Thermodynamic modelling of geochemical phenomena in connection with injection in geothermic research
A small number of possible reactions are selected, based on a geological and geochemical study of the site and an experimental study. Laboratory experiments show that variations in the composition of water due to interaction between water and rock can be observed on a time scale of a hundred or so hours. Under experimental conditions - where the real life precipitation of calcium carbonate by acidification is avoided - the main variations in concentration are those of silica and potassium. A general mathematical model known as STELE has been created, to quantify the development in time and space of the amounts of minerals which may be involved in these reactions. It is constructed from the METIS model, which solves equations for the transfer of fluid, heat and chemical elements in a porous medium by the finite elements method. In addition to these processes, STELE simulates the transfer of chemical elements involved in multiple geochemical reactions. The digital experiments carried out with STELE simulate a storage and destorage cycle. The results show the development of the fluid composition and of the quantities of minerals dissolved or precipitated.
Bibliographic Reference: EUR 12668 FR (1990) 101 pp., MF, ECU 8
Record Number: 199010537 / Last updated on: 1994-12-01
Original language: fr
Available languages: fr