Research Progress of Sand Transport Mechanism and Critical Conditions in Pipelines

Sand deposition and transportation in pipelines has become one of the major concerns for flow assurance in petroleum industry. However, research in this field is still in its infancy. This study describes the current development of sand deposition and sand transport in pipeline. The mechanism of particles deposition is described. The effects of particle properties, fluid properties and pipeline structure on the carrying capacity of single-phase and multiphase flow carrying sand are introduced, with emphasis on factors such as particle size, liquid viscosity, flow regime and pipeline inclination. As for modeling studies, the sand transport models can be classified to three categories based on the approach used to develop them: empirical, mechanistic, and semi-mechanistic. The methods for developing and extending models are illustrated in this study. Based on the experimental data, the prediction accuracy of four multiphase models for critical velocity in stratified flow is verified. Further researches should focus on the mechanisms and the establishment of the accurate model for sand flow pattern transformation boundary.