Mahdi Maleki-Kakelar - Department of Chemical Engineering, Faculty of Engineering, University of Zanjan, Zanjan, Iran
Sirous Ebrahimi - Biotechnology Research Centre, Faculty of Chemical Engineering, Sahand University of Technology, Tabriz, Iran
Farrokh Asadzadeh - Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran

Plugging of porous media by microbial induced carbonate precipitation (MICP) was evaluated in a packed column system. In order to achieve this goal, the MICP process has been separated into improving urease activity (UA) and evaluation of the precipitation induced by the bacteria in unconsolidated porous media. The UA was influenced by Ni2+ and Ca2+. By adding 10μM Ni2+ and 4mM Ca2+ simultaneously in culture media, the UA was increased around 54% after 24h incubation. The MICP process was dependent on the UA of bacterial cells and, as well as concentrations of cementation solution. Experiments indicated that an increase in cementation solution (CS) concentration leads to a significant decrease in permeability of the packed column system due to formation of CaCO3 crystals. Eventually multi-injections of CS at various concentrations had a significant effect on the extent of plugging, observed as a decrease in permeability of packed column. MICP appears to be a very efficient method for select plugging and consolidation of sand in oil reservoir.

Microbial induced carbonate precipitation (MICP), Select plugging, Urease activity