Profitable development technology of the Changning-Weiyuan National Shale Gas Demonstration Area in the Sichuan Basin and its enlightenment

Since the approval to establishment, the Changning-Weiyuan National Shale Gas Demonstration Area in the Sichuan Basin (hereinafter referred to as Demonstration Area) has been built up into a shale gas industry demonstration base characterized with scale, technology, management and green after more than 10 years of exploration and practice. Its successful experience is of great guiding significance to the efficient development of unconventional oil and gas resources in China. In this paper, the technologies which were developed for the beneficial development of the Demonstration Area during the 13th Five-Year Plan are systematically reviewed and summarized. Then, some countermeasures are proposed to solve the difficulties and challenges to the long-term benefit and stable production of middle-deep shale gas in this area. And the following research results are obtained. First, during the construction of the Demonstration Area, the “three-control” shale gas enrichment and high-production theory is innovatively proposed, and the shale gas enrichment model in the southern Sichuan Basin is clarified. Second, a high-production well cultivation method based on geology-engineering integration is established by developing six main technologies for shale gas exploration and development, which effectively supports the large-scale beneficial development of shale gas in the Demonstration Area. Third, the beneficial development model of middle-deep shale gas in the southern Sichuan Basin is preliminarily formed, and the benefit and efficiency of productivity construction are improved comprehensively. Fourth, the three measures of “controlling the decline rate, enhancing the reserve production and expanding the periphery” are used to support the replacement and stable production of middle-deep shale gas. In conclusion, to sustainably ensure the long-term benefit and stable production of shale gas in the southern Sichuan Basin, it is still necessary to deepen fine reservoir description and complex mechanism understanding and explore EOR technologies. What's more, the important mean to improve the single-well shale gas production rate in this area is to strengthen the fine fracturing design and implementation under the deep integration of geology and engineering and improve the construction quality of fracturing network continuously. Furthermore, the only way to the low-cost development of the demonstration area is to promote the management reform and innovation continuously and improve the beneficial development model further.