Particle transport in stratified gas-liquid-solid flow

Solids transport in stratified gas-liquid flow is investigated for both low concentration dispersed flow and high concentration flow in which solid beds could occur. The effect of gas and liquid velocities on solids transport is studied by conducting experiments with entrained solid particles. The effect of gas density and liquid viscosity on stratified flow was also studied. Liquid and gas velocities ranged from 0.06 to 0.16 m/s and 1.2 m/s to 15 m/s respectively, and viscosities ranged from 1 cP to 120 cP. Glass beads with particle sizes of 45-90 mum and 600 mum were used. The secondary goal of this work was to apply this knowledge of solids transport to the energy industry. This was done in two ways: 1) development of an abrasive drilling system applicable for enhanced geothermal systems and oil and gas reservoirs and 2) development of predictive tools to enable transport of sand produced from those reservoirs. The Abrasive Jet Drilling System, consisting of a slurry of high velocity solid particles entrained in a mixture of water and supercritical CO 2, was developed by conducting erosion tests on various rock strata using a nozzle delivery system. The nozzle geometry was optimized to achieve maximum drilling rate for a given set of conditions. Concurrently, an erosion equation has been developed for predicting the material removal rate. The erosion was measured by observing the weight loss of target material caused by impact of high velocity sand in direct impact tests.;This study endeavors to predict particle transport since it is a very important factor for abrasive drilling as well as petroleum production. Particle Image Velocimetry was used to study the structures in the liquid phase. It was determined that three modes of the interface can be defined: 1) Wave buildup, 2) Wave Breakdown, and 3) Inter-crest film. It was also observed that both wave buildup and wave breakdown modes appear to create vertical movement of the fluid layers that can contribute to the pickup and transport of solid particles from the top of a moving or stationary bed. It was determined that the height of the bed decreased with increasing superficial gas velocity and that the bed arranged itself in varying flow patterns coupled with the superficial gas velocity. It was also observed that the height of the bed created with smaller diameter particles was larger than the one created by the bigger particle size. The nozzle exit profile was optimized using the force on the rock face as the optimizing criteria. Finally a model, applicable for both low concentrations as well as high concentrations, has been formulated to predict the sand flow velocity as well as the sand particle holdup in a horizontal pipe. A model has also been developed to predict the amount of material removed from a rock substrate due to the impact of the slurry flowing through the optimized nozzle.