三维裂隙岩体水力耦合多尺度分析相场模型研究

项目名称： 三维裂隙岩体水力耦合多尺度分析相场模型研究

项目编号： No.51474157

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 矿业工程

项目作者： 庄晓莹

作者单位： 同济大学

项目金额： 83万元

中文摘要： 如何有效控制和利用岩体在水力耦合作用下的裂隙扩展行为，是页岩气水力劈裂开采等地下能源开发中面临的核心问题，是我国能源发展中迫切需要解决的关键技术。本项目拟发展、实现和验证三维岩体裂隙扩展水力耦合多尺度分析数值模拟框架；建立显式三维宏观尺度断裂面-多孔介质模型，模拟流体通过断裂面之间的流动过程，以及裂隙在流-固相互作用下的扩展、分叉、贯通等力学行为；建立细观尺度水力耦合模型，发展全新的水力耦合相场势函数与控制方程。结合相场法（Phase field method）无需单独描述裂纹面几何形态、无需引入断裂模式假定并自然得到材料破坏过程的优势，建立细观裂隙在宏观水力边界条件下的演化分析模型，研究渗透张量等材料参数提取理论与方法；并通过压力梯度、渗流速度等一致性约束条件，建立连接宏细观岩体裂隙扩展的物理准则。本项目将最终形成一套有效、准确和可行的岩体水力裂隙分析计算理论与方法。

中文关键词： 三维裂隙；水力耦合；多尺度；相场法；岩体破坏

英文摘要： In the exploitation of geo-energy such as shale gas development using hydraulic fracturing, the fracture propagtion behaviour of fractured geologcal body under the coupled hydromechanical field is generally recognized as a key question in rock mechanics. The key objective of the proposed ressearch project is to develop and implement a robust, accurate and computationally efficient numerical framework for the modelling and optimization of future Energy Exploitation techniques.In the coarse scale model, a two-level model incoporating multiple discrete (explicit) fracutre surfaces and porous media will be developed to model the crack growth, branching and coalesence behaviour of cracks. The fluid flowing throug the crack surfaces will be modeled by Newtonian fluid. A coupled dual-phase field model accounting for the interaction from fluid and mechanical field. It will be the first phase field model to the applicant's knowledge coupling hydromechanical field for rock mechanics modelling. The advatanges of using phase field model is that the fracture geoemetry is the natural outcome of the simultion without any priori assumptions on crack path continuities, crack geometry and crack kinematics.The hydromechanical prameters such as permeability will be extracted through fine scale model. A semi-concurrent multiscalde modelling approach will be utilized to bridge the coarse and fine scale model through material consitency conditions including pressure gradient, strain tensor and fluid velocity.The measurable deliverable of the proposed project is the new theory, model and code implementation that are capable for effective, accurate and efficient fracture modelling of rock mass subjected to hydromechanical field.

英文关键词： 3D fracture;Hydro-mechanical;Multiscale modelling;Phase field method;Rock failure