One-pot method to prepare betaine surfactant from rapeseed oil and its application for enhanced oil recovery

Abstract

The complex production process of amidopropyl betaine surfactants results in high costs, significantly limiting their widespread application in tertiary oil recovery. This study aims to address this challenge by simplifying the production process, reducing costs, and developing an efficient amidopropyl betaine surfactant derived from natural vegetable oil to enhance oil recovery. Using rapeseed oil as the raw material, a betaine surfactant (ROBS) was successfully synthesized via a simple one-pot method. The effects of key reaction parameters—such as the molar ratio of oil to amine, amidation reaction temperature and time, catalyst dosage, quaternization reaction temperature and time, and quaternization reagent ratio—on the apparent viscosity of the ROBS solution were systematically investigated, and the optimal reaction conditions were determined. A comprehensive evaluation of the ROBS solution and gel was conducted, focusing on properties such as apparent viscosity, critical micelle concentration (CMC), surface tension, interfacial tension, wettability, emulsifying ability, oil recovery efficiency, and profile control. The results demonstrate that the prepared ROBS exhibits comparable or superior performance to commercial oleic acid-based surfactants (OAPB) currently used in oilfields. Additionally, ROBS offers significant advantages in terms of ease of processing and low production costs. Compared to traditional manufacturing methods, the production cost of ROBS is expected to be reduced by up to 50.9%, providing a substantial commercial competitive advantage. This work presents a safe, fast, and cost-effective synthetic route for high-performance oilfield surfactants, offering a viable alternative to expensive commercial surfactants. The findings have significant implications for the development of sustainable and economically efficient solutions for enhanced oil recovery, making ROBS a promising candidate for large-scale application in oilfield production.