Randall G. Gillies

Solids transport by laminar Newtonian flows

Abstract An experimental investigation of the horizontal transport of solid particles 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 included pressure gradients, delivered solids concentrations, concentration distributions and fluid velocity distributions. The pressure gradient, velocity distribution and delivered solids concentrations could be explained in terms of the slurry viscosity and the local solids concentration, which varied considerably in the vertical direction. This variation of solids concentration is interpreted in terms of particle–particle interactions which oppose the effect of gravity. The experimental results show that pressure gradients of the order of 2 kPa/m are required to transport significant quantities of sand in laminar flow. The experimental results should find application in horizontal oil well technology.

Pipeline transport of large ablating particles in a non-Newtonian carrier

Substantial environmental advantages can be achieved by transporting overburden in a clay slurry if the rate of ablation of the overburden particles is not excessive. An experimental investigation of this form of hydrotransport has been undertaken and changes in pipeline pressure drop have been used to infer the rate of overburden particle ablation. The experiments suggest that the fine particles disperse quickly and the larger ones remain for longer periods of time. A reasonable model of the experimental results is obtained by assuming the particle diameter decreases at a rate which is independent of particle size.

Flow of sand-water mixtures at velocities below the deposition condition

ABSTRACT An experimental study of sand-water flow in a horizontal pipeline has been conducted for the regime in which a stationary deposit was present. The particle diameter ranged between 0.2 mm and 0.01 mm and the particles were not flocculated. Axial pressure gradients and delivered concentrations were measured as functions of mean velocity and in-situ concentration. A three layer model was found to be useful to predict the pipeline behavior at all but the lowest velocities. The Meyer-Peter sediment transport equation was satisfactory for very low velocities with the larger particles.

Governing Friction Loss Mechanisms and the Importance of Off-Line Characterization Tests in the Pipeline Transport of Dense Coarse-Particle Slurries

For more than 20 years, the Saskatchewan Research Council’s PipeFlow model has been used by companies across the globe to predict pressure losses and minimum operating velocities (‘deposition velocities’) for the pipeline transport of heterogeneous (settling) slurries. The success of this semi-mechanistic, phenomenological model comes from the fact that the friction loss contributions of the dispersed, coarse particle phase are accounted for in a physically meaningful way. The focus of this study is on the need to make accurate off-line slurry characterization measurements to obtain accurate predictions of slurry flow behavior. The results of a number of slurry pipeline tests conducted under controlled conditions are presented. These results clearly demonstrate that, in addition to accurate measurements of particle size distribution and density, proper characterization of the following parameters is also critical: carrier fluid viscosity, settled bed coarse particle concentration, particle drag coefficient / particle terminal settling velocity, and the coefficient of friction between the particles and the pipe wall.© 2013 ASME