Abstract
A general-purpose numerical formulation is presented for the incremental quasistatic stable lateral growth and interaction of fluid driven fractures in reservoir structures. Multiple fractures emanating from multiple wellbores are allowed to evolve on arbitrarily curved trajectories, dictated by non-uniform stress fields arising from interaction of fractures with one another and with material/stress variations. The model simulates fracture growth by simultaneously solving for stresses, displacements and pressure distributions associated with the fracturing configuration at each timestep. The elastostatic computation employs a surface integral method, while the coupled fluid flow and crack opening modelling involves a weak starting assumption of (instantaneous) self-similarity in the opening displacement profile. A search scheme is used to determine the directions and amounts of growth at the end of each timestep. Several sample fracture growth patterns are presented to illustrate the generality and applicability of the simulator, which is verified by comparison with many of our laboratory experiments. The overall scheme provides an efficient, direct and convenient tool for design of multiple fracturing treatments, whenever these begin to be used for creation of suitable underground fracture networks (e.g., for enhanced petroleum recovery or solution mining).
