High pressure-high temperature carbon dioxide adsorption to shale rocks using a volumetric method

With the current increase in hydrocarbon production from shale reservoirs, several methods have been applied to improve recovery from these unconventional oil and gas sources. Carbon dioxide (CO2) injection is one of the methods that can be used to increase oil recovery and store the CO2 in the reservoir via adsorption. This research investigates the CO2 storage applicability in the North East Oklahoma shale, which is part of the southern section of the Kansas Basin for CO2 storage, as well as the factors impacting the storage capacity. The shale mineralogy was initially identified using X-Ray Diffraction (XRD) analysis. CO2 adsorption on shale was measured using a volumetric-based adsorption apparatus. The effect of varying the CO2 phase, injection pressure, temperature, shale particle size, and shale volume in the sample cell was studied. Increasing the pressure resulted in an increase in adsorption, whereas increasing the temperature showed an opposite trend. No trend can be observed when decreasing the shale volume, since decreasing the volume using the volumetric adsorption apparatus will result in erroneous results. This research investigates and highlights the main factors that will impact CO2 adsorption to North East Oklahoma shale during CO2 injection in order to assess the applicability of CO2 injection storage purposes.