弹性气藏中气体渗流的气—固—热耦合数学模型

GAS-SOLID-HEAT COUPLING MATHEMATICAL MODEL OF GAS PERCOLATION FLOW IN ELASTIC GAS RESERVOIR

综合应用渗流力学、岩石力学、热力学理论 ,建立起以气体压力、岩石固相质点位移、绝对温度为基本变量的全新的气—固—热耦合数学模型。该模型假设气藏岩石骨架是可变形的 ,气藏内热量按热力学定律自由传递 ,模型包括完全耦合的气体渗流方程、温度场方程和岩石变形方程。文章所建立的模型实现了气藏中渗流、变形、变温三者间真正意义上的耦合 ,较之已有的气藏渗流模型更能反映气藏实际 ,是对气藏传统渗流理论和流固耦合力学理论的发展 。

A new gas solid heat coupling mathematical model taking the gas pressure,rock solid particle displacement and absolute temperature as the basic varibles was set up by applying comprehensively the theories of percolation mechanics rock mechanics and thermodynamics.Let it be supposed in the model that the rock matrixes in gas reservoir may be deformed and the heat can be freely transferred according to thermodynamic laws and the model includes the fully coupling gas percolation,temperature field and rock deformation equations.The model established by the authors,which realizes the real couplying among percolation flow,rock deformation and temperature change in gas reservoir and can more objectively reflect the gas reservoir reality by contrast to the existent gas reservoir percolation models,has developed the conventional gas reservoir percolation theory and fluid solid couplying mechanical theory and can be widely applied to many realms of gas reservoir engineering.