JET CLEANING DEVICE FOR WELL SHAFT Russian patent published in 2013 - IPC E21B21/00 E21B37/00 

FIELD: oil and gas industry.

SUBSTANCE: device includes housing with thread for connection to pipe string, adapter, hollow shaft connecting the housing to adapter and equipped with stop ring and radial channels for emission of flushing liquid to annular space, bushing that is movable relative to the shaft, and damping assembly. Bushing is rigidly attached to housing and forms cylindrical cavity of the housing and equipped from below with a downward convergent cone. Shaft is connected to housing with possibility of restricted longitudinal movement. Stop ring is rigidly attached to the shaft and forms a piston inserted in cylindrical cavity of the housing, the above-piston cavity of which acts as a damper and is interconnected with cavity of shaft through throttling channel of the shaft. Adapter is equipped from above with inner annular cavity and expansion cone with inclination angle corresponding to bushing cone expansion angle, which do not cover the radial channels of the shaft and solid annular conical channel.

EFFECT: enlarging functional capabilities, increasing technical and economic performance of drilling process, reducing the time costs required for performance of works relating to shaft development prior to well reinforcement.

2 dwg