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LinkingDesalinizationTechnologiestoGeothermalGreenhouseOperations

StudentsandFacultyExploreMasonRadiumSpringsGeothermalGreenhouse(20Acres)LeadInvestigator:MarkPerson,NMTech,HydrologyProgram,markaustinperson@gmail.comCo-Investigators:RobertBalch&JianjiaYu,NewMexicoPetroleumResearch&RecoveryCenter,balch@prrc.nmt.eduyu@nmt.eduRandyShaw,BureauofReclamation,BrackishGroundwaterNationalDesalinationResearchFacility,Alamogordo,NM,rshaw@usbr.govFrankHuang,NMTech,DepartmentofCivil&EnvironmentalEngineering,huang@nmt.eduShariKelley,NMBureauofGeology&MineralResources,sakelley@nmbg.nmt.eduJamesWitcher,JamesWitcher&Associates,jimwitcher@zianet.comLauraCrossey&KarlKarlstrom,UNM,DepartmentofEarthandPlanetarySciences,lcrossey@unm.edukek1@unm.eduQiangWei,NMHighlandsUniversity,ChemistryDepartment,qwei@nmhu.eduJesusGomez-Velez,NMTech,HydrologyProgram,jdgomez@nmt.eduIWGDate:November6-8,2015IWGLocations:TruthorConsequences,NM&MassonRadiumSpringsGreenhouse

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1.SUMMARY1.1 ObjectivesOurinnovativeworkinggroup(IWG)exploredthepotentiallinkagesandsynergiesbetweendifferentdesalinationtechnologiesanddirectuseofgeothermalwatersforandaquacultureoperationsinNewMexico.Applicationstobio-algalindustrywerealsodiscussed.Inaddition,weconsideredhowgeothermalheatcouldbeusedtoincreasetheeffectivenessandreducethecostofdesalinationofoilfieldbrines.Wediscussedopportunitiestocrafttheseideasintoupcomingwater-energyproposalsandpapers.1.2 KeyIdeas&QuestionsLinkinggeothermalanddesalinationtechnologieshasnotreceivedmuchattentiontodate;however,suchsynergycanhavesignificantenvironmentalandeconomicbenefitsbothlocallyandglobally.Weareonlyawareofonestudythatusesdesalination(ofseawater)toprovidewatertogreenhouses.Thatstudydidnotusegeothermalenergy(Mahmoudietal.2010).SeveralimportantquestionswereoutlinedatourIWGthatneedtobeaddressedbyfuturestudies/proposals:Whatwouldbethelong-termhydrologic/thermalimpactsofdesalinatingproducedgeothermalfluidsand/oroilfieldbrines?Dothelong-termimpactsaffectlargeregional-scaletopographicallydrivengeothermalsystems?WhatisthedistributionofbrackishwaterthroughoutthestateofNMandinaridregionsaroundtheworld?Howdoesbrackishwatervolumecomparetofreshwaterresources?Aretheproducedwatertemperaturesandvolumessufficienttoprovidetheenergyneededtoenhancedesalinizationprocesses?Howcouldthemembranesusedforgeothermaldistillationbemodifiedtominimizethethermalleakageandatthesametime,maximizethewaterflux?Aredifferentgeothermalfluidcompositionsandproducedwatersalinitiesbettersuitedfordifferentagricultural,bio-algal,andindustrialapplications?Cangeophysicaltechniques(e.g.TEM-MTsystems)beusedtoquantifybrackishwaterresourcesandidentifyoptimaldrillingtargets?Whatregulatoryhurdleswouldfaceusingdesalinatedfluidsingreenhouseandoilfieldoperations?Threetransformativeideaslinkingdesalinationandgeothermaltechnologieswerediscussedduringourweekendmeetingandaredescribedbelow.FollowingourIWGmeeting,wedevelopedadocumentthatfleshedoutsomeoftheideasandquestionsinitiallydiscussedatourmeeting.Thematerialexceededthepage-limitrequirementsofthissummarydocument.Wehaveincludedthismaterialinanappendix.Idea1:ReducingtheRiskofThermalBreakthroughinDirectUseGeothermalOperationusingDesalinationTechnologies.Re-injectionoflargevolumesofspent,coolgeothermalfluidsbackintoageothermalreservoiraftertheheatisextractedcandegradeathermalresourcethroughtime(Stefansson,1997;Shook,2001).InNewMexico,thermalcoolingofthefractureddikegeothermalreservoiratRadiumSpringswasinitiallydetectedattheMassonFarmsgeothermalgreenhouse.Thisrequireddrillingamuchdeepergeothermalwelltodealwiththisproblem.Desalinationofbrackishgeothermalfluidscouldbeusedforgreenhouseirrigation,reducethevolume

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ofre-injectedwater,andhelptomaintainreservoirtemperatures.Wedevelopedsomebackoftheenvelopecalculationstosubstantiatethisidea(seeAppendix,p.13-14).Possibledegradationofreservoirchemistryandpermeabilityresultingfrominjectionofconcentratedfluidsafterdesalinizationwerealsodiscussed.Idea2:UsingMembraneTechnologieswithLowerEnergyFootprintsforDesalinationofGeothermalFluids.Forwardosmosisandmembranedistillation(MD)aredesalinationtechnologieswithpotentiallylowerenergyfootprintsthanreverseosmosis(RO).Membranedistillationisparticularlyattractivebecausegeothermalfluidscouldbeusedasanenergysource.MDhasmanyadvantagescomparedwithotherseparationmethods.MDhastheoreticallycompleterejectionofinorganiccompounds.Thistypeofsystemcanbeoperatedatlowertemperaturesthanotherseparationprocesses,andisthereforeabletoutilizewasteheat,geothermalheat,andsolarheat.MDisalsorelativelylesssensitivetomembranefoulingandfeedsalinityandisthereforeabletotreathigh-salinitybrackishwaters(Adham,2013;HickenbottomandCath,2014).Reducingthethermalleakagenotonlycanincreasethewaterfluxbymaximizingthetemperaturegradientbutalsowouldenhancetheenergyefficiencyoftheprocess,allowingthepossibleutilizationoflow-gradeheatfromgeothermalfluids.Idea3:UsingGeothermalHeattoDriveDesalinationOperationsinOilProducingBasins.Desalinationoilfieldbrinesusinghumidification-dehumidificationtechnologiesrequiresasourceofheattoenhancetheamountofwaterthatcanbetransferredtothevaporphase.Ahumidification-dehumidificationsystemdeployedinthePermianBasinbyDr.Balchusedsolar-thermalmethodstoheatthewater(BalchandMuraleedharan,2014).Weproposethatusingtheheatfromtheproducedfluidscanalsobeusedtodrivethisoperation(ormakethesystemsmoreefficientwhencombinedwithsolarthermalsystems).Thissystemproducesfreshwateratarateofabout0.25gpm.Itcanbescaleduptotreatlargervolumesofwater.

1.3 OutreachPlansWeputtogetheraonepageideasdocument,whichwepresentedtoAnneJakleandWilliamMicheneratarecenttownhallmeetingatNMTechonNov.20th.Wewillalsoworkonaneditorialstylemanuscriptexploringthesynergiesbetweendesalinationofbrackishwaterandthedirectusegeothermalindustry.2.Outcomes2.1ProposalsEPSCoRTrack-1EnergyCenterProposal:WeplantoadvocatetotheNMEPSCoRprogramthebenefitsofexploringthelinkagesbetweengeothermalenergyanddesalinationtechnologiesinNewMexico.WewillcraftawhitepaperonthistopicinpreparationfortheTrack-1Energycenterproposalthisspring.WehavecontactedDaveHansonatUNMregardingpossiblesynergiesintegratingtheseconceptswiththoseofthebio-algalgroupforthiswhitepaper.

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USBureauofReclamationDesalinationProgramProposal,$150,000forresearchandlaboratorystudies.DeadlineisFeb.8,2016.ShariKelley,MarkPerson,TalonNewton,andStacyTimmonswillworkonthisproposal.http://www.usbr.gov/newsroom/newsrelease/detail.cfm?RecordID=51727NSFFood,EnergyandWaterSystems(INFEWS)NSFhasrecentlyannouncedanewprogramentitled“InnovationsattheNexusofFood,EnergyandWaterSystemstofindsustainablewaystomanagethefood-water-energysystem.WewillexplorethepossibilityofsubmittingaproposalonthistopicwhenanappropriateRFPappears.http://www.nsf.gov/pubs/2015/nsf15108/nsf15108.jspDOEWaterEnergyNexus:Whenappropriate,wewillsubmitgrantstotheDOEontheupcomingwaterenergynexusprogram.http://energy.gov/downloads/water-energy-nexus-challenges-and-opportunities2.2PapersMarkPersonalongwithhisstudentsandcollaboratorshasbeguntoexploretheconsequencesofreducedvolumesofoil-fieldbrinereinjection(duetodesalination)oninducedseismicityaspartofamanuscripttobesubmittedtoathematicissueentitled“RoleofPorePressureinNaturally-TriggeredandHuman-InducedSeismicity”forthejournalGeofluids.TheguesteditorsforthisthematicissuearePaulHsieh,JohnBredehoeft,andKatieKeranen.Thismanuscriptisentitled,“ExploringthePotentialLinkagesBetweenOil-FieldBrineReinjection,CrystallineBasementPermeability,andTriggeredSeismicityfortheDaggerDrawOilField,SoutheasternNewMexico,USAUsingHydrologicModeling”.Themanuscriptisavailableondemand.JimWitcher,MarkPerson,andShariKelleywillworkonaneditorialformatpaperexploringthebenefitsofdirectusegeothermalforthejournalEOSTransactions.ThismanuscriptwillpromotethedirectuseindustriesthatareinNewMexicoanddiscussthepotentialbenefits,amongotherthings,ofdesalinationtechnologies.3.ParticipantsRobertBalch,SeniorScientistandSectionHead,PetroleumResearchandRecoveryCenter,NMT.Humidification-DehumidificationDesalinationTechnologies.WithsupportfromRPSEA,BalchbuiltandtestedapilotHumidification-DehumidificationDesalinationfacilitywithinthePermianBasin,SENMincollaborationwithHarvardPetroleum.LauraCrossey,Professoranddepartmenthead,UNM,DepartmentofEarth&PlanetaryScience.CrosseyfocusesonusingnoblegasgeochemistrytoinferthepresencesofmagmaticgeothermalsystemsacrosstheBasinandRange.Sheandherpartner,KarlKarlstromhavepromotedtheideaof“continentalsmokers”.

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FrankHuang,ProfessorofCivilandEnvironmentalEngineering,NMT,Huanghasdevelopedafabricationlaboratorydevelopingmembranesfordesalinationprocesses.Hisresearchfocushasbeenonosmoticpowergeneration.JesusGomez-Velez,AssistantProfessorofHydrology,NMtech.Jesus’researchfocusesontheanalyticalandnumericalmodelingofflowandtransportinhydrogeologicsystems.Heisanearly-careerfacultyintheDepartmentofEarth&EnvironmentalSciencesatNMTech.KarlKarlstrom,Geology,DepartmentofEarth&PlanetaryScience.Karlstrom’sresearchfocusesonregionalcontinentaltectonicsandusingnoblegasgeochemistrytoinferthepresencesofmagmaticgeothermalsystemsacrosstheBasinandRange.ShariKelley,ResearchScientist,NMBureauofGeology&MineralResources.HeatflowgeophysicistworkingonNewMexicogeothermalresources.Kelleywasaco-PIonseveralgeothermalexplorationgrantsinthelastfiveyearsfundedbytheDepartmentofEnergy.MarkPerson,ProfessorandHeadofHydrologyProgram,NMTech.PersonusesmathematicalmodelingtounderstandtheplumbingofgeothermalsystemsacrossthewesternUSA.PersonwasaPIandco-PIonseveralgeothermalexplorationgrantsinthelastfiveyearsfundedbytheDepartmentofEnergy.RandyShaw,FacilityManageroftheBrackishGroundwaterNationalDesalinationResearchFacility,Alamogordo,NM;ManagestheBrackishGroundwaterNationalDesalinationResearchFacilityoftheBureauofReclamationinAlamogordoNM.ProvidedanoverviewoftheBureauofReclamationresearchprogramandfacilities. QiangWei,NMHighlandsUniversity,DepartmentofChemistry,ResearchScientist,.Wei’sresearchfocusesonmembranefabricationtechnologies.JamesWitcher,JamesWitcher&Associates.GeothermalIndustryConsultant.WitcherhasauthorednumerouspapersonNMgeothermalsystem.HeiswidelyseenasoneoftheleadingadvocatesintheUSAfordirectusegeothermalenergy. JianjiaYu,SectionHead,ProducedWaterandPetroleumEngineering.PetroleumResearchandRecoveryCenter,NMTFabricationofhollowfibermembranetechnologiesforwaterusereductionbypetroleumindustry.

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AppendixInnovativeWorkingGroupOnNovember6-8,ourteammetaspartofanNSF-EPSCoRsponsoredinnovativeworkinggroup(IWG)inthespatownofTruthorConsequences,NMtoconsiderthesynergiesbetweengeothermalanddesalinationtechnologies.Themeetingbroughttogetherexpertsindesalinationtechnologies(Balch,Huang,Wei,Yu,Shaw)withgeothermalscientists(Kelley,Witcher,Person,Crossey,Karlstrom).EachparticipantpresentedtheirworkongeothermalanddesalinationscienceonSaturday(Table1).OnSundaywevisitedMasonRadiumSpringsgreenhouse.JimWitcherwasourtourguide(Fig.1-2).Table1.Presentations

Saturday,Nov7,TorC,CityCommissionChambers,405West3rdSt.TruthorConsequencesNM

StartTime Title Speaker

10.00Welcome&IntroductiontoIWGExploringtheSynergiesbetweenGeothermal&Desalination MarkPerson(NMT)

10.30NewMexicoGeothermalResources,Potential,andUses.

JimWitcher(Consultant)

11.30 Overview:BureauofReclamationDesalinationCenter RandalShaw12.00 Lunch&Discussions

1.00 GeothermalResourcesoftheRatonBasin

Shari&RichardKelley(NMBRMR-LANL)

1.30GeochemicalCharacteristicsofGeothermalFluidsinNM

LauraCrosseyKarlKarlstrom(UNM)

2.00 NSF-EPSCOROsmoticPowerGenerationProgram

FrankHuang(NMT),QiangWei(ENMU)

2.30 DesalusingHumidification-DehumidificationProcessesRobertBalch(PRRC)

3.00DeepGeothermalSystemswithintheBasin&Range:MTdataandnumericalmodeling

JesusGomez-Velez(NMT)

3.30HollowFiberMembranebasedTechnologyforProducedWaterRemediation JianjiaYu(PRRC)

4.00 Discussion&WritingAssignments 5.00 Break 6.30 DinnerBellaLuca

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Sunday,Nov8,TorC,CityCommissionChambers,405West3rdSt.TruthorConsequencesNM

8.00 Discussion&FutureWork 10.15 DepartforMasonGeothermalGreenhouse 3.00 HeadforHome GeothermalResourcesinNewMexicoNewMexicoisranked7thintheUSAforitsknowngeothermalresourcepotential(Williamsetal.2008).TheStateofNewMexicoisendowedwithrelativelyhighbackgroundheatflow(Royetal.1972)andpermeable,fracturedbedrock(Maillouxetal.1999,Pepinetal.2015).Thiscombinationhasgivenrisetonumerouslow-temperaturegeothermalsystemsthroughoutthestate(Summers,1976;SummersandColpitts,1980;BarrollandReiter,1990;Witcher,2002a-h).Thesegeothermalresourcesarepartofconvectivesystems(SmithandChapman,1983)withhotwaterdischargeoccurringinthelowlandportionofwatershedsthroughhydrologicwindows.Maillouxetal.(1999)andPepinetal.(2015)arguethattheseconvectivesystemshaverelativelyvigorousfluidcirculationtodepthsof4-8km.NewMexicogeothermalfluidsarebrackish(500to5000mg/l)withtemperaturesthatrangebetween40-100oC(Figure3).ConductivegeothermalresourcesalsoexistwithinthestateofNewMexico,primarilywithintheoilandgasproducingRaton,PermianandSanJuanbasinsinNE,SEandNWNewMexico,respectively(darkbluepatternsinthelowerleftandupperrightandleftcornersofthestateofFigure4).Conductivegeothermalreservoirsareessentiallyoilreservoirsthatcontainhighheatduetotheirdepthofburialratherthanduetovigorousfluidcirculation.Salinitiesofconductiveresourcesaretypicallymuchhigher(upto200,000mg/l;Figure5)owingtotheirlongresidencetimeandfluidrockinteractionswithevaporiteminerals.Thetemperatureoftheseconductivegeothermalfluidsrangesbetween30to75oC(Figure5).Overthepastseveraldecades,geothermalgreenhouses(e.g.BurgettGreenhouse,Lordsburg,NM;MassonFarmsGreenhouse,RadiumSprings,NM)andaquaculturefacilities(Americulture,Lordsburg,NM)wereestablishedinsouthernNewMexico.Geothermalagribusinessaccountsforover$12Mingrossreceipts(Witcher2002a).Inaridregionsoftheworld,growingcropswithingreenhousescanhavetheaddedbenefitofconsuminglesswaterrelativetoirrigatedcropsgrowingoutdoors(Orgazetal2005).AcrosstheUSA,directuseofgeothermalenergyhasgrownby72%between2005-2010toabout48,500MWt(Lund,2010).Geothermalgreenhousesareattractivetotheagriculturalindustrybecausetheyutilizelow-temperatures(40to80oC)fluids,whichareoftenabundantatshallowdepths(Lund,2010;Karytsasetal.2003).Theyalsoproducemanyjobsatavarietyofeducationallevelswhencomparedtoelectricalpowerplantsthatutilizegeothermalenergy.

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DesalinationTechnologiesintheWesternUSAInaridregionsoftheworld,desalinationofbrackishwaterisincreasinglyconsideredtobeanunconventionalwaterresource(JaberandMohsen,2001).Desalinationtechnologiesincludereverseosmosis(RO),forwardosmosis(FO),membranedistillation(MD),thermaldistillation(TH),anddehumidification-humidification(DH)techniques.Thermaldistillationtechniquesareenergyintensiveandhavenotbeenwidelydeployed.Reverseosmosismethodscreateapressuregradientacrossanosmoticmembranesufficienttoovercomethenaturalosmoticpressure(Shannonetal.2008).Thismethodisconsideredthemosteconomicwhenimplementedatthelargescale(thousandsofm3/day;Bourouniaetal.2001).State-of-the-artROfacilitiescanuseaslittleas2.2kWhtogenerateacubicmeteroffreshwaterfromseawater(Shannonetal.2008).Membranedistillation(MD)isaseparationprocessthatreliesonvaporpressuredifferencetodrivetheproductionofdistilledwateracrossthemembrane(Susanto,2011).TherehasbeengrowinginterestedinDHtechnologiesbecauseoftheireconomicbenefitswhendeployedatthesmallscale(Bourouniaetal.2001).Thismaybeideallysuitedforprocessingoilfieldbrines,asdescribedbelow.ROdesalinationfacilitiesrequiresignificantamountsofenergyandcapital.However,interestindesalinationtechnologiesisgrowingwithintheStateofNewMexicoduringthepastdecadeduetogrowingwatershortagesduringdroughtconditionsandtheperceivedabundanceofuntappeddeepbrackishwaterreservoirs.TheBureauofReclamationestablishedadesalinationresearchcenternearAlamogordo,NMtostimulatedesalinationresearchinNMandacrossthewesternUSA.InElPaso,TX,alargescaledesalinationfacilitywasconstructedthatiscapableofproducing27MGD.Thefacilityisbeingusedduringperiodsofdroughtorwatershortages.Relativelyshallow(>500m),brackishfluids(1000-5000mg/l)areproducedandtreatedusinghollowfibermembranetechnology.Withinthepetroleumindustry,thereisgreatinterestindesalinationofoilfieldbrinestotreatproducedwaterswithinoilbasins.Typically,co-producedwatersarehighlysaline(100,000-200,000mg/l),warm(40-80oC)andcontainorganiccompounds.Thesearetypicallyreinjectedintodeepsalineformations.Duetohightransportationcosts,reinjectionisrelativelyexpensive(typically~$2.5/barrel).Truckingoilfieldbrinesalsoaddsadditionalsocietalcostsduetoitsimpactoninfrastructure.Injectionofhighvolumesofproducedwaterhavebeenlinkedtoinducedseismicity(uptoM5.8)acrossthewesternUSA(Zhangetal.2013;Wiengartenetal.2015).Todate,thewasteheatfromtheseproducedfluidsaretypicallynotusedtodrivethedesalinationprocess.Thefluidsarestoredinseparationtankstoawaitreinjection.AssessingtheTemperatureandSalinityofNewMexico’sGeothermalSystemsandOilFieldBrinesAspartofthisIWG,wehavecompileddatasetsofthesalinityandtemperatureofgeothermalfluidsinNewMexico(Figure3)andoilfieldbrinesinthePermianBasinof

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southeasternNM(Figure5).Wenotethatalmostnothingisknownaboutthevolumeanddepthofnon-thermalbrackishwaterresourcesaroundthestateofNewMexicoandaridregionsoftheworld.Theelevatedtemperaturesofoilandgasfieldbrinescouldbeusedtoimprovetheefficiencyofdesalinationsystems(e.g.humidification-dehumidification).ThermalConsequencesofDesalinationRe-injectionoflargevolumesofspent,coolgeothermalfluidsbackintoageothermalreservoircandegradethethermalresourcethroughtime(Figure6).Agreatdealofworkhasbeendonetodetermineoptimalwelldistanceandre-injectionratesforfracturedbedrockreservoirstodelaythermalbreakthrough(Stefansson,1997;Shook,2001).InNewMexico,thermalcoolingofthefractureddikegeothermalreservoiratRadiumSpringswasinitiallydetectedattheMassonFarmsgeothermalgreenhouse.Thisrequireddrillingamuchdeepergeothermalwelltodealwiththisproblem.Theideaofdesalinationofbrackishgeothermalfluidsforirrigationtoreducethevolumeofre-injectedwaterandhelptomaintainreservoirtemperatureswasanimportantoutcomeofourIWGdiscussions.Considerthefollowingexample(seeTable2forfluidandrockproperties).A100m3fracturedrockreservoirhasaninitialenthalpy(totalheat)of1.98x1014Joules(J).Thisreservoirisfilledwithbrackish,geothermalfluids,hasporosityof5%,aninitialtemperatureof90oC,andafluiddensityof1010kg/m3.Theenthalpy(H)ofthegeothermalreservoirisgivenby:

whereHisthetotalenthalpyofthereservoir,ρfisthefluiddensity,ρristherockdensity,cfisthefluidspecificheatcapacity,cristherockspecificheatcapacity,φisporosity,VTisthetotalvolumeofthereservoir.Let’sassumethat10%ofthefluidsareproduced.Assumingnocoolingoftherockmass,ifthesefluidsarereinjectedatalowertemperatureof50oC,thenthetotalenthalpyofthefluiddecreasesfrom1.9x1013Jto1.69x1013Jresultinginachangingintotalenthalpyofabout0.9%.If,ontheotherhand,4500m3offreshwaterisproducedforirrigationand500m3ofbrineisreinjectedatalowertemperatureof20oC,thenthefluidenthalpyofthereservoirafterreinjectionishigher(1.88x1013)owingtothe90%decreaseinthevolumeofthefluidreinjected(albeitatalowertemperatureandenthalpy).Thetotalchangeinsystementhalpyis0.1%forthisscenario.

H = φcfρ fVT + (1−φ)crρrVT =1.9x1013J +1.78x1014 J =1.98x1014 J

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Table2.FluidandRockPropertiesofa100m3GeothermalReservoirPriortoandafterRe-Injection

50000 InitialReservoirFluidVolume(m3)4185 SpecificEnthalpyFluid(J/kg/oC)

90 InitialTemperatureofFluid(oC)1010 densityofreinjectedFluid(kg/m3)

1.90208E+13 TotalReservoirFluidEnthalpy(J)

950000 InitialReservoirRockVolume(m3)790 SpecificEnthalpyRock(J/kg/oC)

2650 DensityRock(kg/m3)90 InitialTemperatureofRock(oC)

1.78994E+14 RockEnthalpy(J)

5000 ReinjectedFluidVolume(m3)4185 SpecificEnthalpyReinjectedFluid(J/kg/oC)

50 TemperatureofReinjectedFluid(oC)1010 DensityofreinjectedFluid(kg/m3)

1.05671E+12 TotalReservoirFluidEnthalpy(J)

500 ReinjectedbrineVolume(m3)3500 SpecificEnthalpyReinjectedBrine(J/kg/oC)

20 TemperatureofReinjectedBrine(oC)1200 DensityofreinjectedBrine(kg/m3)

4.20E+10 TotalReservoirFluidEnthalpy(J)Thedesalinatedfluidscanbeputtobeneficialusewithinthegreenhouse,increasingthesustainabilityofthegeothermaloperationinaridregions.Producingdeepbrinesdoesnotcompetewithshallowwaterusers.However,theeffectsofpossiblepressuredropsandotherhydrologicimpactscausedbythere-injectionoflessfluidvolumeneedtobeassessed.Verylittleisknownaboutthelongtermconsequencesofproducing(i.e.,mining)brackishaquifers.Producinglargevolumesofwaterfromshallow,unconsolidatedformationscanleadtolandsubsidence(Gallowayetal.1999).Regulatoryquestionsabouttheconsumptiveuseoftheirrigationwaterderivedfromthegeothermalfluidneedtobeaddressed.UsingMembraneTechnologieswithLowerEnergyFootprintsforDesalinationofGeothermalFluidsForwardosmosisandmembranedistillationaredesalinationtechnologieswithpotentiallylowerenergyfootprintsthanRO.Membranedistillationisparticularlyattractivebecauseoflowerenergyconsumptionifgeothermalfluidsareusedasasourceofheat.MDhasmanyadvantagescomparedwithotherseparationmethods.MDhastheoreticallycompleterejectionofinorganiccompounds.Thistypeofsystemscan

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beoperatedatlowertemperaturesthanotherseparationprocesses,andisthereforeabletoutilizewasteheat,geothermalheat,andsolarheat.MDisalsorelativelylesssensitivetomembranefoulingandfeedsalinityandisthereforeabletotreathigh-salinitybrackishwaters(Adham,2013;HickenbottomandCath,2014).MDmembranesaretypicallymadefromhydrophobicpolymers,suchaspolypropylene(PP),polyvinylidenefluoride(PVDF),andpolytertafloroethylene(PTFE).Thehydrophobicmembraneactsasabarriertoholdtheliquid/vaporinterfacesattheentranceofthepores,whereonlyvaporisabletopassthroughthemembrane.Alotofresearchhasbeenfocusedontheimpactofcontactangle,porosity,poresize,pore-sizedistribution,andthicknessonthewaterflux.Forgeothermal-basedmembranedistillation,weareparticularlyinterestedinthemodificationsofMDmembranestominimizethermalleakagefrommembraneconduction.Forexample,PVDFmembranestypicallyhaveathermalconductivityof0.12W/m-Kandthistranslatestosignificantthermalleakage(loss)of390kWperm2ofmembraneforatemperaturegradientof50°Candamembranethicknessof100µm.Reducingthethermalleakagenotonlycanincreasethewaterfluxbymaximizingthetemperaturegradientbutalsowouldenhancetheenergyefficiencyoftheprocess,allowingthepossibleutilizationoflow-gradeheatfromgeothermalfluids.UsingGeothermalHeattoDriveDesalinationOperationsinOilProducingBasinsDesalinationoilfieldbrinesusinghumidification-dehumidificationtechnologiesrequiresasourceofheattoenhancetheamountofwaterthatcanbetransferredtothevaporphase(Figure7).ThesystemdeployedinthePermianBasinbyDr.Balchusedsolar-thermalmethodstoheatthewater.Weproposethatusingtheheatfromtheproducedfluidscanalsobeusedtodrivethisoperation(ormakethesystemsmoreefficientwhencombinedwithsolarthermalsystems).Thissystemproducesfreshwateratarateofabout0.25gpm.Itcanbescaleduptotreatlargervolumesofwater.GeophysicalMethodstoDetectBrackishWaterResourcesOnepromisingapproachtoassessthevolumeofbrackishwaterresourcesistheuseofelectromagneticmethodssuchasmagenetotelluric,audiomagnetotelluric,andtransientelectromagnetictechniques.Magnetotellurics(MT),audio-magnetotellurics,(AMT)andTransientElectromagnetics(TEM)aresurfacegeophysicalimagingmethodsthatcanbeusedtodeterminethedistributionoffreshandbrackishwaterresourcesbetweendepthsof500-1000m(TEM,AMT)toover10km(MT).TheTEMmethodhasbeenusedfordecadesincoastalaquiferstudiestolocatethefreshwater-seawaterinterface(e.g.Marksammeretal.2009).MTimaginghasbeenusedforexplorationofgeothermalsystems(Wannamakeretal.2003)andforexplorationoforedeposits(Zongeetal.1991),butcanalsobeusedtodelineatefreshtosalinewatersatgreatdepths.MTutilizesnaturallyoccurringelectromagneticwavesgeneratedbylightningandtheinteractionbetweensolarwindsandtheEarth’smagnetospheretomeasureelectromagneticinductionwithintheEarth(SimpsonandBahr,2005).TheMTmethodis

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usedtoimagetheelectricalconductivity(orresistivity)ofrocksandfluidsinthesubsurface.Salinefluidsarebetterconductorsofelectricitycomparedtofreshwater.TheTEMsysteminducesanelectromagneticwavebypassingacurrentthrougha100mby100mcopperwireloopasdifferentfrequencies.Thismethodalsomeasurestherelativeconductivityandresistivityofsubsurfacematerials.Becausebrackishwaterandbrinesaremuchmoreconductivethanfreshwater,theycanpotentiallyimagesubsurfacewaterqualityvariations.TEMmethodshavetypicallybeenusedincoastalaquifersaquiferstodetectthemixingzonebetweenfreshandsaltwater(Marksammeretal.2009).NMTechrecentlyacquiredbothofthesesystems.MTmethodshavebeenusedtoidentifygeothermalsystemsatdepthsofupto10km(Wannamaker2003).MTandTEMmethodshavenottypicallybeenappliedtostudythedistributionoffreshwaterandbrackishwatersinNewMexico.Somerecentstudies(Meqbeletal.2013;Jiangetal.2014)havebeguntoapplyAMTandMTmethodstoassesssalinityandgroundwaterflowpatternstodepthshundredsofmeterstoseveralkm(Figure8).WethinkthetimeisripetoapplythesemethodsinNewMexicotoexploreforbrackishwaterresourcesandgeothermalsystems.Dryalluvialmaterialwithairinitsporespacesisarelativelypoorelectricalconductorandhasahighformationresistivityintherangeof120to400Ohm/m(Figure9).Forfreshwatersaturatedsands,electricalcurrentmovesprimarilythroughthefluidphase.Forrelativelyfreshwater(20-50mg/lTDS)formationresistivityrangesbetween80-120Ohm/m.Increasedamountsofdissolvedsolidsequatestoincreasedabilitytoconductelectricity.Brackishwaterhavingasalinityofabout3000mg/l,significantlydecreaseselectricalresistivitytobetween2-10Ohm/m.RegulatoryIssuesTheinstitutional,regulatory,andlegalframeworkforgeothermaldesalinationistiedtothevariablyarrangedmatrixof1)ownerofthesurfacelandestate,2)ownerofthegroundwaterestate(generally,theStateofNewMexicoandpermittedandlicensedappropriatedwaterrights),3)ownerofthegeothermalmineralestateandleaseholders,and4)wheregeothermalisco-producedwithoilandgas,theowneroftheoilandgasestateandleaseholders.Thevariousland,water,andmineralestatesmayhaveonlyoneownerasinthelandsoftheStateofNewMexico.Inothersareas,themineralestatemayhavebeenseveredorevenremovedfromthesurfaceestate.Intermsofdominance,themineralestatehashigherprioritythanthesurfaceestate.Intermsofpriority,environmentalandwaterqualityconcernsmaygivethegroundwaterestatedominanceoverthemineralestatewhetheritisgeothermaloroilandgas.GeothermalenergyisnotwaterandisdefinedasamineralbytheFederal1970SteamActwheregeothermalproductionisfromtheFederalmineralestateandrequiresa

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royalty.Therearedifferentroyaltyrateschedulesdependinguponwhethertheproductioniselectricalpowerandhowitissoldorwhetheritisdirectuseofgeothermalheat.InNewMexico,geothermalproducedfromtheStatemineralestateissubjecttoroyaltyiftheproducedfluidis121oCandaboveandpermittingisdonethroughtheNewMexicoOilConservationDivision(OCD).Ifthefluidproducedislessthan121oC,thenthepermittingisdonethroughtheNewMexicoOfficeoftheStateEngineer(OSE)andnoroyaltyisassessedandthewaterproductionissubjecttoNewMexicowaterlaw.Ingeneral,NewMexicoisownsthesurfaceandsubsurfacewaterestates,exceptwaterthatisreservedforFederaljurisdiction,suchasinstreamflowforwildlife,andreservedbyinterstateandinternationalwateragreementsorcompacts.However,NewMexico’ssurfaceandgroundwatermaybeprivatelypermittedandlicensedasanappropriatedrightfordiversionandbeneficialuse.Anappropriatedrightisaconditionalpropertyrightthatmaybesold,leased,ortraded.Ifthewaterisnotappliedforaperiodoftimetobeneficialuse,thewaterrightmaybesubjecttoforfeitureorabandonment,removingentitlementsecurity.Thisissuecouldbeimportantforgeothermaldesalinationincasethegeothermaloperatorshutsdownforanextendedperiodoftime,goesoutofbusiness,orisnolongerabletoprovidetheheatorelectricalenergyfordesalination.Themeansthatthewaterrightcouldbeinjeopardyafterfouryearsofneglecteduse.Useofgeothermalresourcesfordesalinationhasmanylayersoflegal,regulatory,andpermittingissues,andinstitutionaldomainsandmanyareunchartedortestedinpractice.Clearly,theeconomicapplicationofdesalinizedwatercouldbeconsideredasabeneficialuseandmaybeconsistentwiththeDoctrineofPriorofAppropriationthatisoneofthefoundationsofNewMexicowaterlaw.Severalscenariosofgeothermaldesalinationmatrixareconsideredbelowwithanoutlineofprocessjurisdictiontoidentifypotentialproblemsorhurdlesthatexist.Theinterfaceofgeothermalandwaterislargelydependentupondynamicsofprivate,State,andFederalmineral(geothermal)estatewithStatewaterlaw.Potential“deepconductive”geothermalresourcescanclearlyco-existwiththe“deep”oilandgasproductionandco-producedbrinesofhightemperature.Geothermalcouldprovideanimportantsolutiontothemanagingco-producedbrineswithaneconomicbenefit.Aninstitutional,regulatory,andlegalscenariowillalsobediscussedfor“oilpatch”geothermaldesalination.Theprivategeothermalmineralestateprovidesanexampleofthesimplestscenario,waterusefromthegeothermaldesalinationwouldbeafairlystraightforward,providedthegeothermalproductionwasfromtheprivatemineral(geothermal)estateandthetemperaturewaslessthan121oCandtheendbeneficialuserofdesalinatedwaterhasaconsumptivewaterrightwiththeOSE.Thisscenariorequireswellpermitsandauthorizationtopumporproducewaterfromthewellsforbeneficialusefromthe

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groundwaterbasinthatapplies.InjectionwouldrequireauthorizationfromtheOCDconsistentwiththeNewMexicoWaterQualityControlCommission(WQCC)andEPArulesapplyingtoClassVinjectionwells.StateandFederalgeothermalproductionrequiresalease.Ingeneral,acreageisrequiredtobenominatedandaleaseauctionisheldunderbothStateandFederalrules.However,thereisanexceptionunderFederalleasingrules.Ifdirect-use,theFederalleaseisnon-competitive,providednocompetingapplicationsaresubmittedwithinasettimeperiodstartingwiththeinitialapplication.TheStategeothermalmineralestaterequiresageothermalleaseforproductionoffluidsgreaterthan121oC.Differentroyaltyschedulesapplyforelectricalpoweranddirect-use.Thedirect-useroyaltyrateissimilartotheFederalformulaandwouldapplytogeothermaldesalinization.TheOCDpermitsthegeothermalwellsandproduction/injectionandcollectsproductiondata.Forgeothermalproductionattemperatureslessthan121oC,theOSEpermitsthegeothermalwellsandcollectsproductiondata.InjectionwouldbeundertherulesoftheWQCCadministeredbytheOCD.TheFederalgeothermalmineralestaterequiresageothermalleaseforproductionoffluidandaroyaltyisdueonproduction,whetherforelectricalpowerordirect-use.TheU.S.BureauofLandManagement(USBLM)manageswellpermittingandproduction,withconsultationwithotherFederallandsmanagers,ifforexamplethegeothermalleaseisonNationalForestLand.TheU.S.OfficeofNaturalResourceRevenue(ONRR)collectsroyaltiesandproductiondata.Inaddition,theOCDalsopermitsthewellsandproductionandcollectsproductiondata.Co-productionofgeothermal(extractionofheatfromproduced“brines”)withoilandgasproductionraisesanumberofownershipandlegalissueswhichprobablygobeyondcurrentcaselawandmayrequirelegislativesolutionoradministrativesolutionwhereallpartiesconsultandagree.Forinstance,anoilandgasleasedoesnotallowextractionofheatorgeothermalfordesalinationpurposes.Therefore,theoperatorwouldrequireanoilandgasleaseinadditiontoageothermallease.IfthegeothermalgeneratesbinaryorganicRankinecycle(BORC)electricalpower,thenthegeothermalleasewouldhavetobeacquiredthroughacompetitiveleasesalewhereFederalmineralsapply.WithFederalmineralsanon-competitiveleaseisallowedfordirect-use.Anotherpotentialproblemrotatesaroundthefactthatthehydrocarbonfractionofthefluidproductioncontainsthehighestvalueandwouldbethedominantestateforaleaseoperator;but,thehydrocarbonsellingpricecanbehighlyvolatileandanoperatormaywishtoincreaseordecreaseproductioninconcertwiththemarketwhilethegeothermaldesalinationproduct,beneficialuseofwater,istiedtoaparticularannual

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acre-ftappropriation.Dependinguponthebeneficialuseofthedesalinatedwater,adropbelowacertainthresholdmaynotsustainaparticulardirect-useorfreshwaterenduserbusinessmodel.Asustainableandmutuallycompatibleandbeneficialscenarioofhydrocarbonandgeothermalwouldneedtobeengineered.

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References

Adham,S.,A.Hussain,J.M.Matar,R.Dores,andA.Janson,2013,Applicationofmembranedistillationfordesaltingbrinesfromthermaldesalinationplants,:Desalination,v.314pp.101-108.

Barroll,M.W.,andReiter,M.,1990,AnalysisoftheSocorrohydrothermalsystem:centralNewMexico:JournalofGeophysicalResearch,v.95,no.B13,p.21949-21963.

Balch,R.S.,andMuraleedharan,S.,2014,Cost-efficientwell-headpurificationofproducedwaterusingahumidification-dehumidificationprocess:SPE-169526-MS,10pp.

Bourouni,K.,Chaibi,M.T.,andTadrist,L.,2001,Waterdesalinationbyhumidificationanddehumidificationofair:stateoftheart:Desalination,v.137(1),p.167-176.

Doonechaly,G.Azim,R.A.,andRahman,S.S.,2015,EvaluationofrecoverableenergypotentialfromEnhancedGeothermalSystems:Asensitivityanalysisinaaoro-thermo-elasticframework:Geofluids,doi:10.1111/gfl.12156

Duque,C.,Calvache,M.L.,Pedrera,A.,Martín-Rosales,W.,&López-Chicano,M.,2008,Combinedtimedomainelectromagneticsoundingsandgravimetrytodeterminemarineintrusioninadetritalcoastalaquifer(SouthernSpain):.JournalofHydrology,v.349(3),p.536-547.

Galloway,Devin,Jones,D.R.,and.Ingebritsen,S.E.,eds.,1999,LandsubsidenceintheUnitedStates.Reston,VA:USGeologicalSurvey.

Garcia,J.L.,dellaPlaza,S.,Navas,L.M.,Benavente,R.M.,&Luna,L.,1998,Evaluation

ofthefeasibilityofalternativeenergysourcesforgreenhouseheating:JournalofAgriculturalEngineeringResearch,v.69(2),p.107-114.

Hickenbottom,K.L.andT.Y.Cath,2014,Sustainableoperationofmembranedistillation

forenhancementofmineralrecoveryfromhypersalinesolutions,JournalofMembraneScience:v.454,p.426-235.

Jaber,J.O.,andMohsen,M.S.,2001,Evaluationofnon-conventionalwaterresources

supplyinJordan:Desalination,v.136(1),p.83-92.Jiang,Xiao-Wei,LiWan,Jun-ZhiWang,Bin-XiYin,Wen-XiangFu,andChang-HongLin.

17

"Fieldidentificationofgroundwaterflowsystemsandhydraulictrapsindrainagebasinsusingageophysicalmethod."GeophysicalResearchLetters41,no.8(2014):2812-2819.

Kafri,U.,Goldman,M.,andLang,B.,1997,Detectionofsubsurfacebrines,freshwater

bodiesandtheinterfaceconfigurationin-betweenbythetimedomainelectromagneticmethodintheDeadSeaRift,Israel:EnvironmentalGeology,v.31(1-2),p.42-49.

Karytsas,C.,Mendrinos,D.,andGoldbrunner,J.,2003,Lowenthalpygeothermalenergy

utilizationschemesforgreenhouseanddistrictheatingatTraianoupolisEvros,Greece:Geothermics,v.32.1,p.69-78.

Lund,JohnW.,2010,Directutilizationofgeothermalenergy:Energies,v.3.8,p.1443-

1471.Mahmoudi,Hacene,NawelSpahis,MattheusF.Goosen,NoreddineGhaffour,Nadjib

Drouiche,andAbdellahOuagued."Applicationofgeothermalenergyforheatingandfreshwaterproductioninabrackishwatergreenhousedesalinationunit:AcasestudyfromAlgeria."RenewableandSustainableEnergyReviews14,no.1(2010):512-517.

Mailloux,B.,Person,M.,Strayer,P.,Hudleston,P.J.,Cather,S.,Dunbar,N.,1999,

TectonicandstratigraphiccontrolsonthehydrothermalevolutionoftheRioGrandeRift:WaterResourcesResearch,v.35(9),p.2641-2659.

Mathioulakis,E.,Belessiotis,V.,&Delyannis,E.,2007,Desalinationbyusingalternative

energy:Reviewandstate-of-the-art:Desalination,v.203(1),p.346-365.Marksamer,AndeeJ.,M.A.Person,F.Day-Lewis,J.W.Lane,D.Cohen,B.Dugan,K.Henk,

andM.Willett.IntegratingGeophysical,Hydrochemical,andHydrologicDatatoUnderstandtheFreshwaterResourcesonNantucketIsland,Massachusetts.InHyndman,D.W.,F.D.Day-Lewis,andK.Singha(eds.)DataIntegrationinSubsurfaceHydrology,AGUWaterResourcesMonograph,2007,DOI:10.129/172GM12,17p.

Meqbel,N.MM,O.Ritter,andDESIREGroup."Amagnetotellurictransectacrossthe

DeadSeaBasin:electricalpropertiesofgeologicalandhydrologicalunitsofthe

18

uppercrust."GeophysicalJournalInternational(2013):ggt051.Orgaz,F.,etal.,2005,Evapotranspirationofhorticulturalcropsinanunheatedplastic

greenhouse:AgriculturalWaterManagement,v.72.2,p.81-96.Pepin,J.,Person,M.,Phillips,F.,Kelley,S.,TimmonsS.,Owens,L.,Witcher,J.,GableC.,

2015,DeepfluidcirculationwithincrystallinebasementrocksandtheroleofhydrologicwindowsintheformationoftheTruthorConsequences,NewMexicolow-temperaturegeothermalsystem:Geofluids,v.15,p.139–160,DOI:10.1111/gfl.12111.

Roy,R.F.,Decker,E.R.,andBlackwell,D.D.,1972,Continentalheatflow,inRobertson,

E.C.,ed.,ThenatureofthesolidEarth:NewYork,Mc-Graw-Hill,p.506–543.(http://www.smu.edu/geothermal/heatflow/continental_heatflow.pdf)

Shannon,M.A.,Bohn,P.W.,Elimelech,M.,Georgiadis,J.G.,Marinas,B.J.,andMayes,

A.M.,2008,Scienceandtechnologyforwaterpurificationinthecomingdecades:Nature,v.452(7185),p.301-310.

Shook,G.M.,2001,Predictingthermalbreakthroughinheterogeneousmediafrom

tracertests:Geothermics,v.30(6),p.573-589.SimpsonF.,Bahr,K.,2005,PracticalMagnetotellurics,Cambridge,254p.SmithL,andChapmanD.S.,1983,Onthethermaleffectsofgroundwaterflow:1.

Regionalscalesystems:JournalofGeophysicalResearch,v.88,B1,p.593–608.

Stefansson,V.,1997,Geothermalreinjectionexperience:Geothermics,v.26,p.99-130.

Summers,W.K.,1976,CatalogofthermalwatersinNewMexico:NewMexicoBureau

ofMinesandMineralResourcesHydrologicReport4,80p.Summers,W.K.andColpitts,R.M.,1980,Preliminaryappraisalofthehydrothermal-

resourcepotentialoftheGilaHotSpringsArea,GrantandCatronCounties,NewMexico:W.K.SummersandAssociates,Inc.ReportpreparedforD.A.“Doc”andIdaCampbell,GilaHotSprings,NewMexico,102p.

Susanto,H.,2011,Towardspracticalimplementationsofmembranedistillation,

ChemicalEngineeringandProcessing:v..50,p.139-150

19

Wannamaker,P.E.(2003).InitialresultsofmagnetotelluricarraysurveyingattheDixieValleygeothermalarea,withimplicationsforstructuralcontrolsandhydrothermalalteration.GeothermalResourcesCouncilTransactions,p.37-42.

Weingarten,M.,Ge,S.,Godt,J.W.,Bekins,B.A.,&Rubinstein,J.L.,2015,High-rate

injectionisassociatedwiththeincreaseinUSmid-continentseismicity:Science,v.348(6241),p.1336-1340.

Williams,ColinF.,Reed,MarshallJ.,Mariner,RobertH.,DeAngelo,Jacob,Galanis,S.

Peter,Jr.,2008,Assessmentofmoderate-andhigh-temperaturegeothermalresourcesoftheUnitedStates:U.S.GeologicalSurveyFactSheet2008-3082,4p.

Witcher,J.,2002a,GeothermalEnergyinNewMexico:OregonInstituteofTechnology-

GeoHeatCenterBulletin,v.23(4),p.2-6.Witcher,J.,2002b,TruthorConsequences,NewMexico–ASpaCity:OregonInstitute

ofTechnology-GeoHeatCenterBulletin,v.23(4),p.20-24.Witcher,J.,2002c,GilaHotSprings:OregonInstituteofTechnology-GeoHeatCenter

Bulletin,v.23(4),p.25-29.Witcher,J.,2002e,MassonRadiumSpringsFarm:OregonInstituteofTechnology-Geo

HeatCenterBulletin,v.23(4),p.42-44.Witcher,J.,2002f,J&KGrowers,LasCrucesNM:OregonInstituteofTechnology-Geo

HeatCenterBulletin,v.23(4),p.45.Witcher,J.,2002g,FaywoodHotSprings:OregonInstituteofTechnology-GeoHeat

CenterBulletin,v.23(4),p.46.Witcher,J.,2002h,OjoCaliente–America’sOldestSpa:OregonInstituteofTechnology-

GeoHeatCenterBulletin,v.23(4),p.47.Zhang,Y.,Person,M.,Rupp,J.,Ellet,K.,Celia,M.A.,Gable,C.W.,Bowen,B.,Evans,J.,

Bandilla,K.,Mozley,P.S.,Dewers,T.,andElliot,T.,2013,Hydrogeologiccontrolsoninducedseismicityincrystallinebasementrocksduetofluidinjectionintobasalreservoirs:Groundwater,v.51,Issue4,p.525–538.

Zonge,K.L.,Hughes,L.J.,&NABIGHIAN,M.(1991).Electromagneticmethodsinapplied

geophysics.Electromagneticmethodsinappliedgeophysics.

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Figure1.InsideviewofMason-RadiumSprings20-acregeothermalgreenhouse.Loopedpipesaboveplantscirculatedfluidsheatedbybrackishgeothermalwaters.Heatexchangerstransferheatfromthegeothermalfluidstoafreshwaterloopusedbythegreenhouse.

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Figure2.JimWitcher(left)standingnexttoageothermalwellatRadiumSprings.Dr.ShariKelley(NMBRMR)isintheforeground.TotherightofDr.KelleyisJeffPepin(gradstudent,NMT),RandyShaw(BOR),QiangWei(NMHU),andJesusGomez-Velez(NMT).

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Figure3a.RangeoftemperaturesandsalinitiesofallNewMexicogeothermalfluids.

Figure3b.RangeoftemperaturesandsalinitiesforgeothermalfluidswithTDS<5000mg/l.ThepurplelinesoutlinespringsandwellsassociatedwiththeVallescalderaoutflowplume.

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Figure4.GeneralizedgeothermalresourcemapofNewMexico.Red:Convectivesystems,lightblue:DeepConductiveSystemsinrelativelyyoung(Tertiary)Basins;darkblue:DeepConductiveGeothermalSystemsinrelativelyoldPaleozoicandMesozoicBasins.

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Figure5.Bottomholetemperatures(uncorrected)andsalinityinfiverockunitswithinthePermianBasinofSENewMexico(source:USGSProducedwaters,OCD,andNMBGMR).Notethatfluidsintheolder(deeper)MorrowandPennsylvanian(Penn)strataarewarmerandaregenerallylesssaline.

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Figure6.Numericalmodelofthermalbreakthroughofafracturedgeothermalreservoir(Doonechallyetal.,2015).

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Figure7.SchematicdiagramandphotosofPermianBasinHumidification-DehumidicationDesalinationsystemofDr.RobertBalch,NMTechPetroleumResourceandRecoveryCenter.

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Figure8.(A)Inferredgroundwaterflowpatterns(arrows)acrossOrdosPlateau,ChinausingresistivitypatternsfromAMTsurvey.Thecirclesdenotestagnationzoneswheresalinityishypothesizedtobuildup(afterJiangetal.2014).InferredgroundwaterflowdirectionsusingresistivitypatternsfromMTsurveyoftheDeadSeaRift,Jordan(afterMeqbeletal.2013).

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Figure9.Resistivityofdifferentdrained(fluidabsent)geologicunits,fresh,andsalinewater(afterSimpsonandBahr,2005).