陆相盆地薄层泥岩盖层形成机制、特征与油气成藏关系——以辽东湾地区中南部为例

THE FORMATION MECHANISMS AND CHARACTERISTICS OF THIN-LAYER MUDSTONE CAPROCK AND ITS RELATIONSHIP WITH HYDROCARBON ACCUMULATION IN THE TERRESTRIAL BASIN——AN EXAMPLE OF THIN-LAYER MUDSTONE CAPROCK IN THE SOUTH-CENTRAL LIAODONG BAY

李慧勇 徐长贵 刘廷海 邓津辉 刘明玲 姚长华

Li Huiyong Xu Changgui Liu Tinghai Deng Jinhui Liu Mingling Yao Changhua

中海石油有限公司, 天津分公司, 天津, 塘沽, 300452 2. 中海油能源发展股份有限公司, 采油工程研究院, 天津, 塘沽, 300452

Tianjin Branch, CNOOC, Tanggu, Tianjin 300452, China 2. CNOOC Energy Technology & Services Oilfield Engineering Research Institute, Tanggu, Tianjin 300452, China

渤海海域辽东湾地区中南部近2年发现了一系列薄层泥岩作为有效盖层的油气藏。文章较全面地总结了薄层泥岩盖层特征及形成机制,在此基础上分析了薄层泥岩盖层与油气成藏的关系。通过系统研究得出如下结论:在圈闭形态良好的条件下,薄层泥岩盖层对油气藏具有良好的封盖作用;薄层泥岩质量对油气藏高度有明显的影响,而薄层泥岩盖层厚度与油气藏高度没有明显的关系;在相似薄层泥岩盖层条件下,随着圈闭形态的变好,油气藏高度变高。研究成果有助于拓宽勘探思路:在近物源储层发育的地方,虽然没有区域性盖层,只要圈闭形态良好也能找到大中型油气田。

A series of thin-layer mudstone caprock reservoirs have been found in the last two years in the south-central Liaodong Bay,Bohai offshore area.This paper comprehensively summarizes the formation mechanisms and characteristics of thin-layer mudstone caprock,and then analyzes the relationship between thin-layer mudstone caprock and hydrocarbon accumulation.Through systemic research,the following important conclusions are obtained.Under favorable trap shape condition,thin-layer mudstone caprocks have good sealing effect.Mudstone quality has obvious effect on reservoir height.But mudstone thickness has no relation with reservoir height.Reservoir height raises great along with the better trap shape under the similar sealing condition.The result of this research can broaden exploration thought for the future: In reservoir development area,large and medium oil and gas fields can be found as long as traps are in good condition.

国家“十五”重大科技攻关项目(2003BA613A05)

https://doi.org/10.11781/sysydz201001019