Towards Accurate and Robust Modeling of Fluid-Driven Fracture

Abstract

This work advances a phase-field method for fluid-driven fractures and proposes arobust and efficient discretization framework. It begins by addressing a modeling challenge related to the application of pressure loads on diffuse crack surfaces. Along the way, a new J-Integral for pressurized fractures in a regularized context is devel- oped.Then, the focus turns to a hybrid method to model fluid-driven fracture propaga-tion. A so-called multi-resolution method is presented that uses a combination of en- richment schemes with the phase-field method to address the complex fluid-fracture interaction that occurs during hydraulic fracture. On one hand, the phase-field method alleviates some of the difficulties associated with the geometric evolution of the fracture, which are usually the limiting aspect of purely enrichment-based schemes. On the other hand, the discrete representation allows for a better treat- ment of the fluid loads and crack apertures, which are the main challenges associated with phase-field approaches.The multi-resolution method is first presented in a simplified scheme to treat two-dimensional problems. Various benchmark problems are used to verify the framework against well-known analytical solutions. The method is then extended to three- dimensions. A robust algorithm to handle planar cracks in 3D is developed and its extension to non-planar cases is discussed. Finally, opportunities for improvements and extensions are discussed, paving the road for future work in this area.