Enhancing Oil Recovery through Alkaline Flooding: Investigating Surfactant Formation and Interfacial Tension Reduction

Abstract

Alkaline flooding induces a neutralization reaction between the carboxylic acid in crude oil and the injected alkali, leading to soap formation (saponification). This process reduces water-oil interfacial tension and alters petrophysical properties, enhancing oil recovery. In this paper, the interaction between alkaline flooding chemicals and the carboxylic function of the crude oil was examined by accounting for both physical and chemical properties of the resulting neutralization reactions. Fourier Transform Infrared (FTIR) employed to examine the spectrum of the reservoir crude oil shows the presence of Carboxylic (COOH) and Carbonyl (C O) functional groups which are responsible for the in situ surfactants formation responsible for lowering of the interfacial tension (IFT) of water and oil.  This study evaluates the effect of alkaline flooding on oil recovery using sand-pack experiments. Fourier Transform Infrared (FTIR) spectroscopy was employed to analyze crude oil composition, and interfacial tension (IFT) was measured under varying NaOH concentrations. Results indicate a 6.1% increase in oil recovery compared to conventional water flooding.