4.2.3Elasticity.
Numerical simulations performed for the above Case on the basis of elasticity. The simulations can indicate the potential areas of failure during gas production. Let introduce λ to indicate the distance between the effective stresses and the yield function of the Mohr-Coulomb model, written as
λ=(〖τ_m〗^'-〖σ_m〗^' sin〖ψ_f-c_h cos〖ψ_f 〗 〗)/(√(〖sin〗^2 ) ψ_f+1) (17)
High values indicate potential areas of shear failure, and failure can occur when λ < 0. Fig. 4-6 shows distributions of λ for the base when k=8.76× 〖10〗^(-4) md