Study And Application Of Comprehensive Treatment Technology For Heavy Oil Produced Fluid In Tahe Oilfield

Tahe oilfield, one of the top ten domestic oilfields, has four multi-purpose stations at present. Among them, the second one, which mainly processes heavy oil, is a large-scale integrated station with functions such as crude oil demulsification, oil and gas separation, sewage treatment and reinjection and so on. However, there are a series problems like the large amount of demulsifier consumption, long settling time and poor dehydration effect and so forth in the No.2multi-purpose station. And it is because that the increasing of large-scale stimulation wells in the process of oilfield development makes the dehydration treatment more difficult. Therefore, it is necessary to study of produced liquid of heavy oil dehydration technology, in order to ensure the quality of products and the normal conduct of follow-up oil processing processes.At first, literature research is conducted to acquire a comprehensive and systematic understanding of the mechanism of crude oil emulsion formation and demulsification, oil dehydration methods and its current situation. Then, the sample analysis of No.2multi-purpose station is completed and the basic properties and composition of the oil extraction liquid is cleared. Based on these, the reasons why it is difficult for heavy oil to dehydrate are found out, in combination with the practical situation of No.2multi-purpose station. Next, according to the existing problems of heavy oil dehydration is difficult, to heavy oil recovery experimental study on classified heavy oil, through the normal heavy oil dehydration of produced liquid experiment screened demulsifier suitable for Tahe oilfield heavy oil dehydration, and determines the optimum temperature demulsifier used and dosing; acidification of heavy oil dehydration experiment to find dehydration processing better; aging of heavy oil dehydration experiments to determine the aging thick incorporation into heavy oil with high water content and delay treatment is feasible. According to the classification of dehydration of experimental results, the existence of heavy oil dehydration the processing system problems, put forward for the optimization of heavy oil processing process improvement, the different blocks of high and low water content of normal heavy oil to liquid shunt treatment, acidification of the combined effect of sound of heavy oil processing and aging thick oil circulation to raise temperature delay processing technology processing means, eliminates heavy oil with different water content, the interaction effects of aging on the acidification of heavy oil processing system,the improved processes are proposed and it works well to solve the problems of oil dehydration in the No.2station.