Parallel Pipelining

In this paper we introduce the idea of parallel pipelining for water lubricated transportation of oil (or other viscous material). A parallel system can have major advantages over a single pipe with respect to the cost of maintenance and continuous operation of the system, to the pressure gradients required to restart a stopped system and to the reduction and even elimination of the fouling of pipe walls in continuous operation. We show that the action of capillarity in small pipes is more favorable for restart than in large pipes. In a parallel pipeline system, we estimate the number of small pipes needed to deliver the same oil flux as in one larger pipe as N = (R/r)^α, where r and R are the radii of the small and large pipes, respectively, and α = 4 or 19/7 when the lubricating water flow is laminar or turbulent.