Study On Demulsification Of Crude Oil Emulsions By Microwave Radiation

The demulsification and dehydrating experiments of crude oil emulsion are performed by using the heating method, the thermochemical method, the microwave radial method and the microwave chemical method separately. The primary factor and the influence tendency that affects the demulsification effect are studied by changing the heating temperature, the emulsion breaker amount used and the microwave radiation time in this paper. By carrying on the microwave experiment to the crude oil emulsion of different water content, the effects are studied. According to the crude oil characteristic, as well as the experimental results of thermo chemical method and the microwave radial dehydration method, a process is proposed which can satisfy the SY/T5329-94 of moisture content less than 0.5%.The results indicate that temperature elevation and joining the suitable emulsion breaker are advantageous to the crude oil demulsification and dehydration, but the amount of emulsion breaker used has a best value, otherwise the efficiency of demulsification can be reduced. The increasing of the microwave radiation time is beneficial to the demulsification; also there is a best proportional region between the emulsion breaker amount used and the crude oil volume when the radiation time is fixed. Moreover, the best dehydration rate is almost the same for the thermo chemical method and the microwave chemical method, but less amount of emulsion breaker and shorter time are need for the microwave chemical method than the thermo chemical method. For the crude oil used in this experiment, the result can be obtained that the dehydrating rate is about 96% at the conditions of 100ppm of emulsion breaker, 65℃heating temperature, and 9min heating time for the thermo chemical method; But for the microwave chemical method, the dehydrating rate is about 95% using 50ppm emulsion breaker, 10s radiation time, and 1min settling time. The experiment shows that, for the microwave chemical method, the dehydration effect is better for the high water content crude oil emulsion than that of emulsion with lower water content.Based on comparison of the experiment results from different methods of crude oil demulsification, a dehydration process is proposed in which two times of dehydrated processing are employed. The microwave chemical method is used in the firstly, and then the heating method is carried on upper crude oil emulsion layer that forms in the previous process. To the crude oil emulsion with water percentage of 78%, after the first process, the water content of upper layer is about 18%; then through the second time treatment the water content of the crude oil emulsion is less than 0.3%. The qualified crude oil can be gained.This paper provides a certain partial theory basis and abundant experiment data for the improvement of crude oil dehydration process in oil field.