Crude oil emulsions are frequently found in crude oil production and refining. In the production stage, crude oil is produced along production water that may form very stable emulsions when flowing through choke valves; in the refining stage, crude oil is desalted through mixing it with water and passing the mixture through a mixing valve creating an emulsion. In both cases, crude oil emulsions are resolved using predominantly electrostatic dehydration. Even though this technology is known for more than fifty years, the limiting factors for the efficiency of electrocoalescers are not well understood. In order to contribute to the understanding of the factors that influence the stability to electrocoalescence of water in heavy crude oil emulsions, electrocoalescence tests were carried out in an experimental setup able to measure the current between electrodes during emulsion dehydration. In this way, an emulsion destabilization profile can be drawn and new insights that can not be obtained by standard tests that measure final water content can be obtained. Easy to separate emulsions are characterized by a rapid increase in the recurrent followed by a short peak then a rapid decrease in the current indicating that the water that was between electrodes sedimented rapidly.
展开▼
