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

Abstract

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.

Numerical Simulation of the Simultaneous Development of Multiple Fractures in Horizontal Wells Based on the Extended Finite Element Method

“…The development of gas in low-porosity/permeability reservoirs such as shale gas reservoirs is a solution to the growing demand for energy resources [1,2]. Meanwhile, shale gas, as a clean energy source like geothermal energy, has low-carbon and green characteristics and has taken on an important role in global clean energy [3].…”

Genesis, Identification Method, and Exploration Potential Evaluation of Marine Low-Resistivity Shale Gas Reservoirs

“…In the Sichuan Basin and its surroundings, the Longmaxi Formation shale exhibits characteristics such as significant thickness, high organic matter content, and high thermal maturity. , Previous studies have indicated that this shale formation possesses favorable conditions for gas generation, reservoir development, and preservation, indicating the potential for the formation of a significant shale gas field. − Since 2010, the Fuling, Weiyuan, Changning, and Zhaotong areas have made significant advancements in the extraction of shale gas resources, presenting promising opportunities for exploration and development. − However, actual drilling results reveal that low-resistivity shale gas reservoirs are extensively distributed throughout the Sichuan Basin, exhibiting varying levels of gas contentfrom high to low to completely devoid of gas content. The ambiguous genesis of low-resistivity shale gas reservoirs heightens the risks associated with exploration and development.…”