DEVICE FOR CLEANING OF INNER SURFACE OF TUBING STRING Russian patent published in 2013 - IPC E21B37/02 

FIELD: oil and gas industry.

SUBSTANCE: device contains upper 1 and lower 2 scrapers and sinker bar 3 interconnected along common longitudinal axis. Scrapers 1, 2 contain case 5 in the form of plates interconnected with turning of one plate relatively to another. In both planes from plates there's a pair of hinges 6, 7 and 8, 9 fixed rigidly at the same side in regard to longitudinal axis of the case, at identical distance from the axis and each other. Movable plates 10, 11 are fixed along longitudinal axis of the case 5 at hinges 6, 7 and 8, 9 by means of slots 12, 13 and 14, 15. At butt ends of plates 10, 11 cutters 16 and 17 are fixed rigidly as a flat frame having shape of parallelogram. Outer lateral edges of cutters 16, 17 are cutting edges sharpened at two sides. In space cutters of scrapers overlap each other. Housing of sinker bar 3 is made extended with through hole 20 at longitudinal axis. Calibrating band 4 and connected hinged member 19 of the lower scraper have axial bore that matches through axial hole in the housing of sinker bar completely.

EFFECT: raised efficiency of cleaning and reliability of device operation.

6 cl, 2 dwg