DEVICE FOR TUBE EXPANSION INSIDE WELL Russian patent published in 2006 - IPC E21B29/10 

FIELD: well drilling and overhaul, particularly to expand items made of profiled pipes.

SUBSTANCE: device comprises body with central channel and conical surface provided with depressions in which rollers are arranged. The rollers are secured by pins having upper ends detachably fixed and lower ends installed in supports. The supports are pivotally located in the body so that the supports may rotate in plane extending through longitudinal geometric axes of the body and the rollers. The lower body part is rigidly connected with technological bush formed with axial channel having cross-sectional area less than that of central channel. Sealed annular cylinder having piston is arranged above technological bush and below roller axes. Cavity arranged under the piston communicates with central body channel above axial channel of technological bush. The pins are provided with inner axial cavities. Bushes are located between the pins and the rollers in air-tight manner. The bushes may rotate relative the rollers and are restricted from rotation relative the pins. Outer bush surfaces are provided with helical grooves and parallel flat areas directed in parallel with plane of pin rotation and communicated with cavity arranged above annular cylinder through inner axial cavities of the pins.

EFFECT: increased working ability and tube expansion efficiency.

2 cl, 6 dwg