The Reduction of Pressure Gradients in Oil Pipelines

The use of water flowing as a lower layer to reduce pressure gradients in petroleum pipelines was investigated using 17.5 deg. A.P.I. Lloydminster crude oil in a 1-inch laboratory pipe-line and a 21h-inch field pipeline. The method was found to be very effective in reducing the pressure gradient below that for the oil flowing alone. The factor by which the pres-sure gradient was reduced varied with the percentage of water added, and in general exceeded 10 for water contents ranging from 40 to 60 per cent. Within this range of water content the pressure gradient reduction factor was independent of the oil flow rate.