METHOD FOR LIQUIDATION OF HYDRATE AND PARAFFIN SEDIMENTS AND PLUGS IN OIL AND GAS WELLS Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: according to method, lowered into well down to upper limit of plug is cylindrical electric heater fastened to current-conducting cable connected to power source. Sediment and plug material is heated and transferred into molten state. Electric heater is moved down into depth of well as sediment material is being molten. After sediment and plug material is destructed, electric heater is lifted from well. Heating and melting of hydrate and paraffin sediments and plugs in well being cleaned are carried out with successive lowering and lifting initially of first, then of next electric heater but not less than of two electric heaters. Diameter of first electric heater is 0.22-0.43 of internal diameter of well being cleaned. Diameter of last electric heater is 0.44-0.78 of internal diameter of well being cleaned. Well is cleaned from molten sediments and plugs by means of scraper installed above electric heater with lifting of electric heater from well. Diameter of scraper on first electric heater is 0.28-0.48 of internal diameter of well being cleaned. Diameter of scraper on last electric heater is 0.57-0.87 of internal diameter of well being cleaned. Cleaning of well from molten sediments and plugs is performed by scraper with simultaneous heating of sediment and plug locations by electric heater. Diameter of scraper is 1.12-1.28 of diameter of electric heater used in operation. At leading of first electric heater through well being cleaned, recorded are locations of sediments and plugs along depth of well being cleaned. At subsequent operations, electric heater and scraper are moved downwards and upwards at these locations in well. Application of aforesaid method improves reliability and efficiency of removing hydrate and paraffin sediments and plugs in well. EFFECT: higher efficiency. 3 cl