Author(s)

SANGMOK HAN, NAMSUB WOO, YOUNGJU KIM

Abstract

This paper examines the migration of solid particles in a high-mixing flow inside an inclined annular pipe. An experimental study of non-Newtonian fluids in the layer region through annular tubes with axial flow and rotation of the inner cylinder was carried out. It was demonstrated that the gravitational force acting on the particle stream plays a very important role in directional drilling, cuttings particle movement, and cuttings transport. The pressure drop and the particle velocity of the drilling fluid (CMC and Bentonite solution) corresponding to the inclination and rotation of the drill pipe were measured. The hydraulic pressure drop owing to the mixture flow increased because of the friction between the wall and the solid particles. Further, a high particle feed concentration increased the pressure drop because of the friction between the solid particles in the fluid stream. The advantages of a rotating and an inclined annulus pipe, for the particle transport phenomena, were confirmed in this study.

Keywords

cuttings transport, drilling fluids, directional drilling, pressure drop