长宁——威远国家级页岩气示范区建设实践与成效

四川盆地南部长宁—威远地区下志留统龙马溪组页岩气资源丰富、页岩储层品质较优,2012年被确定为国家级页岩气示范区。为了给中国的页岩气勘探开发提供可资借鉴的经验,在对该示范区勘探开发历程进行划分的基础上,总结了各阶段所形成的主体技术和取得的成果认识,以期为四川盆地页岩气勘探开发迈上新台阶夯实基础。研究结果表明:(1)通过10余年的不断探索,川南地区页岩气勘探开发历经了评层选区、先导试验、示范区建设3个阶段,当前已迈入新的发展时期;(2)该示范区建设经历了3轮优化调整:第一轮建产井严格执行开发方案设计的主体技术、第二轮对设计和工程技术方案进行了全面优化、第三轮全面推广地质工程一体化技术,3轮持续调整优化了设计、完善了主体技术、提高了页岩气单井产量;(3)目前,该示范区已建成25×108 m3的页岩气年产能力,掌握了3 500 m以浅页岩气有效开发的方法和手段,得益于技术的不断进步,已初步实现了页岩气规模效益开发。结论认为,该页岩气示范区建设过程中,持续深化评价了页岩气资源、落实了可工作有利区资源及分布、完成了体系建设,川南地区页岩气快速上产的时机已经成熟。

Practices and achievements of the Changning–Weiyuan shale gas national demonstration project construction

Rich and quality shale gas reservoirs have been found in the Lower Silurian Longmaxi strata in the Changning–Weiyuan area, southern Sichuan Basin, which was identified as the shale gas national demonstration zone in 2012. In order to provide useful experiences for shale gas E&P in China, we summarized the main technologies and achievements in every step of the E&P process in this demonstration project, hoping to lay a robust foundation for the further shale gas E&P in the Sichuan Basin. The following findings were obtained. (1) Over the past one decade, this project has gone through three stages of favorable layers & targets evaluation, pilot tests and project construction, and has come to a new stage of rapid development. (2) Designs, technologies and single-well productivity have been continuously improved because this project construction has undergone three rounds of optimization and adjustment: the first round of main technologies adopted for those production gas wells strictly according to the previous development plan design; the second overall optimal round of design and engineering schemes; and the third all-around promotion round of integrated geological & engineering technologies. (3) Up till now, this project has achieved a commercial gas flow with a shale gas productivity of 25×108 m3 per year and obtained effective development methods and measures for shale gas reservoirs less than 3 500 meters in depth. In conclusion, with this project successfully constructed, the shale gas resources has been evaluated and favorable targets have been clarified in the southern Sichuan Basin, where commercial shale gas production will soon be achieved.