Synthesis and Study of a New Type of Nonanionic Demulsifier for Chemical Flooding Emulsion Demulsification

[Image: see text] The application of chemical flooding improves the stability of the produced emulsion, which reduces the demulsification efficiency of conventional demulsifiers. To improve the demulsification effect, in this paper, a new multibranched nonanionic polyether demulsifier, FYJP, was prepared by grafting carboxylate based on a nonionic demulsifier. The FYJP demulsifier could generate an initiator through p-tert-butylphenol, triethylenetetramine, and methanol, which was polymerized with ethylene oxide (EO) and propylene oxide (PO) to produce a nonionic polyether demulsifier. Sodium chloroacetate was used to modify the polyether demulsifier to obtain a new type of nonanionic polyether demulsifier. The FYJP polyether demulsifier was characterized by the hydrophilic–lipophilic balance (HLB) value, relative solubility (RSN), and surface activity of the demulsifier, and the demulsification mechanism was analyzed by a microscopic demulsification process test, and the effect of demulsifier dosage on the demulsification effect was discussed. Meanwhile, a dehydration test was carried out. The experimental results showed that the highest dehydration rate of the demulsifier was 94.7% at 85 °C, 100 ppm demulsifier dosage, 50 mL of a W/O emulsion, and 120 min demulsification time. The abovementioned studies show that FYJP is an effective demulsifier for chemical flooding emulsions, and this work promises to provide a reference for future demulsifier research.