Solids transport by laminar Newtonian flows

An experimental investigation of the horizontal transport of solid particle s by viscous Newtonian fluids has been conducted. The independent variables were: fluid density, fluid viscosity, particle diameter, pipe diameter, in situ solids concentration and bulk velocity. The measured variables includ ed pressure gradients, delivered solids concentrations, concentration distr ibutions and fluid velocity distributions. The pressure gradient, velocity distribution and delivered solids concentrations could be explained in term s of the slurry viscosity and the local solids concentration, which varied considerably in the vertical direction. This variation of solids concentrat ion is interpreted in terms of particle-particle interactions which oppose the effect of gravity. The experimental results show that pressure gradient s of the order of 2 kPa/m are required to transport significant quantities of sand in laminar flow. The experimental results should find application i n horizontal oil well technology. (C) 1999 Published by Elsevier Science S. A.