WELL PERFORATION DEVICE Russian patent published in 2007 - IPC E21B33/13 E21B37/00 E21B33/122 

FIELD: oil production, particularly well repair.

SUBSTANCE: device is made as packer assembly including bottom-hole packer adapted to close well annulus due to packer diameter increase under axial compression thereof and pipe arranged in bottom-hole packer cavity. During bottom-hole packer compression the packer slides along the pipe in vertical direction. Device comprises two packer assemblies. Pipe of bottom-hole packer included in upper packer assembly has bottom with orifices and thrust for bottom-hole packer supporting. Device also has outer pipe arranged below lower bottom-hole packer and coaxial thereto. Outer pipe has inner diameter and surface finish to provide sliding thereof along outer surface of pipe located inside bottom-hole packer. Outer pipe has bottom-hole packer thrusts arranged at ends thereof. Lower packer assembly is identical to upper one and is upside down. Lower packer assembly is below upper one and is coaxial thereto. Lower and upper packer assemblies define common outer pipe. Tubing string passes through both packing assemblies through central bottom orifices thereof. Remainder bottom orifices communicate well annulus and clearance between tubing string and outer pipe. Tubing string couplings located over upper packer assembly and below lower one limit vertical bottom displacement.

EFFECT: decreased time and improved well flushing.

2 dwg