Variational Reservoir Characteristics of the Wufeng–Longmaxi Formation from Different Sedimentary Region and Its Implications in Southeastern Sichuan Basin, China

Shale gas plays a far-reaching role for meeting the worldly increasing energy demand; however, shale gas development exhibits variable situations for a same geological formation at different sedimentary locations, for example, Wufeng–Longmaxi shale. This work introduced three shale gas parameter wells—target strata of Wufeng–Longmaxi shale—aiming to explore the diversity of reservoir characteristics and its implication. Herein, the mineralogy, lithology, organic matter geochemistry, and trace element analyses of the Wufeng–Longmaxi formation in the southeast Sichuan Basin were evaluated in detail. Meanwhile, this work analyzed the deposit source supply, original hydrocarbon generation capacity, and sedimentary environment of Wufeng–Longmaxi shale. The results show that abundant siliceous organisms may be involved in the shale sedimentation process in the YC-LL2 well. Besides, the hydrocarbon generation capacity of shale in the YC-LL1 well is better than that in the YC-LL2 and YC-LL3 wells. Moreover, the Wufeng–Longmaxi shale in the YC-LL1 well was formed in a strongly reducing and hydrostatic environment, while that in the YC-LL2 and YC-LL3 wells is in a relatively weakly redox environment with poor conditions to preserve organic matter. Hopefully, this work offers salutary information for development of shale gas from a same formation but sedimented from different locations.

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