Abstract: An experimental flow installation is designed and constructed,and it is used to study the flow characteristics and initial deposition process of extra high water-cut crude oil. The effects of the experimental temperature, mixing velocity, and volumetric water content on the initial deposition process of extra high water-cut oil are studied systematically. According to the movement patterns of crude oil and the initial deposition modes gained at different temperatures, the initial deposition process has two types, uniform deposition process and non-uniform deposition process. According to the sedimentary characteristics and the variation trends of the pressure drop curves, the initial deposition process can be divided into three stages:induction period of deposition, period of rapid deposition, and dynamic equilibrium period of deposition. On this basis, through the analysis of the carbon number distributions of the sediments, we find that there exist shear peeling, gelation, and molecular diffusion in the initial deposition process. The experimental temperature and volumetric water content affect the initial deposition process mainly by changing the gelation and molecular diffusion, and the mixing velocity affects the initial deposition process by changing the shear peeling.

Key words: extra high water-cut crude oil, mixed flow, initial deposition, gelation, shear peeling, molecular diffusion