预览加载中，请您耐心等待几秒...

Kirchhoff型反偏移场稳相分析(英文).docx

预览
1/2
2/2

在线预览结束，喜欢就下载吧，查找使用更方便

下载提示 文本预览

如果您无法下载资料，请参考说明：

1、部分资料下载需要金币，请确保您的账户上有足够的金币

2、已购买过的文档，再次下载不重复扣费

3、资料包下载后请先用软件解压，在使用对应软件打开

Kirchhoff型反偏移场稳相分析(英文) Kirchhoff-typeAntimigrationPhaseAnalysis Introduction: Inexplorationseismology,seismicmigrationisaprocessinwhichrecordeddataistransformedintoanimageofthesubsurfacegeologicalstructures,bycorrectingforvariousdistortionscausedbythesubsurfacescatteringandtheacquisitiongeometry.However,incertaincases,migrationcanleadtoartifactsandinaccurateresults,duetothepresenceofcomplexsubsurfacestructures,suchasfaults,saltdomes,orgeologicalboundaries.Onewaytoavoidtheseissuesisthroughtheuseofphaseanalysistechniques,whichapproachmigrationfromadifferentperspective,byfocusingonthepropagationcharacteristicsoftheseismicwavefield.TheaimofthispaperistopresentaphaseanalysisalgorithmbasedonKirchhoff-typereverse-timemigration,thatcanbeusedtoobtainimagesofthesubsurfaceinchallenginggeologicalsettings. Kirchhoff-typeAntimigration: ThebasicprinciplebehindtheKirchhoff-typeantimigrationalgorithmistocomputethephaseofthemigratedwavefield,anduseittoundothemigrationprocess.Thisisachievedbydefininganewwavefieldastheproductofthemigratedwavefieldandanantiphase(complexconjugate)function,whichisdesignedtocanceloutthemigrationartifacts.Morespecifically,theantiphasefunctioniscomputedbytakingtheinverseFouriertransformofthephaseofthemigratedwavefield,andthenapplyinga2DGaussianwindowtosmoothoutthehigh-frequencycomponents.Theresultingfunctionisthenmultipliedwiththemigratedwavefield,beforeapplyingtheinversemigrationoperator,toobtainanimagethatisfreeofmigrationartifacts. StablePhaseAnalysis: Thekeyadvantageofthephaseanalysisapproachisitsabilitytohandlecomplexsubsurfacestructures,withoutintroducingmigrationartifacts.Thisisbecausethephaseofthewavefieldisaglobalproperty,thatisrelatedtothetraveltimeoftheseismicwaves,andhenceinsensitivetolocalperturbations.Therefore,eveninthepresenceofstrongvelocitycontrastsorcomplexboundaries,thephaseanalysisalgorithmcanproducestableandaccurateimagesofthesubsurface.Moreover,theuseofKirchhoff-typemigrationallowsforflexibilityinthemigrationstrategy,whichcanbeadaptedt