PARACHUTE-TYPE AUTOMATIC SCRAPER Russian patent published in 1999 - IPC

FIELD: equipment for removing from inner surfaces of pump-compressor tubes paraffin deposits in wells worked with use of immersible electric centrifugal pumping installations, fountain and gas-lift processes, possibly in oil and gas production. SUBSTANCE: scraper includes housing with cutters and pusher arranged with gap in housing with possibility of relative axial motion. Pusher is formed by sleeve and stop provided with guides mutually joining them and with breaking plug. Housing includes sealing member mounted with possibility of engaging with stop. Cutters are in the form of variable-pitch screw. Stop has holes for liquid overflowing. EFFECT: enhanced operational reliability and increased service life period of scraper. 3 cl, 4 dwg