东濮凹陷天然气成因类型及勘探潜力

Genesis Type of Natural Gas in Dongpu Depression and It’s Range of Profitability of Exploration

何显莉¹ 王秀林^{1 ,2} 武晓玲¹ 王运所¹ 蒋云静¹

1.中原油田分公司勘探开发科学研究院，2. 中国地质大学,北京

Scientific Research Institute of Petroleum Exploration and Development , Zhongyuan Oilfield Company, SINOPEC, Henan 457001 , P. R. China

东濮凹陷是渤海湾盆地中一个既富油又富气的凹陷,该凹陷的发育经历了前断陷期、断陷期和坳陷期3 个发育阶段,发育上古生界和下第三系2 套烃源岩,可形成煤型气和油型气,由于2 套气源岩不同,生成的天然气组分及地球化学特征差异大。根据圈闭类型、储气层产状、天然气地下存在方式、储集空间、天然气成因、水动力条件、所处构造层等对东濮凹陷天然气藏进行分类,并按天然气成因分析了天然气分布规律,划分出古生界—沙四段、沙三—沙二段和上第三系三大成气系统,指出环洼带是寻找下第三系油型气的有利区域,中央隆起带南部和文—卫地区古生界是寻找上古生界煤型气的有利目标区。

Locating in the southern of Bohai Bay Basin , Dongpu depression is abundant of oil and nature gas. Two sets of nature gas source rock were developed in Upper Paleozoic and Eocene during three evolution stages. Two kinds of genesis of natural gas which generated from the two sets of nature gas source rock were found. The component and geochemical feature are different . Natural gas reservoir is classified into eight kinds according to trap type , reservoir rock altitude , the way of occurrence , character , depth and genesis. The distribution rules of natural gas is summarized. Three natural gas bearing intervals are indentified. Range of profitability of exploration is pointed out also.