东濮凹陷北部古近系沙三段超压岩性油气藏成藏机理  

Accumulation mechanism of overpressured lithologic reservoirs of the third member of Paleogene Shahejie Formation in northern Dongpu Sag

作　　者：张磊[1,2] 李莎 罗波波[1,2] 吕伯强 谢敏 陈新平[1,2] 陈冬霞 邓彩云[1,2] ZHANG Lei;LI Sha;LUO Bobo;LYU Boqiang;XIE Min;CHEN Xinping;CHEN Dongxia;DENG Caiyun(Research Institute of Exploration and Production,Zhongyuan Oilfield Company,Sinopec,Puyang 457001,Henan,China;Zhongyuan Oilfield Branch Company,Sinopec,Puyang 457001,Henan,China;National Key Laboratory of Petroleum Resources and Engineering,Beijing 102249,China)

机构地区：[1]中国石化中原油田分公司勘探开发研究院,河南濮阳457001 [2]中国石化中原油田分公司,河南濮阳457001 [3]油气资源与工程全国重点实验室,北京102249

出　　处：《岩性油气藏》2024年第4期57-70,共14页Lithologic Reservoirs

摘　　要：东濮凹陷深部储层致密,超压广泛发育,油气生运聚过程复杂。利用测井、录井、钻井及地球化学分析等资料,对东濮凹陷北部古近系沙三段超压的形成机制、超压对源岩与储层的影响以及油气运移动力进行了系统研究,并阐明深层超压岩性油气藏的成藏机理。研究结果表明:(1)东濮凹陷北部古近系沙三段超压岩性油气藏类型主要包括砂岩上倾尖灭油气藏、砂岩透镜体油气藏、裂缝油气藏3种纯岩性油气藏和岩性-构造油气藏、构造-岩性油气藏2种复合油气藏。岩性油气藏主要分布于东濮凹陷北部地区,尤其在前梨园洼陷、海通集洼陷、柳屯洼陷及濮城—卫城洼陷周边,具有“环洼有序分布”的特征。(2)研究区厚层膏盐岩发育及生烃过程产生的深层超压对烃源岩的生烃具有抑制作用,有效扩大了生油窗,增强了深部源岩的生烃能力,促进了其对环洼岩性油气藏的大规模近源供烃;膏盐岩发育、早期快速埋藏、超压的抗压实作用和晚期发育的溶蚀作用控制了优质储层的分布;深部广泛发育的超压和浮力协同作用为深层油气运移提供了有效动力。(3)研究区东部洼陷带为“单洼单源、早混相晚气相、自生自储、超压驱动运聚”成藏模式;东部陡坡带为“单洼多源、早混相晚气相、超压-浮力驱动侧向运聚”成藏模式;西部斜坡带为“单洼多源、油相、超压-浮力驱动侧向运聚”成藏模式;西部洼陷带为“单洼单源、油相、超压-浮力驱动侧向运聚”成藏模式。The processes of hydrocarbon generation,migration and accumulation are complex with tight reser‐voirs and widespread overpressure in the deep area of Dongpu Sag.A systematic study was conducted on the for‐mation mechanism of overpressure,the effects of overpressure on source rocks and reservoirs,as well as the dyna-mics of hydrocarbon migration in the third member of Paleogene Shahejie Formation in northern Dongpu Sag by using wire-logging,mud-logging,drilling,and geochemical analysis data,and the accumulation mechanisms of deep overpressured lithologic reservoirs were elucidated.The results show that:(1)There are five types of over‐pressured lithologic reservoirs of the third member of Paleogene Shahejie Formation in northern Dongpu Sag,which are three pure lithologic reservoirs and two compound reservoirs.The pure lithologic reservoirs include updip pinch-out sandstone reservoirs,sand lens reservoirs and fractured reservoirs,while the compound reservoirs are lithologic-structural reservoirs and structural-lithologic reservoirs.The lithologic reservoirs are mainly distributed in the northern Dongpu Sag,especially around Qianliyuan subsag,Haitongji subsag,Liutun subsag and Pucheng-Weicheng subsag,with the characteristics of“orderly distribution around sags”.(2)The deep overpressure caused by the thick gypsum salt rocks and the process of hydrocarbon generation in the study area can inhibit the hydrocarbon generation of source rocks,effectively enlarging the oil generation window,enhancing the hydrocar‐bon generation ability of deep source rocks,and promoting large-scale near source hydrocarbon supply to litho‐logic reservoirs around the sag.The distribution of high-quality reservoirs is controlled by gypsum salt rocks,rapid burial in the early stage,anti-compaction of overpressure and dissolution in the late stage.The synergistic action of overpressure and buoyancy widely developed in the deep,provides an effective driving force for deep oil and gas migration.(3)The hydrocarbon accumulation model of

关 键 词：岩性油气藏 近源供烃 膏盐岩 超压驱动 浮力驱动 侧向运聚 沙三段 古近系 东濮凹陷 

分 类 号：TE122.1[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]