Experimental investigation of CO₂–brine–rock interactions in relation with CO₂ sequestration in an Iranian oil reservoir

Abstract

The main purpose of this study is to evaluate the feasibility of geologic CO 2 sequestration in terms of CO 2-brine-rock interactions in Ramin oil field, Iran. Static experiments were conducted with carbonate rocks at 70°C and atmospheric pressure for 14, 30, and 60 days. CO 2-brine-rock interactions were inferred from the evaluation of Ca 2+ , Mg 2+ , Cl − , and SO 2− 4 concentrations and a thorough characterization of the carbonate rocks before and after treatment. Scanning electron microscopy (SEM) micrographs revealed the formation of dissolution pits and the growth of new structures. Energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) indicated these minerals to be calcite. Porosity of the carbonate rocks increased from an initial value of 4.72% to the maximum value of 11.83%. Then, it decreased to a value of 5.48% until the end of the experiments, that is, 60 days. Chemical analysis of brine suggested the precipitation and dissolution of calcium sulfate. In addition, dolomite dissolution and halite precipitation/dissolution were inferred. Calcite precipitation and porosity reduction suggested that CO 2 can be stored via mineral entrapment in the Ramin oil field, which is desired from the perspective of CO 2 geologic sequestration.

Geo-mechanical and geo-morphology characterisation of the cap rocks in the Niger Delta for potential carbon capture and storage

“…This leaves carbon dioxide as the major contributor to global warming [ 9 ]. The increase in average temperature globally can be correlated to the increase in carbon dioxide concentration in the atmosphere [ [10] , [11] , [12] ]. Cao et al [ 13 ], illustrated the correlation (see Fig.…”