Different Ways to Approach Shale Reservoirs' CO2 Storage Potential in America
By: Ruichong Ni, Kegang Ling, Samuel Afari (July 20, 2023)
The escalating urgency to mitigate climate change has made the Net Zero Carbon Emissions (NZCE) target by 2050 an essential goal. One of the principal strategies underpinning this ambition is Carbon Capture, Utilization, and Storage (CCUS). Injecting CO2 into shale reservoirs presents a dual advantage: reducing atmospheric CO2 levels, thereby alleviating the greenhouse effect, and potentially enhancing oil or gas extraction. However, as the global community ventures deeper into this domain, the key question remains: what is the actual storage potential of these reservoirs for CO2?
This study collates and critically evaluates the diverse methods for determining CO2 storage capacities in shale reservoirs, using the insights gathered from recent scientific literature. By analyzing five distinct techniques applied to five shale reservoirs, this paper distills the nuances of the complex technical components of gas storage. Geomechanical properties, petrophysical attributes, and construction parameters emerge as significant factors. Notably, variables like the CO2 injection rate, skin factor, and Knudsen diffusion wield substantial influence over the evaluated storage potential. The study also underscores the paramount importance of maintaining well integrity. Ensuring high-quality cement work and accurate permeability assessments can make CO2 storage simulations much more reflective of real-world scenarios.
In summary, this research serves multiple purposes: it provides a comprehensive guide for gauging CO2 storage capacities in shale oil reservoirs; critically examines the current methodologies and their inherent limitations; and offers forward-thinking recommendations, paving the way for refining existing approaches or innovating entirely new ones. This rigorous analysis is poised to play a pivotal role in the global drive towards a more sustainable energy landscape.