Nature – Tyne et al. (2021): Rapid microbial methanogenesis during CO2 storage in hydrocarbon reservoirs

R. L. Tyne, P. H. Barry, M. Lawson, D. J. Byrne, O. Warr, H. Xie, D. J. Hillegonds, M. Formolo, Z. M. Summers, B. Skinner, J. M. Eiler, C. J. Ballentine  IN: Nature 600, 670–674 (2021).

An understanding of the potential trapping and storage mechanisms is required to provide confidence in safe and secure CO2 geological sequestration. Here the authors present noble gas, stable isotope, clumped isotope and gene-sequencing analyses from a CO2-EOR project in the Olla Field (Louisiana, USA). They show that microbial methanogenesis converted as much as 13–19% of the injected CO2 to methane (CH4) and up to an additional 74% of CO2 was dissolved in the groundwater. Similar geochemical trends in both injected and natural CO2 fields suggest that microbial methanogenesis may be an important subsurface sink of CO2 globally.