Iterative coupling of flow, geomechanics and adaptive phase-field fracture including level-set crack width approaches

TL;DR

This paper introduces an advanced numerical framework for simulating propagating fractures in porous media by coupling flow, geomechanics, and phase-field fracture models with level-set crack width calculations, enhancing accuracy and computational efficiency.

Contribution

It extends fixed-stress iterative coupling to propagating phase-field fractures and integrates level-set crack width approaches for improved fracture permeability modeling.

Findings

Demonstrates accurate fracture opening computation using level-set methods.

Shows improved convergence and computational efficiency in numerical tests.

Validates the approach with multiple numerical experiments.

Abstract

In this work, we present numerical studies of fixed-stress iterative coupling for solving flow and geomechanics with propagating fractures in a porous medium. Specifically, fracture propagations are described by employing a phase-field approach. The extension to fixed-stress splitting to propagating phase-field fractures and systematic investigation of its properties are important enhancements to existing studies. Moreover, we provide an accurate computation of the fracture opening using level-set approaches and a subsequent finite element interpolation of the width. The latter enters as fracture permeability into the pressure diffraction problem which is crucial for fluid filled fractures. Our developments are substantiated with several numerical tests that include comparisons of computational cost for iterative coupling and nonlinear and linear iterations as well as convergence studies in space and time.