PyFracX-Examples

Verification examples for the simulation of fluid-driven frictional ruptures with PyFracX

Description

PyFracX simulate the re-activation and propagation of fluid-induced frictional/shear ruptures allowing also full opening of the fracture. The X hints that the code can simulate multiple intersecting fractures. In PyFracX, the fractures are pre-existing and meshed accordingly. This repository documents a comprehensive series of verification tests of this solver against existing analytical/semi-analytical solutions for this class of hydromechanical fracture problems. This tests are for fluid-induced tensile fracture (hydraulic fracture re-opening of a pre-existing discontinuity) and frictional shear ruptures. The solver can simulate a number of problems, and notably cases where fluid flow can be "uncoupled" from the mechanical problem (e.g. frictional ruptures for which the evolution of pore-pressure is not affected by mechanical deformation) or "coupled" hydromechanical problems (e.g. hydraulic fractures, shear-induced dilatant frictional ruptures). The structure of the sub-folders follows this convention.

How to run these scripts

To run this script you need first to compile BigWham and install bigwham4py. Once done you can install PyfracX. All instructions are given in the associated repositories. We recommend setting up a new python environment for it (using venvthen installing the bigwham4py and pyfracx using pip).

Once done you should be set to execute all the examples of this repository. Each example is composed of a simulation script that will run the simulation and save the results and a post-processing script that can read the results and make the associated plots.

You can run all examples by executing :

./run_all_examples.sh # run all simulations (takes up to a few hours)
./run_all_postprocessing.sh # generate all associated figures
./clean_figures.sh # to clean all the generated figures

These examples have been developed and tested only on Unix OS, some incompatibilities with Windows regarding paths management are to be expected.

Organization

This repository is organized with the following sub-folders

• ReferenceSolutions/ contains python modules containing existing reference solutions with sub-folders HF for hydraulic fracture (tensile mode I case) and FDFR for fluid-driven frictional ruptures
• 2D-uncoupled/ contains sub-folders with scripts for 2D plane elasticity configurations for frictional ruptures for which the evolution of pore-pressure is not affected by mechanical deformation such that only the mechanical part of the solver is used
• 2D-coupled/ contains sub-folders with scripts for 2D plane elasticity configurations using the coupled hydromechanical solver (thus allowing to model coupled as well uncoupled case)
• 3D-uncoupled/ contains sub-folders with scripts for 3D configurations for frictional ruptures for which the evolution of pore-pressure is not affected by mechanical deformation such that only the mechanical part of the solver is used
• 3D-coupled/ contains sub-folders with scripts for 3D configurations using the coupled hydromechanical solver (thus allowing to model coupled as well uncoupled case)
• Axisymmetry-uncoupled/ contains sub-folders with scripts for 2D Axisymmetric configurations (circular rupture) for frictional ruptures for which the evolution of pore-pressure is not affected by mechanical deformation such that only the mechanical part of the solver is used
• Axisymmetry-coupled/ contains sub-folders with scripts for 2D Axisymmetric configurations (circular rupture) using the coupled hydromechanical solver (thus allowing to model coupled as well uncoupled case)

TODO

• Axisymmetry-coupled/Constant-Friction-Constant-Permeability/ConstantRate-SlipWeakeningFriction.py takes too long (only 2d example that can't be run in under 1h).
• 2d HF reopening is broken
• axisym slip weakening with coupled model is broken
• stats plots for Basel are weird, should we get rid of them ?
• this is only compatible with the cuda_dev branch of pyfracx which is itself only compatible with the cuda_dev branch of bigwham

Contributors

• Brice Lecampion
• Antareep Sarma
• Ankit Gupta
• Regina Fakhretdinova
• Sylvain Brisson