Abstract: The naphthenic base oil (U30 transformer oil, N4010 rubber plasticizer) was produced by a high-pressure hydrogenation unit in CNOOC Oil & Gas (Taizhou) Petrochemical Co., Ltd. Aiming at the problem that the calibration results of naphthenic base oil produced by the unit was lower than the designed value, the influence factors was analyzed. In order to improve the yield of naphthenic base oil, some measures was taken, such as increasing the lubricating oil composition of the feedstock, increasing the space velocity, reducing the depth of the dewaxing reaction, and controlling product indicators on their indicator boundaries. The results showed that the average yield of naphthenic base oil was increased from 83.67% to 86.50%, and the highest yield could reach 89%.

Key words: naphthenic, base oil, lubricating oil, high-pressure hydrogenation