Successful cement jobs require that the drilling fluid is fully displaced by the cement slurry. Good mud removal ensures good bonding of the cement to the casing and the formation. Failure to remove all the mud from the annular spaces leads to mud channels, which will weaken the cement bonding and cement-seal integrity.
Conventional hydraulics calculation is necessary, but not enough to cover the displacement efficiency with computational fluid dynamics (CFD). This presentation shows the R&D on the assessment of the risk of mud channeling as a function of fluid properties, flow rate, wellbore geometry, and well path. The goal is to address the risks and optimize the displacement efficiency in order to deliver a cement sheath to be able to retain annular-seal integrity.