Theoretical Study of Sand Entrainment and Deposits in Horizontal Oil Transport

Sand deposition in horizontal pipes transporting crude oil and sand affects oil recovery and causes loss of pipe integrity. One way of avoiding sand deposition in lines is by identifying potential sand deposit points for mounting boosters to help boost the inertia force of the flowing stream. This paper investigates a model approach to the problem. Results from simulation give potential sand deposit points in a 12 km pipeline. The Reynolds numbers estimated, show significant variations between the 6 and 8km points where viscous forces prevailed over inertia forces. Thus, the 6 km point is an ideal point for mounting a booster. Sand velocities remained constant at 0 km at different times down to the 8 km point although, the values differ axially per hour. Variations were incipient at the 10 km point through to the exit owing to hindered settling caused by inherent collisions of particles resting on the pipe wall. However, this also suggests that the 8 km point is a crucial point at or beyond which a booster pump is required to make up for the lost kinetic energy for a reliable and safe flow. Transport flow regimes were also investigated via parametric assessment on hourly basis.