西湖凹陷构造演化特征及油气运聚单元划分  

Characteristics of structural evolution and classification of hydrocarbon migration and accumulation units in Xihu Sag, China

作　　者：于仲坤 丁飞 赵洪 YU Zhong-Kun;DING Fei;ZHAO Hong(Shanghai Branch of CNOOC Ltd.,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《上海国土资源》2018年第4期75-78,共4页Shanghai Land & Resources

基　　金："十三五"国家科技重大专项"东海低渗-致密天然气勘探开发技术"(2016ZX05027001)

摘　　要：西湖凹陷是目前东海陆架盆地油气勘探的重点,但其油气运聚单元始终未进行系统的划分,限制了区域成藏研究及勘探目标的优选。本文从油气运移动力角度系统分析西湖凹陷油气富集分布规律及原因,以该凹陷大量生排烃期的构造活动演化为基础,恢复关键成藏时刻对应的构造特征与沉积,计算出柳浪组沉积末期流体势,明确了该时期流体势场的油气运聚特征。结果表现为由凹陷中心向斜坡逐渐降低的分布规律,在此基础上将西湖凹陷划分9个油气运聚单元。本文研究的运聚单元中Ⅰ、Ⅱ、Ⅲ、Ⅴ、Ⅵ是较好的油气聚集单元,具有利于油气长期运移聚集的条件,是未来西湖凹陷勘探的主要潜力区。Xihu Sag is the focus of oil and gas exploration in the East China Sea Shelf Basin, but the hydrocarbon migration and accumulation units have not been systematically divided. This restricts the study of regional reservoir formation and the optimization of exploration targets. Distribution and cause of oil and gas accumulation are discussed in terms of the dynamics of oil and gas migration, based on the evolution of tectonic activity in the large number of hydrocarbon generation and expulsion stages of the Sag. The fuids’ potential after the deposition of the Liulang Formation is calculated on the corresponding structural features and sedimentary research results. As a result, the characteristics of petroleum migration and accumulation during the period are recognized. This indicates that the fuid potential is of succession and consistency, characterized by its descending movement from the middle to the east and west. Accordingly, Xihu Sag can be divided into nine oil-gas migration and accumulation units. I, II, III, V and VI are better oil and gas accumulation units, and are advantageous to the long-term migration and accumulation of oil and gas. They are the main potential areas for future exploration in Xihu Sag.

关 键 词：海洋地质 西湖凹陷 构造演化 沉积特征 油气运聚 流体势 生排烃期 

分 类 号：P736.1[天文地球—海洋地质]