外文文献及中文翻译accessrelational database大学论文.docx

外文文献及中文翻译accessrelational database大学论文.docx

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外文文献及中文翻译accessrelationaldatabase大学论文

ChemicalandPetroleumEngineering,Vol.40,Nos.11–12,2004

COMPRESSORS,PUMPS,

REFRIGERATIONENGINEERING

UPDATINGPISTONPUMPSFOROIL

PRODUCTION

B.S.Zakharov,1G.N.Sharikov,2

andE.G.Kormishin2

Thethree-plungeracidtreatmentpumpSIN32andthetwo-cylinderdouble-actingpumpNPTs-32withfourworkingchambers（forcementingunits）havebeenupdatedtocontrolpumpdelivery.Thefluiddeliverydiagramsforpumpsofvariousdesignsareexaminedandthetestresultsarereported.

Indrillingandoilproduction,single-actingthree-plunger（triplex）pumpsordouble-actingtwo-cylinder（duplex）pumpsareused.

Ininjectingreagents（claydrillingmud,water,cement,acid,etc.）intowells,dependingonthetechnologyapplied，itisrequiredtoinjectthefluidinamountsrangingfromthemaximumtotheminimuminasingleoperation.Ifthebedacceptstheinjectedfluidwell,itbecomesnecessarytomaximizepumpdeliveryforquickcompletionoftheoperation.Ifontheotherhand,thebeddoesnotacceptthefluidwell,itbecomesnecessarytoreducepumpdeliverysoastorestricttheinjectionpressuretothesafelimit.Atpresent,becauseofwearofwell（down-hole）equipment,thepermissibleinjection

pressureisnothigherthan10–15MPa..

Thedeliveryofapiston（reciprocating）oraplunger（displacement）typeofpumpcanbecontrolledinthefollowingways:

•byinstallingseveralpumpswithidenticalordifferentpumpingcapacities;

•bychangingthedriverotationspeed;

•byusingcylinders（plungers）oftherequiredsize;

•bychannelingapartofthefluidintoabypass;and

•bydismountingoneorseveralvalves.

Thefirstversionisusedessentiallyindrilling.Inoilproduction,generallyallversionsareusedeitherindividuallyorinsomecombination.

Allpumpingunitsdesignedforinjectionofvariousfluids（fluidalmaterials）forcementing,hydraulicformationfracturing,hydraulicsand-jetflushingofsandbridges,andotherflushingoperationsinoilandgaswellsaremountedonthechassisofmotorvehicles（trucks）,tractors,caterpillar（tracked）carriers,andspeciallymadecarriages.

Theoperatingparametersofthepumps（deliveryandinjectionpressure）dependonthepowerofthedriveandmaximumandminimumspeedoftheengineandthepump.Thepumpdeliverycanbechangedbychangingthenumberofpumpstrokeswithoutstoppingtheenginewiththehelpofagearbox（bygearshifting）andwithstoppingoftheenginebyinstallingcylindersoftherequiredsize.Replacementofthecylinderstakesalotoftimeandisnotalwayspossibleinacontinuousechnologicalprocess.Intheexistingpumpingplants,thedeliveryvariationrangeisinadequate.Attheminimumrotationspeedandcylinderdiameter,thedeliveryremainsextremelyhigh,andforinjectingthefluidintothebedthepressurehastoberaisedabovewhatispermissible.

AssignedbyNGDUZainskneft’,Ékogermetcarriedoutupdatingoftwotypesofpumps,namely,SIN32andNPTs-32.

Inthethree-plunger（triplex）acidtreatmentpumpSIN32,forreducingtheminimumdeliverydownto1.0m3/h,plungershavingadiameterof125mmwerereplacedwithplungershavingadiameterof55mm.Asaresult,thetheoreticalpumpdeliverywasreducedfrom16downto3.3m3/h.Furtherreductionofthepumpdeliverywasachievedbyreducingtherotationspeedofthevehicleenginetothepossibleminimum（500–600rpm）.

Simultaneouslywiththis,anewdesignofpackingglands（sealingdevices）ofplungersoftheUPN55typewasdeveloped.ItwasbasedonZakharovmechanicalseal[1],whichdemonstratedhighreliabilityanddurabilityinsucker-rod（oil）pumps.Thesealingunitsandthepistonswithadiameterof55mmweremadefortheSIN32pumpbyÉLKAMneftemashinPerm.ItsfinishingandtestingweredonebyÉkogermetjointlywithNGDUZainskneft’.

ThedesignoftheUPN55-typeplungersealisshowninFig.1.Thecombinedsealconsistsofthemainthreestagemechanicalseal4andanelasticsealingcollar2.Eachstageofthemechanicalsealconsistsoftenringsthatareelasticallypressedagainsteachotherandsimultaneouslyagainsttheplungersurface.Theringsarepressedagainstthe

plungerinpairsfromtheoppositesides.Thenextpairisturnedrelativetotheprecedingoneby90º.Theringsarepressedintheaxialdirectionbyrubberringsofroundcrosssectionandintheradialdirection,byrubbergirdleswitheccentriccollars.Theplunger5ismadeofsteel45andischromium-platedandthesealingringsareofbronze.Three

cartridgeswithmechanicalsealswereinstalledinthehousingbore3withaclearancethathelpsself-centeringofthesealsrelativetotheplunger.Thecartridgesarepressedtogetherbyaroundnut1throughabushingwiththesealingcollar2.Thereareholesinthehousingforinjectingoilanddrainingouttheoverflowintothereceiving（suction）lineofthepump.

Incontrasttothewell-knownelasticglands,themechanicalsealdoesnotrequireperiodicadjustmentsandensuresreliableoperationoftheassemblyoveralongperiod[2].UseoftheupdatedSIN32pumphavingaUPN55typeofmechanicalplungersealsconfirmedthattheproposeddesignoperationallyfit.

FromAugustthroughDecember2003,NGDUZainskneft’carriedoutsevenbottom-holetreatments（BHT）ofsixwellsusingtheupdatedSIN32pump.Differenttypesoftechnologicaloperationswerecarriedoutinthewells:

mudacidBHT,muriatic（hydrochloric）acidBHT,injectionofthereagentsSNPKh-9021,MIAPROM,andRMD,forwhichSIN32andATs-32pumpingunitsweregenerallyused.Ifacidoranyotherreagentcouldnotbeforcedthrough（injected）at12–15MPapressure,alow-capacityunitwasconnectedwiththeSIN32pump.Inthatcase,theinjectionpressuredroppedby2–4MPa。

Injectionwascompletedatthethird-gearspeedoftheengine.

TheNGDUtechnologistsbelievethatconnectingalow-deliveryunitwithanSIN32pumpoffersthefollowingadvantages:

•possibilityforcontinuousinjectionofacidsandreagentsincaseoflowintakecapacityofthebedandforpreventionofopeningupofthefractures（hydraulicfracturing）ofthecollectorandexcessiveriseinflowstringtestingpressure;

•extendedoperatinglifeoftheflowstringbyvirtueofpressurestabilizationduringinjection;and

•actionoftheacidthroughouttheperforationperiodandmorecompletereactionwiththerockwhentheacidinfiltratesthebed.

SincethemaximallypossibledeliveryoftheSIN32pumpisreducedatleastfivefold,NGDUZainskneft’proposedtoperformallBHTsbyinjectingacidsintothebedwiththeaidofalow-capacityunitandallotheroperations,withastandardunit.Inthatcase,however,itwouldbenecessarytoplaceinthewell,insteadofone,twounits,whichhavetobehandled，bytwoteams,i.e.,itwillentailadditionalmanpowerandcosts.Moreover,alow-capacityunitisnotalwaysfullyutilized（doesnotoperatetofullcapacity）andoftenstalls.

Thus,foraspecificsizeofthecylinderitisnecessarytoreducethepumpdeliverydowntotheminimumand,consequently,tobroadentherangeofcontrolofthepumpcapacitytowarditsreductionwhilemaintainingmaximallypossibledelivery.

Inmultichamberpumps,thisissueisresolvedbyshuttingdown（disengaging）oneorseveralworkingchambers.

Induplexplungerpumps,disengagingoneortwochamberswillcausesignificantlyunevendelivery,hydraulicshocks,disruptionofthebalanceofloadsonthedrive,andfailureofthepump.

Indouble-actingtwo-cylinder（duplex）pumpshavingfourworkingchambersoftheNPTs-32（9T）type,whichareinstalled,forexample,inATs-32cementingunits,thedeliverycanbereducedbydisengagingtworodchambers,whichisachievedbyremovingtwodelivery（pressure）valves（Fig.2）.

ThedeliveryoftheNPTs-32typeofpump（duplex）havingfourchambersis

Q=2（2F–ƒ）Sn,

whereFisthecross-sectionalareaofthecylinderwithadiameterDc,dm2;ƒisthecross-sectionalareaoftherodwithadiameterdr,dm2;Sisthestrokelength,dm;andnisthenumberofdoublestrokesperminute.

Ifthedelivery（pressure）valvesareremovedfromtherodchambers,thefour-chamberpumpturnsintoatwo-chamberonewithdifferentiallyactingcylinders.ThedeliveryofsuchapumpQ1=2FSn.

Ifthevalvesfromthefrontchambersareremoved,thepumpdeliverycanbedeterminedbytheequationQ2=2（F–ƒ）Sn.

Reductionofdeliverybydisengagingtherear（rod）chambersdependsonthefactork1=（2–ƒ/F）andbydisengagingthefrontchambers,onthefactork2=[2+ƒ/（F–ƒ）].Itcanbereadilyseenthatforreducingdeliverythefrontchambershavetobedisengaged.However,theoryandpracticeshowthatdisengagementoftherodchambersismoreadvisable.

Thus,inNPTs-32typeofpumphavingcylindersof90,100,115,and127mmdiameterandrodsof45mmdiameterthedeliverycanbereduced1.75–1.87timesbyremovingthevalvesfromtherodchambers.Atlowloads（pressuredrop

notmorethan15MPaandminimaldelivery）,theengineofthemotorvehicleKrAZ-250canrunsteadilyatarotationspeedof550rpm.Inthesecondgearwithminimumenginerotationspeed,thedeliveryofapumpwithacylinderof90mmdiametercanbereduceddownto1.0m3/h.

UnliketheSIN32pump,thedeliveryoftheNPTs-32pumpcanbecontrolledduringthetechnologicaloperationandreducingorraisingthedeliverycanchangethepumpoutput.Removalandinstallationoftwovalvesdonottaketoolong.

Letusseehowtheuniformityofpumpdeliverywillchangeuponremovalofthevalves.

Itiswellknownthattheinstantaneousoutputofasingle-cylindersingle-actingpumpis

q=Frsin〈=0.5FSsin〈,

whereristheradiusofthecrankand〈isthecranks