FINITE ELEMENT ANALYSIS OF TRANSVERSELY ISOTROPIC ROCK WITH MECHANICAL-CHEMICAL-DAMAGE COUPLING

Based on the hydration and continuum damage characteristics of laminated rock, the finite element method (FEM) considering mechanical-chemical-damage coupling is studied, which can be used to analyze the stresses on wellbore and the damage evolution for rock reservoirs. A transverse-isotropic-Biot constitutive relationship is developed, in which Weibull distribution is used effectively to simulate petrophysical heterogeneity characteristics. Regarding the hydration behavior as damage and combining stress damage in a current stress state, an innovative damage tensor is derived for the damage analysis of elastic modulus and permeability. Then the finite element analysis (FEA) technology considering hydraulic-mechanical-chemical-damage (HMCD) coupling is proposed for the damage evolution by hydration and loading. Numerical examples are presented to show the effectivity and reliability of the proposed technology for the hydration characteristic analysis of laminated rock, furthermore to demonstrate the heterogeneous and hydration effect for the stress solution on wellbore.