真三轴应力条件下各向异性煤岩的多场耦合响应特性研究

Geomechanical and fluid flow behaviors of coal under thermal-hydrological-mechanical (THM) coupled conditions are of significant importance for simultaneous exploitations of coal and gas. Coal has strong anisotropy in fracture distributions, aperture, tortuosity and connectivity. Coal is under true triaxial stress conditions as tectonic stress and engineering disturbance exist. In this project, anisotropic coal is considered to be the research objects. Geomechanical and fluid flow behaviors of coal are studied through experiments using the newly developed multi-functional true triaxial geophysical apparatus, theoretical analysis and numerical simulations. The geomechanical properties and permeability evolutions of coal under true triaxial stress conditions are going to be discussed. The relationships among the permeability of coal, the fracture of coal and true triaxial stress are going to be revealed. Based on the consideration of fracture compressibility, a permeability model applicable to anisotropic materials under true triaxial stress conditions is going to be proposed and verified by matching the permeability data in the experiments. A THM coupled model for anisotropic coal is going to be established and used for field simulations. The research results can provide theoretical basis and guidance for optimizing the layouts of methane drainages and improving the efficiency of methane extraction. The results are also of great scientific significance to the basic researches of simultaneous exploitations of coal and gas and deep rock mechanics.

煤岩处于热-流-固等多物理场耦合条件下，结构具有明显的各向异性，其力学特性和渗流规律是影响煤与瓦斯共采的关键因素。由于构造应力和工程扰动的作用，煤岩所处的应力环境为真三轴应力状态。本项目以各向异性煤岩作为研究对象，利用自主研制的多功能真三轴流固耦合试验系统，综合运用试验研究、理论分析与数值模拟等手段，阐明真三轴应力条件下煤岩力学特性与渗流规律；揭示煤岩裂隙形态、真三轴应力与各向异性渗透率之间的相互关系；提出真三轴应力条件下各向异性煤岩渗透率计算模型；建立真三轴应力条件下各向异性煤岩热流固耦合模型并进行应用，揭示真三轴应力条件下各向异性煤岩的热流固耦合响应特性。研究成果可为优化瓦斯抽采钻孔布置和提高瓦斯抽采效率提供理论依据和指导，对煤与瓦斯共采基础研究和深部岩石力学基础研究具有重要的科学意义。

煤岩处于热-流-固等多物理场耦合条件下，结构具有明显的各向异性，其力学特性和渗流规律是影响煤与瓦斯共采的关键因素。由于构造应力和工程扰动的作用，煤岩所处的应力环境为真三轴应力状态。本项目以各向异性煤岩作为研究对象，利用自主研制的多功能真三轴流固耦合试验系统，综合运用试验研究、理论分析与数值模拟等手段，阐明了真三轴应力条件下煤岩力学特性与渗流规律；揭示了煤岩裂隙形态、真三轴应力与各向异性渗透率之间的相互关系；提出了真三轴应力条件下各向异性煤岩渗透率计算模型；建立了真三轴应力条件下各向异性煤岩热流固耦合模型并进行应用，揭示了真三轴应力条件下各向异性煤岩的热流固耦合响应特性。研究成果可为优化瓦斯抽采钻孔布置和提高瓦斯抽采效率提供理论依据和指导，对煤与瓦斯共采基础研究和深部岩石力学基础研究具有重要的科学意义。三年以来，项目组出版专著1部，发表学术论文22篇，其中：SCI论文21篇，EI论文1篇。项目执行期间新申请国家发明专利9项，其中已获得授权国家发明专利4项。项目相关研究内容获得重庆市科技进步一等奖1项和中国煤炭工业协会科学技术一等奖1项。项目组已培养出站博士后1人、联合培养博士生3人、硕士生2人，其中1人入选中国科协青年人才托举工程，1人获“绿色矿山青年科技奖”，1人获得“中国岩石力学与工程学会优秀博士学位论文奖励”。