四川盆地川东南地区“源—盖”匹配关系研究  

Relationship between Hydrocarbon Generation History of Source Rocks and Sealing History of Mudstone Cap—rocks in the Southeast Sichuan Basin

作　　者：袁玉松[1] 孙冬胜 周雁[1] 李双建[1] 汪新伟 张荣强[1] 沃玉进 郑和荣[1] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083

出　　处：《地质论评》2010年第6期831-838,共8页Geological Review

基　　金：国家自然科学基金资助项目(编号40974048);国家科技重大专项(编号2008ZX05005)的成果

摘　　要：采用重建烃源岩生烃史("源")和泥质盖层排替压力演化史("盖")的方法,研究源—盖动态匹配关系,以确定泥质盖层封闭动态有效性。针对川东南地区丁山1井泥质盖层封闭性的研究结果表明:川东南地区寒武系泥质盖层不仅封闭性能形成时间早(早于震旦系烃源岩生烃时间),而且排替压力大(最大排替压力高达26MPa),封闭能力强,具备封闭超高压气藏的能力,"源—盖"匹配关系好,对下伏烃源岩具备有效封盖作用;志留系泥质盖层虽然现今排替压力较大,但封闭性形成时间晚于下伏寒武系烃源岩生烃时间,"源—盖"匹配关系不理想,有效封闭性较差;二叠系和三叠系泥质盖层封闭性形成时间分别早于志留系和二叠系烃源岩的生烃时间,具备有效封闭能力,且最大排替压力都大于10MPa,可封闭高压气藏。In order to determine the effectiveness of the mudstone cap—rocks in the southeast Sichuan basin, both hydrocarbon generation histories of source rocks and sealing histories of the mudstone cap—rocks are reconstructed. The results show that the sealing function of the Cambrian mudstone formed earlier than the onset of gas generation of the Sinian source rock and its maximum displacement pressure was as high as 26 MPa at the end of the Late Cretaceous. Writers, therefore, consider that the Cambrian mudstone was of effective sealing function with respect to the Sinian source rock before Late Cretaceous. Similarly, the Permian and Triassic mudstone cap—rocks were also of effective sealing function before being drastically exhumed or uplifted in the late tectonic events. However, the Silurian mudstone cap—rock was less effective in sealing the gas generated by the Cambrian source rock though its maximum sealing capacity （displacement pressure =16 MPa） is powerful enough to seal high pressure gas reservoir at the end of the Late Cretaceous.

关 键 词：泥质盖层 生烃史 排替压力史 封闭有效性 “源—盖”匹配 川东南 

分 类 号：P618.13[天文地球—矿床学]