川南地区百亿立方米页岩气产能建设地质工程一体化关键技术

四川盆地南部地区下志留统龙马溪组页岩气资源丰富,但地质、工程条件复杂,页岩气规模效益开发面临着严峻的挑战。为了解决川南地区页岩气"部署设计难度大、优质储层钻遇率提高难度大、复杂缝网形成难度大、单井产量和单井估算最终采收量(EUR)提高难度大"等问题,通过系统梳理和总结10余年的页岩气勘探开发成果,形成了适用于该区的页岩气地质工程一体化高产井培育方法,并开展了现场试验和推广应用。研究结果表明:①所形成的三维地质建模、三维地质力学建模、复杂缝网模拟和产能数值模拟等4项关键技术,为该区页岩气井全生命周期的方案设计、现场实施、实时调整提供了重要的决策依据和指导,有效提高了页岩气单井产量和EUR;②实施地质工程一体化高产井培育方法,可以大幅度提高长宁—威远国家级页岩气示范区页岩气单井产量,其中长宁区块井均测试日产量由10.9×10~4 m~3提高到26.3×10~4 m~3、最高测试日产量达到62×10~4 m~3,威远区块井均测试日产量由11.6×10~4m~3提高到23.9×10~4 m~3、最高测试日产量达到71×10~4 m~3;③推广应用地质工程一体化高产井培育方法,可以实现高产井的"复制",培育了一批EUR超过1.5×10~8 m~3、部分超过2×10~8 m~3的高产井,其中泸州区块4口深层页岩气井,井均EUR达1.98×10~8 m~3。结论认为,所形成的地质工程一体化页岩气高产井培育方法,是破解页岩气规模效益开发难题的有效措施,可以为国内外非常规油气藏的规模效益开发提供借鉴。

Geology-engineering integration key technologies for ten billion cubic meters of shale gas productivity construction in the Southern Sichuan Basin

There are abundant shale gas resources in the Lower Silurian Longmaxi Formation of the southern Sichuan Basin, but its geological and engineering conditions are complex, which brings severe challenges to the scale benefit development of shale gas in this area. In order to solve the problems in shale gas development in the southern Sichuan Basin, such as "difficult deployment design, difficult to improve the drilling rate of high-quality reservoirs, difficult to form complex fracture network and difficult to increase single-well production and estimated ultimate recovery (EUR)", this paper developed a high-yield well cultivation method based on geology-engineering integration suitable for shale gas in this area by systematically analyzing and summarizing the shale gas exploration and development achievements in the last ten years. In addition, this method was tested on site and popularized for further application. And the following research results were obtained. First, four key technologies (including three-dimensional geological modeling, three-dimensional geomechanical modeling, complex fracture network simulation and numerical productivity simulation) provide important decision-making basis and guidance for the scheme design, field implementation and real-time adjustment in the whole life cycle of shale gas wells and effectively improve the single-well production and EUR of shale gas. Second, the implementation of the high-yield well cultivation method based on geology-engineering integration can greatly improve the single-well production of shale gas in Changning-Weiyuan National Shale Gas Demonstration Area. The average daily well testing production in Changning Block is increased from 10.9×10⁴ m³ to 26.3×10⁴ m³, and the maximum value reaches 62×10⁴ m³. The average daily well testing production in Weiyuan Block is increased from 11.6×10⁴ m³ to 23.9×10⁴ m³, and the maximum value reaches 71×10⁴ m³. Third, the popularization and application of the high-yield well cultivation method based on geology-engineering integration can realize the replication of high-yield wells. As a result, several high-yield wells with EUR greater than 1.5×10⁸ m³, some of which even exceed 2×10⁸ m³ have been cultivated. And the average EUR of four deep shale gas wells in Luzhou Block is up to 1.98×10⁸ m³.In conclusion, the high-yield well cultivation method based on geology-engineering integration is an effective measure to deal with the difficulties in the large-scale benefit development of shale gas, and it can provide reference for the scale benefit development of unconventional oil and gas reservoirs at home and abroad.