CCS and Power Systems
Carbon Storage - Geologic Storage Technologies and Simulation and Risk Assessment
Advanced CO2 Leakage Mitigation Using Engineered Biomineralization Sealing Technologies
Performer: Montana State University
Project No: FE0004478
Researchers at Montana State University are building and testing a mesoscale (~1 m-diameter), high-pressure rock test system; developing a biomineralization seal experimental protocol; and creating biomineralization seals in different rock types and under actual field conditions. The integrity of the seals—both within the wellbore and between the wellbore and the geologic formation—is critical in minimizing CO2 leakage through formation fractures or within the wellbore during CO2 injection operations. The project is designed to study biomineralization processes that will be effective at sealing flow or leakage pathways near wellbores in subsurface environments (Figure 1). The concept proposed for enhancing geologic carbon storage is based on the use of engineered microbial biofilms capable of biomineralization. The engineered biomineralization process produces biofilm and mineral deposits that reduce the permeability of geologic media while modifying the geochemistry of brines to enhance CO2 solubility and mineral precipitation. This process can be targeted to the geologic media surrounding carbon storage injection wells to provide long-term sealing of preferential CO2 leakage pathways. Because the fluids involved in biofilm formation and biomineralization are low viscosity aqueous solutions, this technology has the potential to seal small aperture leaks or the porous rock itself, potentially providing a leakage mitigation technique that can address issues problematic for cement use.
The research is investigating whether mineral deposits can be formed at a field scale under conditions that mimic subsurface reservoirs and whether they can be kept uniform over relevant distances. The project is also determining whether sealing in disturbed rock-cement and cement-well bore interfaces can be achieved through biomineral deposits that remain stable when exposed to injection and formation fluids. This project is examining these effects by creating a large, tightly controlled testing facility that replicates actual field conditions and uses it to conduct proof-of-principle testing and methodology development for biomineralization.