Benchmark study of simulators for thermo-hydraulic modelling of low enthalpy geothermal processes

In order to assess the thermo-hydraulic modelling capabilities of various geothermal simulators, a comparative test suite was created, consisting set cases designed with conditions relevant low-enthalpy range operations within European HEATSTORE research project. an effort increase confidence in usage each simulator, used as benchmark by 10 simulators diverse origin, formulation, and licensing characteristics: COMSOL, MARTHE, ComPASS, Nexus-CSMP++, MOOSE, SEAWATv4, CODE_BRIGHT, Tough3, PFLOTRAN, Eclipse 100. The synthetic (TCs) consist transient pressure verification (TC1), well-test comparison (TC2), thermal transport experiment validation (TC3), convection onset (TC4), chosen represent well-defined subsets coupled physical processes acting subsurface operations. results from four were compared among participants, known analytical solutions, experimental measurements where applicable, establish them reference expectations for future studies. A basic description, problem specification, corresponding are presented discussed. Most participating able perform most tests reliably at level accuracy that is considered sufficient application tasks real projects. Significant relative deviations solutions occurred strong, sudden (e.g. initial) gradients affected numerical discretization, but also due sub-optimal model setup caused simulator limitations providing equation state water properties).