Hydraulic fracturing is critical for unconventional oil and gas development, yet perforation-induced initial damage impairs the integrity of the casing–cement sheath–formation assembly, causing fracturing fluid channeling and reduced stimulation efficiency. A stress-seepage coupling numerical model was established to simulate interface fracture initiation, propagation, and sealing failure, quantifying axial and circumferential channeling evolution at the cement–formation interface. Key parameters (casing eccentricity, cement elastic modulus, injection rate, and minimum horizontal in situ stress) were systematically analyzed. Results show fluid preferentially migrates through perforation-weakened zones, with channeling initiating via axial debonding, then circumferential propagation, and finally dominant axial extension. Casing eccentricity exacerbates channeling, while higher cement elastic modulus or in situ stress mitigates it significantly; injection rate affects channeling length but not fracture initiation/propagation pressures. This study provides theoretical and practical guidance for fracturing channeling risk control.
Xi et al. (Sat,) studied this question.