ETUDE DU COUPLAGE DES MODELES GEOCHIMIQUES BASES SUR LES EQUILIBRES THERMODYNAMIQUES AVEC LES MODELES DE TRANSPORT D'ELEMENTS EN SOLUTION DANS LES MILIEUX POREUX OU FISSURES
This study is a contribution of analysis possibilities of modelling the transfer of components in the underground taking into account complex geochemical phenomena. The geochemical models are interested by a stable unity of volume. They allow to compute the equilibrium distribution of the components between the chemical species of the solution, and the solid and gaseous phases. They use important thermodynamic data bases corresponding to each possible reaction. To sum up the situation about the geochemical codes in Europe and United States, a list of about thirty codes describe their method and potentialities. The mathematical analysis of the different methods used in both types of codes is presented. Then, the principles of a modelisation associating the potentialities of the transport codes and the geochemical codes are discussed. A general code must be established on the basis of the existing codes but also on new concepts and under new constraints. In such studies one must always deal with the problem of the reaction kinetics. When the velocity of the reactions is big enough versus the velocity of transport processes, the assumption of local geochemical equilibrium can be retained. A simple example illustrates in a particular case, the problems described before. The studied case is the transfer of a solution through a chalky massif. At the origin, the solution is in equilibrium with respect with the magnesite.
Références bibliographiques: EUR 10226 FR (1985) MF, 199 P., BER 300, BLOW-UP COPY BFR 995, EUROFFICE, LUXEMBOURG, POB 1003
Disponibilité: Can be ordered online
Numéro d'enregistrement: 1989125001300 / Dernière mise à jour le: 1987-01-01
Langues disponibles: fr