Dissolution of calcite in CaCO3-CO2-H2O systems in porous media

The study of many geological processes requires the understanding of the dissolution and precipitation of calcite in CaCO3-CO2-H2O systems under dynamical conditions. These processes take place during the deposition of carbonate scales in sandstone reservoirs, which turns out to be an operational problem in the oil industry. This paper presents the results from some calcite dissolution experiments performed in columns packed with calcite in a quartz matrix that simulates sandstone composition. Carbonated water was pumped and then recirculated through the column until calcium saturation in the system was reached. The experiments were designed to investigate the effect of the fluid flow rate, grain size of the sand, CO2 partial pressure and temperature of the system, on the calcite dissolution rate. A correlation between the studied parameters effects is observed.