Abstract
In this study, both experimental and numerical studies were performed to investigate the impact of a bi-material interface on crack propagation. A set of thickness values for the weak interfacial layer was used in the experiments to investigate its influence on fracture propagation. In the numerical studies, the aforementioned experimental phenomena were simulated first, with the focus on calibrating the numerical model. Second, a numerical investigation of the influence of the strength and stiffness of the interface layer on crack propagation was performed. The influence of the interface layer permeability on the propagation of hydraulically generated fractures across the interface layer was also investigated. During the numerical studies, a simplified 3D Finite Element Model was built and used. The poroelastic plastic damage model is used to simulate crack propagation. The load of the numerical model for the 1 set of calculations is the point force in 3-point bending, which simulates the experimental phenomena. Loads in the 2 set of calculations include the gravity load which balances the initial geostress field and the fluid injection flow rate. The results obtained can be used as a reference in the design of hydraulic fracturing for laminated thin formations.