辽河盆地中部构造演化与古潜山油气成藏模式

STRUCTURAL EVOLUTION AND MODEL OF HYDROCARBON ACCUMULATION IN BURIED HILLS IN THE CENTRAL LIAOHE BASIN

张庆龙 葛荣峰 赵立文 杜彦彦 慕德良

Zhang Qinglong Ge Rongfeng Zhao Liwen Du Yanyan Mu Deliang

南京大学地球科学与工程学院, 南京210093 2. 辽河金马油田股份有限公司, 辽宁, 盘锦124000 3. 中国石油大学(北京)资源与信息学院, 北京, 102200

School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210093, China 2. Liaohe Jinma Oilfield Company Limited, Panjing, Liaoning 124000, China 3. Faculty of Natural Resource and Information Technology, China University of Petroleum, Beijing 102200, China

通过区域性平衡地质剖面的构建与定量恢复,揭示出辽河盆地中部构造演化经历了晚中生代初始伸展、古新世-始新世强烈伸展、渐新世右旋张扭改造及中新世以来坳陷萎缩等4个阶段,并计算了每个阶段的地壳伸展量、伸展率、伸展速率等参数,为演化过程提供了详细的定量约束。中央凸起南部倾没端古潜山断裂构造特征指示其可能是起源于晚中生代郯庐断裂带左旋走滑派生的次级剪切破裂,但受新生代强烈伸展作用影响,张性增强,提高了油气运移和储集能力。渐新世郯庐断裂带发生右旋走滑,派生了新的EW向张性断裂,控制了油气的分布。结合该区石油地质特征,推断古潜山表层不整合面上的局部构造高点以及古潜山内幕大断裂端点、拐点、交汇点可能是古潜山油气成藏的有利区域。

The construction and quantitative restoration of regional balanced cross-sections in the central Liaohe Basin have revealed four tectonic evolution stages: the late Mesozoic initial rifting,the Paleocene-Eocene intensive rifting,the Oligocene dextral transtension and the depression since the Miocene.The amounts,ratios and rates of crustal extension were estimated,providing detailed constraints to each evolutional stage.The characteristics of fractures on the buried hills at the southern central uplift of Liaohe Basin were suggested that they were probably secondary shear fractures induced by the sinistral strike-slip of Tanlu fault during the late Mesozoic.These fractures,however,were altered to be competent for hydrocarbon migration and reservation during the Cenozoic rifting stage.Dextral strike-slip was taken place on the Tanlu fault during the Oligocene and new EW fractures were produced,which controlled the hydrocarbon distribution in this region.In terms of petroleum geology we suggested that the local highs on the unconformity surface and the fault terminations,inflexions or intersections in the buried hills were the potential targets of hydrocarbon exploration.

国家自然科学基金项目(40634021)资助

https://doi.org/10.11781/sysydz201003211