SpringerBriefs in Earth Sciences Mehdi Zeidouni Shale Hydrocarbon Recovery Basic Concepts and Reserve Estimation SpringerBriefs in Earth Sciences SpringerBriefsinEarthSciencespresentconcisesummariesofcutting-edgeresearch and practical applications in all research areas across earth sciences. It publishes peer-reviewedmonographsundertheeditorialsupervisionofaninternationaladvi- soryboardwiththeaimtopublish8to12weeksafteracceptance.Featuringcompact volumes of 50 to 125 pages (approx. 20,000–70,000 words), the series covers a rangeofcontentfromprofessionaltoacademicsuchas: (cid:129) timelyreportsofstate-of-theartanalyticaltechniques (cid:129) bridgesbetweennewresearchresults (cid:129) snapshotsofhotand/oremergingtopics (cid:129) literaturereviews (cid:129) in-depthcasestudies BriefswillbepublishedaspartofSpringer’seBookcollection,withmillionsof users worldwide. 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Mehdi Zeidouni Shale Hydrocarbon Recovery Basic Concepts and Reserve Estimation MehdiZeidouni DepartmentofPetroleumEngineering LouisianaStateUniversity BatonRouge,LA,USA ISSN2191-5369 ISSN2191-5377 (electronic) SpringerBriefsinEarthSciences ISBN978-3-031-23558-0 ISBN978-3-031-23559-7 (eBook) https://doi.org/10.1007/978-3-031-23559-7 ©TheAuthor(s),underexclusivelicensetoSpringerNatureSwitzerlandAG2023 Thisworkissubjecttocopyright.AllrightsaresolelyandexclusivelylicensedbythePublisher,whether thewholeorpartofthematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseof illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similarordissimilarmethodologynowknownorhereafterdeveloped. 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ThisSpringerimprintispublishedbytheregisteredcompanySpringerNatureSwitzerlandAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Preface Understanding the challenges specific to shale hydrocarbon recovery and the prac- ticestoovercomethesechallengesisthemainfocusofthisbook.Inthefirstchapter, technologicalevolutionsthatledtosuccessfulproductionfromshaleplays,andthe implications of the shale being a source rock for its hydrocarbon recovery are covered. The characteristics differentiating shale resources and determining play qualityarealsopresentedinChap.1.Thesecondchapterpresentstheoperationsof well drilling, hydraulic fracturing, and monitoring activities. Shale hydrocarbon reserve estimation methods are covered in Chaps. 3 and 4. Chapter 3 provides an overviewoftheavailablemethodsforreserveestimationofshaleresourcesfollowed by comprehensive coverage of decline curve analysis (DCA). The covered DCA methodsincludeArps’(exponential,hyperbolic,andharmonic),Stretchedexponen- tial, Power law exponential, Duong, and Logistic growth. In departure from the mostly empirical rate-time DCA methods covered in Chap. 3, advanced rate-time- pressure analysis—often referred to as rate transient analysis (RTA)—methods are presentedinChap.4.TheconventionalRTAmethodsareextendedtoshalewellsby introducing analysis approaches of transient linear flow, transitional flow, and stimulated-reservoir-volume (SRV) flow. Chapter 4 ends with a discussion on the complications of fluid flow in shale reservoirs and the required modelling improvements. ThisbookstemmedfromteachingacourseonShaleReservoirEngineeringand Evaluation PETE 4190 that the author annually taught at the Craft & Hawkins Department of Petroleum Engineering, Louisiana State University since Fall 2017. PETE 4190 also included additional contents—on the design and execution of hydraulic fracturing and its effect on well productivity—which are not covered in this book. The available literature on hydraulic fracturing stimulation were used to coverthosematerials.Thetargetaudienceofthisbookincludepetroleumengineers and non-petroleum engineers interested in understanding the basic concepts of hydrocarbonrecoveryfromshalereservoirs. Anotethateachchapterincludesquestions(true/false,shortanswer,ormultiple choice) to help the reader better engage in the learning of the presented material. v vi Preface Somequestionsarealsoaimedatcompletingthelearningprocessandmaypresent newinformation (notcovered priortotheraisedquestion).Therefore,thereaderis encouragedtoanswereveryquestionasitispresented.Theanswerstoquestionsare givenattheendofeachchapter. BatonRouge,LA,USA MehdiZeidouni Contents 1De finitions,History,andDifferentiatingCharacteristicsofShale HydrocarbonRecovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 “Shale”Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 ABriefHistory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 OriginofOilandGas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.4 SourceRockVersusReservoirRock. . . . . . . . . . . . . . . . . . . . . . 4 2 Drilling,Completion,andMonitoringOperations. . . . . . . . . . . . . . . 11 2.1 Drilling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Completion(Multi-fracturingofHorizontalWells). . . . . . . . . . . . 15 2.2.1 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2.2 RequiredEquipment,Fluids,andProppant. . . . . . . . . . . . 18 2.3 MonitoringandNear-WellboreDiagnostic. . . . . . . . . . . . . . . . . . 20 2.3.1 ExpectedTemperature,Strain,andAcousticSignals. . . . . 21 2.3.2 Frac-HitIdentification. . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2.3.3 FractureGeometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2.3.4 StageIsolation.. . . . .. . . .. . . . .. . . .. . . . .. . . .. . . . . 24 2.3.5 SlurryAllocationandFractureInitiationPoints(FIPs). . . . 25 2.3.6 ProductionProfiling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.3.7 OtherTypesofData. . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 ReserveEstimationThroughRate-TimeAnalysis. . . . . . . . . . . . . . . 29 3.1 ResourcesandReserves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.2 HydraulicFracturingEffectonWellProductivityandReserves. . . 31 3.3 Arps’DCA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.3.1 Arps’ExponentialDCA. . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.3.2 Arps’HyperbolicandHarmonicDCA. . . . . . . . . . . . . . . 35 3.4 StretchedExponentialDCA. . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3.5 Power-LawExponentialDCA. . . . . . . . . . . . . . . . . . . . . . . . . . . 41 vii viii Contents 3.6 DuongDCA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.7 LogisticGrowthDCA. .. . . . . .. . . . .. . . . .. . . . .. . . . .. . . . . 43 3.8 GraphicalVisualization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4 Rate-Pressure-TimeAnalysisforReserveEstimation. . . . . . . . . . . . 47 4.1 RTAforConventionalVerticalWells. . . . . . . . . . . . . . . . . . . . . 47 4.1.1 Log-LogPlotAnalysis. . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4.1.2 PNRPlot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.1.3 TheFlowingMaterialBalancePlot. . . . . . . . . . . . . . . . . . 56 4.1.4 ExtensiontoGasReservoirs. . . . . . . . . . . . . . . . . . . . . . . 57 4.2 ExtensiontoUnconventionalShaleWells. . . . . . . . . . . . . . . . . . 62 4.2.1 MFHWs’FlowRegimes. . . . . . . . . . . . . . . . . . . . . . . . . 62 4.2.2 MFHWs’FlowRegimesIdentificationandAnalysis. . . . . 63 4.2.3 RTAofMFHWs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 4.2.4 ApplicationtoMFHWBaseCase. . . . . . . . . . . . . . . . . . . 68 4.3 Complications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Appendix1:Pressure-RateRelationshipforBoundary-Dominated FlowUnderConstantRate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Appendix2:Rate-PressureRelationshipforLinearFlowUnder ConstantRateProduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Appendix3:Rate-PressureRelationshipforLinearFlowUnder ConstantWellFlowingPressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 References... .... ... .... .... ... .... .... ... .... ... .... .... 77 Chapter 1 fi De nitions, History, and Differentiating Characteristics of Shale Hydrocarbon Recovery Abstract Inthischapter,themeaningoftheterm“shale”asahydrocarbonresource is described. Next, a brief history of shale hydrocarbon recovery is presented and major steps taken to unlock its significant potential are discussed. As discussed in details in this chapter, most shale reservoirs are petroleum source rocks. The implicationsofthesourcerocknatureofshalereservoirsforhydrocarbonaccumu- lation and reservoir development iscoveredby explaining (1) theorigin ofoil and gas, (2) relative amounts and distribution of source rock resources as compared to conventional reservoirs, and (3) parameters controlling the source rock quality primarilybasedontheformofcontainingorganicmatterandrockporespace.The majorlearningoutcomesofthischapteraretherefore:(1)Definetheterm“shale”in shale hydrocarbon recovery, (2) describe the technological evolutions that led to unlockingshalerecoveryintheUS,and(3)identifytheimplicationsoftheshaleasa source rock for its hydrocarbons content and type, areal extent, and recovery approach. 1.1 “Shale” Definition In today’s industry, the term “shale” is typically used to describe any fine-grain sedimentary rock that require massive stimulation for economic recovery. In this terminologyshalerockmaybecomposedofclayminerals(smectite,illite,chlorite, kaolinite),quartz,feldspar,andcarbonates.Mineralcompositionsintheshalecanbe quite variable. Passey et al. (2010) and Gale et al. (2014) presented the mineral composition in major shale plays in the US (including Barnett, Eagle Ford, and MarcellusFormations)accordingtowhichtheclaycontentvariesbetween~10and 70%intheseplayswhiletherestisquartzandcarbonates. The mineralogy of these rocks is very important for hydrocarbon recovery because rocks with less clay and more quartz and carbonates are more brittle and potentially comprised of larger pores. More brittle rocks are easier to fracture in hydraulicfracturingstimulationcomparedtoductile/deformablerocks.Manyshale reservoirsarepetroleumsourcerocks,mainlycharacterizedbylowpermeabilityless than 1 micro Darcy (μD). Tight reservoirs (which are not source rocks) with ©TheAuthor(s),underexclusivelicensetoSpringerNatureSwitzerlandAG2023 1 M.Zeidouni,ShaleHydrocarbonRecovery,SpringerBriefsinEarthSciences, https://doi.org/10.1007/978-3-031-23559-7_1