On the prediction of gas solubility in brine solutions with single or mixed salts: Applications to gas injection and CO2 capture/sequestration

摘要

Estimation of gas solubility in a brine solution is essential for many chemical/petroleum industrial applications including FOR with gas injection, geological storage of CO2 in deep saline aquifers, mitigation of corrosion related issues for sour gas fields and many more. Since the type of salt can significantly alter the gas-solubility in formation brine, we develop a robust methodology to predict the impact of different types of salts on solubility of a gas in a brine solution. The method uses ionic-strength-based mixing rule and extends the well-known Setschenow relation to capture the impact of mixture of salts containing mono- or multi-valent ions. The model is validated with new experimental solubility measurements of a novel gas (dimethyl either) in brine with various salt mixtures. In addition, the unique/characteristic constants used in model for each component (gas, anions and cations) are correlated with their thermodynamic properties and can easily be obtained for novel gas-salt systems.