【摘要】 昭通国家级页岩气示范区（以下简称示范区）地处四川盆地边缘，由于其具有典型“强改造、过成熟、复杂应力”的盆外山地页岩气特征，进而导致示范区页岩气富集具有复杂性。为了明确示范区上奥陶统五峰组—下志留统龙马溪组页岩气富集主控地质因素，从沉积古地貌、岩性岩相、水文环境、储集空间以及保存条件等方面对页岩气的富集控制因素进行分析。研究结果表明：(1)示范区龙马溪组沉积时期古地貌具有分区分带特征，直接控制了页岩气储层在不同地貌单元内具有不同的储层品质，其中斜坡带和水下隆起区页岩储层品质相对较好；(2)五峰组—龙马溪组页岩岩相具有“控储控气”的特征,含黏土/灰混合质页岩（M-3）和混合质页岩（M-2）为示范区优势岩相；(3)五峰组—龙马溪组页岩有机质富集的关键在于水体的氧化还原保存条件；(4)纳米孔隙的大量发育为页岩气的富集提供了充足的储集空间；(5)良好的顶底板封盖是示范区页岩气富集的关键地质因素。结论认为，“水下古地貌是基础、有机质保存是关键、优势岩相控储控气、纳米孔隙系统发育、顶底板封盖”是示范区五峰组—龙马溪组页岩气富集的关键地质构成要素，该认识可以为我国具有类似地质条件的页岩气新区勘探提供理论指导和依据参考。更多还原

【Abstract】 Zhaotong National Shale Gas Demonstration Area(hereinafter referred to as Demonstration Area) is located at the margin of the Sichuan Basin, and has the typical characteristics of extra-basin mountain shale gas with "strong reworking, over maturity and complex stress", so shale gas enrichment in the Demonstration Area is complex. In order to determine the main geological factors controlling shale gas enrichment in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in the Demonstration Area, this paper analyzes the control factors of shale gas enrichment from the aspects of sedimentary palaeogeomorphology, lithology and lithofacies, hydrological environment, reservoir space, and preservation condition. And the following research results are obtained.First, the palaeogeomorphology in the Demonstration Area has the characteristics of zoning during the sedimentation of the Longmaxi Formation, which directly leads to different reservoir qualities of shale gas reservoir in different geomorphic units. The shale in the slope zone and the underwater uplift area has a higher reservoir quality. Second, the shale lithofacies of the Wufeng-Longmaxi Formation has the characteristics of "controlling reservoir quality and gas enrichment". Clay-bearing/lime-bearing mixed shale(M-3) and mixed shale(M-2) are the predominant lithofacies in the Demonstration Area. Third, the key to the organic matter enrichment in the WufengLongmaxi Formation shale is the redox preservation condition in water. Fourth, the development of a large number of nano-pores provides sufficient reservoir space for shale gas enrichment. Fifth, good sealing of roof and floor is the key geological factor of shale gas enrichment in the Demonstration Area. In conclusion, "underwater palaeogeomorphology is the foundation, organic matter preservation is the key,predominant lithofacies controls reservoir quality and gas enrichment, nano-pore system is developed, and roof and floor provide sealing" are the key geological elements of shale gas enrichment in the Wufeng-Longmaxi Formation of the Demonstration Area. The research results can provide theoretical guidance and reference for the exploration in the new shale gas areas with similar geological conditions in China.更多还原