GEAR TO CLEAN FACE ZONE OF WELL Russian patent published in 2000 - IPC

FIELD: oil industry. SUBSTANCE: invention is meant to work face zones of wells by method of formation of momentary pressure differential. Gear includes two rows of tubes arranged concentrically, outer and inner, and packer. Cylinder with radial windows is linked to outer row of tubes. It houses spring-loaded piston. Inner row of tubes is fitted with well pump. Hollow rod with radial holes interacting with piston is mounted across intake of pump. Windows are shut off by body of piston in its initial position and space under packer is isolated from inner space of tubes. Space under packer communicates with space of tubes through windows in extreme lower position of piston. EFFECT: multiple action on face zone of well by way of formation of momentary pressure differentials in face, possibility of examination of wells to test efficiency of cleaning operation without replacement of underground equipment. 2 dwg