西非加蓬盆地沉积特征及油气成藏规律研究

STUDY OF THE SEDIMENTARY CHARACTERISTICS AND HYDROCARBON ACCUMULATION RULES FOR THE GABON BASIN, WEST AFRICA

刘延莉 邱春光 熊利平

Liu Yanli Qiu Chunguang Xiong Liping

中国石油大学, 北京, 102249 2. 中国石油化工股份有限公司, 石油勘探开发研究院, 北京, 100083 3. 中海石油有限公司, 研究中心, 北京, 100027

China University of Petroleum, Beijing 102249, China 2. Research Institute of Petroleum Exploration and Production, SINOPEC, Beijing 100083, China 3. CNOOC Research Center, Beijing 100027, China

通过对加蓬盆地区域构造背景、沉积演化的研究,综合分析生储盖条件,认为盆地演化经历了裂谷期、过渡期和漂移期3个阶段。各个演化阶段沉积地层3分:盐下层系、盐膏层和盐上层系。主要油气系统为盐下和盐上2套:盐上含油气系统主要分布于北加蓬次盆;盐下含油气系统分布于南加蓬次盆。搞清了盐下、盐上主要层系的沉积体系分布及其对烃源岩和储层的控制。总结出盐上成藏主控因素为"断崖控储,盐控圈闭,构造、圈闭控油";盐下成藏主控因素为"相控源、控储,盐控盖,构造、圈闭控油"。

A comprehensive study of the regional tectonic setting,sedimentary evolution and source reservoir cap conditions indicates that the Gabon Basin has experienced 3 evolutional phases: rifting period,transitional period and drifting period.The sedimentary strata of every evolutional phase are divided into 3 parts: pre-salt sequence,salt sequence and post-salt sequence.The main petroleum systems are the pre-salt and post-salt sequences.The post-salt petroleum system is distributed on the North Gabon sub-basin and pre-salt one is located in the South Gabon sub-basin.It makes clear the main sedimentary distribution of pre-salt and post-salt sequences and their controlment on source rocks and reservoirs.This paper summarizes the main factors of post-salt reservoirs are "reservoir controlled by fault scarp,traps controlled by salt,oil controlled by tectonic and traps" and the main factors of pre-salt reservoirs are "sources and reservoirs controlled by facies,caps controlled by salt,oil controlled by tectonic and traps".

https://doi.org/10.11781/sysydz200804352