Surfactant-less alkaline-polymer formulations for recovering reactive crude oil

摘要

Compositions and methods for oil recovery using a surfactant-less alkaline-polymer system in hard water or hard brine is described in the instant invention. The formulation further includes a chelating agent, an alkaline agent (which can be the same as the chelating agent), and a co-solvent. The formulations as disclosed herein are capable of forming a surfactant in-situ resulting in Winsor Type III micro-emulsions of low interfacial tension.