Petrel官方地震解释培训M7-Depth-Conv.ppt

Seismic Domain ConversionObjectives,Quality control time/depth relationships for wells Define velocity model intervals Create an uncorrected velocity model using well data Create a final corrected velocity model using well data Create a velocity model with uncertainty Depth convert a 3D Grid General depth conversion Optional:Create a velocity model using a seismic velocity cube Create velocity model using stacking velocities(xytv point-data),Overview,Velocity Modeling is separate from Domain ConversionInteractively switch between time and depth for converted objectsDefine the velocity model by:Surfaces/constantsWell Time/Depth RelationVelocity Cubes3D gridsConvert both ways with the same modelConvert objects independent of the 3D gridPerform conversions in the process manager,Velocity model bridges the gap between time and depth domain,The Workflow,Define velocity model Define velocity intervals(usually between time interpretation surfaces)Define velocity functions(automatically calculated or user-defined)Define output(e.g.velocity cubes,V0 and k for Q.C.purposes)Domain convert via Right click on object(uses currently”active”velocity model)General Depth Conversion Process for Multiple objects 3D Grid Conversion Within a workflow in Process manager,The Process,Velocity,Corrections,ZONES,Output,Advanced,Datum,Datum,Vo,Vo+kz,Vo+k(z-z0),A:Auto 1.Correction(Vo)2.TDR(Vo&k)B:User 1.Constant 2.Surface,C:Velocity SEGY(average)D:3D Velocity Property(average),Datum,Vo,Vo+kz,Vo+k(z-z0),1.Seg-Y 2.Velocity Surfaces 3.Well Data Points4.T&V logs 5.Residual Points 6.Output Sheet,1.Constant 2.Surface3.Horizon*4.Well Tops,1.Constant 2.Surface3.Horizon*,Or none,1.Well trace Md inc 2.Depth&Time tolerance3.Velocity&k clipping,Additional Settings+(Gridding&SegY settings),Saved in Model tab,The exercise examples,Time/Depth relationship in wells,Velocity Cube(SEG-Y),Stacking Velocities(Point data),Velocity Model 1,Velocity Model 2*,Velocity Model 3*,Active(selected)Velocity Model,Domain Conversion of objects,*Optional exercises,see Attachments,Define intervals,In the Process pane,open the Geophysics folder and double-click on the Make Velocity ModelClick the”Append item in the table”icon as many times as available input objectsChange Bottom Interval to desired typeSelect the levels to model,from Input or Models tab,click on its name and drop it into the dialog box using the drop in arrow Keep the Correction set to None,3,2,4,5,1,Velocity modeling using well data,Select type of velocity model for each interval.When using the Linvel function for modelling,constants,surfaces or Well TDR can be used as inputSet V0 to Well TDR Surface/ConstantSet k to Well TDR Surface/Constant,Velocity modeling-Output,Open the Output tabClick on the data types needed as output,2,1,5.Defines Gridding algorithms for Surfaces and resolution for Cubes,Surfaces and Logs.,2,3,1,Open the Advanced tab.Check that Well velocity tab is open.Possible to set MD increment,depth and time tolerance and clipping parameters for V0 and k.,4.Activate Output settings tab,4,Velocity modeling Advanced settings,Velocity modeling using well data,Open Settings for Wells and go to the Time tab.Select Checkshots,Well Tops or corrected sonic logs as source for time/depth(move the prefered source to the top)Keep the parameters for the velocity model the same as the values shownClick Apply or OK to generate the velocity model,1,2,3,Velocity modeling with uncertainty,Create a new velocity model with Well tops correction,based on the previous velocity model Toggle on Activate uncertainty page icon to insert a Std Dev column under the Velocity model tab and to activate the Uncertainty tab.Fill in appropriate Std Dev.numbers Go to the Uncertainty tab and fill in appropriate Variogram parameters.Toggle on Iconize uncertainty error surface.Click ApplyA velocity model containing velocity surfaces with uncertainty built into them is generatedCheck uncertainty statistics and display the corresponding deterministic and stochastic V0-surfaces,2,3,1,Deterministic V0-surface,Stochastic V0-surface,4,5,Depth convert a 3D grid,Make sure the correct 3D Model is activeFrom the Process tab,under Structural Modeling,open Depth Convert 3D GridSelect the appropriate Velocity ModelAlternatively change the pillar geometry types for faulted and non-faulted pillars before ApplyingA new 3D Model will appear in the Models tab,with the input 3D grid name and an extension DC,3,4,2,5,1,Depth convert Seismic data,Make sure the correct Velocity Model is active(Bold name).Right click on the 3D volume and select Depth convert by active velocity model.Alternatively,from the Process tab,under Geophysics,open the General Depth Conversion process.Click on the 3D volume name in the Input tab and drop it into the dialog box using the Append selected item to the list icon.Click Apply.,3,4,1,2,Attach seismic to active grid,Make sure the correct depth converted 3D Model is activeFrom the Input pane,right click on the seismic 3D volume and select Attach Seismic Volume to active GridExpand the active depth 3D grid under the Model tab,right click on mig.sgy DC and insert InLine and Xline.View the result in a 3D Window,1,2,3,General depth conversion,Make sure the correct Velocity Model is active(bold text)From the Input pane,right click on the object to be depth converted and use Depth convert by active velocity model Clicking the+in front of the depth converted object shows the now available time and depth domains for the object The Time/depth settings can be changed in the top Toolbar.Alternate between TWT and TVD while observing the effect in a 3D Window,2,1,3,4,General depth conversion,Alternatively,or to depth convert several objects,open the General depth conversion processSelect correct velocity model from the pull down menuDrop in the objects by clicking on their names in the Input pane and then on the Append selected item icon in the process dialogThe Time/depth settings can be changed in the top Toolbar.Alternate between TWT and TVD while observing the effect in a 3D Window,8,5,7,6,9,EXERCISE Domain Conversion,