Entrapment of Water Droplets in Wax Deposits from Water-in-Oil Dispersion and Its Impact on Deposit Build-up

摘要

Wax deposition from water-in-oil emulsion/dispersion can entrap water droplets in the resulting paraffin deposits. This entrapment of water droplets can lead to a significant decrease in the yield stress of the deposits, which can cause the deposit to, slough-off during wax deposition. This investigation presents the most comprehensive characterization of the entrapment of water droplets by deposit formation with cold finger and flow loop wax deposition experiments. NMR techniques were implemented to characterize the droplet size of the bulk and deposit in order to reveal the relationship between the droplet size of the bulk and the water content of the deposit. Furthermore, it is demonstrated that incorporation of droplets in the deposit lowers the yield stress of the deposit and causes the deposit to slough-off during pipe flow. Knowledge of such effects of the water phase on wax deposition is beyond conventional analysis based on heat and mass transfers and is expected to provide additional insights to the design of water oil two phase transport pipelines.