四川盆地陆相油型气分布、成因及来源  

Distribution,Origin and Source of Terrestrial Oil-Type Gas in Sichuan Basin

作　　者：朱童[1,2] 王鹏[1,2] 沈忠民[1,2] 周瑶[1,2] 李延飞[1,2] 张文凯[1,2] 

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,成都610059 [2]成都理工大学能源学院,成都610059

出　　处：《地质科技情报》2015年第2期137-144,共8页Geological Science and Technology Information

基　　金：国家自然科学基金项目(41172119)

摘　　要：四川盆地陆相天然气类型主要为煤型气,而油型气的含量、分布较少,因此在研究四川盆地有利于油型气生成的陆相烃源岩特征及分布的基础上,从全盆的角度通过天然气地球化学特征结合构造条件分析了陆相油型气的分布、成因与来源情况。研究表明:1川西地区须一段、川中地区中下侏罗统发育腐泥型烃源岩,川中地区须一段发育薄层的腐殖腐泥型烃源岩;2油型气在川西地区须二段少量分布,在川中地区中下侏罗统大量分布,须二、须六段少量分布,在川南地区须家河组各段有一定量分布;3川西地区须二段油型气为二次裂解成因,来自川西地区须一段腐泥型烃源岩,川中地区中下侏罗统和须二、须六段油型气为干酪根裂解成因,中下侏罗统和须六段油型气来自川中地区中下侏罗统腐泥型烃源岩,须二段油型气来自川中地区须一段薄层的腐殖腐泥型烃源岩,川南地区须家河组各段油型气为二次裂解成因,来自下伏海相地层。Coal-gas is the predominate terrestrial gas type in the Sichuan Basin,while the content and distribution of oil-type gas is less.Thereby,based on the research of characteristic of source rock and its distribution in terrestrial formation,which is propitious to the generation of oil-type gas,this article studies the distribution,origin and source of terrestrial oil-type gas by the geochemical characteristics of natural gas,combined with tectonic conditions,which from the perspective of the whole basin.It shows that：（1）The sapropelic source rock is developed in the first member of Xujiahe Formation in western Sichuan as well as in the Middle-Lower Jurassic strata in central Sichuan,and the thinly humic-sapropelic source rock is developed in the first member of Xujiahe Formation in central Sichuan.（2）The oil-type gas has a small amount of distribution in the second member of Xujiahe Formation in western Sichuan,and mainly distributes in the Middle-Lower Jurassic strata with a little in the second and sixth member of Xujiahe Formation in central Sichuan,meanwhile it has a certain amount of distribution in the most members of Xujiahe Formation in south Sichuan.（3）The oil-type gas which distributed in the second member of Xujiahe Formation in western Sichuan has the origin of secondary cracking and comes from sapropelic source rock of the first member of Xujiahe Formation in western Sichuan.The oil-type gas in central Sichuan originates from kerogen cracking,which distributed in the Middle-Lower Jurassic Formation and the sixth member of Xujiahe Formation comes from sapropelic source rock of the Middle-Lower Jurassic Formation,while the other in second member of Xujiahe Formation is from the thinly humic-sapropelic source rock of the first member of Xujiahe Formation.The oil-type gas with a certain amount distribution in the most members of Xujiahe Formation in south Sichuan has the origin of secondary cracking,and is derived from underlying marine strata.

关 键 词：油型气 干酪根裂解 二次裂解 腐泥型烃源岩 

分 类 号：P618.130.2[天文地球—矿床学]