<p>During oil and gas production, achieving optimal output is closely linked to the extent to which reservoir areas are effectively stimulated/fractured, especially those with initially ultra-low permeability that have been significantly improved. Multiple staged clusters are implemented to maximize stimulated reservoir volume and boost production. As multiple hydraulic fractures emerge from closely spaced clusters and notched perforations, interactions between fractures are inevitable throughout the fracturing process. These interactions alter fracture propagation from the originally intended paths to the complex propagation, creating a complex fracture network during the post-fracturing phases. To address this, stress–seepage–damage coupled models are proposed that consider pre-existing rock discontinuities, such as natural fractures and beddings, along with complex two-phase fluid flow. These models have been validated through fracturing experiments on bedded shale specimens and prior published simulation results, and are applied herein to investigate interactions between multiple fractures during hydraulic fracturing. The findings indicate that pre-existing shale beddings significantly impact fracture propagation paths, with the proposed model aligning well with laboratory results, supporting its suitability for further study of fracture interactions. Additional numerical results indicate that the fracture interactions in shale reservoirs with randomly distributed natural fractures are more intricate than in conventional reservoirs, being influenced not only by stress shadow effects but also by the directional guidance of pre-existing fractures and beddings on induced hydraulic fractures. Moreover, in compound reservoirs accounting for two-phase water and oil flows, fracture interactions are affected by variations in water and oil pressure distributions within the reservoir,—an effect that cannot be captured by traditional single-phase flow models. Overall, the study underscores the importance of including beddings, natural fractures, and multi-phase flow of reservoir fluids for accurate numerical assessments of fracture interactions in complex reservoir scenarios.</p>