基于离散模型的干热岩裂缝渗透率研究  

Study on fracture permeability of dry hot rock based on discontinuous model

作　　者：李秋辰 谢兴隆[1] 崔芳姿 牛雪[1] 明圆圆[1] 孟兆海[2] 吴燕冈[3] LI QiuChen;XIE XingLong;CUI FangZi;NIU Xue;MING YuanYuan;MENG ZhaoHai;WU YanGang(Center for Hydrogeology and Environmental Geology Survey,China Geological Survey,Baoding 071051,China;Tianjin Navigation Instrument Research Institute,Tianjin 300131,China;School of Earth Exploration Science and technology,Jilin University,Changchun 130026,China)

机构地区：[1]中国地质调查局水文地质环境地质调查中心,保定071051 [2]天津航海仪器研究所,天津300131 [3]吉林大学地球探测科学与技术学院,长春130026

出　　处：《地球物理学进展》2023年第2期542-550,共9页Progress in Geophysics

基　　金：国家重点计划研发项目(2020YFE0201300)资助。

摘　　要：裂缝渗流是进行干热岩储层渗流分析的关键因素,微地震监测做为干热岩开采的主要技术之一,可以对裂缝渗透率进行求解分析.本文探讨了一种基于离散模型的干热岩裂缝渗透率计算方法:首先利用矩张量反演法进行震源机制解,用以获取微地震事件的破裂机制与破裂面的几何参数(包括裂缝的产状、裂缝尺度与裂缝开度等).在震源机制解的基础上,进行基于微地震事件的离散裂缝网络建模,进而根据每个单元格中的裂缝模型数量、裂缝方向和大小计算出离散模型下的渗透率张量,以达到分析储层渗透率的目的.在本文最后,选取了某干热岩的微地震监测数据对该方法进行实际应用.实例结果表明,该方法可有效分析储层裂缝网络的渗流变化规律,对合理制定干热岩开发方案具有一定指导意义.Fracture percolation is the key factor of percolation analysis of dry-hot rock reservoir. As one of the main techniques of dry-hot rock mining, microseismic monitoring can solve and analyze it. In this paper, one of the method of calculating fracture permeability based on discontinuous model is discussed. Firstly, the source mechanism is solved by moment tensor inversion, in order to obtain the fracture mechanism of microseismic events and the geometric parameters of the fracture surface(including the occurrence of fractures, fracture scale and fracture opening, etc.) On this basis, the discrete fracture network was modeled based on microseismic events, and then the permeability tensor under the discrete model was calculated according to the number, direction and size of fracture models in each cell, so as to analyze the permeability of the reservoir. At the end of this article, the microseismic monitoring data of a hot and dry rock is selected to apply the method in practice. The result shows that this method can effectively analyze the law of seepage flow change of reservoir fracture network, and has certain guiding significance to formulate the development plan of dry hot rock rationally.

关 键 词：干热岩 微地震监测 离散裂缝网络 裂缝渗透率 

分 类 号：P314[天文地球—固体地球物理学]