淺談地震勘探采集方法的改進(jìn)

淺談地震勘探采集方法的改進(jìn)

u2004方法su模子、泛在三維研討會(huì)設(shè)計(jì)、菲菲諾伊省魅力分析、進(jìn)程技術(shù)等。重點(diǎn)關(guān)注改進(jìn)的低級(jí)別家庭結(jié)構(gòu)、菲菲諾伊省魅力分析、標(biāo)準(zhǔn)技術(shù)等。首先，確保目標(biāo)區(qū)域的能源陰影區(qū)域由項(xiàng)目實(shí)施。氮省預(yù)算區(qū)域應(yīng)考慮目標(biāo)區(qū)域陰影區(qū)域的能量，預(yù)算區(qū)域應(yīng)考慮陰影區(qū)域的能量。重點(diǎn)關(guān)注天花板上的區(qū)域。采用自我評(píng)估方法，在框架內(nèi)使用目標(biāo)區(qū)域的能量，重點(diǎn)關(guān)注框架內(nèi)的區(qū)域壓力。shctincipar.3.3srexh認(rèn)識(shí)/設(shè)計(jì)背景下的sh科多態(tài)性二十四首Thepurposeoflocalinfillingshotsistoincreasetheilluminationenergyoftheshadowareaofthetargetlayer.Thistarget-orientatedshotmethodisdifferentfromthetotalinfillshotmethod,whichonlyconsiderssurfaceconditions.Therefore,itavoidsredundantshotpoints.Thebasicsofthemethodarethefollowing.First,adensegeometryofshotpointsisdesignedbasedontheworkareamodelandseismicwaveilluminationmodelingiscarriedout,resultinginconcentratingtheenergiesfromallshots(seeFigure1).ThisilluminationenergyisreceivedbytheundergroundCRPbin,whichissimilartotheenergyaftermigration,andthesumofthereceivedenergyfromthisbinisexpressedaswhereswheresFourth,theshotpointwheretheenergymaximuminearesttothetarget-layerenergyshadowarea(seegraypointsintheFigure1)islocatedwherewhereE2Dmodeltestingshctraftingmotisiphinfilling狀況The2Dmodelisbuiltbasedonthethrough-wellseismicsectionofanoilfieldinwesternChina(Figure2)witharelativelycomplexstructure.Bothsidesofthemodelwereequallybroadenedtoadapttothegeometrylayout.SeismicilluminationenergydatawereacquiredbyGaussianbeamforwardmodeling.Single-shotdatawereobtainedbytheforwardwaveequationandthefinalprofilewasobtainedbyprestackdepthmigrationforcomparingthetarget-layerenergybeforeandaftertheinfillingshots.Themodelparametersarethemodeleffectivelength(6900m),theextendlength(30900m),andthedepth(6000m).Thehorizontalandverticalsamplingintervalis10mand20m,respectively.Theforwardmodelinggeometryparametersarethetracespace(30m),theshotspace(60m),thebaseshotspace(360m),thenumberoftracespershot(600),andthenumberofshots(157).Thesamplingintervalis4ms,thenumberofsamplesis1200,andthemodelgeometryis8985–15–30–15–8985m.靜態(tài)與局部同時(shí)點(diǎn)Intheworkarea,theexistingdatashowthattheseismicsectionispoorwhenusingashotspaceof360m.Accordingtofieldprograms,thefoldwouldoveralldouble;thatis,theshotswouldalsodoubleusinga180mshotspaceandadding26shots.However,theresultsdidnotmeettherequirements.Usingtheautomaticinfillshotsmethod,thesame26shotsbasedonthefieldprogramswerechosenbuttheseshotsautomaticallydefinetheweakenergyareawhereitisnecessarytoinfillshots,thusgreatlystrengtheningtheilluminationenergyofthetarget-layershadowareaandforcingtheenergytoreachamaximum.體格檢查3內(nèi)插入測(cè)試depth-migdepth主坐標(biāo),主導(dǎo)地位,主坐標(biāo),主導(dǎo)地位,主坐標(biāo),主坐標(biāo),主導(dǎo)地位,主坐標(biāo),主坐標(biāo),主坐標(biāo),主導(dǎo)地位,主坐標(biāo),主坐標(biāo),主導(dǎo)地位,主坐標(biāo),主導(dǎo)地位,主坐標(biāo),主導(dǎo)地位,主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主坐標(biāo),主導(dǎo)產(chǎn)品,受益.Tofurtherdescribetheeffectivenessoftheproposedmethod,weselectedtotesttheSEGdomemodelusingthehorizontallayerasthetargetlayer.Themodelparametersarethelength(13000m),thewidth(13000m),andtheburieddepth(6000m).Thehorizontalsamplingintervalis20m,theverticalsamplingintervalis20m,andthenumberofsamplesis325.Thegeometryofthemodelisdefinedby201linesthataresimultaneouslyreceivedatshotfiring,a40mtracespace,areceivinglinespace0f40m,201receivingtraces,a300mshotlinespace,anda300mshotpointspace.Wesimulatedatotalof255shotsandthereceivedshotrecordswereprocessedbydepthmigration.Forcomparingtheimagingqualityofthedepthmigration,themigrationsectionsbeforeandaftertheinfillshootingarecombinedintoonesectionbecauseofthemanytracesinthedata(seeFigures10and11).內(nèi)臟器官案例5:非價(jià)格爾斯地區(qū)的非價(jià)值規(guī)制物支出物相對(duì)統(tǒng)一的雙標(biāo)性政策Figures10and11showthedepthmigrationsectionsofinline1340and1370,correspondingtothesingleshotrecordfoursecondsbeforeaddingtheshotsandfoursecondsafteraddingtheshotswithin4–8s.Thefiguresshowthatbeforeaddingtheshotsthehorizontallayerintheshadowareawascompletelydisconnected,whereasaftertheinfillshootingthereisgoodcontinuity,asindicatedbytheblackarrows.Suchaphenomenonisalsoseenabovethehorizontallayer,asindicatedbytheblackarrows.Clearly,theenergyofthisareahasstrengthened.However,itisnotclearwhethertheenergiesofallareashavestrengthened.Tosolvethisproblem,weanalyzedtheeventontheleftofthesectionatthepositionpointedbythebluearrowsinthefigure.Theeventnearlyshowednochangebeforeandafteraddingtheshots.Thisillustratesthattheautomaticinfillshotmethodfocusesonthetarget-layerenergyshadowarea.7年7月21日Seismicimagingiscriticaltoreservoirexploration.Improvingthequalityofseismicimaginghasattractedconsiderableattention,andextensiveresearchhasbeenconductedinChinaamongothercountries.Maetal.(2011)usedtheGulfofMexicoasanexampletosuggestthatwide-azimuthseismicdatacanenhancesubsaltimaging.Thewide-azimuthacquisitionmethodissuperiorforimprovingseismicdataqualityandthequalityofsubsaltimagingindeepwaters,andithasbeenalreadyusedbyothersaswell(Gerardetal.,2007;Bruceetal.,2007;Nicketal.,2008).Someresearchersachievedamoreaccuratedepictionofthemigrationofsaltflanksbyadoptingaseriesofmethods,includingtheinvestigationoftheabnormaltimeinthetimedomainvelocityspectrumandconstrainingthevelocitymodelusinggeologicalandloggingdata,basedontheseismologicalandgeologicalfeaturesofthecomplexsalt-domeregiononlandandeliminatingthesaltimpactontheunderlyingstrata(Zhangetal.,2009;Yueetal.,2012).Thedesignofacquisitionparametersbasedonseismicilluminationmodelingisanotherimportanttopicrelevanttoseismicimagingquality.Dongetal.(2006)determinedtheoptimalinfillshotareaonsurfaceusingtheilluminationstatisticalmethod,whichisbasedontheseismicwaveequationillumination,andsyntheticallyanalyzedtheenergycontributiondistributioncurveandfoldsonthetargetlayer.Theyalsodeterminedtheoptimalarraylayoutandarraylengthforthetargetlayer.Gaussianbeamwassuccessfullyforthedepthmigrationofseismicdatawithlow-foldandpoor-illuminationareas.TheactualdatashowthattheGaussianbeamcanbeusedfornoiseremovalandclearingimages(HuandStoffa,2009).Qin(2010)putforwardadesignmethodfortheacquisitiongeometrybasedontherequirementsofimagingforprestackmigrationandestablishedasetofacquisitiongeometrytemplatesforbetterspatialsamplingthatgraduallyoptimizetheacquisitiongeometry;however,hedidnotconsiderthedifficultyandthecostcontrolofthefieldoperation.Second,toextractthebaseshotpoints(blackpointsinFigure1)accordingtothefieldrequirements,thesimulatedsingle-shotilluminationenergydataareextracted,whiletheaccumulatedenergyforeachbinformstheoriginalgeometrytarget-layerilluminationenergy(theseshotsmeetthebasicoperationrequirements),andtheenergyshadowareacoordinatesinthetargetlayerareestimatedaswhereSThird,thecoordinatesofthemaximumpositiononthetargetlayerissearchedfortheilluminationenergyofeachshot.Theautomaticinfillshotmethodistochoosetheareawithminimumenergyandaddshotsformakingthetarget-layerenergyuniform.Wecallthistheminimumvaluemethod,anditisfastandaccurate.Subsequently,thismethodisusedtorecordthecoordinatesofthemaximumpositionforthetarget-layerilluminationenergyforeachshotFinally,tocalculatetheenergyuniformitybeforeandafteraddingshots,becausetheshotadditiondependsontheuniformityofthetarget-layerenergy,thevariancevalueisusedasthestandardenergyuniformityandtheequationtocalculatethevarianceformulaisIfthevariancevaluedecreases,ashotisadded.Ifthevariancevalueincreases,thenextshotissearchedandtheprocessisrepeateduntiltherequiredshotsnumberisreachedandthenthecalculationsstop.InFigure5,thelocationoftheinfillshotsismostlyinthetwowingsoftheanticline(cyanpoints).Figures3,4,and5showtheilluminationenergydiagramofthebaseshot,thetotalinfillofthe26shots,andtheautomaticallyinfilled26shots.Thevarianceis4.87,4.85,and3.92,respectively.The26automaticinfillshotshavethebestuniformity;however,the26totalinfillshotsdidnotincreasethetarget-layerilluminationuniformitycomparedwiththebaseshots,whichindicatesthatthenew26shotsdidnotaddtothetarget-layershadowareawhereitisneededmost.Thesearetheblindinfillshots.Totesttheeffectivenessoftheautomaticinfillshotsmethod,wegeneratedshotdata(includingbaseshots,regularoverallinfill26shots,andautomaticinfill26shots)usingthewaveequationandprocessedthedatafortheseshotsbyprestackdepthmigration.Theproductprestackdepthmigrationsectionsillustratethesuperiorityoftheautomaticinfillshotmethod.Figure6showstheprestackdepthmigrationsectionofthebaseshots.Fromthisfigure,wecanseethatthebaseshotoftheseismicimageaftertheprestackdepthmigrationdoesnotimproveandrequirestheuseofinfillshots.Typically,accordingtoaregularprogram,wefirstneedtodoubletheaddedshots(additionof26shots).Figure7showstheprestackdepthmigrationsectionsafteraddingtheshotsand,fromthisfigure,wecanseethattheenergyofthetargetlayerhasobviouslyincreasedandtheimagingqualityhasgreatlyimproved.Nonetheless,theoverallinfillenergydistributionuniformityisnotgood(Figure7a),whichaffectsthesubsequentreservoirprediction.Figure7bshowstheprestackdepthmigrationsectionusingtheautomaticinfillshotmethod(alsoadd26shots).Comparingthetwosectionsafteraddingthesamenumberofshotsbyusingthetwomethods,wecanseethattheeventenergiesonbothsidesofthetargetlayer(theredarea)haveobviouslyincreasedbuttheeffectoftheautomaticinfillshotmethodismuchmorepronouncedthanthetotalinfillshotmethod,becausetheformerautomaticallysetstheshotsontheshadowareaofthetargetlayer,wheretheshotenergyjustreachedtheweaklyilluminatedtargetlayer.Fortheenergyofthemiddlepartofthetargetlayer,thereisnodifferencebetweenthetwo,whichfurthershowsthattheautomaticadditionshotmethodisacost-effectivewaytoimproveimagingquality.Thedomemodelgeometryisdefinedbytheshotlinespaceandtheshotpointspaceofthebaseshotof600m.Forexample,about1/4oftheshotsarebaseshotsandtheremainingshotsareusedasinfillshots.Figure8showstheilluminationenergydiagramofthebaseshots.Theblackpointsarethebaseshotsandthegraypointsarethespareshots.Thereisasoutheasternenergyshadowareainthelowerrightcorneroftheenergydiagram.Theenergyofthisareaisonly1/5ofthesurroundingenergy,correspondingtotheAblockinFigure10.TheAblockisnotcontinuousduetoweakillumination.Forthisproblem,wechoosetheautomaticinfillingshotmethod(adding10shots,theblue–blackpoints).Figure9showstheenergydiagramafterinfillshooting.Compar