Effect of Biogeomechanical Altered Properties on Geologic Carbon Storage in Unconventional Reservoirs

Geologic carbon storage (GCS) is part of a process known as carbon capture, utilization, and storage (CCUS); being adopted to mollify extreme weather events (global warming) as a result of CO2 emissions and improve energy production. Previous studies have shown promising potentials of permanent CO2 storage in depleted shale reservoirs. In this study, we experimentally and analytically investigate the impact of microbially-altered mechanical properties on carbon storage in the Niobrara shale reservoir, using a cultured solution and shale samples from Niobrara formation. Firstly, we obtained the properties of the untreated samples. Secondly, we treated and cultivated the samples with the cultured solution at specific conditions. Further, we obtained the new properties of the treated shale rocks. Lastly, we show the impact of the altered properties on CO2 storage integrity in unconventional shale reservoirs. Our results suggest that in shale reservoirs, biogeomechanical alterations can enhance the long-term integrity of geological sequestration of atmospheric CO2, by mitigating any deep subsurface potential leakage to the atmosphere.