Simulation of Progressive Borehole Failure at Multi-Lateral Junctions

Multi-lateral junction failure, one of the challenges introduced by employing multi-lateral technology to improve production of oil and gas wells, has imposed significant impacts on the employment of this new technology. Therefore, a powerful computer simulator is required for analyzing the issues of both fracturing and collapse at the multi-lateral junction. In this study, we present such a simulator, Rock Failure Process Analysis (RFPA(2D)), in which rock is assumed to be heterogeneous at a mesoscopic level and an elastic-damage based constitutive law is used to describe the constitutive law of elements. The applicability of RFPA(2D) to simulate progressive borehole failure processes at junction locations is demonstrated through (1) successful comparisons of the simulated distribution of stress concentration factors with the known analytical solutions for the elastic case; (2) successful comparisons of the simulated borehole failure patterns with experimental observations reported in previous studies; and (3) simulations of progressive borehole failure processes under a variety of geometrical and loading conditions.