地球化学动态示踪油气成藏过程初探——以库车坳陷大宛齐构造为例

doi:10.11743/ogg20050603

摘要/Abstract

摘要：

塔里木盆地库车坳陷大宛齐油气藏中³⁸Ar的富集与缺氧流体及挥发分沿大断裂运移有关,吐孜玛扎断裂是流体活动形成的³⁸Ar运移至油气藏的主要通道;而大北油气藏低的³⁸Ar丰度显示了气源就近成藏的特征。大宛齐油气田为原生油气藏,并非后期气侵作用形成。油气藏形成后期,因圈闭封闭能力弱造成气体轻组分沿破裂部分散逸,形成现今饱和程度较低的凝析气藏。大宛齐油气田为下生上储型成藏,三叠系和侏罗系为其主生油层系。在大宛齐油气田的形成过程中,烃类先沿吐孜玛扎断层运移,再从北向南进入大宛齐构造。大宛齐油气藏中的液态烃为中生界淡水湖相沉积有机质在成熟-高成熟演化阶段的产物。大宛齐油气田经历了早期与晚期两个充注过程,晚期充注的高-过成熟天然气密度较小因而主要聚集在上方,早期形成的相对高密度的天然气主要聚集在下方。

关键词: 同位素组成, 成藏过程, 地球化学示踪, 库车坳陷, 塔里木盆地

Abstract:

In Dawanqi oil/gas pool in Kuqa depression,Tarim basin,the enrichment of ³⁸Ar was related to the migration of anoxic fluids and volatile constituents along large faults.Tuzimazha fault is the major pathway,through which ³⁸Ar generated from fluid activities would have migrated to the oil and gas reservoirs.The low concentration of ³⁸Ar in Dabei reservoir reveals that gas would have been reservoired near the source rocks.Dawanqi oil/gas field is not an oil/gas pool as a result of later gas invasion,but is a primary oil/gas pool.The light components of gas partially dispersed along the fault due to the poor sealing ability of the trap at later reservoiring stage,leading to the formation of the current condensate gas reservoir with relatively low saturation.Hydrocarbons were generated from the Triassic and Jurassic major source rocks below,and were accumulated in the reservoir rocks above,i.e.,hydrocarbons have been generated from the organic matters in the Mesozoic fresh lake facies sediments during mature to high-mature evolutional phases.During the reseroviring process of Dawanqi oil/gas pool,hydrocarbons first migrated upward along Tuzimazha fault,and then entered Dawanqi structure from north to south.Dawanqi oil/gas pool has experienced early and late charging processes.The high-mature to over-mature natural gas charged in later stage would have mainly accumulated in the upper part,due to their relatively low density;while the relatively high density natural gas generated in early stage would have accumulated in the lower part.

Key words: isotopic composition, reservoiring process, geochemical tracing, Kuqa depression, Tarim basin

中图分类号:

TE112.3

刘文汇,张殿伟,郑建京,等. 地球化学动态示踪油气成藏过程初探——以库车坳陷大宛齐构造为例[J]. 石油与天然气地质, 2005, 26(6): 717-723,729. doi: 10.11743/ogg20050603 Liu Wenhui,Zhang Dianwei,Zheng Jianjing,et al. A preliminary discussion on geochemical dynamic tracing of oil/gas reservoiring process—taking Dawanqi structure in Kuqa depression as an example[J]. Oil & Gas Geology, 2005, 26(6): 717-723,729. doi: 10.11743/ogg20050603

参考文献

[1] Stahl W J,Carey Jr B B.Source rock identification by isotope analyses of natural gases from fields in the Val Varde Delaware basins,West Texas[J].Chemical Geology,1975,16:257-267
[2] 戴金星,戚厚发,宋岩.鉴别煤成气和油型气等指标的初步探讨[J].石油学报,1985,6(2):31～38Dai Jinxing,Qi Houfa,Song Yan.Discussion to the guideline of coal type gas and oil type gas distinguishing[J].Acta Petrolei Sinica,1985,6(2):31-38
[3] Chung H M,Gorml J R,Squires R M.Origin of gaseous hydrocarbons in subsurface environments:theoretical considerations of carbon isotope distribution[J].Chemical Geology,1988,71:71-103
[4] 沈平,徐永昌,王先彬,等.气源岩和天然气地球化学特征及成气机理研究[M].兰州:甘肃科学技术出版社,1991.1～248Shen Ping,Xu Yongchang,Wang Xianbin,et al.Study on geochemistry character of gas source rock and natural gas and mechanism of gas forming[M].Lanzhou:Gansu Science & Technology Press,1991.1-248
[5] 徐永昌.天然气成因理论与应用[M].北京:科学出版社,1994.1～414Xu Yongchang.Origin theory and application of natural gas[M].Beijing:Science Press,1994.1-414
[6] 王涛.中国天然气地质理论基础与实践[M].北京:石油工业出版社,1997.1～134Wang Tao.China natural gas geology theoretical basis and practice[M].Beijing:Petroleum Industry Press,1997.1-134
[7] Hanson A D,Zhang S C,Moldowan J M,et al.Molecular orga-nic geochemistry of the Tarim basin,Northwest China[J].AAPG Bull,2000,84(8):1 109-1 128
[8] Zhang S C,Hanson A D,Moldowan J M,et al.Paleozoic oil-source rock correlations in the Tarim basin,NW China[J].Organic Geochemistry,2000,31(4):273-286
[9] Zhang S C,Moldowan J M,Bian L Z,et al.Biological and mole-cualr geochemical evidence for dinoflagellate ancestors in the Upper Sinian-Cambrian[J].Acta Geologica Sinica,2000,74(4):740-747
[10] Schlell M.The hydrogen and carbon isotopic composition of me-thane from natural gases of various origins[J].Geochimica et Cosmochimica Acta,1980,44(5):649-661
[11] James A T.Correlation of natural gas by use of carbon isotopic distribution between hydrocarbon components[J].AAPG Bull,1983,67(11):1 176-1 191
[12] Fan P,Philp R P,Li Z X,et al.Geochemical characteristics of aromatic hydrocarbons in crude oils and source rocks from different sedimentary environments[J].Organic Geochemistry,1990,16(1-3):27-435
[13] 刘文汇,徐永昌.煤型气碳同位素演化二阶段分馏模式及机理[J].地球化学,1999,7(4):359～366Liu Wenhui,Xu Yongchang.A two-stage model of carbon isotopic fractionation in coal gas[J].Geochimica,1999,7(4):359-366
[14] 陈孟晋,胡国艺.流体包裹体中气体碳同位素测定新方法及其应用[J].石油与天然气地质,2002,23(4):339～343Chen Mengjin,Hu Guoyi.A new method in assaying gas isotopes in fluid inclusion and the way of application[J].Oil ＆ Gas Geo-logy,2002,23(4):339-343
[15] 苟捷.天然气烃指纹分析在气藏地球化学描述中的应用[J].石油与天然气地质,2004,25(3):349～354Gou Jie.Application of hydrocarbon finger print analysis to geochemical description of gas pools[J].Oil ＆ Gas Geology,2004,25(3):349-354
[16] 陈晋阳,张红,肖万生.有机油气形成的影响因素--模拟实验的研究进展[J].石油与天然气地质,2004,25(3):247～253Chen Jinyang,Zhang Hong,Xiao Wansheng.Factors affecting generation of organic origin prtroleum:development of simulating experimental study[J].Oil ＆ Gas Geology,2004,25(3):247-253
[17] 梁狄刚,张水昌,赵孟军,等.库车坳陷的油气成藏期[J].科学通报,2002,47(增1):56～63Liang Digang,Zhang Shuichang,Zhao Mengjun,et al.Hydrocarbon sources and stages of reservoir formation in Kuqa depression,Tarim basin[J].Chinese Science Bulletin,2002,47(S1):62-70
[18] 赵靖舟.前陆盆地天然气成藏理论及应用[M].北京:石油工业出版社,2003.1～191 Zhao Jingzhou.Reservoiring theory of natural gas in foreland basins and its application[M].Beijing:Petroleum Industry Press,2003.1-191
[19] 梁狄刚,陈建平,张宝民,等.塔里木盆地库车坳陷陆相油气的生成[M].北京:石油工业出版社,2004.1～265Liang Digang,Chen Jianping,Zhang Baomin,et al.Hydrocarbon generation from terrestrial sediments in Kuqa depression,Tarim basin[M].Beijing:Petroleum Industry Press,2004.1-265
[20] 刘文汇,徐永昌.天然气中氦氩同位素组成意义[J].科学通报,1993,38(9):818～821Liu Wenhui,Xu Yongchang.The significance of He and Ar isotopic composition in natural gas[J].Chinese Science Bulletin,1993,38(9):818-821
[21] 刘英俊,曹励明,李兆麟,等.元素地球化学[M].北京:科学出版社,1984.1～548 Liu Yingjun,Cao Liming,Li Zhaolin,et al.Element geochemistry[M].Beijing:Science Press,1984.1-548
[22] 梅博文,刘希江.我国原油中异戊间二烯烷烃的分布及其与地质环境的关系[J].石油与天然气地质,1980,1(2):99～115Mei Bowen,Liu Xijiang.The distribution of isoprenoid alkanes in China's crude oil and its relation with the geologic environment[J].Oil & Gas Geology,1980,1(2):99-115
[23] Radke M,Welt D H.The methylphenanthrene index(MPI):a maturity parameter based on aromatic hydrocarbon[J].Organic Geochemistry,1981,12:504-512
[24] 田作基,张光亚,邹华耀,等.塔里木盆地库车含油气系统油气成藏的控制因素及成藏模式[J].石油勘探与开发,2001,28(5):12～16Tian Zuoji,Zhang Guangya,Zou Huayao,et al.Tarim basin Kuqa petroleum system controlling factor and reservoir forming pattern[J].Petroleum Exploration & Development,2001,28(5):12-16
[25] 陈义才,沈忠民,李延钧,等.大宛齐油田溶解气扩散特征及其扩散量计算[J].石油勘探与开发,2002,29(2):58～60Chen Yicai,Shen Zhongmin,Li Yanjun,et al.Simulation of diffusion quantity of solution gas in Dawanqi oil field[J].Petroleum Exploration & Development,2002,29(2):58-60