NUMERICAL ANALYSIS OF INFLUENCE OF STRESS-DILATANCY DEPENDENCE OF POROSITY ON THERMO-GAS-MECHANICAL COUPLING IN CO2 INJECTION IN STRATUM
ZHANG Yujun，ZHANG Weiqing
(State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and
Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China)
Abstract：Introducing the existing empirical relationships into a coupled thermo-gas-mechanical model，the porosity and the permeability of rock mass are regarded as functions of mean effective stress and volumetric strain resulted from shear dilation；and a corresponding two-dimensional finite element code is developed. Taking an assumed geological storage system consisted of an under-part reservoir and an upper-part caprock as an analytic object，the numerical simulation of the coupled thermo-gas-mechanical process in the rock mass during CO2 injection is conducted under three cases of different porosities and permeabilities. The calculation results show that the distributions and changes in porosities，pore air pressures，displacements，stresses，zones of tensile and shear failure in the rock mass are obviously different in three cases. Therefore，it is more accurate to consider porosity and permeability of rock as functions of stress，especially reckoning in the effect of volumetric strain resulted from shear dilation than to consider them as constants.
张玉军，张维庆. 孔隙率的应力–剪胀依存性对CO2地层注入
热–气–应力耦合影响的数值分析
[J]. 岩石力学与工程学报, 2010, 29(09): 1774-1781.
ZHANG Yujun，ZHANG Weiqing. NUMERICAL ANALYSIS OF INFLUENCE OF STRESS-DILATANCY DEPENDENCE OF POROSITY ON THERMO-GAS-MECHANICAL COUPLING IN CO2 INJECTION IN STRATUM. , 2010, 29(09): 1774-1781.
2010, Vol. 29 
