A-Practical-Use-of-Shale-Petrophysics-for-Stimulat

SPE115258APracticalUseofShalePetrophysicsforStimulationDesignOptimization:AllShalePlaysAreNotClonesoftheBarnettShaleRickRickman,MikeMullen,ErikPetre,BillGrieser,andDonaldKundert,SPE,HalliburtonCopyright2008,SocietyofPetroleumEngineersThispaperwaspreparedforpresentationatthe2008SPEAnnualTechnicalConferenceandExhibitionheldinDenver,Colorado,USA,21–24September2008.ThispaperwasselectedforpresentationbyanSPEprogramcommitteefollowingreviewofinformationcontainedinanabstractsubmittedbytheauthor(s).ContentsofthepaperhavenotbeenreviewedbytheSocietyofPetroleumEngineersandaresubjecttocorrectionbytheauthor(s).ThematerialdoesnotnecessarilyreflectanypositionoftheSocietyofPetroleumEngineers,itsofficers,ormembers.Electronicreproduction,distribution,orstorageofanypartofthispaperwithoutthewrittenconsentoftheSocietyofPetroleumEngineersisprohibited.Permissiontoreproduceinprintisrestrictedtoanabstractofnotmorethan300words;illustrationsmaynotbecopied.TheabstractmustcontainconspicuousacknowledgmentofSPEcopyright.AbstractThemostcommonfallacyinthequestfortheoptimumstimulationtreatmentinshaleplaysacrossthecountryistotreatthemalljustliketheBarnettShale.ThereisnodoubtthattheBarnettShaleplayintheFt.WorthBasinisthe“granddaddy”ofshaleplaysandeveryonewantstheirshaleplaytobe“justliketheBarnettShale.”Therealityisthatshaleplaysaresimilartoanyothercoalbedmethaneortightsandplay;eachreservoirisuniqueandthestimulationandcompletionmethodshouldbedeterminedbasedonitsindividualpetrophysicalattributes.Thejourneyofselectingthecompletionstyleforanemergingshaleplaybeginsinthelaboratory.Anunderstandingofthemechanicalrockpropertiesandmineralogyisessentialtohelpunderstandhowtheshalereservoirshouldbecompleted.Actualmeasurementsofabsorption-desorptionisotherm,kerogentype,andvolumearealsocriticalpiecesofinformationneededtofindproductiveshalereservoirs.Withthistypeofdataavailable,significantcorrelationscanbedrawnbyintegratingthewirelinelogdataasatooltoestimatethegeochemicalanalysis.Thus,thewirelineloganalysis,oncecalibratedwithcoremeasurements,isaveryusefultoolinextendingthereservoirunderstandingandstimulationdesignasonemovesawayfromthewellborewhereactuallabdatawasmeasured.Arecentstudywasconductedtoreviewalaboratorydatabaserepresentingprincipalshalemineralogyandwirelinelogdatafrommanyofthemajorshaleplays.Theresultsofthisstudyrevealedsomestatisticallysignificantcorrelationsbetweenthewirelineloganalysisandmeasuredmineralogy,acidsolubility,andcapillarysuctiontimetestresultsforshalereservoirs.Amethodwasalsoderivedtocalculatemechanicalrockpropertiesfrommineralogy.Understandingmineralogyandfluidsensitivity,especiallyforshalereservoirs,isessentialinoptimizingthecompletionandstimulationtreatmentfortheuniqueattributesofeachshaleplay.Theresultsofthisstudyhavebeeninpetrophysicalmodelsdrivenbywirelinelogsthatarecommonintheindustrytoclassifytheshalebylithofacies,brittleness,andtoemulatethelabmeasurementofacidsolubilityandcapillarysuctiontimetest.Thisisthefirststepindeterminingifaparticularshaleisaviableresource,andwhichstimulationmethodwillprovideastimulationtreatmentdevelopmentanddesign.Asystematicapproachofvalidatingthewirelinelogcalculationswithspecializedcoreanalysisandalittle“tribal”knowledgecanhelpmoveaplayfromconcepttorealitybyminimizingthefailuresandshorteningthelearningcycletimeassociatedwithacommerciallysuccessfulproject.IntroductionProducingmethanefromshalehasbeenpracticedinNorthAmericaformorethan180years.ThefirstknownwellintheU.S.drilledtoproducenaturalgasforcommercialpurposeswasin1821outsideofFredonia,N.Y.(2008).Thiswellproducedfromafracturedorganic-richshalethroughahanddugwell.Itwasproducedformorethan75years.ProductionfromtheAntrimshaleintheMichiganBasinstartedin1936.Today,therearemorethan9,000wellsproducing,mostofwhichweredrilledafter1987.TheBarnettShale,discoveredin1981,isbeingproducedfrommorethan8,000wellstoday(Wang2008).Fig.1representsthegrowthoftheBarnettShaleplayintheNewark,EastfieldintheFt.Worthbasin.Thecumulativegasproductionfromthisfieldismorethan4Tcf.Onecouldcharacterizethesuccessofthisplayas:therightmarket,therightpeople,andtherighttechnology(Wang2008).ThekeytechnologiesfortheBarnettShalesuccessrevolvearoundhorizontaldrillingandhydraulicfracturestimulation.2SPE115258Fig.1—HistoryoftheBarnettShalePlayannualgasproductionandnumberofwells(HPDI.Note:2008dataonlyforfirstquarter).ThesimpleanswertothequestionofhowtoduplicatetheBarnettShalesuccessintheemergingshaleplaysaroundtheworldwouldbetotreatallshalesliketheBarnettShale.IfthattechnologyworksintheBarnettShale,itshouldbethetechnologyofchoiceforallothershales.Perhapsthisunderstandingisoversimplifyingthecomplexityofshalereservoirs.Theobjectiveofthispaperistoinvestigateuniquenessofeachshaleplay,especiallythestimulationfluidselectionandmappingoutofapathusingthelaboratorymeasurementstocalibratethepetrophysicalmodelthatwillbeusedasapracticalguideforstimulationdesignoptimization.InformationNecessaryforSuccessfulHydraulicFracturingofaShaleFormationThereisarathershortlistofitemsthatneedtobeknowna