Research On The Effect Of Electric Desalting And Dehydration Of Two Kinds Of Crude Oil

With the increasing demand of petroleum resources and exploitation strength increase, domestic and international crude oil supply presents a heavy, bad trend, processing difficulty, Refining industry is eager to hope that crude oil pretreatment levels can have the new breakthrough and promotion in order to effectively solve the problems in the process of crude oil pretreatment.In this paper, the experiments were designed to carry out the research on the desalting and dehydration of Suizhong crude oil and Luning pipe-conveying crude oil. First, screening demulsifier is studied according to the different characteristics of two kinds of crude oil, and carried out a evaluation test of static electric desalting process conditions combined with temperature, demulsifier and its dosage, mixing intensity, water injection rate, electric field intensity and other factors, then got the optimal process condition. For SuiZhong crude oil, the result showed that the salt content in the desalted crude oil is 2.3 mg/L and the water content is 0.21% under the conditions of 30 ppm dosage of demulsifier,6% water injection rate,135℃temperature, mixed strength for manual oscillation frequency is 90 times and 1000 V/cm electric field strength. For Luning pipe-conveying crude oil, the result showed that the salt content in the desalted crude oil is 2.7 mg/L and the water content is 0.18% under the conditions of 30 ppm dosage of demulsifier,5% water injection rate,130℃temperature, mixed strength for manual oscillation frequency is 150 times and 1000 V/cm electric field strength.On the basis of evaluation test of static electric desalting unit, the dynamic simulation test of electric desalting unit is studied and then get the optimal process conditions. One hundred times magnification micrograph results show that the water content decreased significantly after treatment of dynamic electric desalting unit, large droplets almost completely removed, reached the desalting and dewatering effect, water spot diameter in about 10～20μm. Finally the desalting and dewatering effect of two kinds of crude oil are studied in the industrial test unit, the industrial test results showed after the removal of three-stage electric desalting unit of Suizhong crude oil the average salt content is 2.43 mg/L, the average water content is 0.2%; and the average salt content is 2.65 mg/L, the average water content is 0.24% after the removal of two-stage electric desalting unit; After the removal of two-stage electric desalting unit of Luning pipe-conveying crude oil the average salt content is 2.5 mg/L, the average water content is 0.13%. Industrial test results both showed that the salt content of processed crude oil is less than 3 mg/L, the water content of processed crude oil is less than 0.3%, fully meet the prescribed requirement of Sinopec.