Stability of Oil-in-Water Emulsions of Heavy Crude under Flowing Conditions

摘要

A unique experimental device was constructed to investigate the emulsion stability of heavy crude. It mainly consists of a stirred tank with good temperature control, a stirring system equipped with a torque meter and a V-shaped measuring tube. Sensitivity study regarding temperature, salinity, stirring speed, emulsifier dosage, initial water fraction of oil-water mixture was executed by measuring the free water after stirring. In this study, dynamic water fraction was proposed as free water fraction under flowing condition. It was found that the dynamic water fraction of heavy crude decreases with salinity and emulsifier dosage, and increases with temperature. Based on the experimental results, we initially established a water separating fraction model for heavy crude, applicable in both static and flowing conditions. Verification shows a good agreement between prediction and experiment with average relative error below 23.72%. Calculating water separating fraction, this model benefits in estimating pipeline flow condition, and further helps to schedule transportation arrangements.