四川省兴文县志留系龙马溪组页岩有机质特征

Characteristics of organic matter of Silurian Longmaxi Group in Xingwen County,Sichuan Province

为更好地评估四川盆地页岩气资源,结合野外调查和样品实验,研究了四川省兴文县地区志留系龙马溪组页(泥)岩的有机质特征及垂向变化规律。结果表明:研究区内出露的志留系龙马溪组岩层以黑色泥岩为主,厚度为262.91m,泥岩中残余有机碳丰度在地层中由底部至上部呈逐渐减少的趋势;有机质主要来自志留纪的海相笔石群,其丰度属于较好—最好的烃源岩,类型为Ⅰ型(腐泥型)。研究区具备页岩气形成的物质基础,为进一步开展页岩气调查提供了依据。

Aimed at a better evaluation of the prospect of shale gas resources in the Sichuan Basin,this paper introduces the study of the characteristics of crag organic matter of Silurian Department of Longmaxi occurring in Xingwen County in Sichuan Province and the law governing the vertical variation of organic matter,combined with field investigation and sample test.The result indicates that the Silurian Department of Longmaxi,with a thickness of 262.91 m,is dominated by black mudstone in which the abundance of the remaining organic carbon tends to reduces gradually from the bottom to the top.The organic matter mainly from the marine Silurian graptolite groups exhibits the abundance classified as the better or best hydrocarbon source rock of type Ⅰ（spoiled clay mold）.The research area occurring as the material basis for formation of the shale gas provides evidences for further investigation into of the shale gas.