A Numerical Study on Mud Cake Cleaning Using a Multi-Jet Rotating Tube
Dr. Mohamed N. Noui-Mehidi

Abstract
A numerical study of mud cake cleaning using rotating radial jets is presented. The fluid conveying tube has a rotating end equipped with jet nozzles along the circumference. The combination of the radial jets created by the nozzles and the tool rotation generate flow recirculations in the space between the outer tube and the borehole wall. These recirculations result in increasing the local shear rate on the borehole wall and therefore achieving better cleaning of the mud cake deposited on the wellbore wall. The study concerned solving the basic flow equations around the jet zone and revealed the effects of the jet intensity, the rotational speed and the returning axial flow on the flow distribution in the annulus. The numerical calculations revealed that the presence of flow recirculations resulted in higher velocity magnitude in the annulus leading to an increased shear rate on the wall.

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