A study of horizontal and down hill two-phase oil-water flow

Concurrent oil and water flow in inclined pipes is a common occurrence in deviated wells and production gathering systems. To predict properties associated with non-emulsified oil and water flow such as pressure gradient, two-phase flow correlations developed for gas-liquid flow or average flow properties of the oil and water must be used. The objective of this work was to study water holdup (water holdup defined as the in-situ fraction of the pipe occupied by water), and see what, if any, parameters have an effect on its magnitude. Flow pattern formation was also studied to determine its effect on holdup. The oil-water flow experiments were conducted with a flow loop constructed of 2 inch ID clean plastic pipe using a wide range of oil and water flow rates and involving inclination angles of 0, -15 and -30 degrees from horizontal. For each set of flowing conditions, the system was allowed to reach steady-state, then the flow regime was observed and the water holdup was measured. From the experiments, the flow regimes associated with oil-water flow differed greatly from flow regimes encountered with gas-liquid flow. It seems apparent that when comparing experimental flow regime data with modified and established gas-liquid dimensionless parameters there exists no meaningful correlation. Holdup data obtained indicates that it does vary according to certain parameters which include pipe inclination, flow patterns, and input fraction of water