天环坳陷南段中生界断裂特征及其石油地质意义  

Characteristics and petroleum geological significances of Mesozoic faults in the southern section of Tianhuan depression

作　　者：张园园 任战利[1,2] 杨桂林 王琨 吉园园[3] 林清申 ZHANG Yuanyuan;REN Zhanli;YANG Guilin;WANG Kun;JI Yuanyuan;LIN Qingshen(Department of Geology,Northwest University,Xi'an,Shaanxi 710069,China;State Key Laboratory for Continental Dynamic,Northwest University,Xi'an,Shaanxi 710069,China;No.1 Oil Production Department,SINOPEC North China Petroleum Bureau,Qingyang,Gansu 745006,China)

机构地区：[1]西北大学地质学系,陕西西安710069 [2]西北大学大陆动力学国家重点实验室,陕西西安710069 [3]中国石化华北油气分公司采油一厂,甘肃庆阳745006

出　　处：《中国矿业大学学报》2021年第2期318-328,共11页Journal of China University of Mining & Technology

基　　金：国家自然科学基金重点项目(41630312);国家科技重大专项(2017ZX05005002-008);国家重点研发计划项目(2017YFC0603106)。

摘　　要：为探明天环坳陷南段中生界构造特征及其石油地质意义,采用钻井联合三维地震的人机交互式解释方案,分析了镇泾地区中生界断裂体系空间展布特征及其成因机制,明确了断裂对延长组油藏差异分布的影响作用,认为镇泾地区中生界压扭、张扭及转换断裂发育,断裂与砂体匹配共同决定了油气分布规律。研究结果表明:先存基底断裂间歇"隐性"活动导致中生界断裂多期次发育,剖面上高陡产状,断层倾角大于70°,断距多小于70m;平面上北西向、北东东向以及近东西向3组断裂线状延伸,呈雁列式带状走滑.其中印支期北西向区带级断裂走滑,控制了镇泾地区构造格局;中晚燕山期北东向圈闭级断裂活动加强,影响圈闭类型与油气输导;喜山期北东东向断裂密度增大,并派生大量层组间剪切裂隙,改善储层物性.断-砂组合类型决定了油气富集位置,侧向封闭强度影响了烃类富集程度:砂体展布方向垂直于地层倾向且平行于断层走向的圈闭级断裂发育区,匹配砂地比高于60%、断层泥比率大于0.5的长812砂层组最易形成油气聚集.In order to explore the Mesozoic structural characteristics and its petroleum geological significances in the southern segment of Tianhuan depression,the spatial distribution characteristics and genetic mechanism of Mesozoic fault system in Zhenjing area were analyzed by using the interactive interpretation scheme of drilling combined with three dimensional(3D)seismic.And the influences of faults on the differential distribution of oil reservoirs in Yanchang formation were also clarified.It was raised that the Mesozoic compressional,tensional and transitional faults are developed in Zhenjing area,and the matching of faults and sand bodies jointly determines the distribution of oil and gas.The results showed that the intermittent"recessive"activity of pre-existing basement faults lead to the development of Mesozoic faults in multiple stages,with high and steep occurrence on the profile.The fault dip was greater than 70°and the fault throw was less than 70 m.Three groups of faults in NW,NEE,and nearly EW direction extended linearly in plane,showing en echelon zonal strike slip.In addition,the NW trending zone level faults strike-slip in Indosinian period controlled the Mesozoic structural pattern in Zhenjing area.The NE trending trap level fault activity strengthened in the mid-late Yanshanian period,which affected the trap types and hydrocarbon transport.And the density of NEE trending faults increased in the Himalayan stage,deriving the interlayer shear fractures and improving the reservoir’s physical properties.The combination types of faults and sand bodies determined the location of hydrocarbon accumulation,and the intensity of lateral sealing affected the degree of hydrocarbon enrichment.In the oil-source fault development zone in which the strike of sand body is perpendicular to the stratigraphic dip direction and parallel to the fault strike,the matching Chang 812sand group,with the sand ratio higher than 60%and fault mud ratio greater than 0.5,is most susceptible to enrich oil and gas.

关 键 词：鄂尔多斯盆地 镇泾地区 三维地震解释 断裂体系特征 断裂成因及演化 断裂控藏作用 

分 类 号：P548[天文地球—构造地质学]