Research on Oil-Water Displacement in Upward Inclined Pipes

Author of the article:Zhang Peiying1, Zhang Jie1, Li Wang2, Jiang Haibin2, Gong Jing1*

Author's Workplace：(1. Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing , Beijing, 102200, China; 2. PetroChina Southwest Pipeline Branch Company, Chengdu, Sichuan, 610041, China

Key Words：Oil pipeline; Oil-water displacement; Oil-water velocity; Water phase reflux

Abstract：Most of the oil pipelines are put into operation by water transport or partial pipelines filled with water.The residual water remaining in the lower sections of pipelines can be carried away by the oil flow.After the oil carries the water to the upward inclined pipes, the accumulated water continues to move upward along the pipe wall under the shearing force of the oil flow.In order to carry out theoretical research on oil-water displacement process,a model for predicting the oil-water velocity distribution along the upward inclined pipes is proposed based on the theory of oil-water laminar flow.The effects of superficial oil velocity, oil properties, size and inclination of the pipe and water phase thickness on the water phase reflux ratio are analyzed,and the critical parameters of water phase reflux are obtained.The model is also used to analyze some pipe sections of the southwest oil product pipeline.Studies show that under different conditions, the water carrying capacity of the oil is different, and the water phase is only partially refluxed between the two critical values.For the actual engineering pipeline, oil flow has limited ability to carry water.Theoretical support is provided for the oil carrying water in upward inclined pipes.