玛湖凹陷斜坡区中浅层断裂特征及其控藏作用  

Fault characteristics and control on hydrocarbon accumulation of middleshallow layers in the slope zone of Mahu sag, Junggar Basin, NW China

作　　者：陈永波[1] 程晓敢[2] 张寒[1] 李春阳 马永平[1] 王国栋[1] CHEN Yongbo;CHENG Xiaogan;ZHANG Han;LI Chunyang;MA Yongping;WANG Guodong(Northwest Branch of Research Institute of Petroleum Exploration&Development,PetroChina,Lanzhou 730020,China;School of Earth Sciences,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]中国石油勘探开发研究院西北分院,兰州730020 [2]浙江大学地球科学学院,杭州310027

出　　处：《石油勘探与开发》2018年第6期985-994,共10页Petroleum Exploration and Development

基　　金：国家重大科技专项(2017ZX05008-001;2011ZX05003-003)

摘　　要：以地震和钻井资料为基础,开展玛湖凹陷斜坡区中浅层断裂发育特征、演化过程和形成机制以及断裂对中生界油气运聚成藏的控制作用等研究。研究认为,玛湖凹陷斜坡区中浅层发育两种类型的断层,即正断层和走滑断层,主要活动期为燕山期,平面上分为4级断裂,分别是北西西向—近东西向的Ⅰ级走滑断裂,其形成和三叠纪末以来盆地西北缘断裂带的左行压扭有关;北东向—北北东向的Ⅱ级断裂,为分布在西北缘断裂带—斜坡区交界部的正断层,其形成和断裂带继承性鼻隆顶部拉张作用有关;北西西向Ⅲ级断裂为斜坡区低幅度凸起顶部拉张形成的正断层及差异压实有关;北东向的Ⅳ级断裂可能是低幅度凸起倾末端的拉张环境形成的横张正断层。断裂不但是油气垂向运移的通道,还具有控藏作用,玛湖凹陷斜坡区中浅层发育2种油气藏类型:断块油气藏和断层-岩性油气藏,圈闭面积大,勘探程度相对较低,勘探潜力巨大。The development,evolution and formation mechanism of faults and their control on the migration and accumulation of Mesozoic oil and gas in the middle-shallow layers of the slope zone of Mahu sag were studied by the interpretation of seismic and drilling data.Two types of faults,normal and strike-slip,are developed in the middle-shallow layers of the slope zone of the Mahu sag and they are mostly active in the Yanshanian period.They are divided into four grade faults:The grade I strike-slip faults with NWW to near EW direction are related to the left-lateral transpressive fault zones in the northwest of Junggar Basin since the end of the Triassic.The grade II faults with NE to NNE direction are the normal faults located at the junction of the fault zone and the slope zone,and their formation is related to the extension at the top of the nose-like structures in the fault zone.The grade III faults,which are also the normal faults,are the result of the extension at the top of the lower uplifts in the slope zone and differential compaction.The grade IV faults with NE direction are normal faults,which may be related to the extension environment at the tip of the lower uplifts.Faults not only are the channel for the vertical migration of oil and gas,but also control the oil-gas accumulation.There are two types of oil-gas reservoirs in the middle-shallow layers of slope zone of Mahu sag:fault block reservoirs and fault-lithologic reservoirs.They have large traps and promising exploration potential.

关 键 词：准噶尔盆地 玛湖凹陷斜坡区 中浅层 断裂 形成机制 鼻隆 低凸起 油气成藏 

分 类 号：TE121.1[石油与天然气工程—油气勘探]