川西南金石地区筇竹寺组岩石力学及地应力场模拟

Rock Mechanics and Geostress Field Simulation of the Qiongzhu Temple Formation in the Jinshi Area of Southwest Sichuan

摘要: 中国南方海相页岩气资源潜力巨大，但川西南地区下寒武统筇竹寺组页岩普遍经历多期构造运动，导致储层非均质性强、地应力场复杂，制约了页岩气的高效开发。地应力是控制页岩储层裂缝发育、井壁稳定及水力压裂效果的关键因素。现有研究多集中于单一井点的地应力测量或简化模型的数值模拟，缺乏基于高精度三维地质模型与多期构造约束的应力场协同演化研究。本文以川西南金石地区筇竹寺组为研究对象，通过系统的岩石力学测试、构造年代学分析，结合三维地质建模与有限元数值模拟技术，旨在：1) 查明研究区页岩岩石力学参数特征；2) 厘定关键构造期次及古今地应力大小与方向；3) 建立三维地质力学模型，模拟多期构造应力场演化过程；4) 阐明地应力场分布规律及其对页岩气产能的控制作用。研究成果可为该区页岩气勘探开发的工程决策提供科学支撑。

Abstract: The potential for marine shale gas resources in southern China is enormous, but the Xiangzhusi Formation shale in the southwestern Sichuan region has generally experienced multiple tectonic events, resulting in strong reservoir heterogeneity and a complex stress field, which constrain the efficient development of shale gas. Geostress is a key factor controlling fracture development in shale reservoirs, wellbore stability, and hydraulic fracturing efficiency. Existing studies mostly focus on geostress measurements at a single well or numerical simulations based on simplified models, lacking research on the coordinated evolution of stress fields based on high-precision three-dimensional geological models and multiple tectonic constraints. This study takes the Xiangzhusi Formation in the Jinshi area of southwestern Sichuan as the research object. Through systematic rock mechanics testing and tectonic chronology analysis, combined with three-dimensional geological modeling and finite element numerical simulation techniques, the objectives are to: 1) identify the characteristics of rock mechanical parameters in the study area; 2) determine key tectonic periods and the magnitude and direction of paleo and present-day geostress; 3) establish a three-dimensional geomechanical model to simulate the evolution of multi-phase tectonic stress fields; 4) clarify the distribution pattern of geostress fields and their controlling effect on shale gas productivity. The research results can provide scientific support for engineering decision-making in shale gas exploration and development in the area.