Resin transfer in oil-water interface intensified by H2O2 and demulsifier for efficient water separation in tight oil

Tight oil is an important unconventional oil resource, but it is difficult to separate oil and water from produced liquid and make efficient use of it. Due to the stable structure of oil–water interface caused by resin, it is difficult to achieve demulsification. In this work, a series of polyether ester demulsifierswith different degree of polymerization were designed by esterification and polymerization. In addition, hydrogen peroxide was used to regulate the structure of resin to enhance the transmission of polyether ester, and the replacement of resin was strengthened through the structural design of polyether ester. The results showed that the molecular weight and dipole moment of resin oxidized by hydrogen peroxide decreased, which was beneficial to the transfer of demulsifier. With the increase of polymerization degree, the oil solubility and surface activity of polyether ester were improved, and the replacement ability of resin was strengthened·H2O2 and demulsifier were used to synergistically promote demulsification, the dehydration rate could be further increased to 99.2%, and the water content in tight oil could be reduced to 0.56%.