GEAR FOR TREATMENT AND EXAMINATION OF WELLS Russian patent published in 2003 - IPC

FIELD: running of oil wells. SUBSTANCE: gear for treatment and examination of wells includes hollow body with admission valve sunk into well. Body comes in the form of working cylinder. Sealed through windows of working cylinder are shut off from external pressure by piston with seals which are positioned in closed state of admission valve so that upper seal is above and lower seal is beneath sealed through windows. Piston is fixed in this position by means of lockpin sheared away when thrown-off striker hits piston. Internal space of hollow piston can be filled through pipe union with fluid which partially fills internal space of working cylinder. Instrument container is attached to lower part of working cylinder. EFFECT: enhanced functional reliability of gear as force developed with high-speed fall of striker does not lead to any deformation of parts of admission valve and to failure of gear. 2 dwg