鄂尔多斯盆地中生代热异常及烃源岩热演化特征

:10000747(2007)06065806陈瑞银1,2,罗晓容2,赵文智1,王红军1(1.中国石油勘探开发研究院;2.中国科学院地质与地球物理研究所):国家重点基础研究发展规划(973)项目(G2003CB214605):在合理设定热模拟边界条件前提下,模拟分析鄂尔多斯盆地热演化过程,结果表明:在中晚侏罗世,盆地大部分地区中生界地热梯度为4.3~4.6/100m,但在庆阳西峰及其西南部分地区达到5.7/100m结合热流与地壳厚度关系及地震重力磁法方面证据,认为造成鄂尔多斯盆地中生代地温异常的最可能的热事件模式是全盆范围的地壳减薄与局部地区隐伏岩浆体加热的叠加在热异常背景下,三叠系延长组烃源岩层在侏罗纪埋深达到1600m便可成熟排烃,大规模生烃期在早白垩世较长的排烃期与埋藏过程中构造的调整是造成油气多期充注的主要原因图5表2参21:鄂尔多斯盆地;中生代;地热梯度;热演化;烃源岩;生烃门限:TE631.19:AThermalanomalyandthermalevolutionofsourcerocksinMesozoic,OrdosBasinCHENRuiyin1,2,LUOXiaorong2,ZHAOWenzhi1,WANGHongjun1(1.ResearchInstituteofPetroleumExploration&Development,PetroChina,Beijing100083,China;2.KeyLaboratoryofPetroleumResources,InstituteofGeology&Geophysics,CAS,Beijing100029,China)Abstract:Basedonthelogicalboundaryconditionsdefined,theresultsofthermalevolutionmodelingoftheOrdosBasinshowthatthetemperaturegradientoftheMesozoicErathemduringmiddlelateJurassicismainlyfrom43/kmto46/km,andlocally(atXifeng,Qingyangandtheirsouthwesternareas)beyond57/km.Combiningtherelationshipbetweenheatflowandlithosphericthicknesswiththeevidenceofseismic,gravityandmagnetics,thispaperconcludesthatthepatternleadingtotheMesozoicthermalanomalyofthisbasinmaybethestackingofcrustalthinningregionallyandconcealedmagmaheatinglocally.Inthecontextofthermalanomaly,hydrocarbonswouldbegeneratedfromtheTriassicYanchangFormationsourcerockwhenitsburialdepthreached1600metersintheJurassicperiod.ThemasshydrocarbongenerationoccuredintheearlyCretaceousepoch.Multiplephasehydrocarbonfillingsareduetolongexpulsionprocessandtectonicadjustment.Keywords:OrdosBasin;Mesozoic;geothermalgradient;thermalevolution;sourcerock;hydrocarbongenerationthreshold0,,[17],,(Ro),,[3,810][7],Ro,,,,,,[7],,,,,,1,,,,,;,658200712PETROLEUMEXPLORATIONANDDEVELOPMENTVol.34No.6,1.12004[9],1,(8Ma)1(Ma)(Ma)(Ma)(Ma)2308225222.57222.52206220217.54+5217.5205202.5202.5200200197197185180180175175164164154149.5149.5145120100100880(30%,70%),[11,12],67820%,40%,20%~40%(70%,30%);478,46m,11.51501,2.8/100m,t();D(m);R(f)10.94,[10],,Ro,Ro[11,12],3.7/100m1.2[1012],(175Ma)4.0~7.0/100m2,,,Ro,4.3~4.6/100m,7Ro,152843479Ro(2,2),5.7/100m,Ro,Ro,7,4.3~4.6/100m5.7/100m,3,,659200712:27Ro(4.6/100m)27RoRo(%)T4.3/100mT4.6/100mT5.7/100mRo(%)(%)10.680.710.630.05~0.0810.520.540.560.02~0.0460.630.660.650.01~0.0210.640.660.600.04~0.0610.580.60.620.02~0.04360.690.730.740.01~0.0510.680.710.770.06~0.0920.6450.670.630.015~0.0410.7050.740.710.005~0.03150.670.6950.880.910.03280.670.70.900.830.07430.670.6850.860.860470.70.730.980.820.16130.560.580.60.02~0.0430.630.650.670.02~0.04270.680.710.720.01~0.0490.670.7050.920.940.02:T:,,36,Ro600m3,Ro,,,Ro[12],Ro,,336Ro[4],4.0/100m32km,(41km),(32km),[13,14][15],,,[16][17]:,()660!Vol.34No.6Ro44.17,,7,,4.6/100m,3.6~3.7/100m,,7(4)47661200712:7,(180Ma),,,Ro0.5%(149.5Ma),,,Ro0.5%~0.7%,(100Ma),7,()Ro1.0%,4.2,49,8,(5),81470m,80;TTI,8(149.5Ma),1600~1700m;Easy%Ro,81600m,,,1800m,1600m,,(149.5Ma)5,,(164~149.5Ma)(149.5~145Ma)(145~100Ma)(100~8Ma)(8Ma)5,,,80~90100~110[18];82,65~89115~140,82122[19],,110140,3,:,65~90;,100~110;,,1405.7/100m,[20,21]5,,4.3~4.6/100m;,5.7/100m(),(164Ma)662!Vol.34No.6,1600m,3,:[1],,,.[J].,1994,12(1):5665.[2],,,.[J].,2006,80(5):674684.[3],,,.()[J].,2005,79(6):737747.[4],BehrHJ.[J].,1996,17(2):1523.[5],,,.[J].,1997,42(3):306309.[6],,.[J].,1998,20(1):224.[7],,,.[J].,2006,80(5):685693.[8]UngererP,BurrusJ,DoligezB,etal.Basinevaluationbyintegratedtwodimensionalmodelingofheattransfer,fluidflow,hydrocarbongeneration,andmigration[J].Am.Assoc.Pet.Geol.Bull.,1990,74(1):309335.[9]GradsteinFM,OggJ,SmithA.Ageologictimescale2004[M].Carmbrige:CarmbrigeUniversityPress,2004.[10].[M].:,1999.1162.[11],.[J].,1997,71(1):6574.[12],,.[J].,1998,20(1):224.[13].[M].:,1996.98101.[14].[M].:,1998.4886.[15],,.[J].,1991,6(1):314.[16],,.[J].,1985,28(5):460472.[17].[M].:,1989.193250.[18],,,.(4)[M].:,1992.[19],,,.8[J].,2006,27(1):3336.[20],,,.[J].,2003,30(5):15.[21],.[J].,2003,30(2):5153.:陈瑞银(1976),男,山东泰安人,中国石油勘探开发研究院博士后,主要从事油气地质与成藏动力学研究地址:北京市海淀区学院路20号,中国石油勘探开发研究院石油地质研究所,邮政编码:100083Email:[e-mail]:20070421:20070815()(645)[10],,,.[J].,1999,4(3):3135.[11],,,.2[J].,2001,21(1):2330.[12],,,.[J].,2005,(1):3439.[13],,,.[J].,1999,73(2):131139.[14],.()[A].[C].:,1983.2941.[15],,.[J].,1983,10(1):412.[16],.()[M].:,2001.5765.[17].[A].[C].:,2004.49.[18].[A].[C].:,2004.1013.[19].[A].[C].:,2004.1418.[20].[J].,2005,32(5):3841.[21],,,.[A].[C].:,2004.4551.:戴金星(1935),男,浙江温州人,中国科学院院士,中国石油勘探开发研究院教授级高级工程师,从事天然气勘探与研究工作地址:北京市海淀区学院路20号,中国石油勘探开发研究院院部,邮政编码:100083Email:[e-mail]:20070720()663200712: