GOLEM is a modelling platform for thermal-hydraulic-mechanical and non-reactive chemical processes in fractured and faulted porous media. GOLEM makes use of the flexible, object-oriented numerical framework MOOSE (developed at the Idaho National Laboratories), which provides a high-level interface to state of the art nonlinear solver technology. In GOLEM, the governing equations of groundwater flow, heat and mass transport, and rock deformation are solved in a weak sense (by classical Newton–Raphson or by free Jacobian inexact Newton-Krylow schemes) on an underlying unstructured mesh. Non-linear feedback among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state of the system and the local structure, i.e. degree of connectivity, of the fracture system. More information on the governing equations, their derivation and implementation together with a list of synthetic and real case applications can be found in Cacace and Jacquey (2017) - also available from a dedicated github repository.

User group

International user community from geosciences.

Features

GOLEM in a nutshell:

• Complete open source workflow from geologic data integration, pre-processing and Finite Element meshing (MeshIt software, Cacace and Blöcher, 2016), dynamic forward modelling and post-visualization (Paraview)
• Object-orientation: flexible modular structure within easy to be extended modules by the user
• Geometric agnosticism: 1D/2D/3D Finite Elements and their combinations within single applications with no additional coding from the user required
• Hybrid parallelism: multi-threading and MPI
• Proved scalability on HPC architectures: JUWELS cluster Module at JSC
• Saturated single phase fluid flow in fractured Porous Media (FPM)
• Heat transfer (conduction and advection with or withour internal buoyant flow) in FPM
• Rock mechanics porous matrix - linear and non-linear elastic, plastic, visco-elastic, isotropic and anisotropic damage rheology
• Fracture mechanics - elasto-plastic, frictional (rate and state) lower dimensional interface elements
• Non reactive chemical transport (diffusion and dispersion)
• Ongoing activities - reactive chemistry coupling via a dedicated interface to existing open source software

Proof of concept for EGS analysis - sustainability of induced fracture and exploitability of geothermal reservoirs.