CENTRALISER FOR SPLIT HOLE REAMER Russian patent published in 2011 - IPC E21B17/10 

FIELD: oil and gas production.

SUBSTANCE: centraliser for split hole reamer consists of tubular case with radial channels, of hinged spring arcs with their one end fastened on yoke stationary in lengthwise direction and with another end on movable yoke, of working circular cylinder with piston inside, located below radial channels; also piston is coupled with movable yoke. The case is equipped with an external groove, where into there are installed a rotating and travelling with restriction upper yoke made as a bushing, rigidly tied with the piston and a rotating cylinder and a lower yoke made as a sleeve.

EFFECT: simplified design, increased reliability and efficiency of centring, expanded range of implementation.

2 dwg