Numerical Investigation of the Influence of Wave Pressure Amplitude and Frequency on Fracture Morphology Induced by Supercritical CO 2 Fracturing

The mechanisms whereby various parameters influence the evolution of the induced fracture geometry during pulse supercritical CO 2 fracturing (PSCF) were explored through numerical simulations. A novel quantitative index of the induced fractures, termed the “matching degree” (MD), was proposed, and a theoretical framework based on the rock‐bonded particle fatigue model (BPFM) was constructed. The BPFM parameters were calibrated using theoretical and experimental results. In this study, the effects of pulse parameters, namely, pressure amplitude and frequency, on the crack MD were analyzed. Numerical simulation results revealed that the crack MD decreased with increasing loading frequency over the range of 5–30 Hz. Within a pressure amplitude range of 0.7–2.2 MPa, the crack MD increased significantly with the increase in the loading amplitude. These findings lay an important theoretical basis for the efficient development of unconventional oil and gas resources.