PROCESS OF OIL EXTRACTION BY MEANS OF DOWN-PUMP WITH SIMULTANEOUS CLEANING OF TUBING STRING BY FLYING SCRAPER AND INSTALLATION FOR ITS IMPLEMENTATION Russian patent published in 2003 - IPC

FIELD: oil production, cleaning of internal surface of tubing strings from wax-gum accumulation in process of operation of wells. SUBSTANCE: process of oil extraction by means of down-pump with flying scraper includes lift of oil over tubing string with their simultaneous cleaning by flying scraper under working mode, additional cleaning of tubing string by flying scraper during its downward stroke under its own weight to stop anchor, simultaneous lift of oil over production string under cleaning mode. Process is controlled with transfer of well to cleaning mode by opening of shut-off device in hole clearance line and closing of shut-off device in tubing string line with subsequent transfer of well to working mode after expiry of specified time interval by opening of shut-off device in tubing string line and closing of shut-off device in hole clearance line. Installation for extraction of oil by means of down-pump with simultaneous cleaning of tubing string by flying scraper includes tubing string and production string forming hole clearance. Internal space of tubing string communicates with hole clearance through overflow hole. Production string is equipped with shut-off device installed in hole clearance line. Packer is set in hole clearance below overflow hole. Control station has capability to open and close shut-off devices in tubing string line and in hole clearance line. Down-pump is positioned in tubing string below overflow hole. EFFECT: enhanced efficiency of extraction potential of wells and efficiency of their cleaning. 2 cl, 1 dwg