【作者】 郭迎春； 庞雄奇； 陈冬霞； 冷济高； 田军；

【Author】 GUO Ying-chun~(1,2),PANG Xiong-qi~(1,2),CHEN Dong-xia~(1,2),LENG Ji-gao~3,TIAN jun~3 (1 Research Center for Basin and Reservoir,College of Geosciences,China University of Petroleum, Beijing,102249;2 State Key Laboratory of petroleum Resource and Prospecting,China University of Petroleum,Beijing,102249;3 Exploration and Development Research Institute,Southwest Branch Company, SINOPEC,Chengdu,610081)

【机构】 中国石油大学(北京)地球科学学院盆地与油藏中心； 油气资源与探测国家重点实验室； 中国石化西南油气分公司勘探开发研究院；

【摘要】 以川西坳陷中段地区现今压力分布、测井资料分析及其成因机制探讨为基础,以储层实测压力数据为约束,利用盆地模拟技术及其他定量分析方法恢复出该地区的地层压力演化史,并讨论了增压机制的阶段差异性、不同机制增压幅度的差异性以及压力演化对天然气运移聚集成藏的控制作用。研究表明:川西坳陷中段须家河组超压的主要成因机制有:①欠压实作用(上三叠世早期—侏罗纪末),②天然气生成作用(早侏罗世末—新近纪),③构造挤压作用(白垩纪期间及新近纪以来)。并认为构造挤压和天然气生成是现今须家河组地层超压的主要因素,地层普遍致密化对异常高压起到了加强和保存作用。侏罗系地层超压的主要成因机制是超压传递作用,主要发生在白垩纪以来构造活动强烈时期。排烃高峰期的高源储压力差(>25Mp)为深部天然气的高效聚集提供了保障,超压及因其产生的裂缝是天然气运移的主要动力和通道.断裂输导和超压驱动促使了侏罗系"远源次生气藏"的形成。指出侏罗系压力系数高值区和须家河组中高超压带是勘探优选目标。更多还原

【Abstract】 Based on the distribution features of present formation pressure,analysis on logging data and genetic mechanisms of abnormal pressure,the overpressure evolution was reconstructed by means of some techniques including basin numerical stimulation and other quantitative analysis methods,which was restrained by the measured pressures of reservoir.The phase differences of pressure increasing mechanisms, enhancement differences among different mechanisms and the control action of geopressure evolution on gas migration and accumulation were discussed.The research indicates that the causes of overpressure in Xujiahe formation include①under-compaction(from early upper Triassic to the end of Jurassic),②natural gas generation(from end of Early Jurassic to Neogene) and③Tectonic compression(in Cretaceous period and since the Neogene).It is suggested that Tectonic Compression and gas generation are the principal factors of the present overpressure in Xujiahe formation,and the high densification level of Xujiahe formation play an important role on overpressure as enhancement and preservation.Overpressure transference is the main cause of overpressure in Jurassic formation which occurred during the intense tectonic activity periods since Cretaceous.The high differential pressure between source rock strata and reservoir during hydrocarbon expulsion peak ensured the high efficiency of gas accumulation in Xujiahe formation.The overpressure and related microfractures are the hydrocarbon migration force and pathway. Fault transport and overpressure driving brought the formation of Jurassic secondary gas reservoirs with distant sources.The areas with high pressure coefficient in Jurassic and high-overpressure zones in Xujiahe formation are optimum targets for exploration.更多还原