ANCHOR-CENTRALISER OF STEPANOV HYDRO-MECHANICAL STRUCTURE Russian patent published in 2009 - IPC E21B17/10 E21B23/00 

FIELD: oil-and-gas production.

SUBSTANCE: invention related to casing string hole clearance cementing , particularly cementing casing string in a well. Hydro-mechanical anchor centraliser, includes cylinder connected to string, inside which installed 3 barrels, working piston, fixed relatively to cylinder with calibrated pin, slide barrel, centralising arms, roller fixed with string, lockers, executed as a T-shaped channels on the barrels bottom, interacting with T-shaped pins, stiff fixed with centralising arms. Slide barrel installed inside cylinder cavity over barrels. External diametre of slide barrel is smaller than cylinder internal diametre. External surface of working piston bottom part made conical for interaction with centralising arms conical surfaces. On the top part of working piston before its conical surface made diametrically opposed gaps, in a way that its bottom part has radial through pins, created along working piston generating line in pins between centralising arms. Core stepped created along external working surface has radial holes with thread, connecting cylinders and core internal surfaces, destroyable plug threaded in it.

EFFECT: anchor centraliser reliability increase and its simplification.

3 dwg