Impact of different diagenetic minerals on shale reservoirs in Wufeng-Longmaxi Formation in southern Sichuan Basin
The diagenesis of shale and its impact on the evolution of reservoirs has long been a key issue in the exploration of shale gas,but scant research on the types of minerals,their modes of co-evolution,and their impact on the evolution of reservoirs makes it difficult to evaluate high-quality shale reservoirs.In this paper,we use large-field splicing scanning electron microscopy and the quantitative analysis of minerals to identify diagenetic minerals in the Wufeng-Longmaxi Formation shale in the Sichuan Basin,and analyze the impact of their diagenesis on the development of shale reservoirs.We used the degree of development of the pores of minerals to divide them into minerals with and without porous media.We then established a sequence of the diagenetic evolution of minerals in the Wufeng-Longmaxi Formation and discussed the mechanism of formation of the high-quality reservoir.The results showed that minerals without pores formed a brittle framework in the early to the middle diagenetic stages that inhibited compaction and helped maintain the internal pores.The porous minerals and organic matter formed organic complexes in the middle to late diagenetic stages that catalyzed the formation of organic pores.The phased contributions of these two kinds of minerals led to the formation of a high-quality shale reservoir.This provides a sound understanding for examining the influence of the diagenetic evolution of shale minerals on the resulting reservoir.
mineral typesporous mediareservoir evolutionWufeng-Longmaxi FormationSichuan Basin
万方数据
维普
