Flow of cement slurry through an eccentric annulus

A step by step procedure has been developed to design cement hydraulic during cement jobto minimize non cemented channels or bad cement job by taking into consideration thenon-flow area throughout the eccentric annulus. Since cement slurry exhibit non-Newtonian rheological behavior, a good description of the slurry rheology is required inorder to estimate accurately the velocity profile across the annulus. To achieve this goal,six rheological models have been adopted: Power-law, Robertson-Stiff, Bingham, Casson,Modified Power-law, and Modified Robertson-Stiff Models. Using the last five rheologicalmodels, new frictional pressure gradient equations for laminar flow of cement slurrythrough an eccentric annulus have been derived by the author based on slit-approachapproximation.