WELL FLUSHING AND CLEANING DEVICE Russian patent published in 2006 - IPC E21B37/00 E21B21/00 

FIELD: well operation and maintenance, particularly to clean well of mud, as well of sandy and sludge deposits.

SUBSTANCE: device comprises body with radial windows and upper packer. Hollow rod with perforated orifices is concentrically arranged in the body so that the rod may perform limited axial displacement in downward direction. Shank is fixedly secured to lower body part. The shank may cooperate with well bottom. Upper hollow rod part is connected with flow string. Packer is made as self-sealing sleeve and permit liquid passage in down-top direction. Upper body edge has projections. Cylindrical extension is created on inner body surface below radial windows. The body is fixed relatively hollow rod with shear members. Perforated orifices of hollow rod are made as two rows of lower and upper perforated orifices. In initial position lower perforated orifices of hollow rod are closed with cylindrical extension of the body. In initial position upper perforated orifices of hollow rod are closed with bush fixed relatively hollow rod with thread and provided with depressions formed in lower edge thereof. The depressions cooperate with body projections during lower perforated orifices opening. Hollow rod has sealing member arranged on rod outside between lower and upper perforated orifices over the body. The sealing member isolates body interior during lower perforated orifices opening.

EFFECT: increased well cleaning efficiency and guaranteed further well flushing in one trip.

2 dwg