Basic of Seismic Interpretation

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  • Basicsofseismicinterpretation

    WhatisseismicinterpretationBasicprinciples

    Basicsofseismicinterpretation

    Whatisseismicinterpretation

  • WhatisSeismicInterpretation?

    Objectives:lRecognizehydrocarbonanomaly

    lValidateanomalys

    geologicframework

    compositionamplitudeinterpretation

    Jakosky,1960

    ManagementsRiskRequirementIdentifywhereartdominatesandsciencedeviatesinthe

    structuralandamplitudeinterpretations.

    WhatisSeismicInterpretation?

    Objectives:Recognizehydrocarbonanomaly

    Validateanomalys

    geologicframeworkstructuralinterpretation

    amplitudeinterpretation

    ManagementsRiskRequirementIdentifywhereartdominatesandsciencedeviatesinthe

    structuralandamplitudeinterpretations.

  • SuggestionsfromthePastAnomalieswithNewPetrophysicalProperties

    AnomalieswithNewPetrophysicall Oilandgasemitcorpuscularradiation.

    l Desirablemineralsradiateobservablevibrations.

    l Hydrocarbonrockshaveagravityforcethatisproportional

    to1/rratherthan1/r

    l Oilandgassendoutelectromagneticwaves.

    l Organicsubstances,suchasoilandgas,exhibitsexualcharacteristics.

    (Blau,Geophysics,v.1,no.1.pg.1)or(TLE,1983,v.2,#3,p.28

    SlightProblem:Thoughdesirablebymost,noneoftheabovecanbevalidated.

    SuggestionsfromthePastAnomalieswithNewPetrophysicalProperties

    PetrophysicalPropertiesOilandgasemitcorpuscularradiation.

    Desirablemineralsradiateobservablevibrations.

    Hydrocarbonrockshaveagravityforcethatisproportional

    to1/rratherthan1/r2.

    Oilandgassendoutelectromagneticwaves.

    Organicsubstances,suchasoilandgas,exhibitsexualcharacteristics.

    (Blau,Geophysics,v.1,no.1.pg.1)or(TLE,1983,v.2,#3,p.2831)

    SlightProblem:Thoughdesirablebymost,noneoftheabovecanbevalidated.

  • TheArtandScienceofInterpretation

    Art...Systematicapplicationofexperiencetoassignthegeologicframeworkand

    composition(theearthmodel).

    Science... Applicationofphysicalsciencestotheearthmodel.

    Riskisbasedontheuniquenessofthe

    TheArtandScienceof

    ...Systematicapplicationof rules basedonpastexperiencetoassignthegeologicframeworkand

    composition(theearthmodel).

    Applicationofphysicalsciencesto validatetheearthmodel.

    Riskisbasedontheuniquenessofthevalidation.

  • ComponentsoftheHydrocarbonSystem

    Greve,1997

    ComponentsoftheHydrocarbon

  • TheArtandScienceofInterpretation

    ACCH

    Corollary:Geophysicaldatacantbeinterpretedwithoutknowingtheanswer.[Artsetofrules]

    TheArtandScienceof

    ACCH

    Geophysicaldatacantbeinterpretedwithoutknowingtheanswer.[Artsetofrules]

  • Interpretation=>interpretation

    IsTimePullUpaPaleoHigh?

    Interpretation=>ACCHtime

    UpaPaleoHigh?

  • VerificationSeismicreflectionamplitudecaninmanycasesdistinguishbetweengasrelatedamplitudeandotheranomalies

    Interpretation=>interpretation

    VerificationSeismicreflectionamplitudecaninmanycasesdistinguishbetweengasrelatedamplitudeandotheranomalies

    Interpretation=>ACCHamplitude

  • AftertheinventionofCMPmethodthesenewtechniqueincreasedthenumberandvarietyofgeologicaldatawhichcanbeabstractedfromseismicdata.Theapplicationofseismicexplorationismuchmoreprosperousthaneverbefore.

    1970s1960s1950s

    TheOnsetofInteractive

    Realtimeprestackandpoststackprocessingonworkstation

    TheOnsetofInteractiveInterpretation

    Interpretationhavetheabilityofsimplepoststackprecessing

    Interpretation(indoor)

    Processing(ComputerPrecessingCenter)

    Acquisition(Field)

    Theeraofbitchprocessing

    Theonsetofdigitalprocessingera

    Recordingofseismicreflectionisdividedintothreestage

    TheGoodOldDays

    Onlyoneperson(onecomputer)isneededtoperformdataacquisiton,processingand

    interpretateitinthefield

    TraveltimeInterpretationEras

    vibratordigitalprocessing,theuseofthesenewtechniqueincreasedthenumberandvarietyofgeologicaldatawhichcanbeabstractedfromseismicdata.Theapplicationofseismicexplorationismuchmoreprosperousthaneverbefore.

    1980s 1990s The21stcentury

    TheOnsetofInteractiveProcessing

    Realtimeprestackandpoststackprocessingonworkstation

    TheOnsetofInteractiveInterpretation

    Interpretationhavetheabilityofsimplepoststackprecessing

    Processing(ComputerPrecessingCenter)

    Theeraofbitchprocessing

    Theonsetofprocessingintergration

    ProcessingandInterpretationareintegratedintoasame

    platform

    AcquisitonIntergration

    Seismiccrewwithmultitaskofdesign,acquisition,precessing,

    interpretation

    TraveltimeInterpretationEras

  • The1980s

    Rapiddevelopmentofprocessingandinterpretationtechnologiesinthe1980s:

    1Seismicattributesanalysis1Amplitudeattributes(e.g.AVO2Velocityrelatedattributes3Instantaneousattributes

    2Boreholeseismictechnology1Verticalseismicprofile(VSP2crosswellseismic

    33Dseismic

    4Multicomponentseismic

    Rapiddevelopmentofprocessingandinterpretationtechnologiesinthe1980s:SeismicattributesanalysisAmplitudeattributes(e.g.AVO

    relatedattributes

    BoreholeseismictechnologyVerticalseismicprofile(VSP

    Multicomponentseismic

  • AmplitudeInterpretationEras

    FirstEra BrightSpot(19701899 KnottTheory Amplitudevsincidentangle

    1919 ZoeppritzTheory Amplitudevsincidentangle

    1951 GassmannTheory Petrophysicallinktoseismic

    1955 KoefoedApplication

    1961 BortfeldTheory Linearapproximationequation

    1976 RosaApplication

    SecondEraAVO(19821982 OstranderVerificationofAVO

    1985 ShueyApplication Rockpropertyemphasisatdifferentincidentangles.

    AmplitudeInterpretationEras

    BrightSpot(1970 1982)Amplitudevsincidentangle

    Amplitudevsincidentangle

    Petrophysicallinktoseismic

    PoissonsRatiofromRC()

    Linearapproximationequation

    RC()elasticinversion

    AVO(1982 Present)OstranderVerificationofAVO

    propertyemphasisatdifferentincidentangles.

  • Basicprinciples

    Seismicandgeologicalinterfaces

    Horizontrackingandcorrelation

    Wellties

    Faultpatternsandidentification

    2Dmapping

    3Dmapping

    DHIs(DirectHydrocarbonsIndicators)

    Basicprinciples

    Seismicandgeologicalinterfaces

    Horizontrackingandcorrelation

    Faultpatternsandidentification

    DHIs(DirectHydrocarbonsIndicators)

  • Therelationshipbetweenseismicreflectioninterface

    andgeologicalinterface

    a.Well1andwell5

    Therelationshipbetweenseismicreflectioninterface

    andgeologicalinterface

    a.Well1andwell5

  • b.AddWell24tofigurea4tofigurea

  • c.Seismicsectionacrosswell1c.Seismicsectionacrosswell15

  • Notes1. The seismic reflection

    contrast not a lithologicalapproximately correspondsunconformity

    2.Theseismicinterfacesgeological interface,correspondencebetween

    3. Parasequences maybutdonotproducereflections

    reflection is from a velocitylithological contrast it

    corresponds to a geological

    interfacesisoften paralleltotheinterface, but there is no

    betweenthem.

    may affect the wave formsreflections.

  • Geologicalmodelvs.seismicimaging

    Geologicalmodelvs.seismicimaging

    Marmousimodel.A2DseismicmodeldevisedbytheInstitutFrancaisduPetroletotest2Dmigrationalgorithms.Thereisahydrocarbonaccumulation(andflatspot)intheanticlineunderthedecollement.(a)Themodelat1:1scaleratio(fromVersteeg,1994)(b)modelwithdifferentgreydensityindicatingdifferentvelocities:(c)CMPstackoftheseismicdata.(d)TimemigrationoftheCMPstack(e)Prestackdepthmigrationof1%ofthedata.(FromYounandZhou,2001).

  • Basicprinciples

    Seismicandgeologicalinterfaces

    Horizontrackingandcorrelation

    Wellties

    Faultpatternsandidentification

    2Dmapping

    3Dmapping

    DHIs(DirectHydrocarbonsIndicators)

    Basicprinciples

    Seismicandgeologicalinterfaces

    Horizontrackingandcorrelation

    Faultpatternsandidentification

    DHIs(DirectHydrocarbonsIndicators)

  • Horizontaltrackingbasics

    a. Eventcontinuityandsimilarities

    b. Similarwavetrainandcharacteristics:

    amplitude,frequencyandphase.

    Horizontaltrackingbasics

    Eventcontinuityandsimilarities

    Similarwavetrainandcharacteristics:

    amplitude,frequencyandphase.

  • Basicprinciples

    Seismicandgeologicalinterfaces

    Horizontrackingandcorrelation

    Wellties

    Faultpatternsandidentification

    2Dmapping

    3Dmapping

    DHIs(DirectHydrocarbonsIndicators)

    Basicprinciples

    Seismicandgeologicalinterfaces

    Horizontrackingandcorrelation

    Faultpatternsandidentification

    DHIs(DirectHydrocarbonsIndicators)

  • 3000

    2800

    2600

    2400

    2200

    2000

    4 4 9 0

    4 2 9 0

    4 0 9 0

    3 8 9 0

    3 6 9 0

    3 4 9 0

    3 2 9 0

    3 0 9 0

    2 8 9 0

    2 6 9 0

    2 4 9 0

    T0 (s)

    depth (m)99SN10

    40

    K

    T

    J2S5

    J2S4

    J2S3

    J1S2

    J3S6-7

    J1S1T+H

    J1S1LST

    2.3.22.3.2 CalibrationofhorizonCalibrationofhorizon

    80 120 1 10 100

    GR RTu5F

    sequence

    Systemtract

    2 5 3 5

    2 7 0 0

    3 1 6 0

    3 3 5 7

    3 4 6 6

    3 70 4

    3 8 9 4

    4 0 5 0

    m

    m

    m

    m

    m

    m

    m

    m

    J 3 S 6

    J 2 S 5

    J 2 S 4

    J 2S 3

    J 1 S 2

    J 1 S 1

    HST

    TST

    LST

    LST

    TST

    HST

    TST LST

    HST TST LST

    HST TST LST

    LST

    TST

    HST

    Layers

    CalibrationofhorizonCalibrationofhorizon VSP VSP synthetise seismic data