PIPELINE FLOW OF GAS, LIQUID AND SAND MIXTURES AT LOW VELOCITIES

Experiments have been conducted to investigate the ability of gas-liqu id mixtures to transport sand in a horizontal pipe or well at low velo cities. Both laminar and turbulent liquid flow regimes were investigat ed. The gas-containing flows were predominantly in the slug regime. Sa nd transport rates in laminar oil flows were very low until pressure g radient exceeded 1.5 kPa/m. Gas addition did not improve this performa nce. With turbulent liquid flows, sand transport rates at low velociti es could be estimated by the Meyer-Peter equation as long as the sand particle diameter exceeded 0.1 mm. As the gas flowrate increased,sand transport rates eventually exceeded these predictions because of mixin g caused by passage of the slugs. Axial pressure gradients for turbule nt gas-liquid-sand mixtures could be estimated from the Lockhart-Marti nelli correlation.