Pressurized-Fracture Propagation using a Phase-Field Approach Coupled to a Reservoir Simulator

摘要

Tight gas and shale oil play an important role in energy security and meeting an increasing energy demand.Hydrualic fracturing is a widely used technology for recovering these resources.Prediction of fracture growth during slick-water injection and final geometry for single and muti-stage hydraulic allows quantitative assessment of frac-job scenarios.A recently introduced phase-field approach for pressurized fractures in a porous medium offers various attractive computational features for numerical simulations of cracks such as joining,branching,and non-planar propagation for heterogeneous porous media.In this study,we employ the phase-field fracture propagation model is used as a pre-processor in order to couple it to a fractured poroelastic reservoir simulator.This offers the possibility to simulate the entire scenario from hydraulic fracturing to the production process.The proposed algorithm is based on a one-way coupling and is therefore easy to adapt to existing legacy reservoir simulators.The phase-field model can be seen as a fracture-well-model in the reservoir simulator.The key idea behind this strategy is the possibility to couple reservoir and fracture flow in the phase-field formulation from which we obtain an initial condition for the reservoir simulator.Our proposed framework is substantiated with several numerical tests in two-and three dimensions.