Ethanolamine as Alkali for Alkali Surfactant Polymer Flooding - Development of a Low-Complexity Field Implementation Concept

Abstract

Abstract A successful pilot in the Marmul field in the south of the Sultanate of Oman used a formulation consisting of 2% sodium carbonate, 0.3% surfactant, and 0.27% polymer. Marmul crude oil has a high total acid number (TAN = 0.9 mg KOH/ml). The petroleum acids are neutralized by alkali to form soaps which mix with the added surfactant to generate low interfacial tension (IFT) between oil and brine. For a commercial scale chemical-flood the quantity of sodium carbonate that needs to be transported is very large. It has been found that ethanolamine has significant advantages as an alkali for ASP and can substantially improve the logistical challenges faced in implementing a commercial scale flood. Ethanolamine has an improved alkaline density, is a low viscosity liquid, and can function as a solvent for EOR surfactants in the free acid form enabling shipment of a ready to mix liquid AS formulation.