STRATA反演软件简介课件.ppt

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1、EARTHIMAGINGSOLUTIONS1STRATA2Dand3DPost-StackSeismicModelling,Processing&April1999Inversion2STRATAisaninteractive2Dand3Dmodellingandinversionprogramwhichtransformspost-stackseismictracestovelocityoracousticimpedancetraces.Theprogramincludesoptionsforbasicse

2、ismicprocessing,waveletextraction,logeditingandinterpretation,aswellasdifferentmethodsofperforminginversion.3OverviewofInversionPre-StackInversionTravelTimeInversion(Tomography)AmplitudeInversion(AVO)WaveFieldInversionBandlimitedInversionSparse-spikeInversio

3、nModel-basedInversionPost-StackInversionSeismicInversionMethodsAmplitudeInversion(STRATA)4Theinversionprocessistodeterminetheearthimpedancefromthegivenseismictracebasedontheconvolutionalmodelseismic=wavelet*reflectivity+noiseAssumptionsTheseismicdataarealrea

4、dystacked,migratedandnomultiples.Eachtracedependsonlyontheimpedancedirectlybelowthetracelocation.Thewaveletisconstantandnotvaryingwithtime.Thenoiseisrandom,whitenoise,uncorrelatedwiththeseismic.Thereisnocoherentnoise.Objective5Non-UniquenessProblem!非单值问题（CHJ

5、注）Allinversionalgorithmssufferfromthenon-uniquenessproblem.Thismeansthatthereismorethanonepossiblegeologicalmodelconsistentwiththeseismicdata.Inpractice,thisproblemishandledbyusinggeologicalconstraints,providedbywelllogs.6BasicConceptofSTRATASeismicDataVeloc

6、ity/DensityControl(Logs)BuildModelInvertSeismic7BasicSteps(e.g.ModelBasedInversion)(1)Readseismicandwelllogs.(2)Extractastatisticalwaveletfromtheseismic.Correlatelogsandextractagainthebestwaveletusingthewelllogs.(4)Buildinitialmodel.Setupverticalandlateralin

7、terpolation.(5)Applyinversionandvalidatetheoutputimpedanceandsynthetic.(3)Pickorimporthorizons.ImportWellLogOpenSeismicProcessSeismicExtractWaveletExtractWaveletusingLogCreateSyntheticPickSeismicBuildModelInversionCorrelateLog8Step1:DataInput(1)Readseismican

8、dwelllogs.(2)Extractastatisticalwaveletfromtheseismic.Correlatelogsandextractagainthebestwaveletusingthewelllogs.(4)Buildinitialmodel.Setupverticalandlateralinterpolation.(5)Applyinversionandval