江汉盆地西南缘油气运移及其成藏模式

PETROLEUM MIGRATION AND POOL-FORMING MODELS OF THE SOUTHWEST MARGIN OF JIANGHAN BASIN

刘琼 何生

Liu Qiong He Sheng

中国地质大学, 资源学院, 武汉, 430074

Faculty of Earth Resources, China University of Geosciences, Wuhan, Hubei 430074, China

对江汉盆地西南缘的油源对比和流体势分析表明,北部地区的原油主要来自梅槐桥—牛头岗洼陷高成熟度烃源岩,南部地区的原油与本地的低成熟度烃源岩具有亲缘关系,中部地区的原油则具有混源特征.该区的油气明显具有运移距离短、近源聚集的特点;其分布与聚集受到断层和圈闭类型等因素的影响.断层活动使上升盘储层与下降盘烃源岩对接,是新生古储型油气藏成藏的关键;断层的封闭性上部要优于下部,控制着油气富集的层位.圈闭类型以断鼻和断块为主,断鼻油气藏主要分布在断层的下降盘,而断块油气藏主要分布在断层的上升盘.根据油气聚集特点和储集层位的差异,将本区的油气藏划分为自生自储、新生古储和下生上储3种成藏模式.

The results of oil and source rock correlation and fluid potential in the southwest margin of Jianghan Basin show that,the oils in the north primarily come from the high maturity source rock in the Meiguiqiao-Niutougang Sag,and the oils in the south primarily come from the local low maturity source rock,and the oils in the medium are mixed.The distance of petroleum migration in this region is short.The distribution and accumulation of petroleum are controlled by some factors such as faults and the type of entrapment.The reservoir beds in uplifted wall being connected with the source beds in throw wall by fault was the key factor of forming the new-sourced and old-reservoired.The fault seals better in the upside than in the underlayer,fault-seal controlled the distribution of the better reservoirs.There are two important petroleum trap called fault-nose and fault-block,fault-nose locates in throw wall and fault-block locates in uplifted wall.According to the diversities of accumulation and reservoir,the petroleum pools are sorted out three different models which known as self-sourced and self-reservoired,new-sourced and old-reservoired and old-sourced and new-reservoired.

中国石化科技部研究项目(P01047)

https://doi.org/10.11781/sysydz200705166