鄂尔多斯盆地苏里格气田地层水成因及气水分布规律

31520109ACTAPETROLEISINICAVol.31Sept.No.52010:02532697(2010)05076707窦伟坦刘新社王涛(710021):鄂尔多斯盆地苏里格气田是中国目前发现的最大天然气气田,属于低孔隙低渗透低丰度低产量大面积展布的砂岩岩性气藏,含气面积达4104km2地层水地球化学特征地层水产状与成因分析表明,苏里格气田地层水均为CaCl2型,呈弱酸性,总矿化度为2912~6830g/L,氢(2D)同位素-827~-605,氧(18O)同位素-63~-339,锶(87Sr/86Sr)同位素071365~071718,反映了互不连通的深层封存环境的古沉积水特征地层水分布主要受生烃强度和储层非均质性控制,不受区域构造控制,其相对独立不连片无统一气水界面:鄂尔多斯盆地;苏里格气田;岩性气藏;地层水成因;气水分布:TE112322:ATheoriginofformationwaterandtheregularityofgasandwaterdistributionfortheSuligegasfield,OrdosBasinDOUWeitanLIUXinsheWANGTao(PetroChinaChangqingOilfieldCompany,Xi!an710021,China)Abstract:TheSuligegasfieldwithagasbearingareaofabout4104km2intheOrdosBasinisoneofthelargestgasfieldsdiscoveredinChinauptonow.Itbelongstoasandstonelithologicgasreservoircharacteristicsoflowporosity,lowpermeability,lowabundance,lowyieldbutlargescaledistribution.Analysesongeochemistry,occurrenceattitudeandoriginofformationwatershowedthattheformationwaterintheSuligegasfieldwascharacterizedbychloridecalciumtype,slightacidity,totalsalinityof2912g/L~6830g/L,2Dvalueof-827~-605,18Ovalueof-63~-339,and87Sr/86Srvalueof071365~071718,indicatingapalaeodepositionalformationwaterinamutuallyunconnectedanddeeplyclosedenvironment.Thedistributionoftheformationwaterwasmainlycontrolledbytheintensityofhydrocarbongenerationandtheheterogeneityofreservoirsratherthanregionalstructures,anditwasrelativelyindependent,discontinuous,andlackinginauniformgaswaterinterface.Keywords:OrdosBasin;Suligegasfield;lithologicgasreservoir;originofformationwater;distributionofgasandwater(1),,21012m3,,,,188,122[1]81[12],,3~5m/km,384m/km,,,[25],,080~095,,,,,736%~994%,9315%,05471~07427g/cm3,CO2113%,12104m3/d,,,,1~20m3/d,:(2008ZX05044)∀#:,,19634,2005,,,Email:[e-mail]76820103181,,1Fig.1ThetectonicunitandthelocationofSuligegasFieldinordosBasin111[68],,172,,,(1),2912~6830g/L,4837g/L,pH50~60,Ca2+Na++K+Mg2+,Ca2+6~15g/L,Cl-HCO3-SO42-,Cl-18~42g/LCa2+Na++K+Cl-,1Table1TheformationwaterchemicalcharacteristicsofSuligeregionpH(K++Na+)/(mg∃L-1)Ca2+/(mg∃L-1)Mg2+/(mg∃L-1)Ba2+/(mg∃L-1)Cl-/(mg∃L-1)SO42-/(mg∃L-1)HCO3-/(mg∃L-1)/(g∃L-1)E11860615112115602073113401074977CaCl2E685095921391161204110901156534CaCl2S578608400119001103263450007695531CaCl2S668557626112083380323251492295188CaCl2Zh50860606160692250204991492163322CaCl2H2860561658212250193161493183145CaCl2Zh50860538459452250191621493443121CaCl2S60860625252021880190801493373121CaCl2S56860594541178527170295102454204818CaCl2S66860740911642380316352974645149CaCl2S1848609902107685030353473972365715CaCl2S518608296136235010379034951346095CaCl2Ch18609588152953380422395942486830CaCl2Zh101507591114199450336921244765497CaCl2E1216078791005848403010215312015026CaCl2S16416083401027160303153615881275247CaCl2S43160454057803341001820001652912CaCl2(rNa/rCl)065,CaCl2[9],∀%&∋#,,,(2),,,12(rNa/rCl)030~051,(rNa/rCa)044~105,[100rSO4/(rSO4+rCl)]0~376,[(rClrNa)/rMg]781~18001,135:769(),(3)(2D)(18O),2D-605,-827,-7377;18O-339,-63,-470,,(D=818O+10)[10],[11],28Fig.2ThedistributionofformationwatersalinityinMember8ShiheziFormationoftheSuligegasfield3Fig.3TherelationbetweenthehydrogenandoxygenisotopeofformationwaterintheSuligegasfield11(87Sr/86Sr)(),87Sr/86Sr071365~071718,,,,87Sr/86Sr[12],,,(4),,4Fig.4ThestrontiumisotopecharacteristicsofformationwaterinmaingasreservoirandCretaceousoftheSuligegasfield2,,,,,3(5),,87%,,[13],,8%03510-3m2,,&,&,,1~12m3/d,,8%~10%(035~10)10-3m2,10%,1010-3m2,770201031,,12m3/d,5Fig.5TheformationwaterclassificationandcomprehensivedescriptionoftheSuligegasfield331&,30~80m,6~12m,Ro14%~20%,(12~28)108m3/km2,[1416],14108m3/km280%,&,,10%,,[1718]68~148m[1920],,[1721],,,,(6),16108m3/km2,,,6Fig.6TherelationbetweenhydrocarbongeneratingintensityandthedistributionofproducingwellsintheSuligeregion32,,[22],5:771,,,,,,[2324],,,,[25],,,8(7),S61S598,,1260104m3/d878104m3/d,;S18S118,,150104m3/d002104m3/d,106m3/d118m3/d,78Fig.7ThenorthsouthsectionofgasreservoirinMember8ShiheziFormationoftheSuligeregion33,,,3~5m/km,1(100~500m,5~20m,25m[17],8~20m,015MPa,(12MPa)[25]1(,,,,&(8)4,,3,8Fig.8TherelationofregionalstructureanddistributionofproducingwaterwellsinSuligeregion,CaCl2,,(2D)(18O)(87Sr/86Sr)772201031,,,,[1],,,.[J].,2003,24(2):612.HeZixin,FuJinhua,XiShengli,etal.GeologicalfeaturesofreservoirformationofSuligeGasField[J].ActaPetroleiSinica,2003,24(2):612.[2],,,.[J].,2001,6(4):8994.YangHua,FuSuotang,MaZhenfang,etal.ThesuccessfulexperienceoffindingSuligeLargeGasFieldsquicklyandefficiently[J].ChinaPetroleumExploration,2001,6(4):8994.[3]YangHua,FuJinhua,WeiXinshan,etal.SuligeFieldintheOrdosBasin:Geologicalsetting,fielddiscoveryandtightgasreservoirs[J].MarineandPetroleumGeology,2008,25(4/5):387400.[4],,.[J].,2001,6(4):6875.FuJinhua,DuanXiaowen,JiangYingkun.GeologicalfeaturesandexplorationMethodsofnaturalgasreservoirformationintheUpperPaleozoicErathemintheErdosBasin[J].ChinaPetroleumExploration,2001,6(4):6875.[5],,.[J].,2005,25(4):58.YangHua,FuJinhua,WeiXinshan.CharacteristicsofnaturalgasreservoirformationinErduosiBasin[J].NaturalGasIndustry,2005,25(4):58.[6],,,.[J].,2009,29(1):99105.GuoMin,Li