STUDY OF THE DESTRUCTION OF OIL-WATER EMULSION IN THE DOLYNA OIL FIELD UNDER THE INFLUENCE OF TEMPERATURE AND DEMULSIFIER

Abstract

The peculiarities of the process of oil emulsion formation during the extraction of aqueous petroleum products are given. Types of oil emulsions and their characteristics are considered. Methods of oil deemulsification are characterised. The composition of oil emulsions and their stability at temperatures of 21 °С and 50 °С are considered in relation to the conditions of the Dolyna oil field. The oil emulsion of the Dolyna oil field with the following composition was used for the research: volume fraction of bound water – 15 %; volume fraction of mechanical impurities – 0.4 %; chlorine salt content – 10020 mg/l; mass fraction of paraffin – 5.3 %; mass fraction of silica gel resins – 6.1 %; mass fraction of asphaltenes – 0.14 %; The thermochemical method of oil demulsification by simultaneous heating of the emulsion to 50 °С and introduction of a demulsifier into it was studied. Demulsifiers PM-A, PM-B and Disolvan 2830 were studied. The research on demulsifiers was carried out according to a well-known methodology, the Botl test. It was found experimentally that increasing the temperature of the emulsion within feasible limits does not achieve complete dehydration of the oil. The efficiency of emulsion breakage depends on the type of demulsifier and its concentration in the emulsion. At a temperature of 50 °C and a settling time of 360 min, the efficiency of emulsion dehydration is: without the use of a demulsifier – 43%; with the use of different demulsifiers – from 80 to 97%. Demulsifier PM-A at a concentration of 50 g/t was the most effective of the demulsifiers tested. The same dewatering efficiency is obtained with a concentration of PM-A in the emulsion of 70 g/t, but this concentration is clearly overestimated, since a similar result in terms of emulsion dewatering is obtained with a lower concentration of this demulsifier (50 g/t). Dissolvan 2830 demulsifier is characterised by a lower dewatering efficiency compared to PM demulsifiers. It is characteristic that when PM-A and PM-B demulsifiers are used, the efficiency of emulsion dehydration increases sharply from the moment they are introduced into the emulsion and then changes slightly, which allows the duration of the oil demulsification process to be reduced. When Dissolvan 2830 demulsifier is used, there is a gradual increase in dehydration efficiency over time, which makes it necessary to extend the duration of the oil demulsification process. It is recommended to demulsify the oil from the Dolyna field by heating it to 50 °C and using the PM-A demulsifier at a consumption of 50 g/t.