Surfactant adsorption has been a great challenge for surfactant-based chemically enhanced oil recovery (cEOR) techniques as it directly reflects the overall efficiency of a cEOR project. The static adsorption of an in-house-synthesized cationic Gemini surfactant (GS12) has been investigated on carbonate outcrops as a function of concentration, time, salinity, and temperature. Three different types of carbonate outcrop samples taken from the Al-Lidam area with an increasing percentage of silica and clay impurities were investigated. It was found that the higher the presence of silicate and clay minerals in the carbonate outcrops, the higher will be the surfactant adsorption. The adsorption of GS12 was found to decrease at elevated temperatures and in a highly saline environment, especially at very high concentrations of divalent salts (CaCl2 and MgCl2). In addition, a novel adsorption inhibitor─methylene blue─has been proposed in this study, which reduced the surfactant adsorption dramatically on carbonate outcrops. The GS12 adsorption on carbonate samples 1, 2, and 3 was reduced to 0.14 mg/g-rock, 0.48 mg/g-rock, and 2.31 mg/g-rock, respectively, by the addition of 500 ppm methylene blue in a 1500 ppm surfactant solution. Moreover, curve fitting was also performed to analyze the adsorption isotherm and kinetic data. Redlich-Peterson and pseudo-second-order models were found to be the best to describe the adsorption isotherm and kinetics, respectively.
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© 2023 American Chemical Society.
ASJC Scopus subject areas
- General Chemical Engineering
- Fuel Technology
- Energy Engineering and Power Technology