THERMAID - A matlab package for thermo-hydraulic modeling and fracture stability analysis in fractured reservoirs

TL;DR

THERMAID is an open-source MATLAB package that models thermo-hydraulic processes and fracture stability in fractured reservoirs, aiding in geothermal energy, waste water injection, and CO2 sequestration applications.

Contribution

It introduces a validated, efficient numerical tool using embedded discrete fracture modeling for coupled thermo-hydraulic and geomechanical simulations.

Findings

Validated against analytical solutions and numerical benchmarks

Provides a mechanistic assessment of fracture stability and seismic risk

Open source code facilitates further development and high-performance computing adaptation

Abstract

Understanding the dynamics of naturally fractured systems and fractured reservoirs in terms of flow, heat transport and fracture stability (e.g. induced seismicity) is important for a range of applications associated with waste water injection, renewable energy (e.g. geothermal systems), and greenhouse gas mitigation (e.g. geological sequestration of CO2). Here we present the implementation and validation of an open source MATLAB package for efficient numerical simulations of the coupled processes in fractured systems. We take advantage of the embedded discrete fracture model that efficiently accounts for discrete fractures. We perform a series of numerical benchmark experiments to validate the implemented approach against analytical solutions and established numerical methods. Finally, we use a simplified geomechanical model and an integrated fracture stability analysis that allows estimating the potential for shear stimulation, and thus a mechanistic assessment of induced seismic risk during stimulation. The open source distribution of the source code and results can be used as a blue print for the re-implementation of the method in a high performance computing (HPC) framework or as a standalone simulation package for investigating TH(m) problems in geothermal reservoirs.