模拟水压致裂的另一种二维FDEM-flow方法

发布时间：2018-03-31 19:15

本文选题：FEMDEM　切入点：FDEM-flow　出处：《岩土力学》2017年06期

【摘要】：可考虑岩石本身渗透性的FDEM-flow方法充分利用原FEMDEM中节理单元和三角形单元独特的拓扑连接关系,将节理单元作为流体流动的天然通道,基于立方定律来表征流体在岩石本身及裂隙中的流动,而岩石本身渗透性则通过标定合适节理单元张开度来表征。用一个含解析解自由面稳态渗流算例初步验证了本文渗流算法及标定岩石本身渗透率方法的正确性。最后计算了一个水力压裂算例,验证了该FDEM-flow方法可同时考虑岩石本身的渗透性和裂隙的渗透性,用简单的纯裂隙渗流完成了对复杂问题的处理。研究结果表明:修改后的FDEM-flow方法能够很好地再现压裂过程中流体压力的分布及裂隙的扩展,可简洁地求解水力压裂这一复杂力学的问题,适用范围更广。为模拟页岩气开采、干热岩地热获取中的水力压裂问题提供新的求解工具。
[Abstract]:The FDEM-flow method, which considers the permeability of rock itself, makes full use of the unique topological connection between the joint element and the triangular element in the original FEMDEM, and takes the joint element as the natural channel for fluid flow. Based on the cubic law to characterize the flow of fluid in the rock itself and in fractures, The permeability of the rock itself is characterized by the proper opening degree of the joint unit, and the correctness of the proposed seepage algorithm and the method of calibrating the permeability of the rock is preliminarily verified by an example of steady seepage with an analytical solution. Finally, a hydraulic fracturing example is calculated. It is verified that the FDEM-flow method can consider both the permeability of rock itself and the permeability of fractures. Simple pure fracture seepage is used to deal with complex problems. The results show that the modified FDEM-flow method can well reproduce the distribution of fluid pressure and crack propagation during fracturing. The complex mechanics problem of hydraulic fracturing can be solved succinctly, and the application scope is wider, which provides a new solution tool for the hydraulic fracturing problem in the process of simulating shale gas production and geothermic acquisition of dry hot rock.
【作者单位】：中国地质大学工程学院;
【基金】：国家自然科学基金青年项目(No.11602006) 北京市自然科学基金青年项目(No.1174012) 朝阳区博士后科研活动经费资助(No.2016ZZ-01-08)~~
【分类号】：TV223

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