DEVICE FOR CLEANING DOWN-HOLE EQUIPMENT FROM ASPHALT-RESIN-PARAFFIN DEPOSITS Russian patent published in 2000 - IPC

FIELD: servicing of down-hole equipment, particularly, devices for removal of asphalt-resin-paraffin deposits from external surface of sucker rods and internal surfaces of tubing in lifting of sucker rod strings. SUBSTANCE: run into tubing is sucker rod string whose lower part carries scraper mounted for forward and rotary motion. Scraper is made in the form of flexible plane whose length and diameter vary due to its loading during operation. Cup valve is rigidly installed below scraper. Installed on wellhead on tubing string is loosening scraper. T-piece with branch pipe communicates tubing string with vessel for receiving asphalt-resin-paraffin deposits. Installed also on wellhead is sealing head with cup and channel to pass sucker rod string. During lifting of sucker rod string, scraper cleans tubing, and loosening scraper and cup clean sucker rod string. EFFECT: higher cleaning efficiency and operating reliability irrespective of well configuration and composition of produced fluid. 2 dwg