005 4 2 1 3 Data Zooming Data zooming is different from global zooming as data zooming is only performed on an individual chart Like global zooming it is quick and easy Charts zoomed in this way stay zoomed until you revert them to an unzoomed state You can zoom in and out on individual charts by pressing and holding the Control key then rotate the mouse wheel either towards you zoom out or away from you zoom in The zooming will be centred around the position of the mouse Alternative methods for individual chart zooming are described below Figure 4 10 Data Zooming on Charts Seismic Mean TTT TTT rr yt rrr yt rt ty tT T T T TT T T T TT r 50 100 40 S0 BO Freq Hz rege The images in the figure
5. MB3 clicking and selecting the Unzoom All Recentre Data pull down menu item The LH image shows the rubber band box identifying the area that is to be zoomed and the RH image shows the result of the data zoom 4 2 1 4 Moving Data Moving data is a mechanism which allows you to grab hold of the data on a chart and drag it to a new position Essentially you are changing the axes on the chart coordinate system Figure 4 11 Moving Data on Charts Seismic Mean Seismic Mean 40 50 50 10 0 10 20 Freq Hz Freq Hz The images in the figure above show how data on an individual chart can be moved Moving data is achieved by pointing to a position on a chart and moving that position to a new place You invoke move data mode by pointing to the chart where you have data that is to be moved and click MB3 This pops up a menu Select Move Data Ctrl MB1 which will put you into move data mode The next time you click and hold with MB1 on the chart the position to be moved will be identified Whilst holding down MB1 move to the new position Data will move interactively as you move to the new position Letting go the MB1 will leave the data at the new position After data moving the MB1 will revert to its default mode Identify Data To re centre the data press MB3 which will pop up a menu then select Unzoom Recentre Data Shift MB1 A faster method of achieving the same result is to press and hold Ctrl key then press and hold MB1 whilst draggi
6. 4 4 Design Controls 4 4 1 Smooth Seismic Mean 4 4 2 Fit Well Log Curves 4 4 3 Design Operator 4 5 Advanced Controls 4 5 1 Frequency Domain 4 5 2 Design Operator 4 5 3 Time Domain List of Figures 2 1 Seismic Method and Inversion 2 2 Synthetic comparison 2 3 Synthetic comparison in greater detail 2 4 Coloured Inversion and Unconstrained Sparse Spike example 2 5 Improving Interpretation example 2 6 Horizontal Well example 3 1 Attribute Set used to launch SciQt 3 2 Seismic Coloured Inversion main window 3 3 Select Input Data Dialog Input Seismic Tab 3 4 Select Input Data dialog Input Well Log tab 3 5 Design Controls dialog 3 6 Seismic Coloured Inversion main window after analysis and design 3 7 OpendTect Coloured Inversion Processing http opendtect org rel doc arkcls sci index html 3 of 5 21 10 2009 15 29 30 ARK CLS Seismic Coloured Inversion V2 94 OpendTect plugin version 4 1 SciQt main window 4 2 SciQt main window default configuration showing the top four charts 4 3 SciQt main window default configuration showing the middle four charts 4 4 SciQt main window default configuration showing the bottom two charts 4 5 Save Operator dialog 4 6 Export Data Item dialog 4 7 Export Data Item dialog 4 8 Global Chart Area Zooming 4 9 Identifying Data from Charts 4 10 Data Zooming on Charts 4 11 Moving Data on Charts 4 12 Changing Scales on Charts 4 13 Chart Con
7. 6 21 10 2009 15 29 53 3 2 Selecting Data Clicking the Load Wells push button will auto select acoustic impedance log curves in the OpendTect data repository It is assumed that acoustic impedance log will have the characters AI upper or lower case or IMP upper or lower case somewhere within the log curve name If for a given well there are no such acoustic impedance log curves or the log curve doesn t meet the assumed naming convention then the user can still select or generate Al log curves manually This is achieved by right clicking on the well name after first attempting to load the wells automatically Note the Load Wells push button will change to a Reload Wells push button after the initial automatic selection Right clicking will pop up a menu with Select Al Log and Generate Al Log menu items Selecting the first item will pop up the Select Database Logs dialog which lists the available logs allowing you to choose an Al log curve however it is named Selecting the second item will pop up the Generate Al Log dialog which displays two lists The left hand list allows you to select a sonic log and the right hand list allows you to optionally select a density log If no density is available then you can select User for Density Source radio button and for supplying a User Density Value Here the AI log will be generated from the supplied sonic and density In OpendTect log curves are stored in depth SciQt requires t
8. Average Trace Spectrum O Raw Well Logs O Gated Well Logs O Lag Trend Lines O Detrended Logs O Lag Spectra O Average Log Spectrum O Log Curve Fit Design Operator O Beta Curve F Desired Output E Coloured Inversion Operator O Untruncated Operator Colour for New Items TI Default Close The sub sections below describe the various tasks that can be performed from within the Display Options dialog 4 2 3 1 Chart Changing chart titles axes names and line thickness via the Display Data Items dialog is very simple Figure 4 20 Changing Chart Properties W Seismic Coloured Inversion testdata sci v2 93 Mayz2008 dox File View Tools Help s magos FFE Coloured Inversion Operator 40 B0 Frequency Hz Coloured Inversion Operator w Display Options Chart Title Coloured Inversion Operator X Axis Frequency Hz x Fixed Axis Ranges Left Q Bottom Line Thickness 9 Data Items Data Item V Design Operator O Untruncated Operator Colour for New Items TI Default Frequency Hz 33 6310 Amplitude dE 44 33B0 Y Axis Amplitude dB Right 100 Tom The figure above shows how you can change title x axis label y axis label and line thickness In this example we have changed the title the x axis label and y axis label together with the line thickness of data items displayed on this chart As we edit these fields the SciQt main wind
9. Chart Area 4 2 1 Direct Interactions 4 2 1 1 Global Zooming 4 2 1 2 Identifying Data 4 2 1 3 Data Zooming 4 2 1 4 Moving Data 4 2 1 5 Changing Axes 4 2 2 Chart Controller 4 2 2 1 Creating a New Chart 4 2 2 2 Moving Charts 4 2 2 3 Deleting Charts 4 2 2 4 Saving and Loading Chart Configurations 4 2 2 5 Changing the Number of Columns 4 2 2 6 Zooming In and Zooming Out 4 2 3 Display Options 4 2 3 1 Chart 4 2 3 2 Management of Data Items 4 3 Select Input Data http opendtect org rel doc arkcls sci ch04 html 1 of 2 21 10 2009 15 29 58 Chapter 4 User Manual 4 3 1 Input Seismic tab 4 3 1 1 Select trace data 4 3 1 2 Loading and Clearing Data 4 3 1 3 Modifying Time Range 4 3 1 4 Removing Bad Traces 4 3 1 5 Select Volume dialog 4 3 1 6 Horizon Input Dialog 4 3 2 Input Well Log tab 4 3 2 1 ASCII well log loading 4 3 2 2 Define ASCII File Format 4 3 2 3 Database well log loading 4 3 2 4 Modifying Time Range 4 4 Design Controls 4 4 1 Smooth Seismic Mean 4 4 2 Fit Well Log Curves 4 4 3 Design Operator 4 5 Advanced Controls 4 5 1 Frequency Domain 4 5 2 Design Operator 4 5 3 Time Domain Prev Next 3 4 Application of SciQt operator 4 1 Interfacing with the SciQt Application http opendtect org rel doc arkcls sci ch04 html 2 of 2 21 10 2009 15 29 58 4 1 Interfacing with the SciQt Application 4 1 Interfacing with the SciQt Application Prev Chapter 4 User Manual Next
10. Err value as the spectrum is not calculated 4 3 1 5 Select Volume dialog The Select Volume dialog provides you with a 3D seismic volume selector From here simply select the seismic volume you require for your SciQt analysis and operator design A volume filter is provided to reduce the list to a manageable size for projects with many volumes Figure 4 29 Select Volume http opendtect org rel doc arkcls sci ch04s03 html 5 of 12 21 10 2009 15 30 19 4 3 Select Input Data ww Select Volume vY ECCA IM nen Fiker Fiter fF Inv from sci 3 fB2pro 1600 1610 convahe with fix B2prio subset convoled in scigt Bpi subset 1500 1510 delete me E prio subset 1500 1550 delete me3 fB2pria subset 1500 1550 Suns fB2prio 1600 1610 I B2prio subset coherancy fB2prin subset energy fB2prio subset 1500 1510 B2prio subset scaled fB2pria subset 1500 1550 fB2pris subset 1500 1550 SumO s Pas Se Select Cancel Select Cancel see se The images in the figure above show examples of the Select Volume dialog for selection of a seismic volume The LH image shows a seismic volume list without a seismic volume filter The RH image shows the use of a filter to create a shorter list As can be seen the wild card character can be used in the Filter field 4 3 1 6 Horizon I nput Dialog The Horizon Input Dialog provides you with a horizon selector From the Horizon Data tab simply select the horizon you require for y
11. Seismic then the normalisation parameters are obtained from the sample interval and gate length of the seismic data If the source is User then you need to additionally provide the Nominal Seismic Sample Interval ms and Nominal Seismic Design Gate ms see below Nominal Seismic Sample Interval ms This spinbox control allows you to specify the nominal seismic sample interval to be used for normalisation purposes This control is active if User is set for the Interval Source radio button above Nominal Seismic Design Gate ms This line edit field allows you to specify the nominal seismic design gate length to be used for normalisation purposes This control is active if User is set for the Interval Source radio button above Remove Linear Trend from Log Data Detrend This checkbox item allows you to turn on the de trend facility Here the linear trend within the Al Log can be removed before the generation of amplitude spectra The figure below shows on the LH plot the de trend lines on the input log data The RH plot shows the same logs after linear trend has been removed and application of ramp see Ramp Ends of Log Using Papoulis Windowing below Figure 4 47 Effect of Detrending Log Input time domain Log Input Detrend time domain P i a owr 2300 2400 2500 2600 2700 2300 2400 2500 2600 2700 Time ms Time ms Ramp Ends of Log Using Papoulis Windowing Apply Ramps This checkbox item allows you to turn on the
12. This push button is located within the Input Seismic tab on the Select Input Data dialog Changing the time gate and or range mode will update this chart It is recommended that if an interpreted horizon with few undefines is available within the target area then Range mode radio button be set to Horizon Chart 2 Seismic Mean This chart displays the mean seismic spectrum The mean seismic spectrum red is derived from the raw gated seismic trace spectra in chart 1 Clicking the Load Seismic button within the Input Seismic tab on the Select Input Data Dialog will update the data on this chart Also displayed on this chart is a smooth mean seismic spectrum black The amount of smoothing can be controlled by you interacting with the Smooth Seismic Mean control on the Design Operator Dialog Chart 3 Log I nput time domain This chart displays the selected gated Al log data in time In this example only one Al log has been selected Selecting or de selecting Al log http opendtect org rel doc arkcls sci ch04s01 html 7 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application data in the Input Well Log tab on the Select Input Data Dialog will update the data on this chart Also displayed on this chart is the linear trend line black Controls on the Advanced Controls dialog can also have an immediate effect on this chart Chart 4 Log I nput Detrend time domain This chart displays the selected gated A
13. above show how data on an individual chart can be zoomed Data zooming Is the process of identifying a data area within a given chart and arranging the chart axis so that area fills the chart Data zooming is achieved by dragging a rectangular box rubber band over an area of the data on one of the charts that is to be zoomed You invoke data zooming mode by pointing to the chart that is to be zoomed and pressing MB3 This pops up a menu Select Zoom Data Shift MB1 will put you in data zooming mode Now pressing and holding MB1 and dragging will allow you to rubber band the area on the chart that is to be data zoomed Letting go the MB1 will instantly data zoom the chart After data zooming the MB1 will revert to its default mode Identify Data To unzoom the data press MB3 to pop up menu and select Unzoom Recentre Data Shift MB1 Another faster method of achieving the same result is to press and hold the Shift key whilst sweeping out a rectangle by pressing and holding MB1 and dragging over the area that is to be data zoomed To unzoom simply hold down Shift key and press and release MB1 on the chart If you have zoomed in multiple times this action will unzoom in steps Pressing MB2 on the chart will also unzoom in steps Note the icon which unzooms all and recentres the data in one go This can also be achieved by http opendtect org rel doc arkcls sci ch04s02 html 2 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area
14. an interpreted horizon However SciQt recognises certain XML style meta tags which can be used by you to provide additional data Below are the five XML style meta tags recognised by SciQt lt inline gt inline data here lt inline gt lt xline gt xline data here lt xline gt lt horztime gt horizon time data here lt horztime gt lt xcoord gt x coordinate here lt xcoord gt lt ycoord gt y coordinate here lt ycoord gt These XML meta tags are normally inserted on one line within the ASCII file For example in Landmark style ASCII files these would normally be placed on the second line which is blank It is not necessary to include all the meta tags Normally only the lt inline gt and lt xline gt meta tags are supplied as there is then sufficient information for horizon data to be extracted from the supplied horizon In this example the horizon information for well 4 dat well 3 dat and well 3 dat can be obtained from the supplied horizon Horz Scr horz using the In line and X line data supplied via the meta tags inline and lt xline gt For well 1 dat however the horizon information comes from the lt horztime gt meta tag Horz Scr well since no In line or X line data has been supplied 4 3 2 2 Define ASCII File Format This section describes how you can define the format for ASCII file reading of well AI log data Clicking the Define Format push button will pop up the Define ASCII File Format dialog Figur
15. are thin Such high frequency events cannot be resolved within the seismic bandwidth Furthermore using seismic alone it will not be possible to resolve the low frequency trends and for absolute impedance it will be necessary to input a geological model Whilst it may be possible with a good quality input to get a quantitative output these methods are complex requiring skilled specialists Such methods are time consuming and can be a source of error Whilst using good quality input data is always desirable inverting poorer quality data can give very usable results Qualitative or semi quantitative inversion may yield significant benefits on any data and it is much easier to achieve and is less error prone Frequently taking this approach is sufficient and can be done by a non specialist within a much shorter time scale Before embarking on an inversion project it is important to investigate any well log data that is available It is recommended the frequency content required to image the target is investigated 1 Estimate the frequencies available within the seismic by wavelet estimation or spectral analysis 2 Take the well impedance data and bandpass it to the same frequencies as the seismic data As a rule of thumb use 15dB down point as limits 3 If the target is still visible then using Seismic Coloured Inversion should be adequate 4 f not then need to add frequencies by model assumption Note this can be very risky you ge
16. be open at once Use the Shift key modifier to select consecutive files and the Ctrl key modifier to select non consecutive files from within the File Selector dialog You can also MB1 and drag the mouse over a number of ASCII files Figure 4 32 ASCII Well Log Selection http opendtect org rel doc arkcls sci ch04s03 html 7 of 12 21 10 2009 15 30 19 4 3 Select Input Data Select Input Data Input Seismic Input Well Lags Select Wallast Load Wells Load ASCII Wells Define Format Field Wells Logs Top Base Hor Tim Hor In line X lime Cor E field 2000 3186 5 E well 1 dat 2000 3196 2400well 999999 999999 LE IMPEDANCE 2000 3156 E well 4 dat 2000 2964 2432 3hoz 1920 4320 hE IMPEDANCE 2000 2964 E well 3 dat 2000 3196 2361 8horz 1751 4560 hE IMPEDANCE 2000 3196 5 E well 2 dat 2000 3136 23724hoz 1785 4490 t M IMPEDANCE 2000 3138 4 t Clear Wells Glear LUnselected Wells Tima Select Horizon tracked horz time Range Full Horizon i Absolute Sub Start 4250 End 2750 The picture in the figure above shows the Input Well Log tab where well log data has been loaded In this case the well log data was loaded from ASCII files The central list area shows four impedance curves have been loaded One each for four wells Normally well log ASCII data files do not contain inline xline or horizon data So in such cases it is not possible to select a time range relative to
17. dialog with a list of available wavelets This list will include both the Coloured Inversion operator suffix cli and the Band Pass operator suffix bp Both these wavelets were saved during the SciQt analysis and design From the list select the Coloured Inversion wavelet suffix _ ci The final step before running your test will be to give your attribute a name via the input field to the right of Attribute name label and click the Add as new button Now assuming that an In line or X line graphical element is displayed within OpendTect and that one of these items is selected as active then it is very easy to see the effect of the derived Coloured Inversion operator by clicking the id icon within the OpendTect Attribute Set dialog This will immediately apply the Coloured Inversion operator to the selected Input Data in the Attribute Set for the In line or X line graphic element currently displayed Display will then be updated http opendtect org rel doc arkcls sci ch03s04 html 1 of 3 21 10 2009 15 29 57 3 4 Application of SciQt operator and if it is visible in one of the scenes you will immediately see the result This is a very useful QC tool which will allow you to view the results of applying the derived Coloured Inversion operator to your data before committing to processing multiple 3D inlines sub volume or the entire 3D seismic volume 3 4 2 Applying the Coloured I nversion operator Application of the Coloured In
18. domain Chart Title Mew 50 100 Chart Title 30c0g40rpsocgeoc 00 Raw Seismic Edit Freq Hz Raw Seismic Time ims Seismic Mean Log Input time domain Log Input Detrend time Log Input Detrend Lime domain Move Up Seismic Mean domain og Input time domain Log Input Detrend time domain Global en Global individual Wells Delete individual Wells Dalata Design Operalor Design Operator mm Operator time domain Operator time domain Residual Operator QC Load Residual Operator QC Load Convolved Output Mean QC Convolved Output Mean QC The images in the figure above show how a chart can be moved The first image shows the Log Input time domain chart selected The SciQt Main Window shows the Log Input time domain chart in the bottom right corner of the display Clicking the Move Up push button twice causes the chart to move up two positions in the Chart Controller dialog list The Main Window is immediately updated with each click The second image shows the Log Input time domain chart in its new position top right corner of the display The Move Down push button moves the chart in the opposite direction 4 2 2 3 Deleting Charts Like the other tasks described above deleting charts is easy Figure 4 16 Deleting Charts Raw Seismic Log Input time domain Raw Seismic Seismic Mean Chart Controller w hart Controller Chart Title SOCAN SO SOR 700 Time ms Log Input Detrend time Chart
19. example Let us compare a synthetic example Using model data we can generate synthetic seismogram In the figure below we see three relative Al displays which are broadly similar On the left we see the relative Al directly from the input model data This is the result i e the answer On the top right is the Coloured Inversion result generated from the synthetic seismogram On the bottom right is the sparse spike inversion from the same synthetic seismogram Figure 2 2 Synthetic comparison Al Acoustic Impedance Cl Coloured Inversion result SS Sparse Spike result http opendtect org rel doc arkcls sci ch02s04 html 1 of 3 21 10 2009 15 29 47 2 4 Inversion techniques Now if we compare the display above in greater detail we will observe an interesting result Let s consider the figure below The top two displays labelled SS for Sparse Spike and CI for Coloured Inversion On first observation the SS result looks better as it would appear to offer higher resolution However if we compare both the SS and CI with the answer Al bottom right then it is the CI result which more closely resembles the input model Why should this be Tracking down the problem found that the wavelet required by SS was estimated slightly incorrectly difference between the purple and blue curves in the bottom far right plot The original wavelet estimate is deficient at high frequencies for which the derived Al solution must compensate When t
20. export to an ASCII file either all the data items for every group all the data items for a single group or a single data item from a group This is achieved as follows All Data Items Clicking the All Data Items on the Export Data Item dialog will select every data item currently available Then by clicking the Export push button you will be given a file selector dialog allowing you to save all these data items into a single ASCII file Group Item Clicking one of the groups beneath the All Data Items will select that group Then by clicking the Export push button you will again be given a file selector dialog allowing you to save the group data into a single ASCII file Data item Clicking a data item within a group will select that data item Then by clicking the Export push button you will once again be given a file selector dialog allowing you to save the data item to a single ASCII file You can optionally output a header This is useful if you are outputting two or more data items 4 1 2 5 Parameter Report http opendtect org rel doc arkcls sci ch04s01 html 12 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application This ancillary tool allows you to display and optionally save the Coloured Inversion parameters in a nicely formated manner Clicking the File 2Parameter Report menu item will pop up the Parameter Report dialog Figure 4 7 Export Data Item dialog Parameter Report Seismic Colou
21. field to the right displays the 96 Energy captured as you adjust the number of zero crossings QC Against Input Seismic This checkbox control if checked allows you to perform the QC against the original set of random seismic traces instead of the alternative set of random seismic traces 1 QC Against Input Seismic checkbox unchecked default on the distributed template In this mode the calculation of the Coloured Inversion operator is performed using the original set of random seismic trace listed on Select Input Data dialog gt Input Seismic tab gt Input tab The QC of the Coloured Inversion operator is performed on the alternative set of random seismic traces listed on Select Input Data dialog gt Input Seismic tab gt QC tab 2 QC Against Input Seismic checkbox checked In this mode the calculation of the Coloured Inversion operator is again performed using the original set of random seismic trace listed on Select Input Data dialog gt Input Seismic tab gt Input tab However the QC of the Coloured Inversion operator is performed on the same set of random seismic traces listed on Select Input Data dialog gt Input Seismic tab gt Input tab Prev Up Next 4 3 Select Input Data Home 4 5 Advanced Controls http opendtect org rel doc arkcls sci ch04s04 html 6 of 6 21 10 2009 15 30 23 4 5 Advanced Controls 4 5 Advanced Controls Prev Chapter 4 User Manual 4 5 Advanced Controls This
22. is highly configurable allowing you to tailor this area with charts and data which meet your particular project needs Once you have configured this area it can then be saved as a session which will allow you to easily return to the chart data configuration at some future date You can also save the chart area configuration with types of data object to be displayed in a given chart as a template This will allow you or your colleagues to use such templates on other projects Another benefit of saving as a template and or session is that you can apply the chart configuration from a saved template or session to your current session The following figures show an example of an SciQt run using the supplied default template Figure 4 2 SciQt main window default configuration showing the top four charts http opendtect org rel doc arkcls sci ch04s01 html 6 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application Seismic Coloured Inversion testdata sci Itest l O3Apr2008 ses File View Tools Help s i e Bb AL oo Cy amp Haw Seismic Seismic Mean Freq Hz Freq Hz Log Input time domain Log Input Detrend time domain 2400 2400 2500 2600 2900 2400 2500 2600 2700 E Tire mei Time ims Chart 1 Raw Seismic This chart displays the raw gated seismic trace spectra By default a random set of 40 seismic traces within the 3D Survey Area is loaded when the Load Seismic push button is clicked
23. operator Prev Chapter 3 Quick Start SciQt Tutorial Next 3 4 Application of SciQt operator This section describes how the derived Coloured Inversion operator can be applied to your data using the OpendTect plug in Application of the Coloured Inversion operator can be done in various ways Please refer to OpendTect documentation for full details For the purpose of this document we will only describe a couple of the mechanisms which you could use Now depending on whether you wish to run a test or whether you want to process a complete volume or sub volume read the respective sub section below Running a test first is a good idea as you will have the opportunity to quickly view the result of applying your Colourl nversion operator to a sample inline or xline before applying the operator to the entire 3D volume 3 4 1 Testing the Coloured I nversion operator This is best achieved via the OpendTect Attribute Set dialog If you haven t closed the Attribute Set dialog used to launch the SciQt plugin then it should still be somewhere on your desktop possibly hidden behind other windows At this stage you will need to select the operator to use You should see that the desired Coloured Inversion operator has been automatically selected in the Input Wavelet field If not automatically selected or you require a different Coloured Inversion operator then click the Select push button to the right of Input Wavelet label which will pop up a
24. operator set should your list be very long Through this dialog you can either select an existing operator set or specify a new database name to save the current Coloured Inversion operator set A set will consist of two wavelets with the database name being suffixed with ci for the Coloured Inversion operator and bp for the Band Pass operator Print both the report and the charts to a specified printer Alternatively you can print to file However if this option is selected then there is a known bug which will cause the charts to overwrite the report If you need to output both the report and the chart to a file then use menu File gt Print gt Print Report and menu File gt Print gt Print Charts separately Displays parameter report This icon pops up the Parameter Report dialog 4 1 1 2 2 Tools Toolbar http opendtect org rel doc arkcls sci ch04s01 html 5 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application z Pops up the Select Input Data Dialog which allows you to select the seismic and well log data to use in the analysis and operator design Ea Pops up the Design Operator dialog which allows you to control standard parameters in the design of the SciQt operator Pops up the Advanced Controls dialog which allows you to override many of the a istandard parameters in the design of the SciQt operator 4 1 1 2 3 View Toolbar nm Pops up the Chart Controller which all
25. or IMP upper or lower case somewhere within the log curve name If for a given well there are no such Al log curves or the log curve doesn t meet the assumed naming convention then the user can still select or generate AI log curves manually The image to the right above shows in the central area that two AI log curves one each from two wells have been automatically loaded In OpendTect log curves are stored in depth Coloured Inversion requires the Al log curves to be in time During the loading process the Al data which is stored in depth within OpendTect is depth to time converted using the associated time depth model associated with a given well It is then resampled to be regular in time The sample interval used for this purpose can be changed via the Advanced Controls dialog Time domain tab We can also manually select or generate AI well log This is achieved by right clicking on well name which will pop up a menu with Select Al Log and Generate Al Log menu items Selecting the first item will pop up the Select Database Logs dialog which lists the available logs allowing you to choose an AI log curve however it s named Selecting the second item will pop up the Generate Al Log dialog which displays two lists The left hand list allows you to select a sonic log with right hand list allowing you to optionally select a density log If no density is available then you can select User for Density Source radio button and suppl
26. selected This is the recommended method when running SciQt as an OpendTect plug in Whilst it is highly recommended it is not necessary to pre select the input stored cube via the OpendTect Attribute Set dialog prior to launching the SciQt plug in If the selected seismic is not pre selected then you can always select the stored cube by clicking the Select Seismic button With the seismic data selected it is usually desirable to define a sub area This is achieved by clicking the Sub button from the 3D Survey Area radio button group Following this the user would specify the sub area using the Start In line End In line Start X line and End X line edit boxes Finally the number of traces is specified and the Load Seismic button is clicked 4 3 1 2 Loading and Clearing Data With the seismic data volume selected you can now load a set of traces to be analysed Here you can optionally choose to select traces from the full 3D survey area or sub 3D survey area This is achieved using the 3D Survey Area radio button group as follows 1 Full for the complete area 2 Sub for setting the In line and X line Start and End values for a sub area Typically you would select a single sub area Specifying a sub area in this manner enables you to include an area of the survey where the trace data is known to be of good quality and is representative of the survey area as a whole With sub area selected it is simply a case of specifying the number of t
27. the Design Operator dialog and in the Advanced Controls dialog can have an immediate effect on this chart Chart 7 Design Operator This chart displays three curves The curve coloured red is the smooth mean seismic spectrum The green curve is the band limited spectrum derived from the smooth composite curve fit to the average Al spectrum Finally the blue curve is the band limited shaping operator Note the maximum frequency of the chart is determined by the maximum nyquist frequency of either the log data or the seismic data Various controls on the Design Operator Dialog and in the Advanced Controls dialog can have an immediate effect on this chart Chart 8 Operator time domain This chart displays the time converted Coloured Inversion operator Various controls in the Select Input Data dialog Design Operator dialog and Advanced Controls dialog can have an immediate effect on this chart Figure 4 4 SciQt main window default configuration showing the bottom two charts Seismic Coloured Inversion testdata sci test l 03Apr2008 ses File View Tools Help jou Ritz BC 9 Residual Operator QC Convolved Output Mean QC RE N a ae B 1 Chart 9 Residual Operator QC This chart displays the following spectra and is used for QC purposes 1 Smooth mean Coloured Inversion data red 2 Band limited curve fit to global Al spectrum green 3 Residual operator blue This should tend
28. to right and top to bottom 1 Raw Seismic This chart displays the spectra for each of the random set of seismic traces loaded in the main set used in the analysis and design of the Coloured Inversion operator 2 Seismic Mean This chart displays the mean spectrum red of all the raw spectra It also displays the smoothed mean spectrum black The smooth mean spectrum see description in 7 Design Operator is used to derive the Coloured Inversion operator 3 Log Input time domain This chart displays the well impedance logs in time domain In this case there is only one impedance log but typically there are more Also displayed on this chart is the trend line black 4 Log Input Detrend time domain This chart displays the well impedance logs with the trend removed Note that the ramp has also been applied at the end of the impedance log Detrending and ramping are designed to remove the possibility of artifacts being introduced in the Fast Fourier Transform process 5 Individual Wells This chart displays the spectra of well impedance logs On this chart the x axis is displayed using a logarithmic scale 6 Global This chart displays the mean spectrum global of all the well log impedance spectra On this chart the x axis is displayed using a logarithmic scale Also displayed is a curve fit spectrum black The band limited version of this curve fit spectrum see 7 Design Operator is used to derive the Coloured Inversion oper
29. 15 30 23 4 4 Design Controls Seismic Coloured Inversion testdata Untitled File View Tools Help Design Controls De L i led Fi B a pt Smooth Seismic Mean Global Smoothing Operator Len 10 Hz Fil Well Log Curves Low Cul High Cul Full Range Hz IS B Hz Alpha D 30993 Design Operator Auto Calc vw AULO Gale v Auto Calc Freq Hz QC Against Input Seismic Close Full Range This checkbox item allow you to control whether curve fitting is performed on the full range The spinbox controls in this group are the primary parameters used for principal curve fitting 1 Full Range checkbox checked default on the distributed template In this mode curve fitting is performed on the global spectrum and will be performed on the Full Range The Low Cut and High Cut for Fit Well Log Curves will be desensitised 2 Full Range checkbox unchecked In this mode curve fitting consists of three curves Below Principal Principal and Above Principal The intersection between the Below Principal and the Principal curves is at the Low Cut point The intersection of the Principal and Above Principal curves is at the High Cut point The Low Cut spinbox is the Min Fit Frequency of the principal curve and the High Cut spinbox is the Max Fit Frequency of the principal curve The other curves outside this range are generated in accordance with the controls on the Frequency Domain ta
30. ARK CLS Seismic Coloured Inversion V2 94 OpendTect plugin version ARK CLS Seismic Coloured nversion V2 94 OpendTect plugin version Next ARK CLS Seismic Coloured nversion V2 94 OpendTect plugin version ARK CLS Limited Copyright 2008 ARK CLS Limited All rights reserved No part of this publication may be reproduced and or published by print photo print microfilm or any other means without the written consent of ARK CLS Limited Table of Contents Introduction 2 Background and Theory 2 1 Basics 2 2 Benefits of Seismic Inversion 2 3 Inversion Limitations 2 4 Inversion techniques 2 4 1 Parametric Inversion 2 4 2 Coloured Inversion 2 4 3 Synthetic example 2 4 4 Real data examples 2 4 4 1 Comparison between Coloured Inversion and Unconstrained Sparse Spike 2 4 4 2 Coloured Inversion used to Improving interpretation 2 4 4 3 Well Planning 2 5 Seismic Coloured Inversion SCI 2 6 Seismic Spectral Blueing SSB 2 7 References and Acknowledgements http opendtect org rel doc arkcls sci index html 1 of 5 21 10 2009 15 29 30 ARK CLS Seismic Coloured Inversion V2 94 OpendTect plugin version 2 7 1 References 2 7 2 Acknowledgements 3 Quick Start SciQt Tutorial 3 1 Launching the SciQt OpendTect plug in 3 2 Selecting Data 3 2 1 Input Seismic 3 2 2 Input Well Log 3 3 Designing and Saving the Coloured Inversion Operator 3 4 Application of SciQt operator 3 4 1 Testing the Coloured I
31. Coloured Inversion The 3D X line example in the figure above shows a comparison of Full Offset Stack section top and Coloured Inversion section bottom It can be seen that interpreting the Coloured Inversion can make it easier to identify events In particular the fault at L2020 is less likely to have been interpreted using the Full Offset Stack only In contrast on the Coloured Inversion section It would be very difficult to miss This is a good example of how inversion products can help improve interpretation 2 4 4 3 Well Planning Figure 2 6 Horizontal Well example Seismic Al Oil Bearing Sandstone The example in the figure above shows how inversion products using a blue yellow colour bar can be used in well planning bottom left Here the yellow colour indicates pay sands whilst the blue indicates non pay lithologies Compare this with the conventional seismic display top left The display below shows how a horizontal well can be planned on the basis of seismic inversion The correspondence between predicted reservoir and actual reservoir is high Prev Up Next 2 3 Inversion Limitations Home 2 5 Seismic Coloured Inversion SCI http opendtect org rel doc arkcls sci ch02s04 html 3 of 3 21 10 2009 15 29 47 2 5 Seismic Coloured Inversion SCI 2 5 Seismic Coloured I nversion SCI Prev Chapter 2 Background and Theory Next 2 5 Seismic Coloured nversion SCI With the advent of multi version in
32. Data Item Exports one or more of any of the currently http opendtect org rel doc arkcls sci ch04s01 html 3 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application displayed data items to an ASCII file Parameter Report Pops up a dialog which displays various Coloured Inversion parameters nicely formatted Ext Exits ExitstheSciQtapplication SciQt ExitstheSciQtapplication 4 1 1 1 2 View Pops up the Chart Controller Dialog which will allow you to modify Chart Controller ME dem various chart parameters within the central area of the main window Refresh Charts Charts Redraws all the charts within the central Redraws all the charts within the central area of the main window of Redraws all the charts within the central area of the main window main window Provides a global zoom in facility which makes the central chart area grow by a fixed amount each time this menu item is clicked There is an upper maximum Zoom In Provides a global zoom out facility which makes the central chart area Zoom out shrink by a fixed amount each time this menu item is clicked There is a lower minimum 4 1 1 1 3 Tools Pops up the Select Input Data dialog which allows you to select the seismic and well log data to use in the analysis and operator design Input Seismic and Well data Pops up the Design Operator dialog which allows yo
33. Inversion 2 3 Inversion Limitations 2 4 Inversion techniques 2 4 1 Parametric Inversion 2 4 2 Coloured Inversion 2 4 3 Synthetic example 2 4 4 Real data examples 2 4 4 1 Comparison between Coloured Inversion and Unconstrained Sparse Spike 2 4 4 2 Coloured Inversion used to Improving interpretation 2 4 4 3 Well Planning 2 5 Seismic Coloured Inversion SCI 2 6 Seismic Spectral Blueing SSB 2 7 References and Acknowledgements 2 7 1 References 2 7 2 Acknowledgements This chapter provides some background information and theory to Seismic Coloured Inversion SCI and Seismic Spectral Blueing SSB The focus of this chapter will be Seismic Coloured Inversion However the spectral analysis and spectral shaping techniques discussed within also apply to Seismic Spectra Blueing Prev Next Chapter 1 Introduction Home 2 1 Basics http opendtect org rel doc arkcls sci ch02 html 21 10 2009 15 29 32 2 1 Basics 2 1 Basics Prev Chapter 2 Background and Theory Next 2 1 Basics Let us first consider the basis of Seismic Inversion Acoustic Impedance is the product of interval velocity and density and is normally represented by the equation where V is p wave velocity and p is density Seismic reflections are given by the change in the Acoustic Impedance of the layers and are represented by the equation RC j AI j 1 Al ALG 1 AI j Now the normal assumption is that the seismic tr
34. MS Err the smaller the number the better the fit Loaded traces by default are sorted by Trace Id However you can sort the list of traces using one of the other properties This is easily achieved by clicking the column header on the Input list So for example if you want to sort by RMS Amp in ascending order you click the RMS Amp header label To sort in descending order you click the RMS Amp header label again You can also change the position of the property columns This is simply achieved by clicking and holding on a property header then dragging the property header to its new position The image shows the result of clicking the Load Seismic push button Here 40 traces have been randomly loaded and immediately displayed in the Raw Seismic chart within the SciQt Main Window Also visible is a portion of the Select Input Data Dialog showing the trace list on the Input tab sorted by ascending RMS Amplitude values Figure 4 24 Clearing Seismic Data http opendtect org rel doc arkcls sci ch04s03 html 2 of 12 21 10 2009 15 30 19 4 3 Select Input Data w Gajak Colound imwersan Waid Unned Fie Wiew Tools Help Seki Input Dota Oe BB SB XE ee a sime inna wen coge L Traces Raw Seismic ESG ET TUM ma a 10 Burgeg Area Seb rine 1400 Kone 4700 Lod Seine Hum Traces 40 p Dc Fre bd fine Are PHD Amp AS Er Den Traces Geer reae Tree Eubacbaci Linckelin ad The image in the figure above s
35. Quick Start SciQt Tutorial Table of Contents 3 1 Launching the SciQt OpendTect plug in 3 2 Selecting Data 3 2 1 Input Seismic 3 2 2 Input Well Log 3 3 Designing and Saving the Coloured Inversion Operator 3 4 Application of SciQt operator 3 4 1 Testing the Coloured Inversion operator 3 4 2 Applying the Coloured Inversion operator This tutorial is designed to get you up and running with the SciQt software quickly This tutorial is split into the following sub sections Launching the SciQt Selecting data Designing and saving the Coloured Inversion operator Applying the Coloured Inversion operator b odii on Prev Next 2 7 References and 3 1 Launching the SciQt Acknowledgements OpendTect plug in http opendtect org rel doc arkcls sci ch03 html 21 10 2009 15 29 49 3 1 Launching the SciQt OpendTect plug in 3 1 Launching the SciQt OpendTect plug in Prev Chapter 3 Quick Start SciQt Tutorial Next 3 1 Launching the SciQt OpendTect plug in This sub section describes how to launch SciQt from within OpendTect 1 From within OpendTect main window click menu Processing Attribute or click the A icon to pop up the Attribute Set window see figure below 2 Select Coloured Inversion in the Attribute type list to show the parameters required for this attribute 3 Click Select to the right of the Input Data label to pop up a dialog to allow the input volume to be selected 4 Itis recommended that y
36. Seismic I nversion Listed below are some the benefits of seismic inversion 1 More geoscientists understand the concept of impedance and geology than the seismic trace Thus working in the impedance domain is a great mechanism for integrating with the various disciplines in a multidisciplinary asset team Removes the effects of the wavelet within the seismic bandwidth Forces well ties to be made and understood Reservoir properties are separated from the overburden May provide quantitative predictions on the reservoir properties Stratigraphic interpretation may be improved Interpreting in the impedance domain is frequently easier than in the seismic domain 8 Possibility of extending beyond the seismic bandwidth 228 ee d Prev Up Next Home 2 1 Basics 2 3 Inversion Limitations http opendtect org rel doc arkcls sci ch02s02 html 21 10 2009 15 29 33 2 3 Inversion Limitations 2 3 Inversion Limitations Prev Chapter 2 Background and Theory Next 2 3 Inversion Limitations Whilst there are significant benefits there are limitations For quantitative inversion it is necessary to have good quality input as the quality of the output is governed by this With good quality seismic data which matches the well data then it may be possible to get a quantitative output However one must remember that seismic data has limited frequency content Therefore it will not be possible to produce a meaningful inversion if the layers
37. Title i 5D 100 Raw Seismic Freq Hz Log Input Detrend time domain a Log Input Detrend time domain Global Global Individual Wells Imncivicumi els Raw Seismic Seismic Mean domain Design Operator Design Operalor Operator time domain Operator time domain Residual Operator QC Residual Operator OC Convolved Output Mean QC Convolved Output Mean QC The images in the figure above show how a chart can be deleted Just select the chart from the list and click the Delete push button The chart is deleted immediately without any warning so you are advised to be careful when using this option The SciQt Main Window will update immediately to show the chart area with the deleted chart removed The LH image shows the Log Input time domain chart before clicking the Delete push button with the RH image showing the chart area with the Log Input time domain chart removed Note the charts below the deleted chart move up one position http opendtect org rel doc arkcls sci ch04s02 html 6 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area 4 2 2 4 Saving and Loading Chart Configurations Saving and loading the chart configuration is a powerful facility which allows you to view your session in many different ways Chart configurations are saved in XML files Only information about the charts are saved in such files This facility also allows you to use chart configurations saved from previous ses
38. a Select Input Data Input Seismic Input Well Logs Load Wells Load ASCII Wells Define Format Field i Wells Logs Top Base Horz Time Hor In line X dine i F field l 1 3254 5 E ALB HT X1 1045 3254 undelined 320 4320 tL v AL EDT IS 3254 5 O ALB HT X2 1854 2485 undefined 1413 453 L D Al 854 2485 Clear Welk Clear Unselected Welk Time Select Horizon Range Abs clube Full Horan 2250 e Sub Sart End 2750 In the above dialog the large central area is to display and control the selection of Well Log Acoustic Impedance data It consists of the following fields Field Well Logs Top Base Common Well Nm UWI Remark In line X line Horz Time and Horz Src These fields can be moved by grabbing click and hold the field header and dragging to a new position Clicking on the field headers sorts the list according to the data in that field The Field Wells Logs provides a facility to expand and contract the entire list Additionally this field allows Acoustic Impedance data to be selected and deselected The sub sections below describes how you can select and constrain the data 4 3 2 1 ASCII well log loading Loading Acoustic Impedance data from ASCII is straightforward Simply click on the Load ASCII Wells push button to pop up a file selector Within the File Selector you can traverse the file system to locate Acoustic Impedance data in ASCII format The File Selector allows one or more ASCII files to
39. ace is considered to be a primary only reflectivity model convolved with the seismic wavelet which is summed with some uncorrelated noise and can be represented by the equation S t R t W t N t Figure 2 1 Seismic Method and I nversion Rocks Seismic Al Reflectors Convolution Summed Noise Trace The figure above Is a pictorial representation of the convolutional model So in simplistic terms the process of moving rocks on the left to seismic on the right is termed the seismic method On the left we have rock http opendtect org rel doc arkcls sci chO2s01 html 1 of 2 21 10 2009 15 29 33 2 1 Basics property Acoustic Impedance Al So moving left to right changes in Al at layer boundaries result in normal incident reflection coefficients Everywhere there is a reflection coefficient it is replaced by a wavelet which is centred and weighted by the reflection coefficient These individual wavelets are summed and uncorrelated noise is added to generate the seismic trace The process of seismic inversion takes us in the opposite direction trying to determine the Acoustic Impedance of the individual rock layers Prev Up Next Chapter 2 Background and Theory Home 2 2 Benefits of Seismic Inversion http opendtect org rel doc arkcls sci ch02s01 html 2 of 2 21 10 2009 15 29 33 2 2 Benefits of Seismic Inversion 2 2 Benefits of Seismic Inversion Prev Chapter 2 Background and Theory Next 2 2 Benefits of
40. ading acoustic impedance data from OpendTect database is straightforward The details are explained in the table beneath Essentially you click the Load Wells push button which will auto select all the acoustic impedance log curves in the OpendTect data repository Figure 4 34 Database Well Log Loading Fel Wells Logs Top Base Hore Time Horz Src Field Wells Logs Top Base Hor Time Horz Sre in line X L Re field 45 3254 I ALB HT X1 1045 3254 2432 3 horz 1320 L R ALEDT 1045 3254 F ALB HT X2 1854 2485 2438 9 horz 1413 LR AI 1854 2485 LI Select Input Data l Select Input Data input Seismic input Well Logs input Seismic input Well Logs Load Wells Load ASCII Wells Define Format Reload Wells Load ASCII Wells Define Format In line Mine Clear Welk Clear Uneelected Welk Clear Wells Clear Unselected Wells The two images in the figure above show the top portion of the Input Well Log tab used to load OpendTect well log Al data The left image shows the state when the Input Well Logs tab is first selected by you following display of the Select Input Data dialog Click the Load Wells push button which will auto select all the acoustic impedance log curves in the OpendTect data repository It is assumed that acoustic impedance logs will have the characters AI upper http opendtect org rel doc arkcls sci ch04s03 html 9 of 12 21 10 2009 15 30 19 4 3 Select Input Data or lower case
41. and Set From File The following described these controls Type of Fit This radio button control allows you to select the type of fit algorithm Possible values are Least Squares or Robust By default the type of fit is Least Squares Set From File This push button will pop up a file selector dialog allowing you to read a previously saved session file to load the Alpha DC F Shift curve fit Low Cut and curve fit High Cut If there is a session file associated with this SciQt run either via File 2Open or File gt Save As then that session file will be the default You can also use this mechanism to load the above parameters from Coloured Inversion V2 3 x saved files However it should be noted that it is not possible to load from SciQt V2 90 session files as these parameters were not saved in that version This option is useful when no well data is available or you wish to use the same curve fit parameters from a previously saved session 4 5 2 Design Operator Figure 4 45 Design Operator Tab http opendtect org rel doc arkcls sci ch04s05 html 2 of 5 21 10 2009 15 30 25 4 5 Advanced Controls w Advanced Controls Frequency Domain Design Operator Time Domain Options Set Operator Energy 1 There is currently only one parameter in this group The Set Operator Energy 1 checkbox item is here for backward compatibility with earlier versions of the Coloured Inversion software This c
42. apply ramps facility This allows the ends http opendtect org rel doc arkcls sci ch04s05 html 4 of 5 21 10 2009 15 30 25 4 5 Advanced Controls of the input Al Log data to be ramped Ramp Length ms This input field value allows you to specify the ramp length in milliseconds Log Data Resampling Interval Source This radio button allows you to select the source log data resampling 1 Seismic This radio button option specifies that the log data resampling will be to the same sample interval as the seismic The Resampling Interval spinbox is desensitised 2 User This radio button option allows you to specify the log resampling interval in the sensitised Resampling Interval spinbox Resampling Interval This spinbox allows you to specify the resampling interval Prev Up 4 4 Design Controls Home http opendtect org rel doc arkcls sci ch04s05 html 5 of 5 21 10 2009 15 30 25
43. arithmic Scale cascade menu item and releasing MB3 will cause the chart to be redrawn with a logarithmic X axis RH image Other changes to the X and Y axes or chart data can be performed in a similar manner 4 2 2 Chart Controller The Chart Controller dialog allows you to change various properties of a chart The Chart Controller will also allow you to create new charts delete charts edit charts control layout number of columns and change the order of the charts within the chart area A useful feature is that the current chart configuration can be saved to a XML file Subsequently the XML file containing the chart configuration can be loaded to the current session Chart configuration XML files do not save data or SciQt parameters so can be readily used in other projects or sessions The Chart Controller dialog can be popped up by clicking menu item View oo gt Chart Controller or clicking the 40 icon The figure below shows the Chart Controller Changes made via the Chart Controller are immediately updated on the Chart Area of the Main Window Figure 4 13 Chart Controller dialog Chart Controller Chart Title Haw Seismic Log Input time domain Log Input Dietrend time domain Global Ime iri Lil Viells Design Operator Operator time domain Residual Operator QC Convolved Output Mean QC Number of Columns 2 Zoom In Zoom Quit Close The sub sections below outline the various tasks that can be pe
44. atabase name being suffixed with ci for the Coloured Inversion operator and bp for the Band Pass operator Save Operator Print Print both the report and the charts to a specified printer Alternatively you can print to file However if this option is selected then there is a known bug which will cause the charts output to overwrite the report output If you need to output both the report and the chart to a file then use Print Report and Print Charts separately Print gt Print Report Prints the report to a specified printer Alternatively you can print the report to a file Print Charts Print the charts to a specified printer Alternatively you can print the charts to a file All Charts Save all charts in the central area to an image file The following image formats are supported PNG default J PEG and BMP Screenshot Visible Charts Save charts that are currently visible in the central area Import Chart Configuration Pops up a file selector dialog which will allow you to select a previously saved session The chart configuration of that session file is applied to your current session Note the data and parameters stored in the session files are ignored This provides you with a very powerful facility which allows you to view your current data using a variety of different chart configurations Export Operator Allows you to export the operator to an ASCII file Export
45. ate If this is the first time that this is saved then the user will be presented with a file selector dialog for this purpose shortcut Ctrl S Saves the current SciQt session under a different name A file selector dialog will pop up for this purpose See Save above for more details http opendtect org rel doc arkcls sci ch04s01 html 2 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application Saves the current SciQt session as a new template By default new templates will be saved in the site wide templates directory in the software installation tree CLS APP Sci templates Sci However it is likely that you will not have write access to this directory You can get around this problem by setting the environment variable CLS SCI TEMPLATE DIR to a writable directory before starting the Coloured Inversion application This will then give you write access to an alternative templates directory Save As Template Saves the SciQt Coloured Inversion operator set to the database This menu item will pop up a Save Operator dialog The dialog will list all the operator sets currently stored in the OpendTect database A filter facility is provided to help you find an existing operator set should your list be very long Through this dialog you can either select an existing operator set or specify a new database name to save the current Coloured Inversion operator set A set will consist of two wavelets with the d
46. ator 7 Design Operator This chart displays the band limited well log impedance curve fit green the smooth seismic mean spectrum red and the derived Coloured Inversion operator spectrum blue The Coloured Inversion operator shapes the smooth seismic mean spectrum to the band limited well log impedance curve fit at every frequency 8 Operator time domain This chart displays the Coloured Inversion Operator in the time domain with a 90 degree phase shift applied and appropriately truncated By default truncation ensures that at least 99 9 energy is captured 9 Residual Operator QC This chart displays the band limited well log impedance curve fit green This is the same as in 7 Design Operator above Also displayed is the smooth mean spectrum red of the Colour Inverted alternative set QC of random traces As you can see this spectrum overlays the band well log impedance curve fit within the band width The residual operator blue should have essentially zero amplitude within the band width 10 Convolved Output Mean QC This chart displays the mean spectrum red of the Coloured Inverted alternative set QC of random traces Also displayed is the band limited well log impedance curve fit black Prev Up Next 3 2 Selecting Data Home 3 4 Application of SciQt operator http opendtect org rel doc arkcls sci ch03s03 html 2 of 2 21 10 2009 15 29 56 3 4 Application of SciQt operator 3 4 Application of SciQt
47. b on the Advanced Controls dialog Low Cut This spin box allows you to specify the minimum frequency that the curve fit algorithm will attempt to fit for the principal curve By default this is set to zero Hz However if including lower frequencies is not of any concern to you or you wish to additionally use a low frequency curve or linear horizontal low frequency section then setting this to a higher value can often result in a better curve fit over the frequency range of interest http opendtect org rel doc arkcls sci ch04s04 html 3 of 6 21 10 2009 15 30 23 4 4 Design Controls High Cut This spin box allows you to specify the maximum frequency that the curve fit algorithm will attempt to fit for the principal curve By default this is set to the nyquist frequency However if including higher frequencies is not of any concern to you or you wish to additionally use a high frequency curve or linear horizontal high frequency section then setting this to a lower value can often result in a better curve fit over the frequency range of interest Curve fitting is updated immediately the Low Cut control High Cut control or the Frequency Domain controls on the Advanced Controls dialog are changed In this case we have defaulted the Low Cut to zero Hz and have set the high cut to 90Hz The Above Principal curve fit is horizontal At any time you can curve fit to the full spectrum 0 Hz nyquist by toggling on the Full Range
48. checkbox within the Fit Well Log Curves group 4 4 3 Design Operator Figure 4 43 Design Operator block W Seismic Coloured Inversion testdata Untitled File View Tools Help c 1 ar ig Re R5 2 i RM J 1 1000 B g a a E oO s 1000 E Design Controls x aa fl Smooth Seismic Mean 5 100 E Freg Hii smoothing Operator Len 10 Hz Residual Operator QC Fit Well Log Curves Low Cut High Cut Full Range D Hz 100 Hz 50 Alpha 0 90993 Design Operator u Low Cut High Cut a E Auto Calc Full 10 Hz gi Hz 0 a v Auto Calc f A00 y Auto Calc Egy 99 9812 QC Against Inout Seismic http opendtect org rel doc arkcls sci ch04s04 html 4 of 6 21 10 2009 15 30 23 4 4 Design Controls 7 N wv Auto Calc n Egy 99 9812 TY QC Against Input Seismic T T T 5 100 Frag Hz Close Residual Operator QC Freg Hz 125 8727 Amp The Design Operator group provides controls which allow you to perturb how the Coloured Inversion operator spectrum is generated Specifically it allows you to adjust the bandwidth of the designed operator Normally the default is that the bandwidth is automatically calculated The Design Operator chart displays three spectra The first spectrum is the band limited curve fit green curve the second spectrum is the smooth seismic mean red curve and the third spectrum is the Coloured Inversion operator blue curve
49. e 4 33 Define ASCII File Format http opendtect org rel doc arkcls sci ch04s03 html 8 of 12 21 10 2009 15 30 19 4 3 Select Input Data Deline Ascii File Format Select Ascii Formal Landmark ASCII Weer defined Recon and Column Information Fila Time Column Units Mao of Recs to Skip 0 milliseconds n Seconds Time Golumm 14 Impedance Column 2 Close The figure above shows the Define ASCII File Format dialog This dialog has three groups Select ASCII Format Record and Column Information and File Time Column Units Select ASCII Format This group contains a radio button with two options Landmark ASCII and User defined In Landmark ASCII mode default the other two groups are desensitised In User defined mode you can supply additional information in the Record and Column Information and File Time Column Units groups Although no explicit LAS input facility is provided you can normally read LAS files in User defined mode Record and Column Information If your ASCII has header records before the wireline curve data you should skip these by specifying a value in the No of Recs to Skip input field You should also specify which column the time data and the impedance data can be found By default these are set to 1 and 2 respectively File Time Column Units This radio button item allows you to specify whether the time data is in milleseconds or seconds 4 3 2 3 Database well log loading Lo
50. ectly on the chart area whereas other interactions require you to first pop up a dialog 4 2 1 Direct I nteractions Direct interactions with the chart area allow you to interact with the chart without popping up additional dialogs 4 2 1 1 Global Zooming Global zooming allows you to zoom the chart area in or out with the mouse Figure 4 8 Global Chart Area Zooming Raw Seismic Raw Seismic Log Input time domain 10000 S000 Freg Hz E The images in the figure above show how the central chart area can be zoomed in and zoomed out in a global sense Zooming in is achieved by either clicking on the menu item View gt Zoom In or clicking the e icon The LH image shows the result on the charts of zooming in e Zooming out is achieved by either clicking on the menu item View gt Zoom Out or clicking the icon The RH image shows the result on the charts of zooming out 4 2 1 2 Identifying Data Frequently on charts there can be several curves plotted Therefore identifying a particular curve amongst the jumble may appear to be a daunting task However a facility has been provided which allows you to point at a Vertex and clicking with mouse button 1 MB1 will display the name of the curve in the status bar Figure 4 9 Identifying Data from Charts http opendtect org rel doc arkcls sci ch04s02 html 1 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area Haw Seismic Raw Seismic 50 50 Freg Hz
51. endtect org rel doc arkcls sci ch04s03 html 12 of 12 21 10 2009 15 30 19 4 4 Design Controls 4 4 Design Controls Prev Chapter 4 User Manual Next 4 4 Design Controls This section describes how you can tweak various parameters to improve the Coloured Inversion operator Figure 4 40 Design Controls Dialog Design Controls emaoaoth Seismic Maari Smoothing Operator Len 5 Fit Well Log Curves Full Range Alpha 0 541823 Design Operator w Aulo Gale v Aulo Calc QC Against Input Seismic Close SciQt is data driven so once the data is identified and loaded then a Coloured Inversion operator will immediately be available for saving This makes the Coloured Inversion analysis very easy for the end user However the resulting operator may not be optimum Therefore it will frequently be necessary to perturb various design parameters to produce the optimum Coloured Inversion operator The various charts within the main window are used to help you produce the ideal Coloured Inversion operator for your data Below is a description of the primary parameters used to design the Coloured Inversion operator Additional parameters can be found under the Advanced Controls dialog which can be popped up via the Tools gt Advanced Controls menu item or via the a icon The Design Controls dialog is split into three groups Smooth Seismic Mean Fit Well Log Curves and Design Controls The following three sections de
52. erm Trace by trace variation term DA ae These terms are limited on the expected Al values within specified layers The model parameterisation together with the constraints and some of the above terms may extend the inversion beyond the bandwidth of the seismic The most important of the above is the seismic misfit term In order to generate the seismic misfit term this form of inversion requires the user to supply an explicit wavelet This is generally performed prior to performing the inversion itself The benefit of this is that it forces the user to tie and understand the log seismic fit However the downside is the wavelet is affected by calibration errors in the logs Generation of wavelet is a difficult task and can be error prone 2 4 2 Coloured I nversion Coloured Inversion takes a different approach that is more familiar to seismic processing In simple terms we analyse various seismic and well log spectra to define an operator that shapes the average seismic trace spectra to that of a fitted smooth curve which is representative of the average Al log spectrum This defines the amplitude spectrum of the required operator Theory tells us that a 90 degree phase rotation is also required This is incorporated into the operator The assumption is that the input seismic data is zero phase The Coloured Inversion operator is converted to the time domain and simply applied to the seismic volume using a convolution algorithm 2 4 3 Synthetic
53. fine ire PRS Amp ARG Er E TRACE 0b 1882 api 1 27881 B gg EJ TRACE 02 1479 ami 1 25383 7 300 BE E TRACE 0B3 BT 5207 1 29550 5 es F TRACE 054 a 1 18054 B 3125 P TRACED ine E325 1 34450 B ryem s Hmw Ssism z Freg Hzr 235045 Amp dg 26 2773 mar Traces Dap eA Tree 3 Saeba d Linckelin ani The image in the figure above shows the SciQt Main Window with Select Input Data Dialog superimposed The Raw Seismic spectra resulting from clicking the Load Seismic button on the Select Input Data Dialog above left with Num Traces set to 40 and a 3D Survey Area is defined by In line 1400 1800 X line 4300 5400 By default all loaded traces are used in the spectra calculation and contribute to the Seismic Mean Spectrum However you can remove a given trace from the SciQt analysis by deselecting it via the Input list Deselection of a trace is simply achieved by unchecking the checkbox within the list If you want to completely remove the deselected trace you click the Clear Unselected Traces button Alongside each trace on the Input list are various properties associated with the trace These include Trace Id or trace label In line X line RMS Amp RMS Err Horz Time The RMS Amp property is derived from the input seismic trace whereas the RMS Err property is derived from the trace spectrum The latter can be considered as a goodness of fit parameter as it compares trace spectrum with the smooth mean trace spectrum So for R
54. gh more sophisticated techniques such as sparse spike inversion take account of these factors specialist skills are required SCI takes into account the seismic wavelet and is consistent with log data With this technique it is now possible to routinely invert any dataset within hours and establish a base case against which more sophisticated techniques must be judged SCI enable the rapid inversion of 3D and 4D data A single convolution inversion operator is derived that optimally inverts the data and honours http opendtect org rel doc arkcls sci chO01 html 1 of 2 21 10 2009 15 29 31 Chapter 1 Introduction avallable well data in a global sense In this way the process is intrinsically stable and broadly consistent with known Al behaviour in the area Construction of the operator is a simple process and implementation can be readily performed within the processing module As an explicit wavelet is not required other than testing for a residual constant phase rotation as the last step this removes an inherently weak link that more sophisticated processes rely on Prev Next ARK CLS Seismic Coloured Chapter 2 Background and Inversion V2 94 Home Theory OpendTect plugin version http opendtect org rel doc arkcls sci chO1 html 2 of 2 21 10 2009 15 29 31 Chapter 2 Background and Theory Chapter 2 Background and Theory Chapter 2 Background and Theory Table of Contents 2 1 Basics 2 2 Benefits of Seismic
55. gh side 2 Middle Auto Calc checkbox unchecked In this mode you can manually specify the frequency of the 60 dB down point both on the low and high sides Auto Calc The bottom checkbox controls whether the Num Zero X ings i e time http opendtect org rel doc arkcls sci ch04s04 html 5 of 6 21 10 2009 15 30 23 4 4 Design Controls domain operator truncation value is automatically or manually calculated 1 Bottom Auto Calc checkbox checked default on the distributed template In this mode the truncation of the time domain Coloured Inversion operator will be automatically determined This is controlled by a parameter which sets the percentage of energy captured The percentage of energy captured template parameter is currently set at 99 9 It is planned that future versions of SciQt will allow you to set template default parameters It is sometimes desirable to alter the amount of truncation applied in order to reduce the length of long tails of very small sample values or to include additional samples of significant value 2 Bottom Auto Calc checkbox unchecked In this mode the Num Zero X ings spinbox must be set manually This allows you to adjust the length of the time domain operator in steps of zero crossings It is desirable to have the operator truncate to a sample point close to a zero crossings point as it reduces anonymous side effects which might be introduced when the operator is applied A read only
56. he Al log curves to be in time This transformation and resampling is done automatically using the Depth Time model allocated for each well This data in the time domain can be displayed on one or more Main Window charts By default the Al data in time is displayed on the Log Input time domain and Log Input Detrend time domain charts As each AI log curve is loaded its amplitude spectra are also immediately calculated and displayed by default on the Individual Wells chart The central area of the Select Input Data dialog Input Well Log tab shows the available Al log curves for each well You can deselect wells and or log curves by clicking on the appropriate checkbox Set Time Range Again our aim is to design a Coloured Inversion operator for the zone of interest target It is therefore desirable to time gate the selected traces prior to generating well log spectra Ideally you http opendtect org rel doc arkcls sci ch03s02 html 5 of 6 21 10 2009 15 29 53 3 2 Selecting Data should use a well defined interpreted horizon in the target zone to guide the well log trace time gate In this manner the various gated log traces should have sample values over a similar geology Click Select Horizon to pop up a horizon select dialog select the horizon you require and then click Close button to return Click Horizon in the Range radio button and specify the Relative Start and Relative End values A negative numbe
57. he sparse spike inversion is given the correct wavelet it gives a similar result to Cl Thus this example shows how easy it is to get sparse spike inversion wrong even when the answer is known CI doesn t suffer from this problem as it is not necessary to determine the wavelet Figure 2 3 Synthetic comparison in greater detail 2 4 4 Real data examples Below are some real data examples showing the benefits of seismic inversion and in particular Coloured Inversion 2 4 4 1 Comparison between Coloured nversion and Unconstrained Sparse Spike Figure 2 4 Coloured nversion and Unconstrained Sparse Spike example Coloured Inversion Unconstrained Sparse Spike Inversion The real data example within the figure shows great similarity between the Coloured Inversion and the unconstrained Sparse Spike result The advantage of using Coloured Inversion is that the result can be obtained within an hour or two whereas Sparse Spike inversion can take several days to perform and uses specialised software that is not available to many interpreters Furthermore there is no guarantee that the result will be superior and as we have shown if the wavelet is not estimated correctly the result can http opendtect org rel doc arkcls sci ch02s04 html 2 of 3 21 10 2009 15 29 47 2 4 Inversion techniques frequently be worse 2 4 4 2 Coloured I nversion used to I mproving interpretation Figure 2 5 I mproving I nterpretation example
58. heckbox item allows the time converted operator to be normalised With this turned on the amplitude values are adjusted so that the energy in the time converted operator is set to one 4 5 3 Time Domain Figure 4 46 Time Domain Tab w Advanced Controls Frequency Domain Design Operator Time Doman Data Conditioning Normalis aticn interval Source v Monnalse i e Seimic Use Remove Linear Trend from Log Data x4 De trend Ramp End of Log Using Papoulis Windowing Appl Rampa Ramp Length ms 46 Log Data Resampling Interval Source Resampling literal 1 Seimk User eng Chose This group is split into the sub groups Data Conditioning and Log Data Resampling Sub group Data Conditioning http opendtect org rel doc arkcls sci ch04s05 html 3 of 5 21 10 2009 15 30 25 4 5 Advanced Controls For the coloured inversion result to have amplitudes which have physical meaning then it will be necessary to normalise the Al log spectral amplitude This is achieved by compensating for the effects of the relative differences between the seismic and AI log gate lengths together with the relative differences between the seismic and Al log sample intervals Normalisation Normalise This checkbox item allows you to toggle on off the normalisation facility Interval Source This radio button control allows you to specify whether the Sample Interval or Design Gate is determined from Seismic or User If the source is
59. his way inversion can be achieved within hours since the volume data do not have to be exported to another package SCI takes into account the seismic wavelet and is consistent with log data With this technique it is now possible to routinely invert any dataset within hours and establish a base case against which more sophisticated techniques must be judged SCI enables the rapid inversion of 2D 3D data A single convolution inversion operator is derived that optimally inverts the data and honours available well data in a global sense In this way the process is intrinsically stable and broadly consistent with known Al behaviour in the area Construction of the operator is a simple process and implementation can be readily performed within the processing module included in SCI As an explicit wavelet is not required other than testing for a residual constant phase rotation as the last step this removes an inherently weak link that more sophisticated http opendtect org rel doc arkcls sci ch02s05 html 1 of 2 21 10 2009 15 29 48 2 5 Seismic Coloured Inversion SCI processes rely on Generally traditional inversion methods e g sparse spike are time consuming expensive require specialists and are not performed routinely by the Interpretation Geophysicist whereas SCI is rapid easy to use inexpensive robust and does not require expert users SCI and unconstrained sparse spike appear to give broadly equivalent results SCI seamles
60. hows the result of clicking the Clear Lists push button Clear list removes all traces previously loaded to memory and has the immediate effect of removing this data from the Raw Seismic chart within the SciQt Main Window 4 3 1 3 Modifying Time Range Specifying the time range gate is an important step Ideally you should choose a time gate in the range of 500 1000 msec which should be over the zone of interest You can set the Time Range mode in one of three ways via the Range radio button 1 Full this range would cover the full trace length It is rarely used 2 Sub here you additionally need to specify Absolute Start Time and Absolute End Time This Time Range mode is the default 3 Horizon here you additionally need to specify the Relative Start Time and Relative End Time You also need to specify the horizon to be used Of the three options the Horizon Range mode is the preferred mode since it allows the gate to follow the geology and should with a well interpreted horizon in the target zone give in theory trace spectra which are more closely matched Figure 4 25 Modifying Seismic Time Range Full 54 c Cusceded TES matida Lii Fit Wew Toss Hel Tes id fing lt img FG Emp PHEEn Horm Tita a G EE TRACE r TD An 1 29592 AZZ 24 fe EX ts k ar zi B 2 EE TRADE DHZ 5585 Jai 1 20225 EAE under Raw Seismic ED TRCE_teg oe EA LEET DET Bad ED TRACE 0m Tra am LIGE eG zn EE TRACE MS i 8475 LEEF a
61. ift of the Below principal curve However the Set mode is not normally recommended Principal The principal curve is by far the most important curve hence its name The default mode is Curve Fit Curve fitting is performed between the Low Cut and the High Cut frequencies defined in the Fit Well Log Curves group on the Design Controls dialog The Alpha is the key curve fit parameter and is also displayed on the Design Controls dialog The Set mode allows you to manually set the sensitive Alpha DC and F Shift of the Principal curve Above principal The default mode is Force Horizontal n this mode the Alpha DC and F Shift are insensitive and cannot be used The DC value displayed is the value of the Principal curve fit at the High Cut point The Fit Independently mode uses the same curve fit algorithm between High Cut and nyquist as that used for the Principal curve fit The displayed Alpha DC and F Shift are parameters from the independent fit This mode frequently gives strange results and its usage is not normally recommended The Extrapolate Principal mode allows the Principal curve to be extrapolated beyond the High Cut up to nyquist The Set mode allows you to manually set the sensitive Alpha DC and F Shift of the Above principal curve However the Set mode is not normally recommend There are two other Advanced Controls on the Frequency Domain tab Type of Fit
62. indow will also be updated to show the new empty chart To change the name of the new chart simply click on New Chart and type the new name you require directly within the Chart Controller dialog Here we have changed the name from New Chart to Coloured Inversion The Main Window will be updated as soon as you press Return or Enter or by clicking away from the just edited chart name in the list You can change the name at any time of any of the charts in the list With the new chart created it is normal to label the axis and to select the Data Items to be displayed in the chart You can achieved this by clicking the Edit push button to pop up the Display Options dialog In this case the user has labeled the X axis as Freq Hz not visible and Y axis as Amp dB The user has also selected the Convolved Trace Spectra group for the Data Item to be displayed in this chart The first images show Main Window before the new chart is added with the second image showing the Main Window after the new chart has been added and renamed 4 2 2 2 Moving Charts Moving charts is very simple The table below shows an example of moving a chart within the chart area Figure 4 15 Moving Charts http opendtect org rel doc arkcls sci ch04s02 html 5 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area Chart Controller Raw Seismic Seismic Mean Raw Seismic Chart Controller Log Input time
63. ionally the toolbars can be moved off the main window altogether and anchored on the desktop To move the toolbar to a new location grab the handle at one end of the toolbar by pressing and holding mouse button 1 and dragging to the new location 4 1 1 2 1 File Toolbar Creates a new SciQt session Opens a previously saved SciQt session This facility allows you to restore the SciQt parameters together with the data from a previously saved session Restoring a previously saved session can take a few moments while database access is established Note if the stored data within the database has been modified since the session save time then it is possible that a Coloured Inversion operator which is different to that available at the session save time might be generated following a session restore Saves an SciQt session This allows the SciQt parameters together with information about the data used to be saved In this way data can be easily reloaded and the SciQt Coloured Inversion operator generated at some future date If this is the first time that this is saved then the user will be presented with a file selector dialog for this purpose Saves the SciQt Coloured Inversion operator set to the database This menu item will pop up a Save Operator dialog The dialog will list all the operator sets currently stored in the OpendTect database A filter facility is provided to help you find an existing
64. l log data in time with the linear trend line removed In this case end ramping has also been applied so the log ends intercept the zero axis Selecting or de selecting Al log data in the Input Well Log tab on the Select Input Data Dialog will update the data on this chart Controls on the Advanced Controls dialog can also have an immediate effect on this chart Figure 4 3 SciQt main window default configuration showing the middle four charts Seismic Coloured Inversion testdala sci test l 03 File View Tools Help Daci I Individual Wells LET i di Freq Hz Design Operator 50 Freq Hz AprzU us ses oo ue 7 Global Frag Hzj Operator time domain Chart 5 Individual Wells This chart displays the individual Al log spectra As there is only one Al log selected in this example there is only one log spectrum to be displayed Selecting Al log data in the Input Well Log tab on the Select Input Data dialog will http opendtect org rel doc arkcls sci ch04s01 html 8 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application update the data on this chart Chart 6 Global This chart displays the mean or global of the individual AI log spectra In this example there is only one individual Al log spectrum so the global spectrum is the same as the single individual Al log spectrum Also displayed on this chart is the curve fit spectrum black Various controls on
65. lection Clicking the Select push button to the right of the Volume subselection label allows you to specify whether you wish to process the entire input volume or a sub volume 3 Output Cube Clicking the Select push button to the right of the Output Cube label allows you to select an existing cube to be overwritten or to specify a new cube to be created 4 Submit to Click the Single machine radio button to submit this processing job to a single machine Details of using Single or Multiple machines can be found in the OpendTect documentation 5 Store processing specification as Recommend that you accept the default All other parameters on this dialog can be ignored 6 Proceed Click the Proceed push button to start the batch Coloured Inversion processing within OpendT ect Prev Up Next 3 3 Designing and Saving Chapter 4 User Manual the Coloured Inversion Home Operator http opendtect org rel doc arkcls sci ch03s04 html 3 of 3 21 10 2009 15 29 57 Chapter 4 User Manual Chapter 4 User Manual Chapter 4 User Manual Table of Contents 4 1 Interfacing with the SciQt Application 4 1 1 SciQt Main Window 4 1 1 1 Menubar Area 4 1 1 2 Toolbar Area 4 1 1 3 Chart Area 4 1 1 4 Status Area 4 1 2 SciQt Main Window ancillary tools 4 1 2 1 Save Operator 4 1 2 2 Import Chart Configuration 4 1 2 3 Export Operator 4 1 2 4 Export Data Item 4 1 2 5 Parameter Report 4 2 User interaction with
66. list of logs to provide a facility to shorten the list of logs to a manageable size should this be necessary If no density log is available then you can supply a constant density value This is achieved by clicking on User for the Density Source radio button and specifying the density value in the User Density value field 4 3 2 4 Modifying Time Range Specifying the time range gate is an important step Ideally you should choose a time gate in the range of 500 1000 msec which should be over the zone of interest You can set the Time Range mode in one of three ways via the Range radio button 1 Full this range would cover the full trace length It is rarely used 2 Sub here you additionally need to specify Absolute Start Time and Absolute End Time This Time Range mode is the default 3 Horizon here you additionally need to specify the Relative Start Time and Relative End Time You also need to specify the horizon to be used Of the three options the Horizon Range mode is the preferred mode since it allows the gate to follow the geology Figure 4 37 Modify Well Log Time Range Full w Silane Colon beaa xpi miej F a 137 343 3535 38 File View Tools Help E ALB HT X1 iban i x4 m i E D A P PEDANGE 1045083285 42 E k ar il iw e ipm 1350 283535 38 Lag Input time da 1 ALB HT X2 137 34 2600 hore O ipen sone 137 343 2598 05 4 Guar Wels Cour Linzspipciod Woks Tir Peet Hieron Iracked norz
67. more seismic trace spectra displayed on the Raw Seismic plot were anomalous then it is possible to remove those traces from the Seismic Mean Spectrum calculation Let us consider the blue trace which appears to have a particularly low amp dB at around 60Hz Now if we wish to exclude this trace from the mean calculation we must first identify it This is achieved by pointing close to one of the vertexes of this spectrum and clicking on it We need to be within few a pixels of one of vertexes to be able to identify it f we are within range when we click then the spectra named together with the Frequency and Amplitude of the vertex is displayed in the Status Area of the Main Window In this case the raw seismic spectra is identified as TRACE 003 We can now to go to the Input Trace list and click the checkbox to the left of entry TRACE 003 This causes the trace to be flagged as not currently selected and the Raw Seismic plot on the Main Window is updated accordingly The Seismic Mean spectrum black on both displays changes as a consequence An alternative method which works well in this case is to look at the RMS Err property You will note that the RMS Err of TRACE 003 is significantly larger than that of the RMS Err values of the other trace spectra So if you sort by RMS Err you will easily be able to identify any trace spectra with an abnormally large RMS Err value You should note that once you toggled off a trace it may loose its RMS
68. mp mn51532 earls Gear Traces Cion irolortu Trati 40 Setected 3 Lindel ined 5i 1 Ary Gsm Frag Hrer S324 Amp dap 8 The image in the figure above shows the SciQt Main Window with Select Input Data Dialog superimposed Here Full full trace range has been selected for the Range radio button This mode is rarely used since our goal is to design a Coloured Inversion operator over the zone of interest This will optimise the process over that zone However it does allow you although insensitive to see the start and end times of the entire trace Figure 4 26 Modifying Seismic Time Range Sub http opendtect org rel doc arkcls sci ch04s03 html 3 of 12 21 10 2009 15 30 19 4 3 Select Input Data ac F P m wO ime Cbd irwersasf ELS Ls imid m Elle View Tools Hel Tema id ing Ei FMS Amp RM En Hoz Tima a E TRATED ID ARa LEAD EA gans fa a k ar x x a Ed TRACE DHZ UMERSO Ug 1 20225 5355431 umiei Raw Seismic El TRACE 003 582 mA LT a4 BOG sa4z ED TRADE DH 1 atm LIESE RAN E TRACE n25 ime Th LERF amag ga al IC Gear Traces Geer iradad Tiaia 40 paeh 3 Udaina Time Stes Soon auge Full Esh Few Seam Fg Hrer 525185 Amp dar 21 The image in the figure above shows the SciQt Main Window with Select Input Data Dialog superimposed Here Sub sub trace range has been selected for the Range radio button In this mode the Absolute Start time and the Absolute End time Line Edit fields will be se
69. mport the chart configuration from a previously saved session file 4 1 2 3 Export Operator The Export Operator tool allows you to export an operator to an ASCII file Clicking the File mport Export Export Operator menu item will pop up a file selector dialog Here you can traverse the file system to export the Coloured Inversion operator as an ASCII file 4 1 2 4 Export Data Item This is a powerful ancillary tool which allows you to export any of the loaded or generated data items time or frequency domain curves to an ASCII file Clicking the File gt Import Export gt Export Data Items menu item will pop up the Export Data Item dialog Figure 4 6 Export Data Item dialog http opendtect org rel doc arkcls sci ch04s01 html 11 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application w Export Data Item Data Item Haw Traces Gated Traces Trace Spectra Average Trace Spectrum Smoothed Average Trace Spectrum Raw Well Logs Gated Well Logs Log Trend Lines Detrended Logs Log Spectra Average Log Spectrum Log Curve Fit Principal Curva Fit Composite Curve Fit Smooth Composite Curva Fil Below Min Freq Fit Design Operator Untruncated Operator Truncated Operator OC Traces Gated QC Traces Close Export Include Header infe The figure above shows the Export Data Item dialog This dialog contains a list view widget which allows you to
70. neg naue Ful Hiper on Es n The image in the figure above shows the SciQt Main Window with Select Input Data Dialog superimposed Here Full full trace range has been selected for the Range radio button This mode is rarely used since our goal is to design a Coloured Inversion operator over the zone of interest This will optimise the process over that zone However it does allow you although insensitive to see the start and end times of the entire trace http opendtect org rel doc arkcls sci ch04s03 html 11 of 12 21 10 2009 15 30 19 4 3 Select Input Data Figure 4 38 Modify Well Log Time Range Sub Sai ce Coded lmweiza r xli ide E ud 137 343 3532 38 Ee View Tools Help E ALB HT Xx1 iban i 333 4 j A BISMPEDAMCE 1045 063285 42 E k ar ei sd B x O epee 1380 383535 38 Log Input time do 1 ALB HT X2 137 34 2600 4 a dii LI kapen some 137 343 2598 95 4 Car Wels Gwar Linz eieciod Wiplis Tim Select Hieron tracked horn ima naue Ful diners Aes DE ub Geb Lng Input ime domain Times ime 2365 018B A The image in the figure above shows the SciQt Main Window with Select Input Data Dialog superimposed Here Sub sub trace range has been selected for the Range radio button In this mode the Absolute Start time and the Absolute End time Line Edit fields will be sensitised This allows you to specify a time gate for the zone of interest Ty
71. nerated In SciQt these changes occur in real time so you will be able to see immediately the effect of the change you have made Pop up the Design Controls Dialog by either clicking the Design Controls menu item under the Tools menu bar or by clicking the icon Figure 3 5 Design Controls dialog Design Controls Smooth Seismic Mean Smoothing Operator Len 5 Hz Fit Well Log Curves v Full Range Alpha 0 541823 Design Operator v Auto Calc v Auto Cal c v Auto Calc QC Against Input Seismic Close The figure above shows the Design Controls dialog This dialog allows you to tweak various parameters in the generation of the Coloured Inversion operator The steps below give you a brief overview of the parameters found on the Design Controls dialog 1 Smoothing Seismic Mean This controls the amount of smoothing that will be applied to the seismic mean spectra The operator length is specified in Hertz 2 Fit Well Log Curves These spinboxes control the lower and upper boundaries for the principal curve fit Outside this range the curve is by default extrapolated on the lower end and forced to be horizontal on the upper end with smoothing LE 3 applied in the vicinity of the boundary Other curve fitting controls are available via the aS icon or Tool gt Advanced Controls menu item 3 Design Operator By default the low and high cut points are automatically determined You can override these se
72. ng the data to the new position The LH image shows the old position of the data with the RH image showing the new position of the data 4 2 1 5 Changing Axes It is sometimes useful to see axes displayed differently This is easily achieved via a pop up menu Clicking MB3 on a chart will cause the pop up menu to be displayed The menu will show amongst other options a cascade menu for X Axis and Y Axis The cascade menu for the X Axis allows you to toggle between 1 Linear Scale or Logarithmic Scale 2 Increasing Right or Increasing Left 3 Axis at Bottom or Axis at Top The cascade menu for the Y Axis allows you to toggle between 1 Linear Scale or Logarithmic Scale 2 Increasing Up or Increasing Down Figure 4 12 Changing Scales on Charts http opendtect org rel doc arkcls sci ch04s02 html 3 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area Increasing Down X AXIS Logarithmic Scale Logarithmic Scale Data Area Increasing Lett eK E ESI 10 Axis At Top Fraq Hz Help The images in the figure above show how an axis can easily be changed from a linear to a logarithmic scale By pressing and holding MB3 whilst hovering over the y axis or x axis or the data area of the chart you can pop up a menu In this case the user clicked over the y axis Moving to the X Axis item on the pop up menu will cause the X Axis cascade menu to be displayed LH image Then moving to the right over the Log
73. nsitised This allows you to specify a time gate for the zone of interest Typically you would specify a time gate which has a time range between 500msec and 1000msec Figure 4 27 Modifying Seismic Time Range Horizon n P n i DG Sainte L ei aa aa wmi pn ac Ehe Mew Tools Hel Trace id m E ramAcE nm Shee ee a a 5 Raw Seismic Ei TRACE Ma 19 iraciuaci forz _ energy ED TRACE D 17 TRACE DEJ eiir Mie r Coa Traces Chaar Li Select Cancel ime Seat oer mac kid norz nm aane Full Hazon Bah Few Seams Frag Hrer dr 3300 Amp dar 31 1 The image in the figure above shows the SciQt Main Window with Select Input Data Dialog superimposed Here Horizon horizon relative trace range has been selected for the Range radio button In this mode the Relative Start time and the Relative End time Line Edit fields will be sensitised This allows you to specify a time gate for the zone of interest Typically you would specify a time gate which would give you a time range between 500msec and 1000msec Specifying the Start and End times here are relative to a geologic horizon A negative number represents time above the horizon whereas a positive number is a time below the horizon The time gate can be either above below or span the horizon 4 3 1 4 Removing Bad Traces Occasionally it is necessary to remove one or more poor spectral traces which contribute to the generation of the mean spectra This is easily achieved by identif
74. nter is in the range 001 to 999 So the first trace spectrum would be assigned a label TRACE 001 with the second trace spectrum assigned TRACE 002 and so on Similar names are assigned to Raw Trace and Gated Trace groups Now data items can be added to a chart by selecting the group name and the data label name within The image above shows the Display Data Items dialog with the Data Item list displaying the group names and optionally the data label name if the group is open ie expanded Groups can be expanded or collapsed by clicking to the left of the group name So once a data item is selected for a chart whenever that data item is available it will be displayed on that chart In the image above where we have selected the data item labelled TRACE 003 within the Trace Spectra group Notice that displayed the TRACE 003 spectrum is now displayed black line on the Coloured Inversion operator chart If we now clear the traces via the Select Input Data Dialog and reload more seismic traces we will get a new trace labelled TRACE 003 displayed on the Coloured Inversion Operator chart This persistence is a useful feature of the underlying rule based chart control system At the time you select a data item for display you can assign a colour Alternatively you can allow a colour to be assigned automatically Prev Up Next 4 1 Interfacing with the SciQt Application Home 4 3 Select Input Data http opend
75. nversion operator 3 4 2 Applying the Coloured Inversion operator 4 User Manual 4 1 Interfacing with the SciQt Application 4 1 1 SciQt Main Window 4 1 1 1 Menubar Area 4 1 1 2 Toolbar Area 4 1 1 3 Chart Area 4 1 1 4 Status Area 4 1 2 SciQt Main Window ancillary tools 4 1 2 1 Save Operator 4 1 2 2 Import Chart Configuration 4 1 2 3 Export Operator 4 1 2 4 Export Data Item 4 1 2 5 Parameter Report 4 2 User interaction with Chart Area 4 2 1 Direct Interactions 4 2 1 1 Global Zooming 4 2 1 2 Identifying Data 4 2 1 3 Data Zooming 4 2 1 4 Moving Data 4 2 1 5 Changing Axes 4 2 2 Chart Controller 4 2 2 1 Creating a New Chart 4 2 2 2 Moving Charts 4 2 2 3 Deleting Charts 4 2 2 4 Saving and Loading Chart Configurations 4 2 2 5 Changing the Number of Columns 4 2 2 6 Zooming In and Zooming Out 4 2 3 Display Options http opendtect org rel doc arkcls sci index html 2 of 5 21 10 2009 15 29 30 ARK CLS Seismic Coloured Inversion V2 94 OpendTect plugin version 4 2 3 1 Chart 4 2 3 2 Management of Data Items 4 3 Select Input Data 4 3 1 Input Seismic tab 4 3 1 1 Select trace data 4 3 1 2 Loading and Clearing Data 4 3 1 3 Modifying Time Range 4 3 1 4 Removing Bad Traces 4 3 1 5 Select Volume dialog 4 3 1 6 Horizon Input Dialog 4 3 2 Input Well Log tab 4 3 2 1 ASCII well log loading 4 3 2 2 Define ASCII File Format 4 3 2 3 Database well log loading 4 3 2 4 Modifying Time Range
76. oduction Chapter 1 I ntroduction Inversion of seismic data to Acoustic Impedance Al is usually seen as a specialist activity In site of the publicised benefits inverted data are only used in a minority of cases To help overcome this obstacle this algorithm which is quick and easy to use can increase the use of inversion technology Seismic Coloured Inversion SCI performs significantly better than traditional fast track methods such as recursive inversion and benchmarks well against unconstrained sparse spike inversion and gives broadly equivalent results Sophisticated inversion methods are time consuming expensive require specialists and not performed routinely by the Interpretation Geophysicist whereas SCI is rapid easy to use inexpensive robust and does not require expert users With the inclusion of de trend and normalisation functionality within SCI geophysical meaning can now be assigned to the observed amplitude changes in the derived impedance volumes This can be very powerful particularly with 4D projects Once the SCI operator has been derived it can be simply applied using the convolution function within the software In this way inversion can be achieved within hours since the volume data do not have to be exported to another package Traditional fast track methods for band limited inversion to relative Al are prone to error because no account is taken of the seismic wavelet or calibration to the Earth Althou
77. ology This allows SSB analysis operator design and processing to be performed without separately importing or exporting data Prev Up Next 2 5 Seismic Coloured EA 2 7 References and Inversion SCI Acknowledgements http opendtect org rel doc arkcls sci ch02s06 html 21 10 2009 15 29 48 2 7 References and Acknowledgements 2 7 References and Acknowledgements Prev Chapter 2 Background and Theory Next 2 7 References and Acknowledgements 2 7 1 References 1 Lancaster S and Whitcombe D 2000 Fast track coloured inversion SEG 2000 Calgary 2 Walden A T and Hosken J W J 1985 An investigation of the spectral properties of primary reflection coefficients Geophysical Prospecting 33 400 435 3 Velzeboer C J 1981 The theoretical seismic reflection response of sedimentary sequences Geophysics Vol 46 No 6 843 853 2 7 2 Acknowledgements ARK CLS would like to thank Terry Redshaw BP Sunbury and BP for permission to use examples and other material in this chapter We would also like to thank BP for granting ARK CLS the right to implement the technology in the commercial versions of Seismic Coloured Inversion and Seismic Spectral Blueing rrev Up Next 2 6 Seismic Spectral Blueing TA Chapter 3 Quick Start SSB SciQt Tutorial http opendtect org rel doc arkcls sci ch02s07 html 21 10 2009 15 29 49 Chapter 3 Quick Start SciQt Tutorial Chapter 3 Quick Start SciQt Tutorial Chapter 3
78. orizon data is available and if seismic volume is relatively flat then using an absolute sub range would be adequate If it is not flat or the geology changes considerably over the 3D survey area then the selection of a smaller 3D Survey Area might be desirable 3 2 2 Input Well Log With the Select Input Data dialog displayed click the Input Well Log tab http opendtect org rel doc arkcls sci ch03s02 html 3 of 6 21 10 2009 15 29 53 3 2 Selecting Data to select the well log data to use The SciQt software supports reading acoustic impedance in time from ASCII files or by connection to a well log data repository Here we shall assume you will normally wish to obtain data from OpendTect well log data repository and we will describe this route If you wish to load from ASCII files then please refer to the full User Manual Figure 3 4 Select I nput Data dialog I nput Well Log tab Select Input Data input Seis mic Input Wel Logs Reload Welk Load ASCII Wels Define Format Field Wells Logs Top Base Hor imine X ne HorzT E field i021 3254 5 M ALB HT X1 14S 3254horz 1320 4320 LE ALEDT 045 3254 5 E ALB HT X2 IRSA 2465 hore 1413 Am3 L M AI 1854 2465 4 Clear Wells Clear Linselected Wells Time Select Horizon tracked harz Range Horan The list below show the steps to generate well log spectra 1 Load Wells http opendtect org rel doc arkcls sci ch03s02 html 4 of
79. ou don t supply a name for the SciQt wavelet at this time 5 Now click the Analyse and Create to launch the SciQt plug in Figure 3 1 Attribute Set used to launch SciQt E Attribute Set 3D Fe 0g OFFS AB Attribute set A Coloured inversion Input Data f B2prio subset Ingut wawelet AnaNse ard Create Arrinute name Add a5 res Hewver changes s Cancel http opendtect org rel doc arkcls sci ch03s01 html 1 of 2 21 10 2009 15 29 50 3 1 Launching the SciQt OpendTect plug in LLLLS S S EIAAAAAA Once launched the SciQt main window will be displayed This window is the main interface to the application The main window GUI consists of from top to bottom a menu area an icon area a chart area and a status area see figure below The chart area which occupies the large scrollable central area of the main window is used to display various charts of spectra and time data to provide feedback to the Interpretation Geoscientist in his her quest to design a SciQt operator Figure 3 2 Seismic Coloured nversion main window Seismic Coloured Inversion main window Prev Up Next Chapter 3 Quick Start SciQt TOR 3 2 Selecting Data Tutorial http opendtect org rel doc arkcls sci ch03s01 html 2 of 2 21 10 2009 15 29 51 3 2 Selecting Data 3 2 Selecting Data Prev Chapter 3 Quick Start SciQt Tutorial Next
80. our SciQt analysis and operator design A Horizon filter is provided to reduce the list to a manageable size for projects with many horizons Figure 4 30 Select Horizon Select Horizon i v Select Horizon Fitter Fitter time edited hor trac Ked_horz_time tracked horz tracked horz enerngy tracked horz_enengy2 tracked horz lime Sw J o H The images in the figure above show examples of the Select Horizon dialog for selection of a seismic horizon The LH image shows a seismic horizon list without a horizon list filter The RH image shows the use of a filter to create a shorter list As can be seen the wild card character can be used in the Filter field 4 3 2 Input Well Log tab This section describes how to select the input well log Acoustic Impedance data for use in the Coloured Inversion operator design Coloured Inversion requires that you select one or more Acoustic Impedance logs from those available for the project Ideally we would like to generate Al spectra from multiple well logs as this should help to retrieve a better global spectrum to curve fit However data from the different wells might be of variable quality so it is up to you to decide which wells to use The figure below shows the Input Well Log tab on the Select Input Data Dialog Figure 4 31 Select Input Data Dialog Input Well Log tab http opendtect org rel doc arkcls sci ch04s03 html 6 of 12 21 10 2009 15 30 19 4 3 Select Input Dat
81. ow is updated in real time http opendtect org rel doc arkcls sci ch04s02 html 9 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area 4 2 3 2 Management of Data I tems This is a very powerful feature which allows you to specify what data is to be displayed on a given chart Figure 4 21 Management of Data I tems w Seismic Coloured Inversion testdata sci v2 93 Mayz008 docO3 v Display Options File View Tools Help Chart TE A J J i eS in Pi t3 B F Vt a l Title Coloured Inversion Operator X Axis Frequency Hz Y Axis Amplitude dE Fixed Axis Hanes Left 0 Aight 100 10 req Hz Bottom 0 Tox o Coloured Inversion Operator Line Thickness 4 Data Items Data Item O Gated Traces E Trace Spectra O TRACE 01 O TRACE 002 METRACE 003 O TRAGE 004 TRACE 005 O Average Trace Spectrum 3 E F Smoothed Average Trace Spectrum L Raw Wall Logs L Gated Well Logs 2n 40 60 B Frequency Hz L Log Trend Lines Residual Operator QC Colour for New Items li Black Ne The figure above shows how you add and remove data items to a chart Data items are assigned data label names and are grouped together into logical sets The set or group name together with the data label name uniquely identifies the data item So for example in the Trace Spectra group the trace spectra data items are given names of the form TRACE _ lt counter gt where cou
82. ows you to modify various chart parameters HH displayed in the central area of the main window e Redraws all the charts on the central area of the main window Provides a global zoom in facility which makes the central chart area grow by a fixed amount each time this menu item is clicked There is an upper maximum Provides a global zoom out facility which makes the central chart area shrink by a fixed amount each time this menu item is clicked There is a lower minimum This icon pops up the online help system 4 1 1 3 Chart Area This is the main functional area of the SciQt application It is used to display various charts These charts are used to display various spectra data and time domain data The chart area provides graphical feedback of the various stages in the generation of the Coloured Inversion operator for the given data and program parameters supplied by you The chart area is also dynamic allowing you to interface directly with the charts within this area You can interactively update these charts in real time by modifying the various parameters in the Select Input Data dialog Design Operator dialog and the Advanced Controls dialog We call this data driven as the effect of you modifying a parameter within the above dialogs is an immediate update to the graphical charts Whereas in earlier versions of the software it was necessary to click a push button at every stage to see an update The chart area
83. pecific chart configuration to an XML file for future use in this or other projects 4 2 2 5 Changing the Number of Columns The chart area is divided into columns The number of columns parameter allows you to control the number of charts that can be displayed in a chart row This can range from 1 up to 30 The table below gives you an example of how this parameter is used Figure 4 18 Changing the Number of Columns http opendtect org rel doc arkcls sci ch04s02 html 7 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area Raw Seismic Seismic h Raw Seismic Chart Controller Chart Tithe Hew Raw Seismic Globa Seismic Mean Edit Seismic Mean Individual Wells Move Lip Global Log Input Detrend lime domain kaa Doun Design Operator Delete Operator Lime domain Residual Operator QC Convolved Output Mean OC Load Convolved Output Mean OC TTTTTTTTTTT 50 100 Frag H Freq Hz Individual Wells Sumber of Golumns E Zoom In zoom Dul Cose The images in the figure above show how the various charts can be laid out within the central chart area of the main window The parameter which controls the number of columns can be found in the Chart Controller dialog This dialog can be popped up by either clicking on the menu item View gt Chart Controller LI LI OO LI or clicking the DIDI icon The Chart Controller dialog above shows the Number of Col
84. pically you would specify a time gate which has a time range between 500msec and 1000msec Figure 4 39 Modify Well Log Time Range Horizon z li L Se REA be ba L intitle E fal 137 343 3535 38 Ee Mew Ios Hep E ALB HT X1 iB ni 35334 J 1 A FIMPEDANCE 1045 083265 42 ba E h ar ei iw e E immat 1500 3835313 38 Lag Input time da 1 ALB HT X2 137 34 2600 24 bhoz idid LI kapean sone 137 243 2508 95 4 Gor Wels Cigar Linseieciod Wiis Tors Select Heron tracked honr tima naue Full E Heron Ranies Geb The image in the figure above shows the SciQt Main Window with Select Input Data Dialog superimposed Here Horizon horizon relative trace range has been selected for the Range radio button In this mode the Relative Start time and the Relative End time Line Edit fields will be sensitised This allows you to specify a time gate for the zone of interest Typically you would specify a time gate which would give you a time range between 500msec and 1000msec Specifying the Start and End times here are relative to a geologic horizon A negative number represents time above the horizon whereas a positive number is a time below the horizon The time gate can be either above below or span the horizon Clicking the Select Horizon push button will pop up the Horizon Input Dialog Prev Up Next 4 2 User interaction with Chart Area Home 4 4 Design Controls http op
85. r is a relative time above the horizon i e shallower and a positive number is a relative time below the horizon i e deeper The aim is to select a time gate which has a gate length within the range 500 1000 msec The user supplied values here are accepted and the chart area updates when you do any of the following press Return key press Enter key press Tab key or mouse click on a different widget With the seismic and well data loaded the SciQt application will complete all the various steps to generate a Coloured Inversion operator However with this data driven approach the initial derived Coloured Inversion operator may not be ideal As such it may be necessary for you to perturb some of the design parameters before saving the operator Apart from controlling desired data and data ranges all other design parameters are accessible via Design Operator Dialog see section below and the Advanced Controls dialog Prev Up Next 3 1 Launching the SciQt 3 3 Designing and Saving OpendTect plug in Home the Coloured Inversion Operator http opendtect org rel doc arkcls sci ch03s02 html 6 of 6 21 10 2009 15 29 53 3 3 Designing and Saving the Coloured Inversion Operator 3 3 Designing and Saving the Coloured I nversion Operator Prev Chapter 3 Quick Start SciQt Tutorial 3 3 Designing and Saving the Coloured I nversion Operator Various parameters exist which allow the Geoscientist to perturb how the operator is ge
86. races to load default 40 via the Num Traces spinbox widget This is then followed by you clicking the Load Seismic button to load a random set of traces A list of the randomly loaded traces is then displayed in the Input tab beneath the Load Seismic button At the same time an alternative set of traces is also loaded These alternative traces are listed in the QC tab and are used with the derived Coloured Inversion operator for QC purposes The software http opendtect org rel doc arkcls sci ch04s03 html 1 of 12 21 10 2009 15 30 19 4 3 Select Input Data also enables you to select trace data from multiple sub areas This is achieved by specifying another In line X line Start and End range and clicking the Load Seismic button again The goal is to generate seismic trace spectra which is a good representation of the area as a whole If you attempt to specify an area which is outside of the available area then a warning message will be issued when you attempt to load seismic traces by clicking the Load Seismic button You will also get an error message if you set an area which would not allow enough unique traces for the Num Traces requested Figure 4 23 Loading Seismic Data SH Sete Dose innit deen dsldapa ei Ele View Tools Help Select Inpui Data A Prae Md P GR dE pt Te ame mene Tac Raw Seismic Sme parmi ma a 1D Survey Arta Full En E Buh mins 1407 M a 43JUL Las Seine Mum Traces 41 pil DL Tres Id
87. red Inversion Parameter Report General Comment Project testdata Session sci test 1 O3Apra008 ses Operalor Input Selsmic Seismic Volume ls2pno0_subset cmp Area Type Full Traces Used 40 Horizon Time Range Type Absqute Start Time Absoule End Time Input Well Logs Wellset tesl list Logs Used Well Logs ALB HT X1 IMPEDANCE Impedance Horizon Comment Close Save AS Print The figure above shows the Parameter Report dialog This dialog displays the key parameters in the SciQt analysis and design phase nicely formated Click the Save As push button will pop up a file selector dialog allowing you to save to an ASCII file the formated parameter report Prev Up Next Chapter 4 User Manual 4 2 User interaction with Chart Home Area http opendtect org rel doc arkcls sci ch04s01 html 13 of 13 21 10 2009 15 30 04 4 2 User interaction with Chart Area 4 2 User interaction with Chart Area Prev Chapter 4 User Manual 4 2 User interaction with Chart Area SciQt provides various mechanism to allow you to interact with the main window chart area These interactions can be 1 Global The interaction effects the whole chart area eg global zooming 2 Chart level The interaction effects an individual chart eg change title of chart 3 Data object level The interaction effect an individual data curve on the chart eg set up plot rule Some of these interactions can be achieved dir
88. rformed from within the Chart Controller 4 2 2 1 Creating a New Chart Creating a new empty chart is a very simple process The table below shows an example of how this is achieved http opendtect org rel doc arkcls sci ch04s02 html 4 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area Figure 4 14 Create a new Chart Raw Seismic Seismic lk ta Chart Controller Chart Title Seismic Mean Log Input time domain Log Input Detrend time domain Global Drie imd Wide Raw Seismic Coloured In Chart Controller Chart Title Raw Seismic Seismic Mean Log Input time domain Log Input Dietrend lime domain falnihial The two images in the figure above show how a new chart can be created With the Chart Controller dialog displayed select an existing chart from the list of available charts The selected chart will be highlighted reverse video Now click the New push button first image which will cause a new empty chart to be inserted immediately below your currently selected chart ie below the Raw Seismic chart in this case Note in the chart area of the main window charts are arranged in rows So in a two column arrangement the first chart will appear in row 1 column 1 the second chart appearing in row 1 column 2 and third chart in row 2 column 1 and so on In the Chart Title list the new chart named New Chart will become the currently selected chart and will be highlighted The main w
89. scribe these groups 4 4 1 Smooth Seismic Mean http opendtect org rel doc arkcls sci ch04s04 html 1 of 6 21 10 2009 15 30 23 4 4 Design Controls Figure 4 41 Smooth Seismic Mean w Seismic Coloured Inversion testdata Untitled File View Tools Help Fi vi T H w Design Controls k la lel A B A Smooth Seismic Mean l o h P Seismic Mean Smoothing Operator Len J Hz Fit Well Log Curves Full Range Alpha D 541823 Design Operator v Auto Gale Auto Calc v Aulo Cale a QC Against Input Seismic Frag Hz Close Seismic Mean Freg Hz 106 1020 Amp dB 8 The only parameter in this group is the Smooth Operator Len Hz This spinbox controls the length of the smoothing operator used in the smooth mean algorithm that is applied to the seismic mean spectrum It has a range of 1 1 5th nyquist and by default it is set to a value of 1 25th nyquist View the chart named Seismic Mean whilst changing the value in the spinbox to see the effect of this parameter The aim here is to iron out high frequency amplitude variations as we are only interested in the global shape of the seismic spectrum The image in the figure above shows the smooth mean spectrum black overlaying the mean spectrum red Here the Smoothing Operator Len is set at 10Hz 4 4 2 Fit Well Log Curves Figure 4 42 Fit Well Log Curves block http opendtect org rel doc arkcls sci ch04s04 html 2 of 6 21 10 2009
90. section describes the advanced control parameters which can be used with SciQt The advance controls in SciQt allow you to modify various secondary parameters These secondary parameters have been grouped together under the Frequency Domain tab Design Operator tab and Time Domain tab The following three sections describe these groups 4 5 1 Frequency Domain Figure 4 44 Frequency Domain Tab B oa zc 4 Jg J E Advanced Controls Frequency Domain Design Operator Time Domain Curve Fitting Alpha DG F Shifl Below Principal 128 418 Force Horizontal amp Principal 0 90993 128 418 0 27901 Curve Fil Above Principal 83 5B83 Force Horizontal Type o Fit Least Square Set From File The Frequency Domain tab provides you with control over the curve fitting mechanism By default curve fitting is only performed between the Low Cut and the High Cut frequencies the primary controls which are defined in the Fit Well Log Curves group on the Design Controls dialog This curve fit is referred to as the Principle curve Below the Low Cut and above the High Cut we force the curve fit to horizontal with the value of the Principle at the Low Cut and High Cut points Whilst using these advance controls it is advisable to QC the resulting curve fit by always having the spectrum you are trying to fit and the composite curve fit visible on one of the SciQt Main Window charts by default the Global chart Immediatel
91. sions in other projects Note application parameters and information to reload data are not saved The save sessions facility is designed for this purpose Figure 4 17 Saving and Loading Chart Configurations Seismic Coloured Ir Chart Controller Chart Controller Chart Title 30 Chart Title i 50 Freq iF Freg I Raw Seismic bg Input Detrer Raw Seismic a Log Input ti Log Input time domain Log Input Detrend time domain individual Wells Global Coloured Inversion Seimic Mean Log Input time domain Log Input Detrend time domain Individual Wells Design Operator Global Operator time domain Design Operator Residual Operator QC a Convoved Output Mean QC Load Operator time domain Residual Operator OC Convolved Cutpur Mean OC Save pesa p300 2400 251 P p300 2400 251 Time The images in the figure above show how you can load a chart configuration The first image shows a chart configuration with ten charts In this example the user has clicked the Load push button which pops up a file selector dialog Here an alternative chart configuration XML file was selected which changes the chart area by adding another chart named Coloured Inversion The second image shows the chart area has been updated with another chart which in this case was used to display Coloured Inversion spectra At any time you can use the Chart Controller dialog to save a s
92. sly connects with third party seismic and well data repositories including SeisWorks OpenWorks GeoFrame and OpendTect using our client server technology This allows SCI analysis operator design and processing to be performed without separately importing or exporting data Prev Up Next 2 6 Seismic Spectral 2 4 Inversion techniques H Blueing SSB ome http opendtect org rel doc arkcls sci ch02s05 html 2 of 2 21 10 2009 15 29 48 2 6 Seismic Spectral Blueing SSB 2 6 Seismic Spectral Blueing SSB Prev Chapter 2 Background and Theory Next 2 6 Seismic Spectral Blueing SSB Observed behaviour of reflectivity data obtained from wells shows that in a global sense the higher the frequencies the higher the amplitude We refer to this as the spectrum being blued During the processing of seismic data the amplitudes are often whitened Spectral shaping of seismic data using SSB can enhance resolution without boosting noise to an unacceptable level SSB sections are usually easier to interpret and reveal more information about the subsurface Small scale faulting not seen on the original section is often observed Such additional information can be useful during well planning SSB is rapid easy to use inexpensive robust and does not require expert users SSB seamlessly connects with third party seismic and well data repositories including SeisWorks OpenWorks GeoFrame and OpendTect using our client server techn
93. t what you add In most cases using SCI will be sufficient Using more sophisticated http opendtect org rel doc arkcls sci ch02s03 html 1 of 2 21 10 2009 15 29 34 2 3 Inversion Limitations techniques doesn t guarantee a superior result Prev Up Next 2 2 Benefits of Seismic H Inversion mE 2 4 Inversion techniques http opendtect org rel doc arkcls sci ch02s03 html 2 of 2 21 10 2009 15 29 34 2 4 Inversion techniques 2 4 Inversion techniques Prev Chapter 2 Background and Theory 2 4 Inversion techniques There is a variety of techniques available to invert seismic data ranging from very simple to complicated Let s consider two techniques Parametric Inversion sparse spike and Coloured Inversion 2 4 1 Parametric I nversion Most inversion algorithms use parametric inversion where the earth is modelled by a series of parameters Basically parametric inversion works like this Start with an initial estimate of all the model parameters Define a function that characterises where the current model deviates from a desired model Update the model so as to reduce the deviation Iterate 2 and 3 until an acceptable error level is reached ale ole E The model parameters are automatically updated to reduce the error term The error term itself is a weighted sum of a series of different terms For example Seismic misfit term Reflection coefficient threshold term Deviation from the starting model t
94. tect org rel doc arkcls sci ch04s02 html 10 of 10 21 10 2009 15 30 12 4 3 Select Input Data 4 3 Select Input Data Prev Chapter 4 User Manual 4 3 Select Input Data 4 3 1 Input Seismic tab This section describes how to select the input seismic trace data for use in the Coloured Inversion operator design Coloured Inversion requires that you select a predetermined number of seismic traces from the full 3D survey area or sub area determined by the user Trace selection is random within the area Our aim is to select a set of traces which is representative of the 3D Survey Area for which we are trying to derive a Coloured Inversion operator With the data selected it will normally be necessary to constrain it in some manner The sub section below describes how you can select and constrain the trace data 4 3 1 1 Select trace data This section provides a Select Sesimic button which will allow you to pop up a seismic selector dialog This section also allows you to specify the 3D Survey Area to be used to retrieve trace data for Coloured Inversion analysis Figure 4 22 Select Input Data dialog I nput Seismic tab Select Input Data input Seismic input Well Logs Traces mu Usott select Seismic fB2pria subset 3D Survey Ares Full ari e Sub mine 1992 Xine 4300 Load Seismic Num Traces 40 The figure above shows the top portion of the Input Seismic tab where seismic data volume has been pre
95. terpretation of AVO and 4D many more 3D volumes need interpreting Traditional band limited fast track inversion techniques e g trace integration recursive inversion and phase rotation are prone to error because no account Is taken of the seismic wavelet or calibration to the Earth Sophisticated techniques such as sparse spike do take account of the seismic wavelet but require specialist skills and are time consuming Even using sophisticated techniques the resultant seismic inversion can still give an erroneous result What is needed is a technique which is fast easy to use and is calibrated against well log Al data Inversion of seismic data to Acoustic Impedance Al is usually seen as a specialist activity In spite of publicised benefits inverted data are only used in a minority of cases To help overcome this obstacle this algorithm which is quick and easy to use can increase the use of inversion technology SCI performs significantly better than traditional fast track methods such as recursive inversion and benchmarks well against unconstrained sparse spike inversion With the inclusion of de trend and normalisation functionality within SCI geophysical meaning can now be assigned to the observed amplitude changes in the derived impedance volumes This can be very powerful particularly with 4D projects Once the SCI operator has been derived it can be simply applied using the 3D processing tool included within the SCI software In t
96. th the specific seismic selection mechanism Figure 3 3 Select Input Data Dialog I nput Seismic Tab http opendtect org rel doc arkcls sci ch03s02 html 1 of 6 21 10 2009 15 29 53 3 2 Selecting Data Y Select Input Data Input Seismic Input Well Logs Traces Select Seismic fi32prio subset cmp 3D Survey Area Full Sub Load Seismic Num Traces 40 Input QC Trace Id Inline XJine AMS Amp AMS Em Horz Time TRACE_001 1626 4417 1 28660 6 90695 ered W TRACE O02 1551 4871 1 85106 7 36809 2354 2 Mw TRACE 003 1618 5171 1 83945 3 53589 2438 6 F TRACE O04 1602 4731 1 22966 4 93155 2416 8 Mw TRACE 005 1317 5157 1 17902 4 55482 2459 6 eae Ae CE ral d PRETEREA aj Eh oa FETRa GE Fu d P o3 uam Clear Trac es Clear Unselected Traces 40 elected 0 Undefined Time Select Horizon tracked horz lime Range Full Horizon Relative Sub The figure above shows the Select Input Data dialog for seismic selection Whilst this dialog might look busy you should find it easy to provide the required parameters if you follow the steps below 1 Selected Seismic The Select Seismic push button allows you to pop up a seismic http opendtect org rel doc arkcls sci ch03s02 html 2 of 6 21 10 2009 15 29 53 3 2 Selecting Data volume selector allowing you to select a seismic volume 2 3D Survey Area Trace data for the spectral analysis can be selected from either
97. the full 3D survey area or from a sub area using the In line X line Start and End input fields By default the full area is selected 3 Load Seismic Clicking the Load Seismic button causes the random set of traces over the 3D Survey Area to be loaded Input tab for spectral analysis At the same time an alternative set of traces are loaded QC tab which are used to QC the derived operator 4 Set Time Range The aim is to design a Coloured Inversion operator for the zone of interest target It is therefore desirable to time gate the selected traces prior to generating trace spectra Ideally you should use a well defined interpreted horizon in the target zone to guide the seismic trace time gate In this manner the various gated traces should have sample values over a similar geology Click Select Horizon to pop up a horizon select dialog then select horizon and then click Close button to return Click Horizon in the Range radio button and specify the Relative Start and Relative End values A negative number is a relative time above the horizon i e shallower and a positive number is a relative time below the horizon i e deeper The aim is to select a time gate trace which has a gate length within the range 500 1000 msec The user supplied values here are accepted and the chart area updates when you do any of the following press Return key press Enter key press Tab key or mouse click on a different widget Note If no h
98. to be flat and centred around zero http opendtect org rel doc arkcls sci ch04s01 html 9 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application Various controls in the Select Input Data dialog Design Operator dialog and Advanced Controls dialog can have an immediate effect on this chart Chart 10 Convolved Output Mean QC This chart displays the mean Coloured Inversion data red and the smooth mean Coloured Inversion data black Various controls in the Select Input Data Dialog Design Operator Dialog and Advanced Controls dialog can have an immediate effect on this chart 4 1 1 4 Status Area The status area at the bottom of the main window is used to display various messages and other information for you For example if you pass the mouse over a toolbar icon then a tip is displayed in this area indicating what the purpose of the icon is The status area Is also used to display information about a given chart as the mouse passes over the central area of the main window 4 1 2 SciQt Main Window ancillary tools There are various main window ancillary tools within the SciQt application which you might find helpful and deserve a mention These are Save Operator Export Operator Export Data Item and Parameter Report 4 1 2 1 Save Operator The Save Operator tool allows you to save an operator to a database Clicking the File gt Save Operator menu item will pop up the Save Operator dialog If
99. troller dialog 4 14 Create a new Chart 4 15 Moving Charts 4 16 Deleting Charts 4 17 Saving and Loading Chart Configurations 4 18 Changing the Number of Columns 4 19 Display Options dialog 4 20 Changing Chart Properties 4 21 Management of Data Items 4 22 Select Input Data dialog Input Seismic tab 4 23 Loading Seismic Data 4 24 Clearing Seismic Data 4 25 Modifying Seismic Time Range Full 4 26 Modifying Seismic Time Range Sub 4 27 Modifying Seismic Time Range Horizon 4 28 Removing Bad Traces 4 29 Select Volume 4 30 Select Horizon 4 31 Select Input Data Dialog Input Well Log tab 4 32 ASCII Well Log Selection 4 33 Define ASCII File Format 4 34 Database Well Log Loading 4 35 Select Database Logs OpendTect 4 36 Generate Al Log OpendTect http opendtect org rel doc arkcls sci index html 4 of 5 21 10 2009 15 29 30 ARK CLS Seismic Coloured Inversion V2 94 OpendTect plugin version 4 37 Modify Well Log Time Range Full 4 38 Modify Well Log Time Range Sub 4 39 Modify Well Log Time Range Horizon 4 40 Design Controls Dialog 4 41 Smooth Seismic Mean 4 42 Fit Well Log Curves block 4 43 Design Operator block 4 44 Frequency Domain Tab 4 45 Design Operator Tab 4 46 Time Domain Tab 4 47 Effect of Detrending Next Chapter 1 Introduction http opendtect org rel doc arkcls sci index html 5 of 5 21 10 2009 15 29 30 Chapter 1 Introduction Chapter 1 I ntr
100. ttings manually by unchecking the checkbox to the left of the Low Cut and High Cut spinboxes This will sensitise the Low Cut and High Cut spinboxes allowing you to set the lower and upper cuts of the derived operator You can also specify the slope of the operator on the low and high sides by unchecking the checkbox to the middle Auto Calc checkbox and specify the frequency of the 60 dB down points on the low and high sides By default operator length is also automatically determined Here the operator length is truncated to the nearest zero crossing to give a percentage energy captured during the generation of the time domain operator above 99 996 You can override this default by unchecking the checkbox to the left of the Num Zero X ings spinbox This will sensitise the Num Zero X ings spinbox allowing you to manually adjust the length of the operator in multiples of number of zero crossings A facility is provided to automatically QC the derived operator This is achieved by applying the operator to the alternative set of random traces from the same seismic data volume and charting the derived residual operator in the Residual Operator QC chart We are looking for the residual operator to be centred around zero and essentially flat By perturbing the Low Cut and High Cut spinbox controls within the Design Operator group you can usually maximise the bandwidth in such a manner without significant residual correction either end see figure belo
101. u to control standard parameters in the design of the SciQt operator Design Operator Pops up the Advance Controls dialog which allows you Advanced Controls to override many of the standard parameters in the design of the SciQt operator 4 1 1 1 4 Help Quick Start Pops up an HTML browser displaying the Quick i Start document Help Contents Pops up an HTML browser displaying Contents page for software user guide ex up an HTML browser displaying Background POEROIOUIG HO ENEON and Theory to the software Pops up a file selector dialog allowing you to specify a file which will be used to save information about this installation The file will be saved as a gzipped compressed text file ARK CLS support staff may ask you to generate a report to help them resolve issues with the software If requested please email this file to Support arkcls com Generate Installation Status Report http opendtect org rel doc arkcls sci ch04s01 html 4 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application Website Pops up an HTML browser displaying the home v page of ARK CLS Limited website About Pops up the About SciQt window 4 1 1 2 Toolbar Area This sub section describes the actions performed by the various toolbars and their icons The toolbars can be positioned in various locations within the main window top default beneath the menu bar left right and bottom above status area Addit
102. umns parameter set to 2 which would cause the central chart area of the SciQt main window to appear like the chart area on the left ie two columns of charts The RH image shows the central chart area with one column of charts ie the Number of Columns parameter set to 1 4 2 2 6 Zooming In and Zooming Out The Zoom In and Zoom Out push buttons perform the same functions as those described in the section entitled Global Zooming 4 2 3 Display Options The Display Options dialog allows you to control what data is displayed in a given chart The Display Options dialog will also allow you to change some chart properties including Title can also do this on the Chart Controller the labels on the X Axis and Y Axis and Line Thickness Currently Line Thickness parameter controls the thickness of every data item on the chart It is not possible to change the Line Thickness of an individual data item The Display Options dialog can be popped up by clicking the Edit push button on the Chart Controller dialog or by MB3 on the chart and selecting from the pop up menu Display Data Items Figure 4 19 Display Options dialog http opendtect org rel doc arkcls sci ch04s02 html 8 of 10 21 10 2009 15 30 12 4 2 User interaction with Chart Area w Display Options Chart Title Design Operator X Axis Freq Hz Y Axis Amp dB Fixed Axis Ranges Line Thickness 3 Data Items Data Item O Average Trace Spectrum Smoothed
103. version operator is achieved via the OpendTect attribute processing facility see OpendTect documentation chapter 5 for details of how to do this In brief this can be achieved by either clicking Processing Create Seismic output menu item or clicking the icon within the OpendTect main window This will pop up the Process dialog Figure 3 7 OpendTect Coloured I nversion Processing Create 3D seismic output Quantity t output mr scDI IOoApe2008 Volume subsekcion 140094300 1600 5400 1 Muliraces Discard Pass Format Scaling Auto None Specihy Output Cube sci imersion Sect Subimda t 3 Saige machine Multiple rnachames Stare processing specication as rr sc IG6Apezo008 par Select Proceed s Cancel The list below describes how you specify the various parameters to the Process controller to Create a Coloured Inversion output http opendtect org rel doc arkcls sci ch03s04 html 2 of 3 21 10 2009 15 29 57 3 4 Application of SciQt operator 1 Quantity to Output Clicking the Select push button to the right of the Quantity to output label allows you to select the named attribute to be used in the processing The named attribute should be the attribute you added as new in section Testing the Coloured Inversion operator The named attribute knows the type of attribute process in this case Coloured Inversion the input data and the input wavelet to be applied 2 Volume subse
104. w for example of a corrected chart Figure 3 6 Seismic Coloured nversion main window after analysis and design http opendtect org rel doc arkcls sci ch03s03 html 1 of 2 21 10 2009 15 29 56 3 3 Designing and Saving the Coloured Inversion Operator v Seismic Coloured Inversion Vietnam alb04_16Apr2008 ses Ax Ele Vew Tools Help xs oo D x BBB amp yt iz gg 2 eS Raw Seismic Seismic Mean Log Input time domain Log Input Detrend time domain Individual Wells 35000 90 M 10000 30000 80 7 7 a 5000 70 E 25000 60 0 20000 at y 50 5000 50 100 2300 2400 2500 2600 2700 2300 2400 2500 2600 2700 1 10 100 Freq Hz Freq Hz Time ms Time ms Freq Hz Global Design Operator Operator time domain Residual Operator QC Convolved Output Mean QC 500 4 N 50 50 80 j g e oj g 70 g amp 0 g i 3 1 E 0 1 0 M 60 4 500 4 3 4 50 1 50 r T Zz T rT T T T TT T T f TTT TT TOT PT PO Pe gt gt gt T rere TT T T T T T T T T T T T Y T T T T T7 T T T T T T T T 1 10 100 100 50 0 50 100 50 100 50 100 Freq Hz Freq Hz Time ms Freq Hz Freq Hz The figure above shows a typical SciQt main window with the default charts re arranged in five columns Note the default templates arrangement of charts is two columns The following gives a brief description of each of the charts displayed using the supplied default template moving left
105. with the SciQt Application 2400 25D 30 30 2400 eun 2500 Time ms Time ms 4 1 1 1 Menubar Area This sub section describes the actions performed by the various menu items 4 1 1 1 1 File Creates a new SciQt session using the default template shortcut Ctrl N Creates a new SciQt session a using a user saved template By default the software will look for templates stored in a special directory created for this purpose within the SciQt installation tree However if you have set the environment variable CLS SCI TEMPLATE DIR to point to another directory then it will look in this location for templates Opens a previously saved SciQt session shortcut Ctrl O This facility allows you to restore the SciQt parameters together with the data from a previously saved session Restoring a previously saved session can take a few moments while database access is established Note if the stored data within the database has been modified since the session save time then it is possible that a Coloured Inversion operator which is different to that available at the session save time might be generated following a session restore New New From Template Open Save z AS Saves a SciQt session This allows the SciQt parameters together with information about the data used to be saved In this way data can be easily reloaded and the SciQt Coloured Inversion operator generated at some future d
106. y you make a change to one or more of the Frequency Domain parameters you will see the change on your Main Window chart Note it might not be possible to QC against a spectrum if no well data is available Under such circumstances you would need to supply the curve fit parameters manually or read them from file Within the Curve Fitting group there is a matrix of Alpha DC and F Shift for Below principal principal and Above principal curves For each curve there is a combo control to the right which specifies the mode of curve fit We will now consider each of these three curves and describe their mode of use http opendtect org rel doc arkcls sci ch04s05 html 1 of 5 21 10 2009 15 30 25 4 5 Advanced Controls Below principal The default mode is Force Horizontal n this mode the Alpha DC and F Shift are insensitive and cannot be used The DC value displayed is the value of the Principal curve fit at the Low Cut point The Fit Independently mode uses the same curve fit algorithm between 0 Hz and Low Cut as that used for the Principal curve fit The displayed Alpha DC and F Shift are parameters from the independent fit This mode frequently gives strange results and its usage is not normally recommended The Extrapolate Principall mode allows the Principal curve to be extrapolated below the Low Cut back to 0 Hz The Set mode allows you to manually set the sensitive Alpha DC and F Sh
107. ying a User Density Value Here the AI log will be generated from the supplied sonic and density The push buttons Clear Wells and Clear Unselected Wells are self explanatory Note the Load Wells push button will change to a Reload Wells push button after the initial automatic selection 4 3 2 3 1 Select Database Logs dialog This dialog allows you to select the Acoustic Impedance Well Log data that is to be used from the OpendTect data repository The figure below shows the Select Database Logs dialog in OpendTect Figure 4 35 Select Database Logs OpendTect Select Database Logs Acoustic Impedance Log Fher A EDT CALI RHOB ve EDT This dialog provides a wild card filter field which operates on the list of logs to provide a facility to shorten the list of logs to a manageable size should this be necessary 4 3 2 3 2 Generate Al Log dialog This dialog allows you to generate an Acoustic Impedance Well Log curve from the sonic and optionally density logs that are stored in the OpendTect data repository The figure below shows the Generate Al Log dialog in OpendTect Figure 4 36 Generate Al Log OpendTect http opendtect org rel doc arkcls sci ch04s03 html 10 of 12 21 10 2009 15 30 19 4 3 Select Input Data Wo Generate Al Log Density Source Log User Select Sonic Log Select Density Log Filer AlLEDT OT RHOB Cancel This dialog provides wild card filter fields which operate on the two
108. ying problem spectral traces from the chart and deselecting these traces from within the Select Input Data Dialog Figure 4 28 Removing Bad Traces http opendtect org rel doc arkcls sci ch04s03 html 4 of 12 21 10 2009 15 30 19 4 3 Select Input Data Sajas Coheed dwersakn Waid untill pal ac File View Tools Hel Time bd mine Eine RMG Ame ARTS Er F a F EE TSACE r 1m an 1 25945 5 gHzT b z m k ar i a 5 a EETRACE DHZ lap aji 1 RH ai Fo Raw Seiemie ED TRADE nea ae am 1 3D 74 Toa 3 EE TRACE DHA lap 45d 1 24 vun 5 303057 Af j El TRACE 005 3848 apm 1 31058 B asd CAR i AE i F ad i WM i H Gear Traces Gar iiaeiai Tiree 5 Sms z Linckestiner f w i 5 Time z j i Select Hiron macka Morr ng 5 4 x vj la f Ful Hieron ADi cula W ES Euh Stan P End 2750 Few Seismic Freq zy 4325828 Amp dS 13 F a Missis dr Hada Lindy pa 6 Ele View Tools Hel Trac id mina Xing RMEAmp ee EPTRACE DW mm amz 1 25246 T t m ard d m d RE EM ElTRACE 0P2 api api 1 ZEI aiea Fl Raw Seismic O TRACE M3 1a 4303 1 30744 LMII E TRADE D map am 124746 ouam E TRACE DHS 88 4555 1 31558 5 asap k Gear Traces Giger radarid True a Setected Linceliner me Select Urn Iracked horz nm ange Ful Moree on Abe Sila End 2750 Dore Fw Seismic Freq Her 1 9975 Amp dS 14 L If one or
109. you haven t saved the operator during your session or if the operator has changed since you last saved it then you will be prompted to save the operator before the SciQt program exits Figure 4 5 Save Operator dialog http opendtect org rel doc arkcls sci ch04s01 html 10 of 13 21 10 2009 15 30 04 4 1 Interfacing with the SciQt Application Save Uperator Filter alb sci 1 O7apr2008 alb sci 2 7aprz B alb sci 21aug2007 v1 alb temp 19mar2eD08 alb test 16May2007 alb test 17Magy2007 count 1 caunt z count 3 count d delete me 2 Jackie scio The figure above shows the Save Operator dialog This allows you to select a previously saved Coloured Inversion operator or to specify a new Coloured Inversion operator Either way when you click the Save push button the current time domain operator will be saved to the database by the name in the Select Operator input field here If the operator already exists in the database you will be warned that you are about to overwrite the operator 4 1 2 2 Import Chart Configuration The Import Chart Configuration tool allows you to import from a saved session the chart configuration defined within that session This is a powerful facility allowing you to rapidly change your display layout using your current data items Clicking the File gt Import Export Import Chart Configuration menu item will pop up a file selector dialog Here you can traverse the file system to i

ARK CLS Seismic Coloured Inversion V2.94

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