鄂尔多斯盆地古峰庄地区断裂特征及油气地质意义

Fault Characteristics and Petroleum Geological Significance in the Gufengzhuang Area,Ordos Basin

开展断裂研究对认识盆地构造特征及演化、分析其对油气成藏的控制作用具有重要意义。以三维地震资料为主,应用多种方法和资料,对鄂尔多斯盆地西部古峰庄地区的断裂特征进行了系统研究,并结合钻探结果分析断裂对油气运聚成藏的控制作用。研究表明:古峰庄地区共发育北东东、北西和近南北向3组近直立、断距小、隐蔽性强的断裂,在空间上具有“纵向分层,带状分布”的特点;各组断裂的平面展布特征和剖面构造组合样式存在较大差异;3组微小断裂依次形成于燕山期右旋张性走滑、印支期左旋张性走滑和加里东期拉张背景;北西向断裂有利于油气运聚成藏,在断裂伴生圈闭、断裂强活动带、裂缝发育处三者耦合的部位是油气成藏的有利区。

Research on fault characteristics is of great significance for understanding the structural characteristics and evolution process of the Ordos Basin and analyzing its control effect on hydrocarbon accumulation.Taking Gufengzhuang area in the western Ordos Basin as the research object,the characteristics of faults are systematically studied by using 3D seismic data,and the control effect of faults on hydrocarbon migration and accumulation is analyzed combined with drilling data.It is found that the Gufengzhuang area has developed three groups of nearly upright,small fault distance and strong concealed fault zones,NEE,NW and near NS,which have the characteristics of"vertical stratification and zonal distribution"in space.There are great differences in the plane distribution characteristics and sectional structural combination styles of each group of faults.The three groups of micro faults were formed successively in Yanshanian dextral strike-slip background,Indosinian sinistral transtensional strike-slip background and Caledonian extensional background.NW faults are conducive to hydrocarbon migration and accumulation.The coupling part of the fault-associated trap,the strong active zone of the fault,and the fracture development site is a favorable area for hydrocarbon accumulation in the Gufengzhuang area.