There are five to six spiral bars. Two rollers are installed on each of the bar. The rollers axis is perpendicular to the centralizers Axis. The rollers envelope outside diameter is slightly larger than the centralizer bars outside diameter.The rollers envelope inside diameter is slightly larger than the centralizer bars inside diameter. The friction between the casing and the borehole changes from sliding friction to rolling friction when the casing equipped with roller rigid casing centralizers run into the inclined section or the horizontal section. This can reduce the friction force between the casing and the borehole wall and we can run the casings to the reserved position successfully. When the hole diameter is irregular, the borehole ball should have an impact force on the spiral centralizer during running casings.The roller can reduce the impact. The spiral centralizer can make the mud and the slurry form bumpy flow to wash false filter cakes out and improve Displacement efficiency, the bonding strength of the slurry and the borehole wall, and cementing quality. During cementing. Therefore the roller Rigid casing centralizers are adopted to be used in the inclined section.
Faridabad, Haryana, India
