基于双重孔隙介质模型的渗流-应力耦合并行数值分析

为模拟天然岩石中孔隙和裂隙的不同渗透性能及应力耦合特性,基于双重孔隙介质模型,建立渗流–应力耦合分析的迭代计算模型。岩石基质渗透系数和孔隙率通过体积应变进行更新。裂隙系统的耦合模型通过立方体单元模型来建立,渗透系数和孔隙率随有效应力的变化进行更新。考虑到耦合分析时步多、计算量大的问题,采用基于element-by-element策略的有限元并行计算方法进行数值模拟。编制相应的耦合分析并行程序CoupledGF,并在分布存储的并行机上实现。对包含一个生产井和一个注入井的封闭区域进行渗流–应力耦合分析,模拟约22 000个时步。计算结果表明,并行耦合分析模型对于渗流应力的耦合分析是很有效的。

PARALLEL NUMERICAL ANALYSIS OF COUPLED FLUID FLOW AND STRESS BASED ON DUAL POROSITY MEDIA MODEL

To simulate the permeability and coupling characteristics of pores and fractures in intack rock,an iterative computation model for the analysis of coupled fluid flow and stress is established based on the dual porosity media model.The permeability coefficient and porosity of rock are updated by volumetric strain.The coupling model of fracture system is established by cubic element model;and the permeability coefficient and porosity are renewed as effective stress changes.Considering enormous time steps and huge workload in the coupling analysis,the element-by-element(EBE) finite element parallel computation method is adopted for numerical simulation.Corresponding parallel program for coupling analysis,GoupledGF,is developed and then implemented on cluster of workstation.Coupling analysis of fluid flow and stress is conducted for an enclosed area including a production well and an injection well.The total amount of time steps is about 22 000.Computational results show that the parallel coupling analysis model is very effective for the coupling analysis.