Cement Channeling: How to Predict and Prevent

Abstract

Summary This paper describes experiments with a large-scale flow loop (45 ft of 7-in. pipe in nominal 8½-in. open hole) that measure the velocity of the interface between fluids of varying densities and rheologies. The work showed that single-fluid velocity profiles cannot be used to predict interfacial profiles (e.g., between spacer and cement) and confirmed the importance of turbulent flow in minimizing channeling through mechanisms of increased frictional pressure drop and mixing across the annulus. Large density differences, both negative and positive, also minimized channeling.