地质科技通报 (Jul 2024)
Development geology avaluation of normal-pressured shale gas in the Baima area, eastern margin of the Sichuan Basin
Abstract
Objective The Fuling Gas Field as the first commercial shale gas field in China has stably achieved an annual gas production of over 7 billion cubic meters in recent years, which is a good development result. With the increasing demand for development, the development targets have gradually shifted from the high-pressured shale gas reservoirs, e.g., the Jiaoshiba region, to the normal-pressured shale gas reservoirs of the Baima region. In 2021, the Baima area submitted a proven reserve of 104.883 billion cubic meters, consolidating its geological resource foundation. Development geology evaluation and target optimization are the first steps to efficiently achieve the utilization of reserves. Methods Based on core testing, well logging interpretation, seismic prediction, and gas testing data, the favourable intervals and targets for the development of normal-pressured shale gas in the Baima area were evaluated in this study. Results The research results indicate that the organic-rich shale of the Ordovician Wufeng Formation and Silurian Longmaxi Formation in the Baima area was deposited on the deep-water shelf. Thereinto, the deep-water shelf siliceous shale is the most favourable layer for development. The key parameters for the development geology evaluation of normal-pressured shale gas include the formation pressure coefficient, porosity, natural fractures, and stress properties. Conclusion A geological parameter system has been established for the development of target areas, which suggests that the southern part of the Baima Syncline can be selected as the first target for development and production. The Baima Region has achieved large-scale economic production and can be an important reference for the development of normal-pressured shale gas.
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