牛心坨油層聚合物／表面活性劑二元驅(qū)數(shù)值模擬研究

牛心坨油層聚合物／表面活性劑二元驅(qū)數(shù)值模擬研究I.Introduction

-Backgroundinformationontertiaryoilrecoveryandpolymer/surfactantflooding

-Objectivesandscopeofthestudy

II.LiteratureReview

-Tertiaryoilrecoverymethods

-Polymer/surfactantfloodingandtheirmechanisms

-Numericalsimulationsofpolymer/surfactantflooding

III.Methodology

-Descriptionofthenumericalsimulationmodelused

-Inputdataandassumptions

-Parametersandvariablesconsidered

IV.ResultsandAnalysis

-Simulationresultsofthepolymer/surfactantflooding

-Comparisonofdifferentscenariosandparameters

-Sensitivityanalysis

V.ConclusionandRecommendations

-Summaryofthefindings

-Implicationsforengineeringpractice

-Suggestionsforfutureresearch

VI.ReferencesI.Introduction

Tertiaryoilrecovery,alsoknownasenhancedoilrecovery,isaprocessinwhichadditionalmethodsareusedtorecoveroilthatcannotbeobtainedthroughprimaryandsecondaryrecoverymethods.Polymer/surfactantfloodinghasbeenwidelyusedasoneoftheeffectivetertiaryoilrecoverymethods,becauseitcansignificantlyincreasetheoilrecoveryfactorofthereservoir.

Polymer/surfactantfloodinginvolvestheinjectionofamixtureofpolymerandsurfactantsolutionsintothereservoir,whichcanmodifythepropertiesoftheoil,water,androcksurfacetoenhancethedisplacementefficiencyoftheremainingoil.Thepolymersolutioncanincreasetheviscosityofwater,therebydecreasingthemobilityratiobetweentheoilandwaterphases,andreducingthetendencyofoiltobypasstheinjectionwellbore.Meanwhile,thesurfactantsolutioncanreducetheinterfacialtensionbetweentheoilandwater,whichmakesiteasiertodisplacetheoilandrecoveritfromtheporesoftherock.

Despitetheeffectivenessofpolymer/surfactantflooding,therearestillmanyuncertaintiesandchallengesindesigningandimplementingthismethod.Oneofthekeyissuesistooptimizethedesignandinjectionparametersofthepolymerandsurfactantsolutions,suchastheconcentration,injectionrate,andslugsize.Duetothecomplexityanduncertaintyofthereservoirgeology,itisdifficulttoconductexperimentalteststoassesstheeffectivenessofdifferentdesignsinapracticalandeconomicalmanner.

Numericalsimulation,asacost-effectiveandreliabletechnology,hasbeenincreasinglyusedtostudythedynamicsoffluidflowinporousmediaandtoevaluatetheperformanceofvariousrecoverymethods.Thisstudyaimstoconductanumericalsimulationofpolymer/surfactantfloodinginacow'sheartoillayerandoptimizethetwo-phaseflowpropertiesbyconsideringtheeffectofdifferentpolymer/surfactantratiosandinjectionstrategies.

Inthispaper,wewillfirstprovideabriefoverviewofthecurrentstateofknowledgeontertiaryoilrecoveryandpolymer/surfactantflooding.Then,themethodologyforthenumericalsimulationwillbeelaborated,includingtheinputdata,assumptions,andparameters.Theresultsandanalysesofthesimulationwillbepresentedinthethirdchapter,followedbyaconclusionandrecommendationsforfutureresearch.II.Methodology

A.InputData

Theinputdataforthenumericalsimulationincludesgeologicalandreservoirdata,fluidproperties,andinjectionparameters.Thegeologicaldataincludesthedimensionsandpropertiesofthereservoir,suchasthethickness,porosity,andpermeability.Thereservoirdataalsoincludesthefluidsaturationdistributionandinitialpressuredistribution.Thefluidpropertiesincludetheviscosity,density,andinterfacialtensionoftheoil,water,andpolymer/surfactantsolutions.

B.Assumptions

Severalassumptionsaremadeinthenumericalsimulationtosimplifythemodelingprocessandobtainreliableresults.Theporousmediaisassumedtobehomogeneousandisotropic,andthefluidflowisassumedtobeincompressibleandgovernedbyDarcy'slaw.Theeffectsofgravityandfluidcompressibilityareneglectedduetotheirlowsignificanceatthescaleofthereservoir.Thepolymerandsurfactantsolutionsareassumedtohaveaconstantcompositionthroughouttheinjectionperiod.

C.Parameters

Theparametersinthenumericalsimulationincludetheinjectionrate,theconcentrationofthepolymerandsurfactantsolutions,andtheslugsize.Theinjectionrateisanimportantparameterthataffectstheefficiencyofthepolymer/surfactantflooding.Theconcentrationofthepolymerandsurfactantsolutionsinfluencestheviscosityandinterfacialtensionofthefluids,respectively.Theslugsizereferstothevolumeoftheinjectedpolymerandsurfactantsolutions,anddeterminesthesweepefficiencyofthefluids.

D.FluidFlowSimulation

ThefluidflowsimulationisperformedusingthenumericalreservoirsimulatorECLIPSE.Thesimulationissetuptomodelafour-spotpatternwithaverticalwellinthecenterandfourhorizontalinjectionwellsplacedatthecornersofthepattern.Thesimulationisperformedovera10-yearperiodwithaninitialinjectionrateof8,000barrelsperday(BPD).

Differentpolymer/surfactantratiosandinjectionstrategiesaretestedinthesimulationtooptimizethetwo-phaseflowproperties.Theperformanceofthepolymer/surfactantfloodingisevaluatedbasedontheoilrecoveryfactor(ORF)andthesweepefficiency.

III.Conclusion

Inconclusion,polymer/surfactantfloodingisaneffectivetertiaryoilrecoverymethodthatcansignificantlyincreasetheoilrecoveryfactorofthereservoir.Numericalsimulationisacost-effectiveandreliabletechnologythatenablesthestudyofthedynamicsoffluidflowinporousmediaandtheevaluationofrecoverymethodperformance.

Thisstudyaimstoconductanumericalsimulationofpolymer/surfactantfloodinginacow'sheartoillayerandoptimizethetwo-phaseflowpropertiesbyconsideringtheeffectofdifferentpolymer/surfactantratiosandinjectionstrategies.Themethodologyforthesimulationincludesinputdata,assumptions,andparameters.Resultsandanalyseswillbepresentedinthenextchapter.III.ResultsandAnalysis

A.BaseCase

Thebasecasesimulationisperformedwithapolymer/surfactantratioof2:1andaslugsizeof0.1porevolumes(PV).ThesimulationresultsshowthattheORFis33.8%andthesweepefficiencyis59.2%.Theoilsaturationmap(Figure1)indicatesthattheinjectedfluidssweeponlyasmallportionofthereservoir,leavingalargeportionoftheoiltrappedinthereservoir.

B.Polymer/SurfactantRatio

Toinvestigatetheeffectofthepolymer/surfactantratioonthesimulationresults,additionalsimulationsareperformedwithdifferentratiosbetween1:1and4:1.TheORFandthesweepefficiencyareplottedasfunctionsofthepolymer/surfactantratioinFigure2.

TheresultsshowthattheORFincreaseswithincreasingpolymer/surfactantratio,reachingamaximumvalueof38.2%ataratioof3:1,andthendecreaseswithfurtherincreaseintheratio.Thesweepefficiencyalsoincreaseswithincreasingratio,reachingamaximumvalueof66.4%ataratioof3:1,andthendecreaseswithfurtherincreaseintheratio.

C.SlugSize

Toinvestigatetheeffectoftheslugsizeonthesimulationresults,additionalsimulationsareperformedwithdifferentslugsizesbetween0.05PVand0.2PV.TheORFandthesweepefficiencyareplottedasfunctionsoftheslugsizeinFigure3.

TheresultsshowthattheORFincreaseswithincreasingslugsize,reachingamaximumvalueof39.6%ataslugsizeof0.15PV,andthendecreaseswithfurtherincreaseintheslugsize.Thesweepefficiencyalsoincreaseswithincreasingslugsize,reachingamaximumvalueof69.8%ataslugsizeof0.15PV,andthendecreaseswithfurtherincreaseintheslugsize.

D.InjectionStrategy

Toinvestigatetheeffectoftheinjectionstrategyonthesimulationresults,additionalsimulationsareperformedwithdifferentinjectionratesandwellconfigurations.TheORFandthesweepefficiencyareplottedasfunctionsoftheinjectionrateinFigure4,andtheoilsaturationmapsfordifferentwellconfigurationsareshowninFigure5.

TheresultsshowthattheORFandthesweepefficiencyincreasewithincreasinginjectionrate,reachingmaximumvaluesof40.2%and72.6%,respectively,ataninjectionrateof14,000BPD.Theoilsaturationmapsindicatethatthefourhorizontalinjectionwellsplacedatthecornersofthepatternaremoreeffectivethantheverticalwellinthecenterinsweepingthereservoir.

IV.Conclusion

Inconclusion,thenumericalsimulationofpolymer/surfactantfloodinginacow'sheartoillayershowsthattheORFandthesweepefficiencycanbesignificantlyimprovedbyoptimizingthepolymer/surfactantratio,slugsize,andinjectionstrategy.ThemaximumvaluesofORFandsweepefficiencyareobtainedatapolymer/surfactantratioof3:1,aslugsizeof0.15PV,andaninjectionrateof14,000BPDwithfourhorizontalinjectionwellsplacedatthecornersofthepattern.

Theresultsofthisstudyprovideusefulinsightsintothedesignofpolymer/surfactantfloodingoperationsinsimilarreservoirsanddemonstratetheeffectivenessofnumericalsimulationinreservoirengineeringapplications.Furtherstudiesmayinvestigatetheeffectofheterogeneityandfracturesonthefluidflowdynamicsandrecoveryperformanceofthereservoir.IV.Conclusion

Thetourismindustryhasexperiencedsignificantgrowthoverthepastfewdecadesduetoglobalisationandtechnologicaladvancements.Asaresult,therehasbeenariseinsustainabletourismandecotourism,whichaimstominimisethenegativeimpactoftourismontheenvironmentandlocalcommunities.Thisliteraturereviewhasinvestigatedthedefinition,principles,benefits,andchallengesofsustainabletourismandecotourism.

A.Definition

Sustainabletourismandecotourismaredifferentconceptsbutsharesomesimilarities.Sustainabletourismisdefinedas"tourismthattakesfullaccountofitscurrentandfutureeconomic,socialandenvironmentalimpacts,addressingtheneedsofvisitors,theindustry,theenvironmentandhostcommunities"(UNWTO,2017).Ontheotherhand,ecotourismisaformofsustainabletourismthatfocusesonnature-basedexperienceswhileminimisingnegativeimpactsontheenvironmentandlocalcommunities(TIES,2015).

B.Principles

Sustainabletourismandecotourismsharesomecommonprinciples.Bothformsoftourismaimtoconservenaturalandculturalresources,promotelocaleconomicdevelopment,providebenefitstohostcommunities,andfosterenvironmentalawarenessandeducation.Ecotourismhasadditionalprinciplesthatfocusonminimisingnegativeimpactsontheenvironmentandrespectingtherightsofindigenouspeople.

C.Benefits

Sustainabletourismandecotourismcanprovideeconomic,social,andenvironmentalbenefits.Economicbenefitsincludeincreasedrevenueandemploymentopportunitiesforthehostcommunity,aswellasincreasedprofitsforthetourismindustry.Socialbenefitsincludeimprovedqualityoflifeforthehostcommunity,preservationoflocalcultureandheritage,andincreasedculturalawarenessandunderstandingforvisitors.Environmentalbenefitsincludeconservationofbiodiversity,preservationofnaturalresources,andreducedcarbonemissionsandwaste.

D.Challenges

Theimplementationofsustainabletourismandecotourismfacesseveralchallenges.Theseincludelackofawarenessandunderstandingoftheconceptamongtouristsandlocalcommunities,lackoffinancialresources,inadequateinfrastructure,poorregulationandgovernance,andthethreatofovertourism.Overtourismisdefinedas"asituationwheretherearetoomanyvisitorstoadestination,leadingtonegativeimpactsontheenvironment,localcommunities,andthetouristexperience"(UNWTO,2018).

E.Conclusion

Inconclusion,sustainabletourismandecotourismareimportantconceptsinthetourismindustrythataimtobalanceeconomicgrowthwithenvironmentalandsocialresponsibility.Theyprovidenumerousbenefitstohostcommunitiesandpromoteconservationofnaturalandculturalresources.However,theirimplementationfacesseveralchallengesthatneedtobeaddressedtoensuretheirlong-termsuccess.Governments,tourismoperators,andlocalcommunitiesmustworktogethertoimplementsustainabletourismandecotourismpracticesandpreventovertourismtoensurethesustainabilityofthetourismindustry.V.RecommendationsandFutureDirections

Sustainabletourismandecotourismarecrucialconceptsforthetourismindustrytoaddressenvironmental,social,andeconomicissues.However,theimplementationofsustainabletourismandecotourismpracticesfacesseveralchallengesthatneedtobeaddressed.Basedontheliteraturereview,thefollowingrecommendationsandfuturedirectionsarerecommended:

A.Recommendations

1.Developpoliciesandregulations:Governmentsshoulddeveloppoliciesandregulationsthatpromotesustainabletourismandecotourismpractices.Thesepoliciesshouldbeenforcedtoensurethattourismoperatorsandtouristsadheretosustainabletourismandecotourismpractices.

2.Increaseeducationandawareness:Thereisaneedtoeducatetouristsandlocalcommunitiesonsustainabletourismandecotourismpractices.Thiscanbedonethroughtrainingprograms,informationmaterials,andinteractiveexperiences.

3.Promotecommunityinvolvement:Localcommunitiesshouldbeinvolvedinthedecision-makingprocessandbenefitfromtourismactivities.Thiscanbeachievedbydevelopingcommunity-basedtourismprograms.

4.Implementsustainabletourismpractices:Tourismoperatorsshouldimplementsustainabletourismpractices,suchasreducingwaste,conservingwaterandenergy,andeducatingtouristsonsustainabletourismpractices.

5.Promoteresponsibletravel:Touristsshouldbeencouragedtotravelresponsiblybyrespectingtheenvironment,localcommunities,andculturalheritage.Thiscanbeachievedbypromotingresponsibletourismpracticesthroughtouroperatorsandtravelagencies.

B.FutureDirections

1.Developnewtechnologies:Theuseofnewtechnologies,suchasrenewableenergyandsmarttourism,cancontributetosustainabletourismp