Analisis of Oil-Water Flow Tests in Horizontal, Hilly-Terrain, and Vertical Pipes

Abstract The flow pattern, pressure drop and water holdup were measured for oil-water flow in horizontal, hilly-terrain (± 0.5° and ± 3°) and vertical pipelines at a temperature of about 35 ± 5 °C and a pressure of about 245 kPa using the large-scale multiphase flow-test facility of Japan Oil, Gas and Metals National Corporation (JOGMEC). Test lines of 4.19 inch (106.4 mm) ID and 120 m total length were utilized which included a 40 m horizontal or hilly-terrain and a 10 m vertical test sections sequentially connected. The flow pattern was determined by visual observation with video recordings, and a flow pattern map was made for each condition. New flow patterns were identified for horizontal and hilly-terrain flow, such as oil flow in a snake-like shape at top of pipe at high rate of water flow, and water flow at bottom of pipe at high rate of oil flow. New holdup and pressure drop data are presented for each flow condition. The flow rate and inclination angle influences holdup and pressure drop behaviors. In vertical flow, when the oil superficial velocity exceeds a certain value, the pressure drop decreases exponentially as the superficial oil velocity increases. Slippage between the phases was analyzed using the measured water holdup plotted against the input water cut with inlet oil flow rate as parameters. It was found that the slippage changed significant with slightly changes in inclination angle. This paper provides new experimental data of flow pattern, water holdup and pressure drop measured particularly at horizontal, hilly-terrain and vertical conditions with large-diameter pipes. These are the indispensable information of developing reliable prediction models for oil-water two-phase and gas-oil-water three-phase flow in pipelines.