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264OIL&GASGEOLOGY20058:(G1999043307):,,30,,:2005-08-01:0253-9985(2005)04-0444-06、1,1,2(1.,163318;2.,400061):、、,3,,:1),、;2),,K;3)-,α;4)、。,,。,。:;;;;;:TE112.111:AForecastingmodelofsolubilityofCH4,CO2andN2incrudeoilXueHaitao1,LuShuangfang1,FuXiaotai2(1.DaqingPetroleumInstitute,Daqing,Heilongjiang;2.ChongqingMedicineIndustryInstitute,Chongqing)Abstract:DissolutioncharacteristicsandmechanismsofCH4,CO2andN2incrudeoilarestudiedthroughsolubilityexperiments,resultinginthefollowingunderstandings:①hydrocarbonsplayakeyroleintheprocessofgasdissolutionincrudeoil,whilemacromolecularsubstances,suchascolloidandasphaltene,havealittleinfluencesonthegassolubility.②Gasmoleculesandmacromolecularsub-stancesincrudeoilcanformadductmolecules;thisprocesscanbetreatedasanapparentchemicalreac-tionanditsreactiondegreecanbedescribedbyanequilibriumconstantK.③Earlyformedgas-hydro-carbonadductmoleculeshavecertainsolvencytosubsequentlyformedgasmolecules,whichcanbede-scribedbyasecondarydissolvingcoefficientα.④Physicalpropertiesofcrudeoilcanbecharacterizedbythedensity(ρo)ofsurfacecrudeoilandthemassfraction(xT)andaveragemolecularweight(MT)ofhydrocarbonsincrudeoil.Combinedwithotherfactorsthathaveinfluencesongasdissolution,thetheoreticalequationofgas’molesolubilityincrudeoilandthatofgas-oilratioincrudeoilarederived.Comparisonwithexperimentaldatashowsthatcalculatedandmeasuredvalueshaveagoodconsistency.Keywords:Methane;CO2;N2;crudeoil;solubility;theoreticalmodel,[1,2]、[3]、。,[4～6]。,,[7]。4,:、445[8],[9]。(CH4)、(CO2)、(N2)[10]。,。,()[4～6],-。,,。,。1,。CH4,CO2N2[10]:1),。。2)CO2,。,CO2(Cv)-(p),Cv-p。CO2,CO2。3)N2,。,N2,CO2。。,,。,,CH4,CO2N2。,。22.1(t)、(p),(ρg)(ρo)。,。N20.966,CH40.552。,N2,(、,N2。,[10])。,。,。,Lasater[5],,4(ρg,ρo,tp)。,,,;,;。,。1),。2),。3)(xT)。。,5!～20!,3000～5000[11]。(),。、(200～300),,1。xT,。4)(MT)。。5),。6)(K),。2.244626,,、。MT。(G)-(OT),G(g)+OT(l)⇔GOT(l)+ΔH(1)、,K=[GOT]p[OT]=ngVTpnT-ngVT=ngP(nT-ng)(2)[GOT],mol;[OT],mol;p,MPa;nTng,mol;VT,cm3。K。,K,。,(GOT),(2)[GOT]。,,。()。,。,CO2,,CO2Cv-p[10]。CO2-CO2。,CH4-CH4。,,α,[OT]=nT-αngVT(3)α,。α,,;α,,。(3)(2),K=ngp(nT-αng)(4)2.3,(4)ng=KpnT1+αKp(5)(5)V2C=ngV2=Kp1+αKpnTV2(6)C,mol/cm3;V2p,cm3。VT=nTMTρT=ρoVoxTρT(7)nT=VTρTMT(8)ρT,g/cm3;MT;VT;Vo,cm3;ρo,g/cm3;xT,。(7)(8),B[12],(6)C=Kp1+αKpnTV2=Kp1+αKPρTMTVTV2=Kp1+αKpρoxTMTVoV2=Kp1+αKPρoxTMT1B=KpxTρoMTf(t)+αKpMTf(t)+KpxTρof(t)Vgm(9)ρo,xTMT;Vgm,cm3/mol;f(t),[12]。CCv(cm3/cm3),C22400。,Kα,。,,Kα。。(9)Co=ngVo=ngV2V2Vo=CB=Kp1+αKpρoxTMT(10)Co、,mol/cm3。4,:、447(10),Co,,1mol22400cm3,,(10)RS=22400Co=22400Kp1+αKpdoxTMT(11)RS,m3/m3。,(11)(9),,,。xT0.8534,MT215.36。3Kα3.1Kα(9)CKα[10]CH4,CO2N2。,,α,αK。0～25.33MPa。α,K(K)。Kα。,Kα。3.2KαCH4,CO2N23Kα,K,(1/T)(1)。1,lnK1/T,。N2,,,。N2,35℃1CH4,CO2N2lnK1/T(1/K)Fig.1lnKvs.1/T(1/K)ofCH4,CO2andN2(35℃)。,N2。,N2。N2[13]。1,lnK1/T,CH4,CO2N2CH4:lnK=481.7411T-18.3874(12)CO2:lnK=773.2471T-18.5898(13)N2:lnK=-702.4061T-16.1372(14)αt,2。2,αt。CH4,CO2N2α-t,α-t(℃)CH4:α=0.0002763t-0.06333(15)CO2:α=0.00008286t-0.7061(16)N2:α=-0.00244571t-0.8644(17)2CH4,CO2N2αtFig.2Secondarydissolutioncoefficient(α)ofCH4,CO2andN2vs.temperature(t)41,23CH4,CO2N2[10]。,CH4,CO2N2448261.07!,3.07!1.93!。。1CH4Table1ComparisonofthecalculatedandmeasureddissolubilityvaluesofCH4incrudeoil/℃/105Pa/(cm3!cm-3)/(cm3!cm-3)/(m3!m-3)3543.1581.89128.50179.50220.6014.726.838.552.660.614.626.339.151.660.715.328.443.659.571.94544.1383.85129.00177.50223.6014.026.337.350.359.814.325.937.949.659.715.128.242.657.571.25525.5050.9984.34130.40179.50221.68.415.525.237.048.157.48.115.725.137.148.657.88.516.827.541.956.869.27548.0582.38132.40180.90221.1013.823.235.446.955.013.823.035.446.454.914.925.540.554.866.52CO2Table2ComparisonofthecalculatedandmeasureddissolubilityvaluesofCO2incrudeoil/℃/105Pa/(cm3!cm-3)/(cm3!cm-3)/(m3!m-3)3515.030.045.260.212.225.742.660.912.326.242.260.512.828.247.671.74515.030.045.060.512.523.637.053.811.123.437.153.011.725.341.662.05515.530.345.560.211.021.531.845.110.521.433.646.511.123.237.653.97515.530.346.561.09.817.028.538.98.917.828.238.09.519.531.643.83N2Table3ComparisonofthecalculatedandmeasureddissolubilityvaluesofN2incrudeoil/℃/105Pa/(cm3!cm-3)/(cm3!cm-3)/(m3!m-3)3551.0100.0149.0199.53.57.09.812.63.66.89.812.63.77.010.113.04550.5100.0152.5201.03.97.510.513.33.87.210.613.43.97.511.014.05560.0101.0153.0200.05.17.811.614.54.87.711.214.14.98.111.714.87550.0103.0158.0199.04.48.812.515.54.48.712.715.54.79.213.616.61,.[M].:,1993.113～116ChenZhangming,XuJingzhen.Evaluationmethodsofoilandgastraps[M].Harbin:HarbinIndustrialUniversityPublish-ingHouse,1993.113-1162,.[J].,1991,12(2):153～160LuJialan,FuJiamo.Experimentalstudyonsimulationofin-fluentialfactorsofgasmigrationunderdifferentconditions[J].Oil&GasGeology,1991,12(2):153-1603,,.、、[M].:,1993.90-91PangXiongqi,ChenZhangming,ChenFajing.Numericalsimu-lationofhydrocarbongeneration,remainingandexpulsionfromsourcerocksingeohistoryandtheirquantitativeevalua-tion[M].Beijing:GeologicalPublishingHouse,1993.90～914StandingMB.Apressure-volume-temperaturecorrelationformixturesofCaliforniaoilandgas[J].DrillandProdPrac,1947,(5):275-3865LasaterJA.Bubblepointpressurecorrelation[J].Trans,AIME,19