As the hydrocarbon generation and storage mechanisms of high quality shales of Upper Ordovician Wufeng Formation- Lower Silurian Longmaxi Formation remain unclear, based on geological conditions and experimental modelling of shale gas formation, the shale gas generation and accumulation mechanisms as well as their coupling relationships of deep-water shelf shales in Wufeng–Longmaxi Formation of Sichuan Basin were analyzed from petrology, mineralogy, and geochemistry. The high quality shales of Wufeng–Longmaxi Formation in Sichuan Basin are characterized by high thermal evolution, high hydrocarbon generation intensity, good material base, and good roof and floor conditions; the high quality deep-water shelf shale not only has high biogenic silicon content and organic carbon content, but also high porosity coupling. It is concluded that: (1) The shales had good preservation conditions and high retainment of crude oil in the early times, and the shale gas was mainly from cracking of crude oil. (2) The biogenic silicon (opal A) turned into crystal quartz in early times of burial diagenesis, lots of micro-size intergranular pores were produced in the same time; moreover, the biogenic silicon frame had high resistance to compaction, thus it provided the conditions not only for oil charge in the early stage, but also for formation and preservation of nanometer cellular-like pores, and was the key factor enabling the preservation of organic pores. (3) The high quality shale of Wufeng–Longmaxi Formation had high brittleness, strong homogeneity, siliceous intergranular micro-pores and nanometer organic pores, which were conducive to the formation of complicated fissure network connecting the siliceous intergranular nano-pores, and thus high and stable production of shale gas.

由于上奥陶统五峰组-下志留统龙马溪组优质页岩的生烃机制尚不清楚，根据页岩气形成的地质条件和实验模型，页岩气的生成与成藏机理以及它们之间的耦合关系。从岩石学，矿物学和地球化学分析了四川盆地五峰—龙马溪组的深水架页岩。四川盆地五峰—龙马溪组优质页岩具有高热演化，高生烃强度，良好的物质基础以及良好的顶板条件。优质的深水层状页岩不仅具有较高的生物硅含量和有机碳含量，而且还具有较高的孔隙率耦合度。结论是：（1）页岩在早期具有良好的保存条件和较高的原油滞留性，页岩气主要来自原油的裂解。（2）在成岩早期，生物硅（蛋白石A）转变为晶体石英，同时产生大量微细的晶间孔。此外，生物硅骨架具有较高的抗压实性，因此不仅为早期装油提供了条件，而且为形成和保存纳米细胞状孔提供了条件，并且是能够保存有机物的关键因素。毛孔。（3）五峰—龙马溪组优质页岩脆性高，均质性强，硅质粒间微孔和纳米有机孔隙，