Investigation of Shale Permeability Evolution considering Bivalued Effective Stress Coefficients for CO₂ Injection

Figure 8

(a) CO₂ permeability data of a 3.71 mm shale disk linearized by plotting a logarithm of permeability versus confining pressures at constant pore pressures to determine the sensitivity of confining pressure to permeability. (b) CO₂ permeability data of a 3.71 mm shale disk linearized by plotting a logarithm of permeability versus at constant confining pressures to determine the sensitivity of pore pressure to permeability. The slopes are positive when pressures are above ~4 MPa and negative when below ~4 MPa.

(a)

(b)