东海盆地西湖凹陷新生代构造演化对油气的控制作用——以平湖组油气响应为例

CONTROL ON PETROLEUM BY CENOZOIC TECTONIC EVOLUTION IN THE XIHU SAG, THE EAST CHINA SEA BASIN—TAKING PETROLEUM RESPONSE OF THE PINGHU FORMATION AS AN EXAMPLE

何将启 梁世友 陈拥锋 付洁

He Jiangqi Liang Shiyou Chen Yongfeng Fu Jie

南京大学, 地球科学系, 南京, 210093 2. 中国石油化工股份有限公司, 石油勘探开发研究院, 无锡石油地质研究所, 江苏, 无锡, 214151

Department of Earth Sciences, Nanjing University, Nanjing, Jiangsu 210093, China 2. Wuxi Research Institute of Petroleum Geology, Research Institute of Petroleum Exploration and Production, SINOPEC, Wuxi, Jiangsu 214151, China

东海陆架盆地西湖凹陷自新生代以来经历了陆内拉张断陷、转换边缘坳陷、陆内迁移坳陷和陆架边缘坳陷等4种原型演化,对油气的生成、运聚起到了重要的控制作用。从地质作用与油气响应的关系出发,以平湖组为例探讨了西湖凹陷新生代构造演化对油气的控制作用。受构造演化影响,平湖组不同时期的厚度(或残留厚度)在凹陷不同部位有所不同,导致主力烃源岩生烃条件多期变化。同时,构造演化控制了西湖凹陷温度场在时间和空间上的变化,提供了烃源岩成熟或资源结构变化的地温条件。另外,构造演化造成油气运移方向的变化,龙井运动以前,油气主要向西部斜坡带和东部隆起带运移;而在龙井运动以后,除上述方向外,油气还在中央背斜带发生短距离的侧向运移和垂向运移。

The Xihu Sag of the East China Sea Basin has experienced 4 prototype evolution stages since Cenozoic,including intracontinental extensional fault depression,transform marginal depression,intracontinental migrated depression and shelf marginal depression.The tectonic evolutions have controlled hydrocarbon generation and migration.Based on the relationship between geological process and petroleum response,it is discussed in this paper the control on petroleum by Cenozoic structural evolution in the Xihu Sag,taking the Pinghu Formation as an example.Influenced by tectonic evolutions,thickness(or residual thickness) of the Pinghu Formation in different parts of the sag is different,which results in the changes of hydrocarbon generation conditions of main source rocks.Meanwhile,evolutions have controlled spatial and temporal changes of temperature field in the Xihu Sag,and provided enough heat for source rocks maturing or resource type transformation.In addition,it has altered the direction of hydrocarbon migration.Oil and gas mainly migrates to the Western Slope and the Eastern Uplift Belt before the Longjing Movement.Afterwards,petroleum also moves in short distances laterally and vertically in the Central Anticline Zone.

国家高技术研究发展计划(863计划)项目(2006AA09A101)

https://doi.org/10.11781/sysydz200803221