印度河盆地T区块构造特征与油气成藏  

Tectonic characteristics and hydrocarbon accumulation in the Block T,Indus River Basin

作　　者：陈旭[1,2,3] 刘彩芹 王红梅 谢锐杰 杨建房[2] 董锡岩 

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [2]东方地球物理公司研究院,河北涿州072750 [3]长江大学地球物理与石油资源学院,湖北武汉430100

出　　处：《石油地球物理勘探》2017年第6期1305-1314,共10页Oil Geophysical Prospecting

基　　金："十三.五"国家专项"川西源内成藏体系成藏机理研究"(2016ZX05002-004-009)资助

摘　　要：依据大量的地震剖面解释及地质综合分析成果,探讨了印度河盆地T区块区域构造演化特征,总结了研究区扭张性断裂构造组合样式和有利圈闭类型,进一步讨论了构造运动与油气成藏的关系,得出以下认识。(1)盆地演化主要经历了基底期、侏罗纪裂谷期、白垩纪斜向拉张断陷期和古近纪以来的板块碰撞及构造反转等演化阶段。多期次构造运动导致研究区断裂系统发育,构造内幕破碎。(2)由于白垩纪印巴板块的漂移、旋转和分离,导致了强烈的斜向拉张作用,形成了总体上垒堑相间、局部断块复杂化的构造格局,并于白垩纪末期基本定型。结合白垩系扭张性断裂构造样式分析,识别了6类平面、7类剖面的典型组合样式。(3)T区块具备优越的油气成藏条件,构造运动促进生油岩的成熟和排烃;扭张性断裂构造样式组合形成了多种圈闭类型,包括断块、断鼻、断背斜和构造—岩性复合圈闭等;深大断裂沟通了油源和圈闭,提供油气运移通道,利于油气成藏,扭张性断裂活动与源岩排烃和圈闭形成期构成良好的匹配关系。最后在构造特征和油气成藏分析的基础上指出了有利油气勘探区带。Based on a large number of seismic interpretation and geological comprehensive analysis,the re-gional tectonic evolution characteristics in the Block T,Indus River Basin are discussed in this paper;the transtensional fault combination styles and favorable trap types are summarized;and the relationship between tectonic activities and hydrocarbon accumulation is further analyzed.The cognitions are as follows:(1)The tectonic evolution has mainly experienced four stages:basement,Jurassic rift,Cretaceous diagonal extension-depression and plate collision,and tectonic reverse since Paleogene.Multistages of tectonic movements resulted in well-developed fault systems and broken structures in the study area;(2)India Plate drift,rotation,and splitting caused diagonal extension-depression in the study area,which helped to form horst-graben structures and locally complex fault blocks,and tectonic patterns were basically formed in late Cretaceous.Combined with the analysis of transtensional faults combination characteristics,6 kinds of plane and 7 kinds of vertical types of combinations are identified;(3)The Block T has favorable hydrocarbon accumulation conditions,tectonic activities promote the maturity and hydrocarbon expulsion from source rocks,and different transtensional structure combinations formed various hydrocarbon trap type,including faulted blocks,faulted noses,faulted anticline and structure-lithology composite traps.Major huge faults provided the hydrocarbon migration channel by connecting oil sources and traps.It shows that there is a good spatial and temporal relationship among transtensional fault activities,hydrocarbon expulsion,and trap forming period.At last,based on the structure characteristics and hydrocarbon accumulation analysis,the paper discusses favorable hydrocarbon exploration zones.

关 键 词：构造演化 扭张性断裂 油气成藏 印度河盆地 勘探潜力 

分 类 号：P631[天文地球—地质矿产勘探]