Limitations of PRMS System for Estimating CO2 Storage Resources Management System

Abstract The goal of the CO2 storage resources management system (SRMS) has been to provide a consistent approach for estimating storable quantities. This paper analyses the major limitations of PRMS (Petroleum Resources Management System) and its inapplicability to SRMS for estimating the CO2 that can be stored in a geologic formation. In the paper, we show how SRMS ignores a fundamental aspect of CO2 storage related to the reactivity of CO2 with the porous system. We analyzed various aspects of CO2 reactions with rock and fluid. This included chemical reactions with minerals. We studied CO2 dissolution in water under pressure, forming carbonic acid (H2CO3) and its interaction with various minerals, leading to the dissolution of certain components and the formation of bicarbonate and carbonate ions. We also looked at the reactions of silicate and carbonate minerals in rocks. The interaction of CO2 with fluids changes the chemical composition of the pore water, which can have several effects, including changes in the pH, leading to a more acidic environment. This can enhance the dissolution of certain minerals and affect their solubilities. The dissolution of CO2 and subsequent chemical reactions can also alter the ionic strength of the fluid, impacting the transport properties within the reservoir. We also note that the dissolution of minerals can lead to precipitation reactions, particularly when the concentration of dissolved ions exceeds solubility limits, and the reactions between CO2, rocks, and fluids can lead to the formation of geochemical traps, which can enhance the immobilization of CO2. Furthermore, when CO2 reacts with certain minerals to form solid carbonate compounds, CO2 is mineralized and chemically locked. We also noted that with such reactions, there will be a change in the porosity and permeability of the rock formation, trapping any remaining CO2 in less mobile forms and providing long-term storage and environmental safety. CO2 reactions with rocks and fluids are complex processes that play a critical role in carbon sequestration, effectiveness, and storage capacity evaluation. We discuss how the reactivity of CO2 is a matter that is not considered SRMS.