Synthesis and application of amphiphilic copolymer as demulsifier for super heavy oil emulsions

Abstract

A series of amphiphilic copolymers (PIDs) were synthesized through free radical copolymerization of isobutyl acrylate (IBA) with N,N-dimethylacrylamide (DMAA). The structure, composition, and average molecular weights of these copolymers were characterized by 1H NMR spectra, infrared spectra, elemental analyse, and gel permeation chromatography. The solubility and aggregation behavior of these copolymers in different solvents were studied. In addition, thermo-responsive behavior of water-soluble copolymers in water was investigated by means of transmittance tests and DLS tests. The demulsification experiment showed that PID demulsifiers had excellent demulsification efficiency toward super heavy oil emulsions. The dehydration ratio reached 92.69 % at a concentration of 400 mg·L−1 for 210 min at 80 °C. Combined with the morphological changes of water droplets and active substances during demulsification, the characteristics of viscosity and interfacial activity proved that the higher content of lipophilic segments in PID copolymer could facilitate the diffusion of demulsifiers at the oil-water interface and accelerate the condensation of water droplets. Therefore, it is envisioned that this heavy oil demulsifiers with excellent demulsification performance and clean water phase will have promising prospects.