Effect of a new nano‐viscosity reducing agent on the rheological properties and wax deposition characteristics of waxy crude oil

Abstract

Wax inhibitors are widely applied during the process of waxy crude oil production, storage, and transportation. However, their effects on the crude oil rheological properties and wax deposition characteristics are still not well understood. Herein, a new nano‐viscosity reducing agent was chosen to investigate its influences on the physical properties and the wax deposition process of Liaohe crude oil in a cold finger experimental device. Firstly, the rheological property variations of crude oil with different dosages of reagent added were tested. Furthermore, the changes of wax deposit morphology, wax deposition rate, and wax precipitation characteristics were studied, and the influencing mechanism was elucidated. It was found that the new nano‐viscosity reducing agent can significantly alter the crude oil rheology properties and wax deposition process. The gel point, wax appearance temperature (WAT), and viscosity all decreased after addition of the reagent. With the dosage of the new reagent increasing from 0 to 120 mg/kg, the wax deposition rate decreased greatly, but the wax content and WAT of the deposits increased obviously. Further, the wax content and WAT are larger in the bottom layer. The wax particles in the bottom layer present smaller size and larger size for the blank crude oil and additive crude oil, respectively, which are caused by the variation of physical properties and molecular diffusion process. This research provides valuable information for the action mechanism of the new nano‐viscosity reducer on Liaohe crude oil, which can guide the optimization of the oil transmission process.