Listof figures
FIGUREI.1 ShalegasproductiontrendsintheUnitedStates1
FIGUREI.2 TightoilproductiontrendsintheUnitedStates2
FIGUREI.3 Illustrationofthecombinationofhorizontaldrillingandstagedhydraulicfracturing technologyusedforshalegas.Nottoscale7
FIGUREI.4 Trendsinworldoilandgasproductionbytopproducers10
FIGURE1.1 PhotographofcontactbetweentheblackClevelandShaleandtheunderlyinggrayChagrin ShaleinadrillcorefromOhio16
FIGURE1.2 Rock-EvalplotofhydrogenindexversusTmaxshowingdifferentareasofthegraph occupiedbydifferenttypesofkerogen.ThesamplesplottedarefromtheNiobrara FormationinSouthDakotaandindicateimmatureTypeIIkerogenwithabitofTypeIII21
FIGURE1.3 VanKrevelendiagramofhydrogenindex(HI)versusoxygenindex(OI)fromRock-Eval pyrolysisdata.TypeIandTypeIIkerogens(oilandgasprone)arereadilydistinguishable fromTypeIIIkerogen(coaly,gasprone)andtheinertTypeIV.DatafromtheNiobrara FormationinSouthDakota 22
FIGURE1.4 ProductiontrendsofconventionalversusunconventionalnaturalgasintheUnitedStates25
FIGURE1.5 Illustrationofunconventionalhydrocarbonsbeingproduceddirectlyfromtheshalesource rockversusconventionaloilandgasthatmigratedintopermeable,porousrockandwas trappedbystructureorstratigraphy27
FIGURE2.1 Theresourcetriangleillustratingthedistributionofmostnaturalresources,including hydrocarbons,whenquantityisplottedagainstquality34
FIGURE2.2 Vehicleslinedupwaitingforgasolineduringthe1973 74energycrisis39
FIGURE2.3 VisualizationofthephysicalparametersusedtodefineDarcy’slawofpermeability42
FIGURE2.4 ScanningelectronmicrographofafreshlybrokensurfaceonMarcellusShaleperpendicular tobedding.Scalebaris10 mm.Clayfabricandstructureareclearlyvisible,butthe “pores” areactuallyvoidscreatedbytheremovalofpreexistinggrains46
FIGURE2.5 ScanningelectronmicrographofaBarnettShalesurfacemilled flatusingafocusedion beam(FIB).Scalebaris1 mm.Porosityisvisiblewithinorganicmaceral,asare nanometer-scaleporesinmatrix47
FIGURE2.6 Alarge, “triple” hydraulicdrillriginstallingalateralintotheNiobraraFormationat adepthofapproximately8000ft(2.4km)intheDenver JulesburgBasin,EasternColorado. Scaleisindicatedbythestairwayandentrancedoorofthe “doghouse” officetrailerattached tothesideoftheplatformandusedtooperatetherig.Asecondrigisvisibleinthe backgroundatleft 48
FIGURE2.7 PolycrystallinediamondcompositedrillbitusedontheNiobraraFormationinthe Denver JulesburgBasin,EasternColorado.Jetsinthehubaredesignedto flushmudoff thecuttingteeth.Coininthecenterforscaleis2cmindiameter50
FIGURE2.8 HydraulicfracturingoperationunderwayontwoMarcellusShalewellheadsin southwesternPennsylvania.Pumptrucksareontheright,blenderandmanifoldincenter, proppantsandinleftbackgroundwithtwomenontank,monitoringandcontroltrailer toleft.Watersupplywasinalargeimpoundmentbehindphotographer51
FIGURE2.9 ShalegasandtightoilplaysinNorthAmerica.Muchofthecurrentfocusisonstacked playsintheAppalachian,Permian,andPowderRiverbasinsandonliquids-richplayslike theEagleFord,Bakken,andUtica53
FIGURE2.10 Aslickensidedfaultsurfacecuttingacrossa3.5inch(9cm)diameterEGSPshalecore54
FIGURE2.11 Orthogonaljointsona flatbeddingplaneoftheMarcellusShale,exposedinthebed ofOatkaCreek,Leroy,NY.Thecompasspointstothenorth55
FIGURE3.1 MapofproductionwellsintheBarnettShaleintheFortWorthbasinofTexas69
FIGURE3.2 NumerousBarnettShaleproductionwellpads(arrowed)interspersedamongthehousing developmentsofsuburbanFortWorth,Texas,southwestofDFWAirport70
FIGURE3.3 MapofstructuresintheFortWorthbasinofTexas,includingisopachsoftheBarnettShale thicknessinfeet.Theshalethickensanddeepenstothenorth71
FIGURE3.4 Northtosouthgeologiccross-sectionthroughtheFortWorthbasinshowingthelocation oftheBarnettShaleaboveanunconformityontopoftheEllenbergerlimestone.Theshale becomesmoreshallowandthinstothesouth,terminatinginoutcropsontheLlanoUplift72
FIGURE3.5 OutcropofweatheredBarnettShalewithledge-forminglimestonebedsontheLlanoUplift nearSanSaba,Texas 73
FIGURE3.6 ThemassivelybeddedEllenbergerlimestoneexposedatthebaseofanoutcroponthe LlanoUpliftnearSanSaba,Texas,overlainbyaboutameterofChappellimestonebeneath theweatheredslopesofthebasalpartoftheBarnettShale74
FIGURE3.7 ThermalmaturityintheBarnettshaleexpressedasvitrinitereflectance(Ro)76
FIGURE3.8 ContactbetweentheFayettevilleShaleandtheoverlyingPitkinlimestoneinaroadcutin northwestArkansas.ArkansasGeologicalSurveyphoto78
FIGURE3.9 ConcretionzonenearthebaseoftheFayettevilleShaleinArkansas.ArkansasGeological Surveyphoto 78
FIGURE3.10 FayettevilleShaledevelopmentregionsinArkansas.ArkansasGeologicalSurveymap79
FIGURE3.11 RedstripedareashowinglocationofHaynesvilleShaledevelopmentintheArkansas, Texas,andLouisianaborderregionknownastheArkLaTex.TexasBureauofEconomic Geologymap 83
FIGURE3.12 NaturalgasproductionfromtheHaynesvilleShaleinmillionsofcubicfeetperday (MMCFD)from2009to201884
FIGURE3.13 Schematiccross-sectionoftheAppalachianBasin,showingMiddleandUpperDevonianrocks. TheMarcellusShaleisatthebaseofathickalternatingsequenceoforganicrichandlean shaleswithafewlimestones.Coarsersedimentstotherightareclasticsfromthe Catskilldelta 88
FIGURE3.14 BasalcontactoftheMarcellusShaleabovetheOnondagaLimestone,SenecaStone quarry,SenecaFalls,NY 91
FIGURE3.15 TiogaAshbedsinanoutcropoftheUnionSpringsMemberoftheMarcellusShalenear Bedford,Pennsylvania.Rockhammerforscaleis13inches(33cm)inlength91
FIGURE3.16 CherryValleyLimestonememberoftheMarcellusShaleexposedinaquarrynearOriskany Falls,NY 92
FIGURE3.17 OatkaCreeknorthofLeroy,NY.ThestreambedhereiscomposedoftheOatkaCreek MemberoftheMarcellusShale.Ball-likeobjectsinthestreamaresideriteconcretions93
FIGURE3.18 PermitsforMarcellusShalegaswellsissuedinPennsylvaniaasof2012showcore productionareasinthenortheasternandsouthwesternpartsofthestate.Thesouthwestern productionareaextendsintoWestVirginia.PennsylvaniaDepartmentofConservationand NaturalResourcesmap 94
FIGURE3.19 CrudeoilfromtheBakkenFormation floatingonproducedwater.Ahandsampleof Bakken-equivalentshalefrombeneaththeLodgepolelimestoneisshownintheforeground96
FIGURE3.20 TripledrillrigontheBakkenplayintheParshallField,MountrailCounty,NorthDakota98
FIGURE3.21 LocationmapofUSandCanadianproductionfromtheBakkenFormationinthe WillistonBasin 99
FIGURE3.22 SatelliteimageoftheUnitedStatesatnight,takenin2017.TheilluminationfromBakken flaresislabeled.NASAimage100
FIGURE3.23 UpperblackshalememberoftheBakkenFormationinacoreslab,showingpyritelaminae, fossilshells,andmultiplefractures.Coinforscaleis2cmindiameter101
FIGURE3.24 Middlelimestone/sandstonememberoftheBakkenFormationinacoreslab,showing sedimentarystructures.Coinforscaleis2cmindiameter102
FIGURE4.1 WellscompletedintheWoodfordShaleinOklahomabetween2004and2012.BlueDark squaresareverticalwellsandstarsarehorizontal.TheplayrunsfromtheArkomabasin intheeasttotheArdmorebasininthesouth,andthennorthwestintotheAnadarkobasin109
FIGURE4.2 Bitumen- filledfracturesinaWoodfordShaleoutcropinMcAlesterCemeteryQuarry, Oklahoma.Coinforscaleis17mmindiameter110
FIGURE4.3 NiobraraFormationisdistributedwithinthe browndashedline (lightgrayinprintversion).Easternbiogenicaccumulationsofgasanddeeper,thermogenic hydrocarbonsareseparatedbythedot-dashedredline.Oilproductionisshownin green (grayinprintversion)andgasin red (darkgrayinprintversion)112
FIGURE4.4 Dr.FosterSawyerofSDMinesatthecontactbetweenthechalkyNiobraraFormation andtheoverlyingPierreShaleatElm-CreekneartheMissouriRiverinSouthDakota113
FIGURE4.5 Geologicwest-to-eastcross-sectionofthehighlyasymmetricDenver-Julesburg(D-J) basininColoradoshowingbasin-centeredgasaccumulationsindeeplyburiedCretaceous rocksformingtheWattenbergGasField114
FIGURE4.6 NiobraraformationoutcropatSlimButte,OglalaLakotaCounty,SouthDakota.Despite thelightcolor,TOCcontentmeasuredinthelayerbelowtherockhammeratleftwas nearly6% 115
FIGURE4.7 ThinsectionphotomicrographoftheNiobraraFormationfromGraves#31coreshowing amixofgrayclay,blackorganiccarbon,andwhitecalcareousmicrofossils.Stainonthe rightidenti fiescalcite;scalebaratupperleftequals0.5mm116
FIGURE4.8 Organic-richPierreShaledrillcorefromPresho,SDwithanammonitefossilon apartingsurface 116
FIGURE4.9 Prominent,yellowvolcanicashbedswithintheblackPierreShaleonanoutcropatBuffalo Gap,SD.Peopleinthebackgroundprovidescale117
FIGURE4.10 Viewingthecontact(justabovehardhatofpersonpointingtooutcrop)betweenthe DolgevilleandoverlyingIndianCastlemembersoftheUticaShalealongtheNewYork ThruwaynearLittleFalls,NY118
FIGURE4.11 UticaShalestratigraphiccorrelationfromcentralKentuckytocentralNewYork120
FIGURE4.12 FissileandmoderatelyorganicUtica PointPleasantshalebelowtheslabby,calcareous KopeFormationataroadcutinKentuckyneartheOhioRiver120
FIGURE4.13 MapoftheEagleFordshaleplayinTexas,showingzonesofdifferenthydrocarbon productionasafunctionofthermalmaturityanddepth122
FIGURE4.14 EagleFordShaleinoutcrop,showingthealternatingslabbylimestoneandcalcareousclay shalebeds 122
FIGURE4.15 MapofthePermianbasinshowingstructuralboundariesandmajortightoilplays124
FIGURE4.16 OilproductionhistoryinthePermianbasin125
FIGURE4.17 MapofsmallMesozoicriftbasinsalongtheUSEasternSeaboardindicatingthoseassessed forshalegasandcondensateresourcesbytheUSGS130
FIGURE5.1 Worldwidesedimentarybasinscontainingassessedorsuspectedtightoiland/orshale gasresources 137
FIGURE5.2 PotentialshalegasinGreatBritain142
FIGURE5.3 LithofaciesandisopachmapoftheBazhenovFormationintheWestSiberianBasin,Russia. Scalebaris200km(124miles)146
FIGURE5.4 MapoftheKarooBasininSouthAfricashowingEccaGroupshalesandigneousintrusions153
FIGURE5.5 SedimentarybasinsinArgentinacontainingprospectiveshalegasresources156
FIGURE5.6 LocationsofshalegasassessmentsinthePeople’sRepublicofChina158
FIGURE5.7 BlocksofLongmaxiShaleawaitingrockpropertiestestingattheChineseAcademy ofSciencesinWuhan,China160
FIGURE5.8 Australiangovernmentmapofoilandgasbasinsandinfrastructure164
FIGURE5.9 BasinsinMalaysiawithprospectiveshalegasandtightoil167
FIGURE6.1 A flammablekitchenfaucetcausedbynaturalgasenteringawatersupplywellin Pennsylvania.Somepeoplehavelinkedthistofracking179
FIGURE6.2 HeightsofhydraulicfracturesontheMarcellusShalemeasuredwithmicroseismicdata plottedagainstthedepthofthedeepestfreshwateraquiferineachcounty(bluezones attopofgraph) 188
FIGURE6.3 Photographofablacksubstanceidenti fiedasdrillingmudoozingoutoftheground fromanerodedstreambankbelowadrillpadandintoIndianRuninHarrisonCounty, WestVirginia,in2010 192
FIGURE6.4 Carbondioxidelevelsintheatmospheremeasuredsince1957atMaunaLoainHawaii203
FIGURE7.1 TheNorthRampoftheExploratoryStudiesFacility(ESF)tunnelunderYuccaMountain, Nevada.ThisU-shapedtunnelintoandoutofthemountainis fivemiles(8km)inlength and25ft(7.6m)indiameter215
FIGURE7.2 TheShippingportAtomicPowerStationontheOhioRiverwestofPittsburgh,PA,the first commercialnuclearreactorintheUnitedStates.USDepartmentofEnergyphotograph234
FIGURE7.3 TheGeysersgeothermalpowerplantinCalifornia.CaliforniaStateEnergyCommission photograph 239
FIGURE7.4 CrescentDunessolarpowertowersurroundedby10,347heliostatmirrorsintheNevada desertnearTonopah 242
FIGURE8.1 USliquefiednaturalgas(bcf)importsandexports,1985 2017258
FIGURE8.2 USexportsofliquefiednaturalgas2017over2016258
FIGURE8.3 USpetroleumconsumption,production,imports,exports,andnetimports259
FIGURE8.4 USprimaryenergyconsumptionbysourceandsector,2017260
FIGURE8.5 Crudeoilproduction,millionbarrelsperday,2017261
FIGURE8.6 Naturalgasproductionbytype,trillioncubicfeet261
FIGURE8.7 Lower48onshorecrudeoilproductionbyregion,referencecase262
FIGURE8.8 Shalegasproductionbyregion,trillioncubicfeet262
FIGURE8.9 USenergyconsumptionandoutlookyearend2007263
FIGURE8.10 Energyconsumptionbyfuel,quadrillionBritishthermalunits263
FIGURE8.11 USnaturalgasconsumption,dryproduction,andnetimports,1950 2017265
FIGURE8.12 USannualenergyconsumptionandenergy-relatedCO2 emissions265
FIGURE8.13 USenergy-relatedcarbondioxideemissions,1980 2019266
FIGURE8.14 PetroleumAdministrationforDefenseDistricts(PADD)267
FIGURE8.15 LocationsandrelativesizesofUSrefineries,2012269
FIGURE8.16 DensityandsulfurcontentofcrudeoilbyPADDandUSaverage,2011269
FIGURE8.17 USatmosphericcrudedistillationcapacity,2009 18270
FIGURE8.18 UScrudeproduction,netimports,andgrossinputstorefineries,2009 17270
FIGURE8.19 DOEShaleGasR&Dcomparedtoproduction271
FIGURE8.20 Productsupplyoverview:Midwest(PADD2)andRockyMountain(PADD4)Generalized FlowofTransportationFuels273
FIGURE8.21 NaturalgaspipelinecapacityintotheSouthCentralUnitedStates,2000 18274
FIGURE8.22 StrategicReserveinventoriesandplannedsales,2017 28275
FIGURE9.1 Carbondioxideconcentrationintheatmosphereoverthepast400,000years280
Introduction
Itisvirtuallyimpossibletooverstatetheimportanceofthesuccessfuldevelopmentof shalegasandtightoiltotheenergyeconomyoftheUnitedStates.Accordingtodata trackedbytheUSEnergyInformationAgency(EIA),by2009,shalegashadledtheUnited Statesfromnaturalgasshortagestobecomingthelargestproducerofnaturalgasinthe world(USEIA,2018).Liquefiednaturalgas(LNG)terminalsconstructedontheUSEast Coastatthestartofthe21stcenturyforenergyimportswereconvertedlessthanadecade latertoexportLNGtoEuropeandelsewhere.TheMarcellusShaleintheAppalachian basinisnowthemostproductivenaturalgasformationintheUnitedStates(Fig.I.1).
Liquidproductionfromlow-permeabilityshalesandlimestones,knownas“tightoil,” hasexperiencedasimilarboom.Massiveoilimportsfromthe1970sthroughthefirst decadeofthe21stcenturybroughtinmorethanhalfoftheannualUSoilsupplyfrom overseas.By2013,tightoilmadeAmericatheworldleaderincrudeoilproduction (USEIA,2018).
ThesetwostunningfactshavenotonlychangedtheenergypictureintheUnited Statesbuthavedisruptedtheenergyeconomyoftheentireworld.Thebusinessplansof manyinternationalandstate-ownedoilcompaniesweredependentuponexportstothe UnitedStates,oneoftheworld’slargestconsumersofpetroleum.Thankstoabundant tightoilproductionfromtheBakkenShale,thesecondlargestoil-producingstateinthe
FIGUREI.1 ShalegasproductiontrendsintheUnitedStates. U.S.EnergyInformationAdministrationreportsand webpages.
UnitedStatesispresentlyNorthDakota,exceedingotherformeroilgiantslikeAlaska, Oklahoma,Louisiana,California,andColorado.IttrailsonlyTexas,whichretainsfirst placebecauseofequallyprolificliquidhydrocarbonproductionfromtheEagleFord ShaleandagroupoftightoilformationsinthePermianBasin(Fig.I.2).
FIGUREI.2 TightoilproductiontrendsintheUnitedStates. EIAderivedfromstateadministrativedatacollected byDrillingInfoInc.DataarethroughJuly2016andrepresentEIA’sofficialtightoilestimates,butarenotsurvey data.Stateabbreviationsindicateprimarystate(s).
Althoughthedevelopmentofshalegasandtightoilcreatedarevolutioninfossil fuels,ithasalsosparkedarevolutioninthepoliticalsenseoftheword.Likemostpoliticalrevolutions,thereareardentsupportersandadedicatedandvehementopposition.Intheearlydays,theoilandgas(O&G)industryusedtheslangterm“frack”to describetheprocessofhydraulicfracturing.ThistechnologywasinventedinKansasby FloydFerrisofStanolindOilin1947toimprovehydrocarbonproductionfromlow permeabilityor“tight”reservoirs(MontgomeryandSmith,2010).Itistheprimary technologyappliedtoshalestostimulateproduction.Shalegasopponentsadopted “fracking”asatriggerwordtoserveasaprotestandacalltoarms,andproudlyselfidentifiedthemselvesas“fracktivists.”Thefracktivistsusedthewordtorefertothe entireshalegasdevelopmentprocess,fromthearrivalofthefirstdrillrigonsitetothe productionof“frackedgas”fromacompletedwell.
TheO&Gindustry,ontheotherhand,restrictsusageofthetermfrackingtodescribe onlytheactualhydraulicfracturingstimulationprocessitself.Todistinguishtheoriginal intentoftheexpressionfromthenegativeconnotationsofthetermco-optedby fracktivists,industrydroppedthe“k”andchangedthespellingto“frac.”This,however, doesnotworkverywellascolloquialEnglish,leadingtospellingslike“frac’ed,”“fracced” or“frac’ing.”Nevertheless,usageoftheterm“frac”versus“frack”iscriticaltosome people,asithasbecomeawaytoquicklyidentifywhichsideoftheshalegasrevolution someoneison.
Weremindreadersthatthisisamade-upwordwithnostandardspellingandargue that“frack”spelledwiththe“k”hasagreatdealincommonwiththespellingsforreal, similar-soundingwordslike“back”or“crack.”Assuch,wehavechosentousethe
spelling“frack”inthisdocumentforphoneticreasons.However,wealsoagreewiththe O&Gindustrythatthetermshouldbeusednarrowlytoreferonlytothehydraulic fracturingstimulationprocess.Describingtheactionofabulldozerclearingoffawell padas“fracking”isbothincorrectandabsurd.Statingominouslythatapipelinewillbe carrying“frackedgas”makesnosensewhenthereisnodistinguishabledifferencebetweenfrackedgasandanyotherkindofgas.
Disagreementsovershaledevelopmentgrewmoreintenseasthemassiveeconomic promiseoftheresourcecollidedhead-onwithfearsanduncertaintiesaboutthepotentialenvironmentalrisks.Withnoactualdataonenvironmentalimpacts,fracktivists couldconjureupmonstersunderthebedofeverystripeandcolor.Likewisewithno actualdata,theO&Gindustrytriedtoreassurepeoplethattheyknewwhattheywere doing,thesafetyofthepublicwasparamount,andeveryoneshouldjusttrustthemas theexperts.Unfortunately,intermsoftrust,sociologicalstudieshaveshownthatthe onlyindustryAmericansconsidertobelesstrustworthythanoilandgasisbigtobacco (Theodori,2008).Thus,whentheO&Gindustryrespondedtoenvironmentalconcerns raisedbyfracktivistswith“trustus,alliswell,remaincalm,”itwasmetwithalmost universalskepticismbytheAmericanpublic.
Theissuesoonbecameexplosive.Disagreementsbetweenshalegasproponentsand opponentsattownhallsandothercivicmeetingsescalatedintovirulent,fierceargumentsfoughtmoreintenselythananythingontheworstrealityTVshows.Muchofthis dramawasdutifullyrecordedanddisseminatedbythenewsmedia,resultingindeep concernsamongthegeneralpublicaboutthesupposedrisksoffracking.Publicrelations peopleintheO&Gindustrygenerallyhandledtheseissuespoorly,whentheyresponded atall.Certainfracktivistsweremotivatedtofantheflamesofconcernbybookdealsand filmproductions.Somepoliticiansrespondedtotheworriedpublicbyimposingbanson frackinginplaceslikeNewJerseyandVermont,whichcostnothingbecausethereislittle ornoshalegasinthegeology.
NewYorkisastatethatdoeshaveshalegasresourcesinboththeMarcellusandUtica shales,andstrongdisagreementsoverfracking.Itbecametheepicenterformanyofthe mostcontentiousdebates.Thestatewasstronglydividedbetweenthosewhothought frackingwouldbeanunacceptablerisktotheenvironment,versusthosewhoconsidered shalegasdevelopmenttobeimportantforthedepressedNewYorkeconomy,especially upstate.
TheNewYorkStateDepartmentofEnvironmentalConservationcarriedoutan exhaustiveenvironmentalimpactstudyontheMarcellusShale,producingamassive, 1500-pageSupplementalGenericEnvironmentalImpactStatement(SGEIS)in2009that wasrevisedin2011inresponsetothousandsofpubliccomments(NewYorkState DepartmentofEnvironmentalConservation,2011).Rigorousanalysespresentedinthe NewYorkSGEISdemonstratedthatnosignificantadverseimpactstoairorwaterresourceswerelikelytooccurfromprojectedMarcellusShaledevelopment.TheSGEIS alsoprovideddetailedrecommendationsformitigationmeasuresthatcouldbeimplementedtoavoidanypotentialproblems.
Despitethefindingsofhisownenvironmentalagency,thegovernorofNewYork imposedabanonfrackingshalegaswellsin2014,citingunacceptableenvironmental risk(Kaplan,2014).Ithasbeenestimatedthattheultimatecostofthisbantothestate willbe$1.4billioninlosttaxrevenuesandupto90,000directandindirectjobs (Considineetal.,2011).
FrackinghasalsobeenbannedinMarylandandintheCanadianprovinceofQuebec, bothofwhichhavesomesmallshalegasresources,andbanshavebeendiscussedbut notimplementedinColoradoandCalifornia.TheNewYorkbantaughttheO&Gindustrythatproperlyaddressingenvironmentalconcernsupfrontisnecessaryfor communitiestobeabletoweightherisksandbenefitsofgrantinga“sociallicense”for thedevelopmentofshalegasandotherresources.
Researchoverthepastdecadehasreducedtheuncertaintiesbehindmanyofthe concerns,showingforexamplethathydraulicfracturesdonotextendupwardhigh enoughtocontaminateshallowaquifersfrombelow,andthat99.5%ofshalewellsare typicallycompletedwithoutanyreportableenvironmentalincidents(Soederetal., 2014).Theshrillnessofthedebatehasbackedoffsomewhatinrecentyearsbutmany hardfeelingsstillremain.
In2010,theUSCongressaskedtheEnvironmentalProtectionAgency(EPA)to investigatetherisksthathydraulicfracturingmightposetoundergroundsourcesof drinkingwater.Theagencyheldaseriesofworkshopstogatherexpertopinions,ran severalretrospectivefieldstudies,andsynthesizedtheresultsina1000-pagefinalreport (U.S.EnvironmentalProtectionAgency,2015).Thereportconcludedthatwhilethere wereoccasionalaquifercontaminationincidentsfromsurfacespills,nosystemic contaminationofdrinkingwateraquifersfromshalegasdevelopmentorfrackinghad beenfound.ManyfracktivistsfoundtheseresultstobedisappointingandtheEPA ScienceAdvisoryBoardcriticizedthereportforreachingsuchbroad,sweepingconclusionsbasedonminimaldata.Thereportwasrevisedwiththeconclusionstoneddownsomewhat,butthebasicfindingsremainthesame.
Thisdiscussionisnotmeanttoimplythattherearenoenvironmentalrisks.Stray gasandsurfacespillsofchemicalscancontaminatestreamsandgroundwater, methaneleaksandparticulatesmaypollutetheair,andwellpadsandroadsoften affectbothterrestrialandaquaticecosystems(Soederetal.,2014).Moredetailsabout thepotentialenvironmentalimpactsofshalegasdevelopmentwillbeexploredinlater chaptersofthisbook.
Sowhataretheoriginsoftheshalerevolution?Inlessthanadecade,O&Gproduction intheUnitedStateswentfromlargelyconventionalonshoreandoffshoreresourcesto beingdominatedby“unconventional”shalegasandtightoil.Tosome,itfeltlikeabolt fromtheblue.Inreality,ittooknearly3decadesofhardworkandmanyfailuresto developandapplythepropertechnologytoeconomicallyproducetheseresources (Soeder,2018).
ThefirstcommercialAmericangaswellwashand-duginFredonia,NewYorktoa depthofabout10m(28ft)intotheUpperDevonianDunkirkShalebyanentrepreneur
namedWilliamHartin1821tosupplyfuelforagristmill,atavern,andthevillagestreet lighting(Curtis,2002).Hartreportedlyinvertedhiswife’swashtuboverthetopofthe openholetocreateaprimitivewellheadofsortstocontainthegas.Small-scalegas productionfromsimilarDevonianShaleunitsalongthesouthshoreofLakeErie continuedthroughoutthe19thandearly20thcenturies,asdidthelimitedexplorationof shaleselsewhere.Thenotionthatorganic-richor“black”shalesmaycontainnaturalgas hasbeenunderstoodhistorically.
Themoderndevelopmentofshalegasasasignificantdomesticenergyresourcecan betracedtotheaftermathoftheso-called“energycrisis”intheUnitedStatesduring the1970s.This“crisis”wasactuallytwoseparateevents.Thefirstresultedfroma MiddleEastwarinOctober1973betweena numberofArabcountriesandIsrael. BecausetheUnitedStateswassupportingIsrael,oilministersfromtheOrganizationof PetroleumExportingCountries(OPEC)led byLibyaimposedanembargoonAmerican oildeliveriesthatlasteduntilthespringof1974(Yergin,1991 ).Atthetime,significantly lessthanhalfoftheoilusedintheUnitedStateswasimported,buttheactionstill resultedinafour-foldincreaseingasoline prices,severeshortages,consumerpanic, andlonglinesatservicestationswhenfue lwasavailable.Asecondoilshockfollowed laterinthedecadewhenIranianexportswerebrieflydisruptedduringtheIslamic revolutionof1979.Theseenergyshortageswereunexpectedandprofoundlyshocking atthetime,significantlyinfluencingtheUSforeignpolicyfordecadestocome (Yergin,1991).
In1975,soonaftertheOPECembargo,theUSEnergyResearchandDevelopment Administration(ERDA)beganaprojecttoassessthenaturalgasresourcepotentialof Devonian-ageblackshalesintheAppalachianbasinaswellassimilarrockunitsinthe adjacentMichiganandIllinoisbasins(Soeder,2012).ERDAwasincorporatedintotheUS DepartmentofEnergy(DOE)whenitwascreatedbytheCarterAdministrationin1977 andtheinvestigationbecameknownastheEasternGasShalesProject(EGSP).Theproject consistedofthreemajoreffortsunderDOE:1)resourcecharacterization,2)development ofproductiontechnology,and3)thetransferofthattechnologytoindustry(Cobband Wilhelm,1982).Cooperativeagreementswithoperatorswereusedtoobtaindrillcores fromtheDevonianShalestratigraphicsectionintheAppalachianbasinrangingfromthe MiddleDevonianMarcellusShaletotheUpperDevonianClevelandMemberoftheOhio Shale.ThecoreswerealsocollectedfromtheUpperDevonianAntrimShaleinthe Michiganbasinandthesimilar-ageNewAlbanyShaleintheIllinoisbasinproviding samplesfromatotalof44wellsfortheproject(Bolyard,1981).Thecoreswerecharacterizedforlithology,frequencyandorientationofnaturalfractures,colorandotherunusualfeatures,thenphotographedandscannedforgammaradiationreadings.Rock samplesandsubcoreswerecollectedforthevarioustestinglabs,governmentagencies, anduniversitiesthathadrequestedthem.Thedrillcoreswereeventuallytransferredtothe stategeologicalsurveyinthestatewhereeachhadbeenobtained.
Innovativewellloggingtechniques,directionaldrillingtechniques,assessmentsof reservoiranisotropy,newhydraulicfracturingprocesses,andothercutting-edge
technologiesweretriedoutongasshalesduringthecourseoftheEGSP.Oneofthefirst experimentalhorizontaltestwellsinagasshalewasdrilledbytheEGSPinDecember 1986(Dudaetal.,1991).LaboratorymeasurementsonEGSPcoresfoundthatthe MarcellusShalecontainedalargercomponentofadsorbedgasthanpreviouslythought, implyingthatthegas-in-placeresourcewasmoresignificantthantheassessedvalues acceptedatthetime(Soeder,1988).Amajorthrustofthefield-basedengineeringexperimentswasanattempttocreateanetworkofhigh-permeabilityflowpathsinthe shalebylinkingtogetherexistingnaturalfracturesusingavarietyofstandardandnovel hydraulicfracturingtechniques(Horton,1981).Manyoftheresultswerehit-or-miss, andthebasicproblemdiscoveredmuchlaterwasthatverticalboreholesthroughshale simplydonotcomeintocontactwithenoughrock.
Transferoftheseandothertechnologiestoindustrywasaccomplishedbyperiodic workshopsjointlysponsoredbyDOEandtheSocietyofPetroleumEngineers(SPE).The EGSPresearchprovedtobeextremelyvaluabledecadeslaterinassistingtheO&Gindustrywiththecommercialdevelopmentofshalegas,andthemodestDOE/SPEtechnologytransferworkshopshavesinceevolvedintothegiant,annualUnconventional ResourcesTechnologyConference,orURTeC.Theterm“unconventional”isdefinedby DOEasaresourcethatrequiressomeformofengineeringtreatmentlikefrackingtobe economicallyproductive(Soeder,2017).Incontrast,“conventional”O&Gresourcescan usuallybeproduceddirectlywithsimplewellcompletions.
Creditfortheactual,successfulapplicationofnewtechnologytothecommercial developmentofshalegasgoestothelateGeorgeP.Mitchell,cofounderwithhisbrother JohnnyofTexas-basedMitchellEnergy(Soeder,2017).Mitchellhadbeeninvolvedwith shalegassincetheearlydaysoftheEGSP,drillingseveralAppalachianbasinshalewells incooperationwithDOE(CobbandWilhelm,1982)andmaintaininganongoinginterest inproducinggasfromtheBarnettShaleintheBendArch FortWorthbasinofTexas (HickeyandHenk,2007).GeorgeMitchelltriednumerousexperimentaldrillingtechniquesandreservoirstimulationproceduresintheBarnettoveraperiodof18yearswith manytechnicalfailuresandafewtechnicalsuccessesthatweresimplynoteconomical (Montgomeryetal.,2005).
MitchelleventuallydiscoveredthattheproductionofeconomicalquantitiesofnaturalgasfromtheBarnettShalerequiredtheapplicationoftwokeytechnologies:1)long, horizontalboreholesor“laterals”thatmaintainedkilometersofcontactwiththetarget formationand2)theuseofa“slickwater”hydraulicfracturingformulationthatconsistedofmostlywaterwithafrictionreduceradded,verylittlesandforproppant,and avoidedthethickgelsandgumsusedinconventionalfracking(e.g., Moritis,2004; Mason,2006;Pickett,2008).Mitchellfoundthatunlikeverticalboreholes,whereasingle frackwillpropagateoutwardintwovertical“wings”alongthedirectionofleastprincipal stress,lateralboreholescouldsupportmultiplefracksperformedinstagesatevenlyspacedintervals.Horizontalwellsalsocanbedrilledindirectionsthatcrossmultiple setsofnaturalfractures,whichtendtobeorientedverticallyandaredifficulttocapture inaverticalborehole(Hilletal.,1993).
Thus,thetwotechnologiesthatmadeshalegasandtightoilsuccessfulashydrocarbonresourcesintheUnitedStatesweredirectionaldrillingandstagedslickwater hydraulicfracturing.Applicationofthesefinallyallowedhigh-permeabilityflowpaths intoashalegaswelltomakecontactwithasufficientvolumeofrocktoproduce economicalamountsofgasoroil(Fig.I.3).Itisimportanttonotethatneitherofthese technologieswasactuallyinventedbyGeorgeMitchell;hisgeniuswasinapplying existingtechnologytotheBarnettShaleandachievingsuccess.
FIGUREI.3 Illustrationofthecombinationofhorizontaldrillingandstagedhydraulicfracturingtechnologyused forshalegas.Nottoscale. ModifiedfromSoeder,D.J.,Kappel,W.M.,2009.WaterResourcesandNaturalGas ProductionfromtheMarcellusShale,U.S.GeologicalSurveyFactSheet2009 3032,6p.
Directionaldrillinghadbeeninventedinthe1930swiththeintroductionofa flexiblelengthofdrillpipecalleda“whipstock”thatwasdesignedtopreventthedrill stringfromshearingoffasitwentthrough abend.However,turningtheentiredrill stringfromthesurfaceandsteeringthebitthroughcurvesoftenresultedindeviated boreholesorbrokendrillpipeevenwhenawhi pstockwasused.Downholenavigational apparatuswithacompassandgyroscopewas alsoquiteprimitive,commonlyleaving drillerswithnopreciseideaaboutwherethebottomoftheholewaslocated (Mantle,2014).
Technologicaladvancesindirectionaldrillingcameaboutinthe1990s,drivenby venturesintoincreasinglydeeperwaterbythemajoroilcompaniesinvolvedinoffshore oilproduction(Soeder,2018).Semi-submersible,tension-legdrillingplatformsanchored inseveralkilometersofwaterarerisky,expensive,andtime-consumingtomovearound fromprospecttoprospect.Therewasadesiretoreachmultiplereservoircompartments incomplexstructureslikesaltdomesinextremelydeepwaterwithouthavingtomove theplatform(Crombetal.,2000).Themajorsputsignificantfundingandresearch
resourcesintodevelopingadvanceddirectionaldrillingtechnologythatwouldallow multiplewellstobeinstalledfromasinglelocation.Tension-legplatformsarecurrently abletodrilldozensofwellswithoutmoving.
Directionaldrillingimprovementsincludedadownholehydraulicmotorandbottomholeassemblythatgreatlyimprovedsteeringandnavigationofthedrillbit.Without havingtoturntheentiredrillstringfromthesurface,thedrillpipewasmuchmore flexibleandcouldturntightercorners.Someadvancedbottomholeassemblieshave thrustbearingsthatprovideprecisedirectionalcontrol.Improvementsindownhole positionmeasurementbasedoninertialnavigationandreal-timetelemetryofdataback tothesurfacenowallowtheuseof“geosteering”topreciselyplaceandaccurately monitorthedownholelocationofthedrillbitandtheconfigurationoftheborehole (Mantle,2014).
GeorgeMitchellremainedconvincedthattheBarnettShalehadhydrocarbonpotential(Kinleyetal.,2008)andadaptedthedirectionaldrillingandstagedhydraulic fracturingtechnologytoshalethroughaseriesoffieldexperimentsinTexasuntil eventuallyfindingacombinationthatwaseffectiveontheBarnettatalowercostthan otherapproaches.Anincreaseingaspricesinthemid-1990simprovedtheeconomics. By1997,MitchellEnergyhadperfectedtheslickwaterfracktechniqueinverticalBarnett wellsandstartedtryingitinhorizontalwells.ThecompanybegansuccessfullyproducingcommercialamountsofgasfromtheBarnettShaleinthelate-1990s,using horizontalboreholesandstagedhydraulicfracturing,andstartedthemodernshalegas revolution(Martineau,2007).
MitchellEnergywasacquiredin2002byDevonEnergyfor$3.1billion(Sideland Cummins,2001).GeorgeP.MitchellreceivedaLifetimeAchievementAwardfromthe GasTechnologyInstituteonJune16,2010forhispersistenceindevelopingshalegasinto aneconomicresource.HediedonJuly26,2013attheageof94.
LikeHollywoodmoviesequels,theO&Gindustryiswell-knownforcopyingsuccess. SouthwesternEnergynoticedthattheFayettevilleShaleinnorthernArkansaspossessed manyofthecharacteristicsoftheBarnettandquietlyboughtupleases.By2004,they hadadaptedtheMitchelltechniquesforFayettevilleproduction.ChesapeakeEnergy followedontheHaynesvilleShaleintheArkansas Louisiana Texasborderregion.In 2006,EOGandContinentalResourceshadbothbegunusinghorizontaldrillingand stagedfrackingtosuccessfullyproducetightoilfromtheBakkenShaleintheWilliston basininMontanaandexpandeditintotheParshallfieldofNorthDakotaafewyears later.AfterstrugglingtoadapttheMitchelltechniquestotheAppalachianbasin,Range ResourcessuccessfullybroughttheirGulla#9horizontalMarcelluswellonlinein2007at aninitialproduction(IP)rateof4.9millioncubicfeetofgasperday(MMCFD),asocalled“barn-burner”previouslyunheardofinAppalachianbasinshales(Soeder,2017).
Shalegasdevelopersbecamevictimsoftheirownsuccess,withtheproliferationof gaswellsdrivingdownprices.Operatorsbegantomoveawayfrom“drygas”andfocus insteadonresourcescontainingnaturalgasliquids(NGL)or“condensate”andoil.NGLs typicallyexistinavaporphaseunderdownholepressuresandtemperaturesandcanbe
producedasavaporwiththenaturalgas.Thecompoundsthencondenseintoliquids likepropane,butane,andethaneundercoolerconditionsandlowerpressuresatthe surface(Soeder,2017).NGLaresignificantlymorevaluablethandrygasandfetcha correspondinglyhigherprice.In2008,PetrohawkEnergybegandevelopmentofthe liquids-richEagleFordShaleinTexas,andafewyearslaterAnadarkoPetroleumand WhitingPetroleumbeganproducingcondensatefromtheNiobraraFormationinthe Denver JulesburgbasinofColorado.TheUticaShale,alsoknownasthePointPleasant FormationinOhio,isanotherlarge,liquids-richshaleplaydevelopedbymultipleoperatorsbeginningin2011(Hohnetal.,2015).Themostsignificanthydrocarbonproductionofalliscomingfromastackofsixunconventionalformationsbeingdeveloped inthePermianBasinofTexas,whichareproducingoil,NGL,andgas(USEIA,2018). Cumulativeproductionnumbersin2016(themostrecentdata)publishedbytheEIAfor tightoilplayswere864millionbarrelsfromTexas(PermianBasinandEagleFord),375 millionbarrelsfromNorthDakota(Bakken),and27millionbarrelsfromOklahoma (Woodford).
PotentialfutureshaledevelopmentmayincludetheRogersvilleShaledeepinthe AppalachianbasintheMontereyShaleinmultiplesmallbasinsinCalifornia,andeven someofthethick,organic-richshalesfillinganumberofTriassic-ageriftbasinsalong theUSeasternseaboard(Milicietal.,2012).Otherfuturedevelopmentmayincludetight limestonessuchastheMississippiLimeinOklahomaortheTuscaloosaTrendin MississippiandLouisiana.
Thisbookisintendedtoserveasareferenceandresourceonshalegasandtightoil forabroadspectrumofO&Gindustrypersonnel,undergraduateandgraduatestudents, engineers,geoscientists,andothers.Unconventionaloilandgasisauniquetypeof petroleumextraction,requiringcomplexengineeringforsuccessfulproduction.Itplays asingularroleinboththeUnitedStatesandworldeconomy.Eachmajorshaleformation isuniqueintermsofthetechnologyneededtoproduceitandtheregulatoryandeconomicforcesgoverningitsdevelopment.Wehaveattemptedtoprovideexplanationsof thehistoryandthephysicsofshalegasproduction,alongwithdescriptionsanddefinitionsforeachofthemajorshaleplays.Shalegasandtightoilresourcesinothernationsarealsoaddressed,alongwithdiscussionsaboutenvironmentalconcerns, economics,energysecurity,energypolicy,andfossilfuelsustainability.
Somereadersmayfeelweareoverstatingtheimportanceofshalegasandtightoilto theenergyeconomyoftheworld,andthatperhapswearenotjustifiedincallingita fossilfuel“revolution.”Inresponse,wesummarizethefollowinginformationgleaned fromtheU.S.EIA:Shaleresourcesbegansignificantdevelopmentintheearlyyearsof the21stcentury,andunconventionalhydrocarbonshaveincreasednaturalgasand petroleumproductionintheUnitedStatesbynearly60%since2008.TheUnitedStates surpassedRussiain2009asthetopproducerofnaturalgasintheworldandexceeded SaudiArabiaasthetopoilproducerin2013(Fig.I.4).ShalehastakentheUnitedStates fromadependenceonenergyimportstobecomingthelargestfossilenergyproducerin theworld.Ifarevolutionisdefinedasacompleteparadigmshift,thisqualifies.
FIGUREI.4 Trendsinworldoilandgasproductionbytopproducers. ReproducedfromU.S.EnergyInformation Administrationwebpage(https://www.eia.gov/todayinenergy/detail.php?id¼36292)datedMay21,2018.
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