DEVELOPMENT OF SULFONATED ALKYL ESTER AND ITS INJECTION METHODS TO IMPROVE OIL RECOVERY IN SANDSTONE RESERVOIR
» Gedung UPT Perpustakaan
to examine the application of sulfonated alkyl ester (SAE), fatty ester oleate (FEO) surfactants, and their mixtures for waxy oil from the T-KS field, which features very low brine salinity, through laboratory tests and analysis, (ii) to develop correlations between phase behavior and the interfacial tension for the new surfactants, and (iii) to determine the appropriate injection method for applying the surfactant at the laboratory scale. Two surfactants were synthesized. They were sulfonated alkyl ester (SAE) and fatty ester oleate (FEO). The SAE surfactant was an amphoteric type surfactant where the sulfonate and ethoxylate groups occurred in one single compound. The SAE is a new surfactant which has a different structure than the existing surfactants. Meanwhile, the FEO surfactant was a nonionic type of surfactant. New formulation of SAE and FEO surfactants were also developed in this research which produce very low IFT of oil-brine. This study revealed that an ion-dipole interaction occurred in the mixture of SAE and FEO surfactants. The strength of ion-dipole interaction was affected by the ratio of each surfactant. It was observed that the mixture of SAE and FEO surfactants in a weight ratio of 1:1 developed a more stable ion-dipole interaction compared to other formulations. Under the condition of this study, the surfactant was stable up to salinity of 2,000 mEq/L (or about 100,000 ppm) The correlation of phase behavior and interfacial tension was also developed in this study. The Huh Equation was used as a basis for the development. In particular, this study examined the CHO and n constant in the Huh Equation. It was revealed that the Huh Equation constant was affected by the surfactant polarity. Lower polarity decreases the n value, and in general, also decreases the CHO value. At high polarity, Huh Equation tends to predict a lower IFT value, at low polarity, it tends to overestimate the IFT value. Therefore, an adjustment to the values of CHO and n that previously proposed by Huh was needed. The potential incremental oil recovery by injecting the surfactant continuously in coreflooding tests using Berea cores was up to 43.3%. Nevertheless, the effective and efficient injection method proposed was injecting surfactant 0.5 PV surfactant slug continued by 1 PV polymer slug and followed by water injection. This method produced a 27.47% incremental oil recovery or 18.31% per unit volume of chemical usage.