Sorption of CO2 in Shales Using the Manometric Set-up (SPE 154725)

Description The storage capacity of gas reservoirs for CO2 depends not only on its dissolution in brine but also on the sorption in the omnipresent minerals and shales. It can be expected that the sorption characteristics depend on the composition of the shales. This implies that measurements on shales of various compositions are required to estimate the sorption in practice. The sample of our choice is a Black Shale from Belgium. The procedure is as follows: the sample has been sieved and granulized to a size of 40-220 (lower case mu) m. we determined the mineral composition and elemental composition using XRD and XRF. We use the manometric set-up to obtain the sorption data. The equilibration time is about 40 hours for our granulized sample. The excess sorption isotherms was measured at a constant temperature of 318 K, up to a pressure of 1.8 MPa. These conditions are representative of typical European reservoirs. Our measurements are compared with existing data in the literature on sorption of CO2 on minerals. Applications To determine the effective storage capacity of CO2 in geological formations, e.g. abandoned gas reservoirs Results, Observations, Conclusions: -Preliminary experiments show that it is indeed possible to use the manometric set-up to determine the adsorption rate of CO2 on clays. -Accurate determination of the sorption rate requires an accurate equation of state, e.g., the Span-Wagner EOS. -The measured equilibrium time of CO2 on shale is of the order of tens of hours -The first two sorption points are 0.132648 and 0.169854 mmol CO2/ gsample for Black shale. Significance We propose the manometric set-up as a simple and straightforward measurement procedure for obtaining kinetic data of CO2 sorption in shale. The data are essential to quantify CO2 sequestration in gas fields .