Research progress on the water entrainment in the deposition layer of emulsified waxy crude oil

The water entrainment in the deposition layer of emulsified waxy crude oil is a new hot spot in the research field of wax deposition of oil-water two-phase flow in transportation pipelines. In recent years, domestic and foreign scholars analyzed the factors influencing the water entrainment in the wax deposition layer of emulsified water-bearing crude oil by means of cold finger and loop deposition experiment, and accordingly clarified the influences of the volumetric water content of oil phase, the size of dispersed water drop and other factors. In this paper, the influencing factors and related mechanisms of water entrainment in the deposition layer of emulsified water-bearing crude oil were reviewed, and the effects of water entrainment on the wax content and rheological behavior of the deposition layer were discussed. Then, the current dominant models and methods for predicting the wax deposit in emulsified oil-water systems were listed. Finally, the future research direction on the deposition mechanisms of emulsified water-bearing crude oil was prospected, so as to provide the theoretical basis for the design, operation and management of deepsea mixed transportation pipelines of waxy crude oil.