WELL WIDENING DEVICE Russian patent published in 2009 - IPC E21B7/28 

FIELD: oil-and-gas production.

SUBSTANCE: invention related to boring equipment, particularly to equipment for widening well diametre on at particular interval. Well widening device includes case with an extensional surface and central canal, installed with ability to interact with toothed rolling cutter extensional surface, piston rod and a spring. On the case located, with limited movement ability, spring-mounted relatively to the top case surface collar with roll shaped radial cuttings for the rolling cutter. Rolling cutter located on a plane perpendicular to device axes and fixed on axels in rolling cutters holes, which diametres are greater on value equal to rolling cuttings radial displacement then axles diametres. Rod connected to the bottom case, which extensional surface executed as double-staged and consists of upper cylindrical operational extensional surface of a great diametre with radial holes created for rolling cutter tooth and bottom cylindrical transportation extensional surface, in a way that piston with rod located inside a cylinder, which connected to central canal and installed with an ability of limited movement upwards and interaction with collar. Invention develops in formula subclaime.

EFFECT: increase in operation integrity, reliability, and device more convenient operation.

4 cl, 4 dwg