DESIGN OF A SUBMARINE OIL PIPELINE

Submarine oil pipelines carry hot crude oil obtained from offshore oil wells to an onshore location. As the flow proceeds, the crude oil progressively cools down, drastically changing its kinematic viscosity. This cooling increases the surface resistance to flow considerably. Analysis of such a pipeline is complicated because it involves a large number of variables representing fluid, flow, thermal properties, and geometry. Furthermore, as the liquid cools down the flow may change from turbulent to laminar. This paper reports a unified friction factor equation valid in laminar as well as in turbulent flow that deals with this complex flow situation. This equation can aid development of a methodology for analysis and design of offshore pipelines.