Ureolysis-induced calcium carbonate precipitation (UICP) in the presence of CO2-affected brine: A field demonstration

Biomineralization is an emerging biotechnology for subsurface engineering applications like remediating leaky wellbores. The process relies on ureolysis to induce precipitation of calcium carbonate in undesired flow paths. In geologic storage CO2, there a potential leakage and low pH conditions, thus, ureolysis-induced (UICP) was tested at field scale seal channel the wellbore cement annulus presence CO2-affected brine. Conventional oil methods were used deliver UICP-promoting fluids downhole treatment zone approximately 1000 feet (305 m) below ground surface (bgs). Over 4 days, 242 L (64 gal) heat-treated Sporosarcina pasteurii cultures (22 bailers) 329 (87 urea – chloride solution (30 injected. UICP resulted 94% reduction injectivity ultrasonic well logging showed noticeable increase percentage solids outside casing, including more than 30 m (100 ft) above injection point. Subsequent 11 months after demonstration that significant portion new remained but compromised following sustained pumping. results this experiment suggest can be promoted brine pathways. Additional research required optimize long term integrity ensure CO2 carbon sequestration scenarios.