Sand accumulation in a pipeline could result in blockage and mechanical damage. Although pigging can remove accumulated sand, it can only be used when small amounts of sand are deposited. Another method is to use downhole sand exclusion systems. However, the difficulty of retrofitting these after the reservoir is producing, along with the disruption to operations, cannot be ignored. Sand production management is a method to keep relatively high production rates and maintain system integrity. An essential sand management aspect is to operate the production fluid transport system to satisfy the sand minimum transportation condition (MTC).
A number of definitions for MTC are encountered in the literature due to the different mechanisms that exist for solids transport. Also, various velocity names are used to refer to the similar solids transport conditions by different authors, such as Minimum Transport Velocity, and Solid Transport Velocity, etc. (Yan (2010)). Oroskar and Turian (1980) used the term "critical velocity" as the velocity that marks the transition from the settling of solid particles at the bottom of the pipe to the full suspension of the particles in the flowing fluid. Durand (1952) proposed to use pressure gradient against liquid velocity to identify the critical velocity, which is the velocity corresponding to the minimum pressure gradient level. Thomas (1962)'s definition of MTC was the mean stream velocity required to prevent the accumulation of a layer of sliding particles at the bottom of a horizontal pipe. It is this last definition that is used in this discussion.