南海南部陆缘盆地反转构造及其油气成藏意义
——以礼乐盆地北部坳陷为例

Characteristics of inversion tectonic and its impact on hydrocarbon accumulation in southern continental basins of South China Sea: a case study of northern Depression, Reed Basin

吴智平 2 张杰¹ 裴健翔³ 张道军³ 贾博¹

中国石油大学（华东）地球科学与技术学院，山东 青岛 266580 青岛海洋科学与技术国家实验室，山东 青岛 266235 中海石油（中国）有限公司湛江分公司，广东 湛江 524057

School of Geosciences, China University of Petroleum, Qingdao 266580, China Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China Zhanjiang Branch of CNOOC, Zhanjiang 524057, China

礼乐盆地是南海南部陆缘重要的深水沉积盆地之一，复杂的区域动力背景导致其反转构造发育。文中以其北部坳陷作为研究重点，利用最新处理的二维地震资料，对反转构造的类型和发育期次进行研究，并探讨反转构造的油气成藏意义。结果表明：该区反转构造可分为断层相关型和褶皱挠曲型两大类，主要形成于早渐新世末和中中新世初，为南海周缘板块重组引起的区域应力场调整事件在盆内的响应结果；2期反转构造对油气成藏的意义不同，早期造成生烃作用停滞，不利于油气聚集，油气成藏条件较差，晚期因具有良好的生储盖组合、圈闭和保存条件，且邻近的大型断裂在不同阶段可成为重要的运移通道或遮挡层，具有较好的油气成藏条件。

Reed Basin is one of the important continental basins in South China Sea. Complicated area dynamic results in the obvious inversion tectonic development. Based on the interpretation of newly re-integrated 2D seismic data for the northern Depression, the study analyzes these inversion tectonics, including their types, development phases and impact on hydrocarbon accumulation. The results show that the inversion tectonics, which can be divided into two types (fault correlation and bending folds), mainly developed in two phases: the late of Early Oligocene and the early of Middle Miocene. They were both the response to the change of regional stress field caused by tectonic recombination of periphery plates. The two phases of inversion tectonics have different impact on hydrocarbon accumulation. The early phase of inversion tectonics was bad for hydrocarbon accumulation because it caused stagnation of hydrocarbon generation. The late phase of inversion tectonics has positive effect on hydrocarbon accumulation for its favorable source-reservoir-cap assemblage, preservation condition, anticline traps and nearby large faults, which can be important migration channel or barrier for hydrocarbon accumulation in different tectonic stages.

10.6056/dkyqt201801001