Microscale solute transport and precipitation in complex rock during drying

Formation drying and salt precipitation due to gas injection or production can have serious consequences for upstream operations in terms of injectivity and productivity. Recently, evidence has been found that the complexity of the pore space and microscopic capillary-driven solute transport plays a key role in the relationship between permeability and porosity. In this study, we investigate drying and salt precipitation due to supercritical CO2 injection in single-porosity and multiporosity systems under near well-bore conditions. We image fluid saturation states and salt deposition by means of microcomputerized tomography scanning during desaturation. We observe capillary-driven transport of brine and the respective solutes on the pore scale. Solute transport between porosity classes determines the distribution of the deposits in the pore space and the permeability porosity relationships - K(φ) - for flow-through drying.