DOWNHOLE DEVICE WITH PULLOUT ROLLER BEARERS Russian patent published in 2015 - IPC E21B10/34 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions is referred to the downhole device with pullout roller bearers and to drill stem with the above downhole device and method of vibration and torsion torque stabilization and reduction in the drill stem by means of the above device. The downhole device with pullout roller bearers comprises a housing with longitudinal axis, at least one piston installed in the housing and moving radially in regards to the longitudinal axis between the position wherein the piston is pulled inside and the alternative position wherein the piston is pulled outside under action of fluid pressure in the housing towards the surface, at least one piston placed inside the housing, at that at least one roller bearer is installed so that it may be rotated at one or several pistons and it may be rolled through the well bore side when at least one piston is retracted outside in its activated position; moreover the device has an opening passing through at least one piston and having the axis perpendicular to the housing radius and at least one removable fixing element installed in the housing and retracted to the corresponding opening both in pulled in and pulled out position of the piston activated position in order to prevent removal of the corresponding piston from the housing and counteracting to the piston rotation in regards to the housing.

EFFECT: provision of stability and reduced vibration and torsion torque of the drill stem.

22 cl, 29 dwg