双重介质非饱和两相流岩体热流固损伤模型研究

本文以孔隙-裂缝双重孔隙介质为研究对象，建立孔隙度与岩体应变数学模型和温度场诱导应力模型。基于Terzaghi有效应力原理，建立注水开采过程温度-流体-岩石骨架的应力分布模型。考虑注水压力和注水温度场应力导致的岩体孔隙-裂隙的变形、成核和增长，采用应变孔隙度定义损伤变量，建立了以Gurson-Tvergaard-Needleman圆柱体胞模型为塑性屈服函数的双重孔隙介质饱和热流固损伤本构模型。以某1口生产井为研究对象，通过有限元软件数值模拟得到：温度场诱导应力、注水压力诱导应力和岩石应力分布规律；应力与损伤变量、应变孔隙度演化规律。新模型对油田注水开采过程中储层孔隙和裂缝的变化提供了新的研究方法和理论依据。

Study on thermal deterioration model of liquid and solid in double porous medium rock matrix with unsaturated two-phase flow

The double porous medium that is a medium between pore and fracture is selected as an object of study.The inductive stress model of thermal field is built,as well as the mathematical model of porosity and rock matrix strain.Based on the Terzaghi effective stress principle,the stress distribution model is built which is the relationship of temperature,liquid and rock skeleton during period of waterflood exploitation.The processes are considered,which are deformation,nucleation and growing of pore and fracture that are induced by stress of injection pressure and injection temperature field stress.The damage variable is defined by strain porosity.The constitutional equation of double pore medium saturated liquid-solid is set up where the Gurson Tvergaard Needleman cylindric representative volume element(RVE) is taken as plastic yielding function.Take some well in one oil field,the result is concluded form numerical simulation of finite element software,which are induced stresses of thermal field and waterflood pressure and rock stress distribution rule,together with evolving regulations of stress and damage variable and strain porosity.The new model provides new research method and theoretical base for reservoir pore and fracture change in period of waterflood exploration.