METHOD FOR CLEANOUT OF TUBING STRING CAVITY FROM ASPHALT, RESIN AND PARAFFIN DEPOSITS Russian patent published in 2015 - IPC B08B9/00 

FIELD: oil and gas industry.

SUBSTANCE: while cleaning tubing string cavity using heated working fluid the tubes (1, 2, 3, 4) are assembled in sequence and placed into a closed system that includes a pump (7), a tank for working fluid treatment (8), a heating element (12) and a tank for deposits collection (10). Then the working fluid is heated up to 35-50°C and supplied under pressure of 2-4 atm to the closed system arranging its circulation through cavity of the tubes. Aqueous solution containing non-ionic and amphoteric surfactants, alkali components and complexing agents is used as the working fluid and separated paraffin is removed from the tank for deposits collection. Elements of the closed system are interconnected by quick-detachable tight joints (6). High degree of the flow string cavity cleanout is attained due to circulation of the working fluid with the preset composition in heated condition inside the contaminated tubes through the closed system.

EFFECT: high degree of cleanout for cavity of heavily contaminated tubes at low energy costs of the method implementation.

2 cl, 1 dwg