Hydraulic Fracturing Behavior in Shale with Water and Supercritical CO₂ under Triaxial Compression

Figure 8

Curves of hydraulic fracturing using (a) water and (b) SC-CO₂ of shale with bedding plane angle of 0° under axial stress 25 MPa, confining pressure 20 MPa, and injection rate 0.3 ml/s. (The fracture width evolution was calculated. The maximum fracture width was calculated by the circumference difference from fracture initiation to the valley. The opening fracture width during the equilibrium state was by circumference difference from fracture initiation to the stable. The closure of the fracture was by circumference difference from fracture stable to the valley.)

(a)

(b)