准噶尔盆地阜康凹陷东部深层二叠系超压形成机制及演化特征  

Formation mechanism and evolution characteristics of overpressure in deep Permian in eastern Fukang Sag,Junggar Basin

作　　者：魏成林 张凤奇 江青春[3] 鲁雪松[3] 刘刚[3] 卫延召[3] 李树博[4] 蒋文龙 WEI Chengin;ZHANG Fengqi;JIANG Qingchun;LU Xuesong;LIU Gang;WEI Yanzhao;LI Shubo;JIANG Wenlong(School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an 710065,China;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an Shiyou University,Xi’an 710065,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;Research institute of Exploration and Development,PetroChina Xinjiang Oilfield Company,Karamay 834000,Xinjiang,China)

机构地区：[1]西安石油大学地球科学与工程学院,西安710065 [2]西安石油大学陕西省油气成藏地质学重点实验室,西安710065 [3]中国石油勘探开发研究院,北京100083 [4]中国石油新疆油田公司勘探开发研究院,新疆克拉玛依834000

出　　处：《岩性油气藏》2024年第5期167-177,共11页Lithologic Reservoirs

基　　金：国家自然科学基金面上项目“压力—应力耦合对前陆冲断带深层—超深层碎屑岩储层异常高原生孔隙的保存机制研究”(编号:42172164);中国石油前瞻性基础性科技攻关项目“深层超深层油气成藏过程与油气分布规律研究”(编号:2021DJ0203)联合资助。

摘　　要：利用钻井、录井、测井以及实测地层压力等资料,采用考虑多种超压机制的盆地模拟技术,综合判识了准噶尔盆地阜康凹陷东部二叠系地层超压的成因机制,定量恢复了各成因类型的超压演化特征。研究结果表明:(1)准噶尔盆地阜康凹陷东部二叠系发育弱超压—强超压,地层压力系数为1.36~1.88,过剩压力为12~49 MPa,不同构造部位发育的超压存在明显差异。凹陷区超压最强,地层压力系数为1.50~1.88,过剩压力为23~49 MPa;斜坡带次之,地层压力系数为1.52~1.79,过剩压力为24~37 MPa;凸起区相对最弱,地层压力系数为1.36~1.59,过剩压力为12~23 MPa。(2)研究区不同岩性的地层超压成因不同,芦草沟组烃源岩超压成因为生烃和欠压实作用;上乌尔禾组储层超压成因为超压传递和欠压实作用;上乌尔禾组泥岩盖层超压成因为欠压实作用。(3)研究区芦草沟组烃源岩和上乌尔禾组泥岩盖层的超压具有持续增大的特征,芦草沟组烃源岩生烃增压贡献率沿凸起区、斜坡带至凹陷区逐步增大,上乌尔禾组泥岩盖层欠压实增压量也具有相同变化趋势;上乌尔禾组储层超压经历了晚三叠世至晚侏罗世缓慢增大、晚侏罗世末期至早白垩世快速增大、早白垩世末期至现今缓慢增大3个阶段,其中超压传递增压对现今储层超压的贡献率为58.46%~78.86%。Based on the data of drilling,mud-logging,wire-logging,and measured formation pressure,the basin simulation technology considering multiple overpressure mechanisms was applied to identify the overpressure origins of Permian in the eastern Fukang Sag of Junggar Basin,and the evolution characteristics of overpressure of various origins were quantitatively restored.The results show that:(1)The Permian in the eastern Fukang Sag develops weak to strong overpressure,the formation pressure coefficient ranges from 1.36 to 1.88,and the excess pressure ranges from 12 to 49 MPa.The overpressure developed in different structural parts is obviously different.The overpressure in the sag is the highest,with formation pressure coefficient of 1.50-1.88 and excess pressure of 23-49 MPa,followed by slope zone,with a formation pressure coefficient of 1.52-1.79 and excess pressure of 24-37 MPa.It is relatively weakest in the uplift,with formation pressure coefficient ranging from 1.36 to 1.59 and excess pressure ranging from 12 to 23 MPa.(2)The origins of overpressure in the strata with different lithologies in the study area are different.The overpressure in the source rocks of Lucaogou Formation is caused by hydrocarbon generation and undercompaction,it is caused by overpressure transference and undercompaction in the reservoirs of the Upper Urho Formation,while it is caused by undercompaction in the mudstone cap rocks of the Upper Urho Formation.(3)The overpressure in the source rocks of the Lucaogou Formation and the mudstone cap rocks of the Upper Urho Formation in the study area has a continuous increasing cha-racteristic.The contribution rate of hydrocarbon generation and pressure increase of the source rocks of the Lucaogou Formation gradually increases along the uplift,slope zone to the sag.The undercompacted pressure increase of the mudstone cap rocks of the Upper Urho Formation also shows the same changing trend.The overpressure in the reservoirs of Upper Urho Formation slowly increased from the Late Triassic to the Late J

关 键 词：地层超压 生烃增压 欠压实超压 超压传递 上乌尔禾组 芦草沟组 二叠系 阜康凹陷 准噶尔盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]