石柱复向斜五峰组—龙马溪组笔石页岩特征浅析  

Study of Relationship between Graptolite and Shale Gas Origin of Wufeng Formation—Longmaxi Formation in Shizhu Syncline

作　　者：张翔[1] 陈波[1] 郭志辉[2] 

机构地区：[1]长江大学(武汉)非常规油气湖北省协同创新中心,湖北武汉430100 [2]长江大学(武汉)地球科学学院,湖北武汉430100

出　　处：《非常规油气》2016年第6期49-54,共6页Unconventional Oil & Gas

摘　　要：为了探讨石柱复向斜及周缘地区五峰组—龙马溪组笔石与页岩有机质的关系,基于前人研究成果,结合研究区3处野外露头剖面(武隆黄莺、利川毛坝和石柱漆辽)观测及样品分析,对笔石页岩的总有机碳含量、反射率特征和保存特征进行了综合分析。结果表明,C元素含量与笔石的丰度有着必然联系,笔石丰度大的地层,总有机碳含量也较高;通过公式可将笔石反射率转换为等效镜质组反射率,从而有效指示成熟度;有机质压扁薄膜状态、立体—半立体黄铁矿化是笔石的两种保存状态,受陆源物质影响程度不同,其对有机质和孔隙的贡献也有所差异,前者有机质丰富,利于页岩气的成烃和保存,后者陆源碎屑多,有机质较少,且填充矿化现象严重,孔隙贡献率非常低,对页岩气形成不利。This paper is focused on the relationship between graptolite and shale gas origin of Wufeng Formation-Longmaxi Formation in Shizhu Syincline and its surrounding area. Based on the previous research results and combined with observation of three outcrops（ Huangyin profile in Wulong,Maoba profile in Lichuan and Qiliao profile in Shizhu） and analysis of samples,it makes a comprehensive analysis of total organic content,reflectivity characteristics and preservation characteristics of graptolite shale. The results indicate that the content of C element is inevitably related to graptolite abundance. The formation with high graptolite abundance has a high content of organic carbon. The formula can turn graptolite reflectivity into vitrinite reflectivity,thus effectively indicating the degree of maturity. Graptolite has two states of existence- organic matter flattening film form and stereo-half stereo pyritization. The different influences of terrigenous material lead to the different contributions to organic matter and pores. The former is rich in organic matter and in favor of formation and preservation of shale gas. The latter has more terrigenous debris but less organic matter,with serious filling and mineralization. The porous contribution is low and unfavorable to formation of shale gas.

关 键 词：五峰组—龙马溪组 笔石体 成熟度 有机质 保存状态 

分 类 号：P618.13[天文地球—矿床学] P588.2[天文地球—地质学]