Characterization of Oil/Water Flows in Horizontal Pipes

Abstract

Abstract The dynamic characteristics of oil-water flow systems have not been fully understood. The need for improved design methods has led researchers towards its continuous investigation. The objective of this study was to characterize oil-water flow in horizontal pipes. The tests were conducted in a 2-in. horizontal test section using Tulsa City tap water and a mineral oil (density = 0.85 g/cm3 and viscosity = 15 cp) with superficial velocities ranging from 0.025 m/s to 1.75 m/s. Various data were acquired on flow patterns, pressure drop, phase fraction and droplet size as function of flow patterns and were used in characterization of the flow and performance evaluation of an oil-water model. A high speed video camera was used to identify flow patterns, measure droplets and ten conductivity probes were used to obtain phase distributions. New experimental data on pressure drop, holdup, phase distribution and droplet size distribution in oil-water flows are presented. Three probabilistic distributions were tested for fully dispersed flows. Sauter Mean Diameter (SMD) analysis were conducted across the pipe diameter. Droplet size data were used to evaluate existing models such as Hinze1, Kubie and Garner2, Angeli and Hewitt3, and Kouba4. An empirical correlation to predict the SMD profile of droplets across the pipe cross section was developed for flow pattern of dispersed oil in water and water (D o/w & w). Log-normal distribution was the best probabilistic distribution for representing the data for fully dispersed systems. The empirical correlation gave acceptable results. Model comparisons revealed that none of them could accurately represent the experimental data. The new data can lead to better modeling and design of dispersed systems and the new information on droplet sizes can have significant impact on separator design. Moreover, the interpretation of production logs in horizontal wells heavily relies on the flow behavior.