Research on ultrasound-assisted demulsification/dehydration for crude oil.

Crude oil demulsification and dehydration are important links in the process of crude oil exploitation, transportation, and refining. In recent years, with the development of crude oil exploitation, the content of colloid and asphaltene in crude oil has been increasing, and the properties of crude oil emulsion have become more stable. In addition, the development and application of oil recovery technology and the use of a large number of oilfield chemicals have made the composition of crude oil more complicated. The water content and salt content of oil produced fluid increase year by year, which aggravates the task of crude oil dehydration and desalination. Therefore, it is particularly important to study the demulsification and dehydration of crude oil. In this paper. Research on ultrasound-assisted demulsification/dehydration for crude oil in investigated. Results indicate that the demulsification effect varies with the increase of ultrasonic radiation time, but the difference is not significant; with the increase of temperature, the effect of ultrasonic on the demulsification of crude oil emulsion is decreased, or the advantages of ultrasonic can be fully displayed only at low temperature; ultrasonic power has a critical value, when it is lower than this critical value, ultrasonic wave acts as demulsifying agent, and with the increase of power, dehydration rate of the crude oil emulsion increases; when higher than the critical value, the separated oil and water can be re-emulsified; ultrasonic demulsification can both shorten settling time and reduce the amount of demulsifier; ultrasound is suitable for demulsification and dehydration of crude oil emulsions with high water content. Results also prove that chemical demulsifier has a better effect for crude oil demulsification /dehydration than that of ultrasonic treatment alone. In addition, recent progress on ultrasonic demulsification equipment is introduced. The purpose of this paper is to offer equipment and technical support for crude oil demulsification/ dehydration.