Numerical simulation of hydraulic fracture propagation is increasingly used to evaluate the effect of various mechanistic aspects (e.g., inclusion of poroelastic effects, proppant transport, etc.), and of several variables, on the result of a stimulation operation at varying scales. The evaluation of alternative scenarios provides key information for decision making.
In this work, we present the latest developments of our in-house framework for simulation of hydraulic fracture propagation, describing its main characteristics.
The capability is based on a combined Discontinuous Galerkin finite elements formulation and cohesive zone modeling for crack propagation, and it shows excellent scalability in parallel computations.
Accuracy of the simulator is demonstrated with selected verification tests. Its strengths are illustrated by way of an application example, where we analyze the effect of the stimulation strategy on fracture interferences and the potential for mitigating them.
Several processes in nature involve fluid-drive fracturing, both taking place spontaneously and as engineering applications. Most of these processes relate to geosciences and civil engineering, including magma-driven cracks (Spence and Turcotte, 1985; Rubin, 1995), soil remediation (Murdoch, 2002; Frank and Barkley, 1995), carbon sequestration (Rudnicki, 2000) and cave preconditioning (van As and Jeffrey, 2000). Hydraulic fracture even takes place in biological settings (Casares et al., 2015; Dumortier et al., 2019). Its largest impact as of today is in the stimulation of unconventional hydrocarbon reservoirs (fracking), to enhance productivity and turn reservoir production economically viable (Economides and Nolte, 2000). Simultaneous reservoir stimulation and carbon sequestration by means of CO2-driven fracturing is currently under study (Middleton et al., 2015). Other energy-related applications include radioactive waste disposal and enhanced geothermal systems (EGSs) (Kneafsey et al., 2018), the Habanero Project in Australia probably being the most prominent as of today.
Given the general difficulty in, and elevated costs of, measuring quantities in the subsurface, modeling and simulation is a highly desirable tool to better understand the complexities involved in the operation, enhancing the development of fields. Several models and numerical methods were developed since the 1950’s, with increasing levels of complexity and physical phenomena incorporated.
