測(cè)井知識(shí)幻燈片(英文版)

WELLLOG(TheBoreHoleImage)WhatiswellLoggingWelllogisacontinuousrecordofmeasurementmadeinboreholerespondtovariationinsomephysicalpropertiesofrocksthroughwhichtheboreholeisdrilled.TraditionallyLogsaredisplayongirdedpapersshowninfigure.Nowadaysthelogmaybetakenasfilms,images,andindigitalformat.MoreFreepowerpointsatHISTORY1912ConradSchlumbergergivetheideaofusingelectricalmeasurementstomapsubsurfacerockbodies.

in1919Conrad

SchlumbergerandhisbrotherMarcelbeginworkonwelllogs.ThefirstelectricalresistivitywelllogwastakeninFrance,in1927.TheinstrumentwhichwasuseforthispurposeiscalledSONDE,thesondwasstoppedatperiodicintervalsinboreholeandtheandresistivitywasplottedongraphpaper.In1929theelectricalresistivitylogsareintroduceoncommercialscaleinVenezuela,USAandRussiaForcorrelationandidentificationofHydrocarbonbearingstrata.Thephotographic–filmrecorderwasdevelopedin1936thecurveswereSN,LNANDLATThedipmeterlogweredevelopedin1930TheGammaRayandNeutronLogwerebeginin1941LOGGINGUNITS

Loggingservicecompaniesutilizeavarietyofloggingunits,dependingonthelocation(onshoreoroffshore)andrequirementsoftheloggingrun.Eachunitwillcontainthefollowingcomponents:loggingcablewinchtoraiseandlowerthecableinthewellself-contained120-voltACgeneratorsetofsurfacecontrolpanelssetofdownholetools(sondesandcartridges)digitalrecordingsystemWorkFlowChartdepthtolithologicalboundarieslithologyidentificationmineralsgrade/qualityinter-boreholecorrelationstructuremappingdipdeterminationrockstrength

in-situstressorientationfracturefrequencyporosityfluidsalinityDepthOfInvestigationOfLoggingToolsLOGINTERPRETATIONOBJECTIVESTheobjectiveofloginterpretationdependsverymuchontheuser.Quantitativeanalysisofwelllogsprovidestheanalystwithvaluesforavarietyofprimaryparameters,suchas:porositywatersaturation,fluidtype(oil/gas/water)lithologypermeabilityFromthese,manycorollaryparameterscanbederivedbyintegration(andothermeans)toarriveatvaluesfor:hydrocarbons-in-placereserves(therecoverablefractionofhydrocarbonsin-place)mappingreservoirparametersButnotallusersofwirelinelogshavequantitativeanalysisastheirobjective.Manyofthemaremoreconcernedwiththegeologicalandgeophysicalaspects.Theseusersareinterestedininterpretationfor:well-to-wellcorrelationfaciesanalysisregionalstructuralandsedimentaryhistory

Inquantitativeloganalysis,theobjectiveistodefinethetypeofreservoir(lithology)itsstoragecapacity(porosity)itshydrocarbontypeandcontent(saturation)itsproducibility(permeability)GAMMARAYLOGGammaRaysarehigh-energyelectromagneticwaveswhichareemittedbyatomicnucleiasaformofradiationGammaraylogismeasurementofnaturalradioactivityinformationversesdepth.ItmeasurestheradiationemittingfromnaturallyoccurringU,Th,andK.Itisalsoknownasshalelog.GRlogreflectsshaleorclaycontent.Cleanformationshavelowradioactivitylevel.Correlationbetweenwells,Determinationofbedboundaries,Evaluationofshalecontentwithinaformation,Mineralanalysis,Depthcontrolforlogtie-ins,side-wallcoring,orperforating.ParticularlyusefulfordefiningshalebedswhenthespisfeaturelessGRlogcanberuninbothopenandcased

holeSpontaneousPotentialLog(SP)Thespontaneouspotential(SP)curverecordsthenaturallyoccurringelectricalpotential(voltage)producedbytheinteractionofformationconnatewater,conductivedrillingfluid,andshaleTheSPcurvereflectsadifferenceintheelectricalpotentialbetweenamovableelectrodeintheboreholeandafixedreferenceelectrodeatthesurfaceThoughtheSPisusedprimarilyasalithologyindicatorandasacorrelationtool,ithasotherusesaswell:permeabilityindicator,shalevolumeindicatorporosityindicator,andmeasurementofRw(henceformationwatersalinity).NeutronLoggingTheNeutronLogisprimarilyusedtoevaluateformationporosity,butthefactthatitisreallyjustahydrogendetectorshouldalwaysbekeptinmindItisusedtodetectgasincertainsituations,exploitingthelowerhydrogendensity,orhydrogenindexTheNeutronLogcanbesummarizedasthecontinuousmeasurementoftheinducedradiationproducedbythebombardmentofthatformationwithaneutronsourcecontainedintheloggingtoolwhichsourcesemitfastneutronsthatareeventuallyslowedbycollisionswithhydrogenatomsuntiltheyarecaptured(thinkofabilliardballmetaphorwherethesimilarsizeoftheparticlesisafactor).

Thecaptureresultsintheemissionofasecondarygammaray;sometools,especiallyolderones,detectthecapturegammaray(neutron-gammalog).

Othertoolsdetectintermediate(epithermal)neutronsorslow(thermal)neutrons(bothreferredtoasneutron-neutronlogs).

ModernneutrontoolsmostcommonlycountthermalneutronswithanHe-3typedetector.

TheDensityLogTheformationdensitylogisaporositylogthatmeasureselectrondensityofaformationDenseformationsabsorbmanygammarays,whilelow-densityformationsabsorbfewer.Thus,high-countratesatthedetectorsindicatelow-densityformations,whereaslowcountratesatthedetectorsindicatehigh-densityformations.Therefore,scatteredgammaraysreachingthedetectorisanindicationofformationDensity. Scaleandunits:Themostfrequentlyusedscalesarearangeof2.0to3.0gm/ccor1.95to2.95gm/ccacrosstwotracks.Adensityderivedporositycurveissometimespresentintracks#2and#3alongwiththebulkdensity(rb)andcorrection(Dr)curves.Track#1containsagammaraylogandcaliper.ResistivityLogBasicsabouttheResistivity:

Resistivitymeasurestheelectricpropertiesoftheformation,Resistivityismeasuredas,RinWperm,Resistivityistheinverseofconductivity,

The

abilitytoconductelectriccurrentdependsupon:TheVolumeofwater,TheTemperatureoftheformation,TheSalinityoftheformationTheResistivityLog:

Resistivitylogsmeasuretheabilityofrockstoconductelectricalcurrentandarescaledinunitsofohm-meters.TheUsage:Resistivitylogsareelectriclogswhichareusedto:DetermineHydrocarbonversusWater-bearingzones,IndicatePermeablezones,DetermineResisitivityPorosit