珠三坳陷阳江凹陷构造特征及其对油气成藏的影响

Structural features and impact on hydrocarbon accumulation in Yangjiang Sag of Zhu Ⅲ Depression

杨海长 徐建永 武爱俊 印斌浩 李建红

YANG Haizhang XU Jianyong WU Aijun YIN Binhao LI Jianhong

中海油研究总院, 北京 100027

CNOOC Research Institute, Beijing 100027, China

在对研究区地震资料精细解释的基础上,对原阳江凹陷及其南缘低凸起重新进行了构造单元划分。阳江低凸起北支将原阳江凹陷分隔为阳江东、西两个凹陷,阳江东凹陷可以进一步分为东1洼和东2洼。阳江北断裂是阳江东、西两个凹陷主要的控凹断裂,根据断裂走向拐点和阳江东、西凹陷的分界可以把阳江北断裂划分为3段,分别是西段、中段和东段,西段控制阳江西凹陷,中段控制东1洼,东段控制东2洼。断裂各段活动规律不同,其中断裂中段控制的东1洼的主要活动期在晚始新世和早渐新世,控制文昌组和恩平组的湖相沉积,勘探潜力最好。继承、叠加发育的伸展构造样式是阳江东、西两凹陷的主要构造样式,断层型圈闭和披覆背斜型圈闭是该地区发育的主要圈闭类型。勘探实践表明,垂向运移和近源成藏是阳江东、西两凹陷主要的成藏规律。

The structural unit of Yangjiang Sag and its southern low uplift were redivided on the basis of fine seismic interpretation. The northern part of the low uplift vSeparated Yangjiang Sag into two sags, east and west, and the east one can be further divided into east 1 sub-sag and east 2 sub-sag. As the main controlling fault of east and west sags, the Yangjiang north fault can be divided into three parts, the west, the middle and the east according to the fault strike and the boundary of east and west sags. The west part controls the west sag, the middle part controls the east 1 sub-sag and the east part controls the east 2 sub-sag. Different parts of the Yangjiang north fault have different activity periods. The late Eocene and early Oligocene is the main activity period of the middle part, which controls the lacustrine sedimentation of Wenchang Formation and Enping Formation and has the best hydrocarbon potential. The inherited and superimposed extensional structural style is the main structural style of Yangjiang east and west sags, and the fault trap and drape-anticline trap are the main trap types. The exploration indicated that vertical migration and near-source accumulation are main accumulation patterns of Yangjiang east and west sags.

国家科技重大专项课题"近海富烃凹陷资源潜力再评价和新区、新领域勘探方向"(编号:2008ZX05023-001)项目资助。

https://doi.org/10.3969/j.issn.1008-2336.2011.02.020