Method for reducing loss of crude oil during venting before starting centrifugal pump in oil transportation station

Venting is an essential operation step before starting the centrifugal pump. During the process of venting, the centrifugal pump faces the problems of oil splash, slop oil in the slop tank and excessive loss of crude oil during venting. Through the analysis on the actual production and operation of one oil transportation station in Xinjiang Tarim-Shihezi Pipeline, it is concluded that the main causes of the excessive crude oil loss during venting attribute to the excessively shallow and overlong guide oil tank for draining, and the air bubbles in the vent pipeline. Based on the investigation on venting of centrifugal pumps before pump starting in China and abroad, the following improvement measures were proposed according to the starting steps, precautions and the actual situation of the oil transportation station. The additional three-way funnel can be used to cope with the crude oil loss caused by the excessively shallow and overlong tank. The vent pipeline can be moved from the side of the centrifugal pump to the rear (the moving distance of about 47 cm) and connected with the three-way funnel to avoid crude oil splashing caused by bubbles in the vent pipeline. The practice shows that this method can effectively reduce the loss of crude oil during venting before starting the centrifugal pump, and the single loss of crude oil during venting declines from 79 g to 0. The improvement measures are simple and safe for operation and capable of meeting the actual needs of the site, so they are supposed to provide important practical significance for optimizing and improving the overall performance of the centrifugal pump.