Today, to increase oil recovery, waterflooding technologies are actively used. Emulsions that are formed when oil and water move along the wellbore and pipelines are especially stable in the case of oils with a high content of resin-asphaltene components. Therefore, the development of new technologies for the dehydration of highly resinous oil is very relevant; hence the optimal conditions of oil treatment are important for the use of physical methods of water-oil emulsion treatment.
This work deals with the study of the effect of time, temperature, and intensity of ultrasonic treatment on the stability of model and native emulsions. A mixture containing 80% of solution of petroleum paraffin in kerosene (6 % wt), 10 % of distilled water and 10 % of highly resinous oil is used as a model emulsion. The model emulsion is prepared by mixing the components at the temperature 20 °C for 10 min. The native emulsion contains 19% of formation water. Ultrasonic treatment of emulsions is carried out at the field frequency 22 kHz, intensities 2, 6 and 18 W/cm2 for 1–15 min at the bath temperature 0 and 20 °C. The consequences of ultrasonic treatment are evaluated by the amount of released water (‘bottle test’ method) and the water content in the oil layer (Russian National Standard GOST 2477-65). An AXIO LAB.A1 Carl Zeiss optical microscope is used for examination of the microstructure of emulsions. It is shown that a low-frequency ultrasound (22 kHz) promotes demulsification of the model emulsion at the optimal parameters of ultrasonic treatment: bath temperature 20 °C, time 10 min, field intensity 18 W/cm2. The maximum dehydration of a stable native emulsion (up to 3% of residual water) is achieved at the lower field intensity (2 W/cm2). Low-frequency ultrasound treatment may be used for the development of a very promising technology of the crude water cut oil transport.
Acknowledgement. This work was supported by the Ministry of Science and Higher Education of the Russian Federation (Project No. 44.3.1).
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