四川盆地五峰组—龙马溪组页岩气优质储层成因机制  

Genetic mechanism of high-quality shale gas reservoirs in the Wufeng–Longmaxi Fms in the Sichuan Basin

作　　者：聂海宽 何治亮[1,2,4] 刘光祥 杜伟[1,2,3] 王濡岳 张光荣[5] NIE Haikuan;HE Zhiliang;LIU Guangxiang;DU Wei;WANG Ruyue;ZHANG Guangrong(State Key Laboratory of Shale Oil&Gas Enrichment Mechanisms and Effective Development,Beijing 100083,China;Sinopec Key Laboratory of Shale Oil/Gas Exploration&Production,Beijing 100083,China;PetroChina Research Institute of Petroleum Exploration&Production,Beijing 100083,China;Department of Science and Technology,China Petroleum&Chemical Corporation,Beijing 100728,China;School of Energy Resource,China University of Geosciences,Beijing 100083,China)

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室 [2]中国石油化工集团有限公司页岩油气勘探开发重点实验室 [3]中国石化石油勘探开发研究院 [4]中国石油化工股份有限公司科技部 [5]中国地质大学(北京)能源学院

出　　处：《天然气工业》2020年第6期31-41,共11页Natural Gas Industry

基　　金：国家科技重大专项“彭水地区常压页岩气勘探开发示范工程”(编号:2016ZX05061);国家自然科学基金项目“四川盆地五峰组—龙马溪组页岩气储层演化机理及评价方法”(编号:41872124);“特提斯域内大陆单向裂解—聚合过程中的油气大规模富集效应”(编号:9175520021)。

摘　　要：上奥陶统五峰组—下志留统龙马溪组是四川盆地页岩气勘探开发的重点层系,但对其储层成因机制、演化历史以及矿物成岩演化对页岩气储层形成控制作用等的认识目前尚不明晰。为此,通过岩石学、矿物学和有机地球化学等分析,结合盆地模拟和页岩气勘探开发实践,分析了四川盆地及其周缘五峰组—龙马溪组有机质孔隙演化历史和矿物成岩演化过程,探讨了页岩气优质储层的类型和成因机制,明确了页岩气优质储层的发育层段。研究结果表明:①该盆地五峰组—龙马溪组页岩气开发层段的岩石类型主要包括硅质页岩、含灰硅质页岩和黏土质页岩,岩石类型对页岩储集空间类型和特征具有重要的控制作用,其中硅质页岩、含灰硅质页岩的有机质孔隙最为发育,储集能力最强;②矿物成岩演化对页岩气储层的形成具有重要的控制作用,生物成因硅在早成岩阶段形成,并以微晶聚集体的形式与陆源碎屑硅、黄铁矿一起形成颗粒支撑格架,有效抑制了压实作用,保存了大量残留粒间孔隙,有利于页岩气优质储层的形成;③WF2—LM4笔石带(五峰组—龙马溪组底部)硅质页岩具有“多藻控烃源、生硅控格架、协同演化控储层”的优质储层成因机制。结论认为,WF2—LM4笔石带硅质页岩、含灰硅质页岩为页岩气优质储层的主要发育层段。The Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation are important strata for shale gas exploration and development in the Sichuan Basin,but the genetic mechanism,evolutionary history and the controlling effect of mineral diagenetic evolution on the formation of shale gas reservoirs are not clear.In this paper,the evolution history of organic matter pores and the diagenetic evolution of minerals were analyzed based on the analysis of petrology,mineralogy and organic geochemistry,combined with basin simulation and practical shale gas exploration and development.Then,the types and genetic mechanisms of high-quality shale gas reservoirs were discussed,and the development intervals of high-quality shale gas reservoirs were determined.And the following research results are obtained.First,the shale gas development intervals of Wufeng–Longmaxi Fm in the Sichuan Basin are mainly dominated by siliceous shale,limy siliceous shale and clay shale.Rock type has an important controlling effect on the types and characteristics of shale reservoir space.Siliceous shale and limy siliceous shale have the highest reservoir capacity with the most developed organic pores.Second,the diagenetic evolution of minerals controls the formation of shale gas reservoirs.Biogenic silicon,was formed in the early diagenetic stage,together with terrestrial detrital silicon and pyrite,constitutes particle support lattices in the form of microcrystalline aggregates,so as to resist the compaction effectively and preserve a great number of residual intergranular pores,which is beneficial to the formation of high-quality shale gas reservoirs.Third,siliceous shale in the WF2–LM4 graptolite zone(from Wufeng Formation to the bottom of Longmaxi Formation)presents a high-quality reservoir genetic mechanism of"multicellular algae controlling hydrocarbon source,biogenic silicon controlling framework,and co-evolution controlling a high-quality reservoir".In conclusion,the siliceous shale and limy siliceous shale in the WF2–LM4 g

关 键 词：四川盆地 晚奥陶世五峰期 早志留世龙马溪期 页岩气 优质储集层 成因机制 生物成因硅 

分 类 号：P618.13[天文地球—矿床学]