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

摘要

In this work, we present numerical studies of fixed-stress iterative couplingfor solving flow and geomechanics with propagating fractures in a porousmedium. Specifically, fracture propagations are described by employing aphase-field approach. The extension to fixed-stress splitting to propagatingphase-field fractures and systematic investigation of its properties areimportant enhancements to existing studies. Moreover, we provide an accuratecomputation of the fracture opening using level-set approaches and a subsequentfinite element interpolation of the width. The latter enters as fracturepermeability into the pressure diffraction problem which is crucial for fluidfilled fractures. Our developments are substantiated with several numericaltests that include comparisons of computational cost for iterative coupling andnonlinear and linear iterations as well as convergence studies in space andtime.