焉耆盆地博湖坳陷油气形成条件分析

焉耆盆地位于南天山造山带东部,作为西北地区一个小型的侏罗纪含油气盆地,除与周缘的塔里木、吐哈盆地有相似性外,它亦有自己独特的石油地质条件。笔者从生、储、盖、圈等基本石油地质特征出发,对博湖坳陷油气形成条件进行研究。通过对烃源岩有机质类型、丰度及热演化程度的分析,认为下侏罗统八道湾组泥质岩是主要烃源岩;储层研究表明,侏罗系为低孔、低渗型储层;钻探证实的储盖组合有两套。通过烃源岩的生烃史、储层自生伊利石年代学研究和矿物流体包裹体均一温度研究,表明博湖坳陷主要有两期油气生成和成藏事件。油气成藏有宝浪苏木构造带、种马场构造带、博南鼻状构造带三种主要成藏模式。

Conditions of Petroleum Generation of Bohu Depression in Yanqi Basin

The Yanqi basin is located in the east of South Tianshan orogenic belt.As a small Jurassic petroleum basin,the Yanqi basin,which is similar to the surrounding basins such as the Tarim,and the Tupan basins,has its owns peculiar characteristics of petroleum geology.This study,based on the essential characteristics of generation,reservoir,cap rocks,and trap,focuses on the conditions of the petroleum formation of Bohu depression.Through organic matter types,abundance and degree of thermal evolution,it shows that pelites of the lower Jurassic Badaowan group are main hydrocarbon source rocks. The reservoir has low porosity and permeability and drilling data indicate there are two suites of reservoir- cover.Hydrocarbon generation history,authigenici llite chronological study and homogenization temperatures of fluid inclusions,show that there have two stages of petroleum generation and accumulation.