Ultrasonic Technology Heavy Dehydration Of The Acid Tahe Oilfield

Tahe oilfield is one of the top ten domestic oilfields and its main products are heavy oil and extra-heavy oil. Besides, acidizing operation is applied in75%of the oil wells in Tahe, producing acidification oil. It is more difficult for the acidification oil to be dehydrated and the technological requirements of dehydration can not be meet when ordinary thermal chemical process is adopted alone. Therefore, additional treatments are necessary for the acidification oil dehydration. Some measures, such as optimizing the demulsifiers, increasing the temperature of dehydration and extending the time of settlement process, etc., have been taken in the early stage. However, the effects are not satisfying since there are still lots of problems, like the thickness of the emulsion layer after dehydration, the large quantity of repeated processing, the instability of the system and the substandard of the dehydrated oil and so on.In this paper, the causes and influence factors of the stability of crude oil emulsion are analyzed and all kinds of dehydration technologies are compared with each other on the basis of literature research. In addition, considering the properties of the acidification oil and the situation of Tahe oilfield, the author suggest that the ultrasonic technology be used for the acidification oil dehydration. In the study, taking the acidification oil and aging dirty oil of Tahe oilfield as the samples, a series of comparative experiments are carried out to investigate the demulsification and dehydration effect and influence factors of ultrasonic. And the operating parameters are also optimized according to the experiments. Furthermore, the field testing and evaluation of ultrasonic technology in dehydration are conducted. The results show that the ultrasonic technology can meet the technological requirements of the acidification oil dehydration in Tahe and the product quality is better while the cost of oily sewage treatment is less. Moreover, the dehydration efficiency can be significantly improved if the ultrasonic is combined with demulsifiers and electric dehydration technology, along with the dosage of demulsifier and the electric current reducing.