PULSING DEVICE FOR WASHING OPEN HOLE OF HORIZONTAL WELL Russian patent published in 2015 - IPC E21B21/00 E21B37/00 

FIELD: oil and gas industry.

SUBSTANCE: device comprises a body with tangential feeder and discharge channels, attachment installed in the discharge channel so that it can be rotated freely in the body, centred rotor with alternating slots and ledges interacting with fluid flow. In tangential feeder and discharge channels between the body and rotor there are slots due to offset of the feeder and discharge channels. The tangential feeder channel is offset per a bigger value than the tangential discharge channel. Cross-sectional area of a slot in the tangential feeder channel s more than cross-sectional area of a slot in the tangential discharge channel. The rotor is mounted in the body at ball bearings by means of plugs. The upper part of the body is connected to the washover string. A rod with feedthrough channel is installed from the body top. The rod is equipped with the upper and lower rows of radial openings separated by a solid partition installed in the feedthrough channel of the rod and interconnected by by-pass longitudinal channels made at inner surface of the body. At outer surface of the body there are tangential blades that allow rotation of the body in operating position in regard to the rod. Coil tubing is used as the washover string.

EFFECT: improved operational efficiency of the device, reduced probability of freezing, reduced time of tripping operation.

4 dwg