Phase Field Model of Hydraulic Fracturing in Poroelastic Media: Fracture Propagation, Arrest, and Branching Under Fluid Injection and Extraction

TitlePhase Field Model of Hydraulic Fracturing in Poroelastic Media: Fracture Propagation, Arrest, and Branching Under Fluid Injection and Extraction
Publication TypeJournal Article
Year of Publication2018
AuthorsSantillán, D, Juanes, R, Cueto-Felgueroso, L
JournalJournal of Geophysical Research: Solid Earth
Pagination2127 - 2155
Date PublishedJan-03-2018
Abstract

The simulation of fluid-driven fracture propagation in a porous medium is a majorcomputational challenge, with applications in geosciences and engineering. The two main families ofmodeling approaches are those models that represent fractures as explicit discontinuities and solve themoving boundary problem and those that represent fractures as thin damaged zones, solving a continuumproblem throughout. The latter family includes the so-called phase field models. Continuum approachesto fracture face validation and verification challenges, in particular grid convergence, well posedness,and physical relevance in practical scenarios. Here we propose a new quasi-static phase field formulation.The approach fully couples fluid flow in the fracture with deformation and flow in the porous medium,discretizes flow in the fracture on a lower-dimension manifold, and employs the fluid flux between thefracture and the porous solid as coupling variable. We present a numerical assessment of the modelby studying the propagation of a fracture in the quarter fi ve-spot configuration. We study the interplaybetween injection flow rate and rock properties and elucidate fracture propagation patterns underthe leak-off toughness dominated regime as a function of injection rate, initial fracture length,and poromechanical properties. For the considered injection scenario, we show that the final fracturelength depends on the injection rate, and three distinct patterns are observed. We also rationalizethe system response using dimensional analysis to collapse the model results. Finally, we propose somesimplifications that alleviate the computational cost of the simulations without significantloss of accuracy.

URLhttps://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/2017JB014740
DOI10.1002/jgrb.v123.310.1002/2017JB014740
Short TitleJ. Geophys. Res. Solid Earth