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 sandy and sludge deposits present in well. 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. Perforated orifices of hollow rod are made as two rows of lower and upper perforated orifices. The hollow rod is provided with groove located over upper perforated radial orifices. The groove includes radial and axial parts connected one to another. 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 finger installed in radial groove part in initial position. Bush is provided with check valve located inside bush and made as valve cage and ball arranged in the cage. Cylindrical extension with through orifices is made in lower bush part. Lower edge of cylindrical bush extension is provided with depressions cooperating 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