Reactions of calcite in water in the presence of stearic acid

Abstract

In

Impact of Modified Seawater on Zeta Potential and Morphology of Calcite and Dolomite Aged with Stearic Acid

“…Although natural outcrop carbonate rocks have been reported to be water-wet, carbonate oil reservoirs are generally characterized to be neutral to oil-wet. − The change in carbonate rock wetness has been attributed to the adsorption of carboxylic acids that are present in crude oil. ,− Stearic acid in particular has been used widely as a model carboxylic acid in studying reservoir rock wettability alteration because of its ability to alter the carbonate rock wettability to hydrophobic conditions. ,− Ricci et al showed that stearic acid molecules tend to act as “pinning points” on pure calcite surfaces, initiating a potential monolayer or bilayer growth and slow the crystal restructuring kinetics. Once immersed into the supersaturated brines, crystal growth around the stearic acid patches was induced.…”

“…Rezaei Gomari et al , reported that an adsorption plateau of fatty acids on calcite surfaces can be achieved at an acid concentration of 0.01%. Mihajlović et al , studied stearic acid adsorption on calcite surface using dry and wet adsorption methods. In the “dry” method, they proposed surface dissociation of stearic acid occurs where H + ions go to a surface carbonate ion and the stearate ion is chemisorbed on the primary surface center of the Ca 2+ ion which is available only for chemisorption.…”