The theoretical model for porosity evolution during coal deformation process
For coal beds, the change of porosity may cause significant reservoir permeability change. In this study, the change laws of coal pore structure evolution during deformation process have been analyzed, and a theoretical model is derived to describe the porosity evolution induced by gas adsorption and the stress state. According to the constitutive equations based on the theory of mixtures, the stress-strain relation of coal containing gas under loading is established by means of the porous media mechanics analytical methods, in which porosity and its evolution have been considered. Meanwhile, the relations can be used to analyze porosity evolution of coal in the stressstrain process with the aid of numerical calculation. The elastic modulus and Poissons ratio of coal matrix, gas adsorption isotherm, and other measurable parameters, including coal initial porosity, are required in this model. Numerical results show that the porosity varies in the stress-strain process, and it differs in evolution with respect to gas adsorption.
porosity coal containing gast stress-strain relation adsorption
J.Zhu Y.D.Jiang Y.X.Zhao Q. Q. Song
School of Mechanics. Architecture and Civil Engineering, China University of Mining and Technology, State Key Lab of Coal Resources and Mining Safety, Beijing, 100083, China
国际会议
徐州
英文
266-270
2009-09-24（万方平台首次上网日期，不代表论文的发表时间）