Validation of MARTHE-REACT coupled surface and groundwater reactive transport code for modeling hydro systems.

Dominique Thiéry (1) , Nicolas Jacquemet (1) , Géraldine Picot-Colbeaux (1) , Christophe Kervévan (1) , Laurent André (1) , Mohamed Azaroual (1)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)

This paper presents the validation of the computer code MARTHE-REACT enabling the simulation of reactive transport in hydrosystems. MARTHE-REACT results from coupling the MARTHE code (flow and transport in porous media) with the chemical simulator TOUGHREACT. The resulting coupled model takes advantage of the functionalities already available in each of the two codes. In particular, it is now possible to simulate flow, reactive mass, and energy transfer in both saturated and unsaturated media (vadose zone), taking into account the soil-atmosphere exchange (rainfall, evapo-transpiration), and runoff into rivers and infiltration. Four examples of verification are presented in comparison with calculations using the reference coupled codes TOUGHREACT, PHAST, PHREEQC, and MARTHE-SCS. 1) Continuous injection of acidified CO2-rich aqueous phase into a fictitious limestone core sample. Simulations performed with several transport schemes are compared with results from PHREEQC and MARTHE-SCS. 2) Injection of CO2-saturated water into a Dogger carbonate reservoir (Paris Basin, France). The reservoir is modeled with a 2D radial geometry. Chemical simulations are compared with those obtained using the TOUGHREACT code. 3) Diffusion of acidified water within a cap rock overlying the Dogger aquifer, in which (hypothetical) large amounts of CO2 are stored. 4) Carbonated brine percolation through a weathered cement sample for 7 days, accounting for coupled advection-diffusion-reactions having various kinetics. These simulations are compared with those obtained with the TOUGHREACT code. The coupling in MARTHE-REACT is based on a sequential noniterative algorithm, so that parallelization of the chemical calculations has been easily implemented. Preliminary results on a 64-processor computer show a dramatic decrease of needed CPU time, even with a moderately complex geometry.

Mots clés: Modélisation hydro-géochimique couplée; Modèle MARTHE

Domaines: Hydrologie; Milieux et Changements globaux

Dominique Thiéry, Nicolas Jacquemet, Géraldine Picot-Colbeaux, Christophe Kervévan, Laurent André, et al.. Validation of MARTHE-REACT coupled surface and groundwater reactive transport code for modeling hydro systems.. TOUGH Symposium 2009, Sep 2009, Berkeley (California), United States. pp. 576-583. ⟨hal-01061807⟩