渤海东部先存构造斜向拉伸作用及其石油地质意义  

Oblique extension of pre-existing structures and its control on oil accumulation in eastern Bohai Sea

作　　者：任健 吕丁友 陈兴鹏 刘朋波 官大勇 苏凯 张宏国 REN Jian;LV Dingyou;CHEN Xingpeng;LIU Pengbo;GUAN Dayong;SU Kai;ZHANG Hongguo(Research Institute of Bohai Oil Field,CNOOC Tianjin Branch Company,Tianjin 300452,China;School of Geoscience,China University of Petroleum,Qingdao 266580,China)

机构地区：[1]中海石油(中国)天津分公司渤海石油研究院,天津300452 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《石油勘探与开发》2019年第3期530-541,共12页Petroleum Exploration and Development

基　　金：国家科技重大专项"大型油气田及煤层气开发"(2016ZX05024-002-006);中海石油(中国)有限公司科技项目"渤海东部走滑断裂带控藏机理研究与有利勘探目标预测"(YXKY-2017-TJ-01)

摘　　要：为揭示渤海东部地区的构造发育成因及其对油气成藏差异性的控制作用,基于三维地震资料,综合运用构造样式分析、断裂活动性分析、构造物理模拟以及实钻井对比等多种手段,剖析研究区断裂特征及发育机理。分析表明:研究区在古近纪的走滑派生及裂陷作用下产生了走向多变、数量众多的复杂断裂体系,该断裂体系在新近纪近南北向拉伸应力场的作用下部分活化、继承性发育并发生斜向拉伸作用,受先存断裂影响小的位置主要发育与拉伸方向近于垂直的新近纪新生断层。研究区的构造发育并非是受到压扭为主的走滑作用的结果。在先存断裂斜向拉伸作用下,先存断裂走向与晚期拉张方向夹角不同,其走滑-拉伸应力配比也不同,两者夹角越大,则断裂拉张分量越强,断裂的油气封闭能力越差,但油气的运移能力越强;反之,则走滑分量越强,断裂的油气封闭能力越好,运移能力越弱。考虑断裂走向方位的成藏条件分析结果与研究区实钻井油气显示情况有着良好对应关系,可以为该区下步油气勘探提供借鉴。Based on 3D seismic data,the evolution mechanism and characteristics of faults were investigated to reveal the structural origin and its control on differential hydrocarbon accumulation through comprehensive analyses,including structure style analysis,fault activity analysis,analogue modelling and comparison among the wells.The complex fault system with differently trending faults resulted from strike-slip and rifting in Paleogene was partly activated,developed successively and stretched obliquely by the near-NS extensional stress field in Neogene.In the area little affected by pre-existing faults,new faults nearly perpendicular to the extension direction developed.The structural development in the study area was not caused by transpressional strike slip.Under the oblique extension effect of pre-existing faults,if the angle between the strike of pre-existing fault and the extensional direction is different,the strike-slip and extensional stresses are different in ratio.The larger the angle between the two is,the stronger the extensional component,the poorer the sealing ability of the fault,and the stronger the oil and gas migration capacity will be.Conversely,the smaller the angle between the two is,the stronger the strike-slip component,the better the sealing ability of the fault,and the poorer the oil and gas migration capacity will be.The accumulation condition analysis results considering the fault trend are in good agreement with the oil and gas shows in wells drilled in this area.

关 键 词：斜向拉伸 先存断裂 走滑分量 伸展分量 古近纪 新近纪 渤海海域 

分 类 号：TE122[石油与天然气工程—油气勘探]