SPRINGER BRIEFS IN PETROLEUM GEOSCIENCE & ENGINEERING Amin Taghavinejad Mehdi Ostadhassan Reza Daneshfar Unconventional Reservoirs: Rate and Pressure Transient Analysis Techniques A Reservoir Engineering Approach SpringerBriefs in Petroleum Geoscience & Engineering SeriesEditors JebraeelGholinezhad,SchoolofEngineering,UniversityofPortsmouth, Portsmouth,UK MarkBentley,AGRTRACSInternationalLtd,Aberdeen,UK LateefAkanji,PetroleumEngineering,UniversityofAberdeen,Aberdeen,UK KhalikMohamadSabil,SchoolofEnergy,Geoscience,InfrastructureandSociety, Heriot-WattUniversity,Edinburgh,UK SusanAgar,Oil&Energy,AramcoResearchCenter,Houston,USA KenichiSoga,DepartmentofCivilandEnvironmentalEngineering,Universityof California,Berkeley,USA A.A.Sulaimon,DepartmentofPetroleumEngineering,UniversitiTeknologi PETRONAS,SeriIskandar,Malaysia The SpringerBriefs series in Petroleum Geoscience & Engineering promotes and expedites the dissemination of substantive new research results, state-of-the-art subject reviews and tutorial overviews in the field of petroleum exploration, petroleumengineeringandproductiontechnology.Thesubjectfocusisonupstream explorationandproduction,subsurfacegeoscienceandengineering.Theseconcise summaries (50-125 pages) will include cutting-edge research, analytical methods, advancedmodellingtechniquesandpracticalapplications.Coveragewillextendto all theoretical and applied aspects of the field, including traditional drilling, shale-gas fracking, deepwater sedimentology, seismic exploration, pore-flow modellingandpetroleumeconomics.Topicsincludebutarenotlimitedto: (cid:129) PetroleumGeology&Geophysics (cid:129) Exploration:ConventionalandUnconventional (cid:129) SeismicInterpretation (cid:129) FormationEvaluation(welllogging) (cid:129) DrillingandCompletion (cid:129) HydraulicFracturing (cid:129) Geomechanics (cid:129) ReservoirSimulationandModelling (cid:129) FlowinPorousMedia:fromnano-tofield-scale (cid:129) ReservoirEngineering (cid:129) ProductionEngineering (cid:129) WellEngineering;Design,DecommissioningandAbandonment (cid:129) PetroleumSystems;InstrumentationandControl (cid:129) FlowAssurance,MineralScale&Hydrates (cid:129) ReservoirandWellIntervention (cid:129) ReservoirStimulation (cid:129) OilfieldChemistry (cid:129) RiskandUncertainty (cid:129) PetroleumEconomicsandEnergyPolicy Contributionstotheseriescanbemadebysubmittingaproposaltotheresponsible Springercontact,[email protected]. Moreinformationaboutthisseriesathttp://www.springer.com/series/15391 · · Amin Taghavinejad Mehdi Ostadhassan Reza Daneshfar Unconventional Reservoirs: Rate and Pressure Transient Analysis Techniques A Reservoir Engineering Approach AminTaghavinejad MehdiOstadhassan DepartmentofPetroleumEngineering KeyLaboratoryofContinentalShale AmirkabirUniversityofTechnology HydrocarbonAccumulationandEfficient Tehran,Iran Development,MinistryofEducation NortheastPetroleumUniversity RezaDaneshfar Daqing,Heilongjiang,China DepartmentofPetroleumEngineering PetroleumUniversityofTechnology Ahwaz,Iran ISSN2509-3126 ISSN2509-3134 (electronic) SpringerBriefsinPetroleumGeoscience&Engineering ISBN978-3-030-82836-3 ISBN978-3-030-82837-0 (eBook) https://doi.org/10.1007/978-3-030-82837-0 ©TheAuthor(s),underexclusivelicensetoSpringerNatureSwitzerlandAG2022 Thisworkissubjecttocopyright.AllrightsaresolelyandexclusivelylicensedbythePublisher,whether thewholeorpartofthematerialisconcerned,specificallytherightsoftranslation,reprinting,reuse ofillustrations,recitation,broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,and transmissionorinformationstorageandretrieval,electronicadaptation,computersoftware,orbysimilar ordissimilarmethodologynowknownorhereafterdeveloped. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant protectivelawsandregulationsandthereforefreeforgeneraluse. Thepublisher,theauthorsandtheeditorsaresafetoassumethattheadviceandinformationinthisbook arebelievedtobetrueandaccurateatthedateofpublication.Neitherthepublishernortheauthorsor theeditorsgiveawarranty,expressedorimplied,withrespecttothematerialcontainedhereinorforany errorsoromissionsthatmayhavebeenmade.Thepublisherremainsneutralwithregardtojurisdictional claimsinpublishedmapsandinstitutionalaffiliations. ThisSpringerimprintispublishedbytheregisteredcompanySpringerNatureSwitzerlandAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Thisbookisdedicatedto: Dr.MohammadSharifi, professorofpetroleumengineeringatthe AmirkabirUniversityofTechnology. Acknowledgements The authors would like to express their sincere appreciation to the Department of PetroleumEngineeringattheAmirkabirUniversityofTechnologyfortheirimmense supportsandfeedbackduringthepreparationofthisbook.Additionally,we’dliketo thanktheKeyLaboratoryofContinentalShaleAccumulationandEfficientDevel- opmentattheNortheastPetroleumUniversityinDaqingChina,fortheircontinuous encouragementofouracademicendeavors. LastbutnotleastMehdiOstadhassanwouldliketoextendhissinceregratitude to his wife Bailey without whom and his full-time support, encouragement, and dedicationhiscontributiontothisbookwouldn’thavebeenpossible.Shewasaway when this book was being developed in a separate country to take care of our two beautifulsons,ElijahAliandJonasReza. Ultimately,wethankourfriends,colleagues,andcollaboratorsfortheirfeedback, input,andscientificdiscussionswhichsignificantlyimprovedthequalityofthisbook. vii Contents 1 UnconventionalOilandGasReservoirs .......................... 1 1.1 IntroductiontoUnconventionalReservoirs ..................... 1 1.2 UnconventionalGasReservoirs ............................... 2 1.2.1 TightGasReservoirs ................................. 3 1.2.2 ShaleGasReservoirs ................................. 4 1.2.3 Coal-BedMethaneReservoirs ......................... 5 1.3 UnconventionalOilReservoirs ............................... 5 1.3.1 TightOilReservoirs .................................. 6 1.3.2 ShaleOilReservoirs .................................. 7 1.4 UnconventionalReservoirsDevelopment ...................... 7 References ..................................................... 9 2 UnconventionalReservoirEngineering ........................... 11 2.1 FluidFlowinReservoirs .................................... 11 2.1.1 HydraulicallyFracturedWells ......................... 11 2.1.2 NaturallyFracturedReservoirs ......................... 12 2.1.3 FluidFlowinPorousMediaofURs .................... 13 2.2 UnconventionalReservoirEngineeringWorkflow ............... 22 2.2.1 ReservoirandHydraulicFracturesCharacterization ....... 23 2.2.2 HydraulicFractureModeling .......................... 29 2.2.3 ReservoirModeling .................................. 30 2.2.4 DevelopmentalandEconomicalPlanning ................ 32 References ..................................................... 32 3 PressureTransientAnalysis ..................................... 35 3.1 Pre-FracWellTest .......................................... 35 3.1.1 Mini-DST ........................................... 35 3.1.2 Mini-FracTest ....................................... 38 ix x Contents 3.2 Post-FracWellTest ......................................... 41 3.2.1 BilinearFlowAnalysis ............................... 41 3.2.2 LinearFlowAnalysis ................................. 47 3.2.3 TypeCurveMatchingAnalysis ......................... 51 References ..................................................... 63 4 RateTransientAnalysis ......................................... 65 4.1 DeclineRateAnalysis ....................................... 65 4.1.1 ArpsDeclineCurveAnalysis .......................... 65 4.1.2 UnconventionalReservoirsDeclineCurveAnalysis ....... 68 4.2 RateTransientAnalysis ..................................... 71 4.2.1 PrimaryRateTransientAnalysisTechniques ............. 71 4.2.2 UnconventionalReservoirsRTATechniques ............. 77 References ..................................................... 98 AppendixA ....................................................... 101 AppendixB ....................................................... 103 AppendixC ....................................................... 109 Chapter 1 Unconventional Oil and Gas Reservoirs 1.1 IntroductiontoUnconventionalReservoirs Unconventionalresourcesorunconventionalreservoirs(UR)refertoacategoryof undergroundhydrocarbondepositswhicharedifferentinoperationsandmethodsof recoverycomparedtoconventionalreservoirs.Asamatteroffact,suchdiscrepancies originatefromtheirspecialgeological,geochemical,andpetrophysicalcharacteris- tics.ThemostimportantfeatureofURsistheirlow-permeabilitynature.Also,some storageandflowmechanismsofthesereservoirsarenotcommoninconventionaloil andgasdeposits.Thus,itcanbeexpectedthatURsrequirespecialstudiesinorder toenhancetheirefficiencyalongwithaneconomicalproduction. Consideringthegeologyandstructureofunconventionalresources,itissignifi- cantlyimportantthatthemajorityofthesereservoirsareseenasrelativelydeep,exten- sive,aswellasgreatlylow-permeableporousrocklayers.Hencemostofthesereser- voirsarepetroleumsourcerockswherehydrocarbonmigrationintoupperpermeable layershavenotoccurred,andsubsequentlyconventionalreservoirrockscannotbe identifieddistinctly.Infact,inthiskindofreservoirs,theproductionoperationstake placedirectlyfromthesourcerocks.However,URssuchascoal-bedmethaneand gas hydrates are exempted from this specific feature of unconventional resources; while,differences inphysicochemical properties withconventional reservoirs,and the necessity of special production techniques will categorize them under URs. In thisbookouremphasisismostlyonshaleandtightreservoirsallofwhichareoften consideredrelativelydeepsourcerockswithverylowpermeabilityandhugelateral- extent.Thisbeingsaid,inthefollowingsection,importantfeaturesofthesereservoirs along with coal-bed methane—that in retrospect share similar characteristics with shalegasreservoirs—arediscussed. Schematicofalarge-scalegeologicalprofileinFig.1.1,demonstratesstructural geology,lateralextent,andgeologicalsequenceofthesereservoirsaswellastheir differences from the conventional reservoirs in a glance. This figure indicates that thetightandshaleoil/gaslayershaveanextensivedistribution,accommodatingfor ©TheAuthor(s),underexclusivelicensetoSpringerNatureSwitzerlandAG2022 1 A.Taghavinejadetal.,UnconventionalReservoirs:RateandPressureTransientAnalysis Techniques,SpringerBriefsinPetroleumGeoscience&Engineering, https://doi.org/10.1007/978-3-030-82837-0_1