摘要 |
FIELD: crude oil treatment. ^ SUBSTANCE: oil emulsion is preliminarily separated from drainage water and, after addition of demulsifier, oil desalting process is carried out by washing moving emulsion under dispersing conditions with a washing fluid in at least two steps. Volume of washing fluid added in the first desalting step is larger than that in the second step by a factor of 2.0-2.5. Washing fluid is notably 3-10% aqueous sodium nitrate solution, which is preheated before addition to at least 45°C in both desalting steps. In the first step, oil is subjected to hot settling preferably for 2 h and, in the second step, 3 h. Demulsifier utilized is based on oil-soluble surfactants added in amounts 25 to 55 g/t. ^ EFFECT: reduced consumption of demulsifier at higher degree of desalting, in particular for oils with high level of chlorides. ^ 7 cl, 2 ex |