随机分布裂隙煤岩体模型及其应用

煤层中随机裂隙展布模拟技术是瓦斯抽放数值模拟中的关键技术。利用Monte-Carlo模拟技术模拟实际煤岩裂隙的随机性，建立了随机分布裂隙煤岩体模型，并在Matlab平台下开发了二维随机裂隙煤岩体生成程序RFSS 2D。在煤岩实测数据和统计分析的基础上，利用编制的程序不仅能生成与实际煤岩具有相同统计分布裂隙网络的虚拟煤岩体，而且能实现有限元网格自动剖分。以辽宁某瓦斯抽放试井作为数值算例，依据实测和统计数据建立了随机裂隙分布的煤岩体模型，模拟了瓦斯压和应力的演化规律，结果表明，与瓦斯抽放井连通的裂隙对瓦斯运移影响很大，与瓦斯抽放井不连通的裂隙对瓦斯运移也有影响，但影响有限。

Model with random cleats distribution for coal seams and its application

How to simulate random distribution of cleats in coal rock is key technique for simulation of methane recovery. Monte Carlo simulation technique is adopted to simulate the randomness of cleats distribution; and the model with random cleats distribution for coal seams is presented. RFSS2D (Random Fracture Simulation System in two dimensions) is developed with Matlab. Based on spot data for coal and their statistical analysis, not only the virtual fractured coal seams in which there is the same fractured statistical law with real engineering rock can be generated, but also FEM grid can be performed automatically by RFSS 2D. As a numerical case, a gas production well in Liaoning is studied with the model. According to spot and statistical data the model of random fractured coal is set up; and gas pressure and stress evolution are simulated. The results are as follows: Cleats which are connected with gas well greatly effect on gas flow; and cleats which are not connected with gas well finitely effect on gas flow.