Very Low Concentration Sand Transport in Multiphase Horizontal Pipelines: An Experimental Study and Modeling Guidelines
Very low concentration sand transport in multiphase horizontal pipes is experimentally investigated in this study. Sand concentration is chosen to be low enough to ignore the effect of particle-particle interaction. This is done to obtain the liquid and gas threshold flow rates which are required to move particles at low concentration (0.002 volume percent) of particles in multiphase pipelines. Along with obtaining the threshold flow rates, the effects of sand concentration, sand size, pipe size and liquid viscosity are also experimentally investigated. Critical velocity is defined to make sure all grains of sand continuously move in the pipe. The experimental data were obtained for a wide range of operating conditions in both intermittent and stratified flow regimes. A comparison of the obtained experimental data in this study with similar studies in the literature reveals the effect of some physical parameters affecting sad transport in multiphase flow pipelines. This study also gives some general guidelines for a more accurate model to predict minimum flow rates to move sand in multiphase flows.