伊通盆地天然气成因类型与成藏

Genetic types and pooling of nature gas in the Yitong Basin

郭小文 何生

Guo Xiaowen He Sheng

在评价伊通盆地烃源岩的基础上,分析了天然气地球化学特征和成因,并利用Basinflow软件模拟天然气运移方向,判断天然气有利聚集区。研究结果表明,伊通盆地存在古近系双阳组、奢岭组和永吉组3套烃源岩,以双阳组烃源岩有机质丰度最高,有机质类型主要为Ⅱ型和Ⅱ型,少部分为Ⅲ型和Ⅰ型。天然气主要以湿气为主,成熟度在1.3%以下,属于原油伴生气。天然气成因判别结果指示伊通盆地天然气主要为油型气,少部分为混合成因气,气源岩母质类型主要为Ⅱ型和Ⅱ型。天然气运移与聚集模拟结果表明,伊通盆地万昌构造带和五星构造带二号断层上升盘是汇集流聚集地区,而且具有双源供烃的特征,是最有利的天然气聚集区。

Based on the appraisal of source rocks in the Yitong Basin,we studied the geochemical characteristics and origin of natural gas in that basin.Using the Basinflow software,and simulated the directions of gas migration to recognize the favorable accumulation zones.The results show that there are three sets of source rocks in the Yitong Basin,including the Shuangyang,Sheling and Yongji formations,among which the Shuangyang Formation source rocks are the highest in the organic matter abundance.The types of organic matter are mainly TypeⅡ and Ⅱ,partly Type Ⅲ andⅠ.The natural gas,with its maturity below 1.3%,is mainly composed of wet gas and is classified as associated gas.The gases in the Yitong Basin are mostly of oil-type and partly of mixed origins.The kerogens of the source rocks are mainly of TypeⅡ and Ⅱ.The simulation results of gas migration and accumulation show that,the Wanchang structural belt and the hanging wall of No.2 fault in the Wuxing structu-ral belt of the Yitong Basin are the most favorable areas for gas accumulation and are characterized by contribution from two sources.

10.11743/ogg20090302