川南威远地区筇竹寺组页岩力学性质及可压性评价

川南龙马溪页岩气规模开发已取得理想效果，但由于页岩气开采具有明显的快速产量递减规律，因此探索新层系的勘探开发和压裂潜力必须提前谋划。文章以川南威远地区筇竹寺组页岩为研究对象，通过X衍射分析、电子显微镜扫描、岩石强度试验、地应力大小测试等方法，综合分析了该地区筇竹寺组页岩力学性质及可压性，并与龙马溪组页岩进行了对比。结果表明：威远地区筇竹寺组页岩为硅质页岩，脆性矿物含量高，天然微裂缝发育，具有良好的储层改造基础物性；页岩层理面内不同方位力学参数变化小，抗拉/抗压强度比值低，且地应力差异系数较小，具有产生复杂裂缝的力学条件；结合微观特征和力学特征的综合可压性评价认为，威远地区筇竹寺组页岩可压性优于龙马溪组页岩，展示了良好的资源接替潜力。

Mechanical Properties and Compressibility Evaluation of Qiongzhusi Shale in Weiyuan AreainSouthern Sichuan

The large-scale development of Longmaxi shale gas in southern Sichuan has achieved ideal results. However, due to the obvious rapid production decline in shale gas exploitation, the exploration development and fracturing potential of new formations must be planned in advance. In this paper, the mechanical properties and compressibility of the Qiongzhusi Shale in the Weiyuan area of southern Sichuan basin were comprehensively analyzed by X-ray diffraction analysis, electron microscope scanning, rock strength test and in-situ stress test, and compared with that of the Longmaxi Shale. The results show that the Qiongzhusi Shale in Weiyuan area is siliceous shale with high brittle mineral content and well-developed natural microfractures, which has good physical properties for reservoir reconstruction. The variation of mechanical parameters in different directions of the shale bedding plane is small, the ratio of tensile strength to compressive strength is low, and the difference coefficient of ground stress is small, having mechanical conditions to produce complex fractures. According to the comprehensive compressibility evaluation of microscopic and mechanical characteristics, the compressibility of the Qiongzhusi Shale in Weiyuan area is better than that of the Longmaxi Shale, which shows a good potential of resource replacement.