海上油田特稠油静电聚结脱水实验研究

Experimental study on electrostatic coalescence dehydration of extra-heavy oil in offshore oilfields

针对渤海特稠油的原油黏度大、油品密度高,油水分离十分困难的特点,研制了绝缘电极并开展了室内自然沉降和静电聚结脱水实验。实验结果表明,所研制的绝缘电极可以适应高含水特稠油脱水工况,对于初始含水70%~90%的乳化液,处理温度110℃,在适当的电场强度和药剂浓度作用下,沉降时间40 min,脱后含水可以低于30%;对于初始含水30%~60%的乳化液,处理温度130℃,在适当的电场强度和药剂浓度作用下,沉降时间40 min,脱后含水可以低于30%,满足相关规范中对进入常规电脱水器进一步处理的要求。通过与自然沉降脱水实验进行对比,静电聚结脱水技术能够较大幅度地提高特稠油脱水效率,大幅降低海上特稠油脱水设备的尺寸和质量。本文实验结果对海上特稠油静电聚结脱水处理工艺设计具有一定指导意义。

Bohai extra-heavy oil has the characteristics of high viscosity and high density. In order to solve the problem of the oil dehydration, an insulated electrode was developed and experiments on natural precipitation and electrostatic coalescence dehydration were carried out. The experimental results show that the insulated electrode is applicable in the dehydration operation conditions of high WOR emulsion. For emulsions with initial water content ranging from 70% to 90%, at operation temperature of 110 ℃, the water content would be lower than 30% after 40 min precipitation under appropriate electric field intensity and chemical concentration. If the initial water content ranges from 30% to 60%, the same results could be achieved under similar operation conditions except a high temperature of 130 ℃. The dehydration results meet the requirements in related specifications for further processing in conventional electrostatic dehydrators. Compared with the experimental results of natural precipitation dehydration, the electrostatic coalescence technology can greatly improve the dehydration efficiency of heavy oil, and greatly reduce the size and weight of offshore equipment. The experimental results have important guiding significance for the design of electrostatic coalescence dehydration process of extra-heavy oil.