DEVICE FOR CLEANING OF INNER SURFACE OF LIFTING PIPE (VERSIONS) Russian patent published in 2010 - IPC E21B37/02 

FIELD: oil and gas production.

SUBSTANCE: group of inventions relates to oil industry and may be used to remove deposits from surface of lifting pipes. Device comprises lengthy vessel, which simultaneously serves as weighting agent. Scrapers are rigidly fixed at the ends of vessel. Free end of upper scraper is movably fixed to swivel. Through hole is arranged in vessel in upper part. According to the first version: each scraper comprises two identical vertical knives in the form of symmetrical octahedron. Knives are rigidly joined at the right angle between each other along vertical axial line by means of groove made in each of knives along vertical axial line and further welding. Inclined knives are rigidly fixed on knives at the outside in the form of plate bent towards cleaned surface. The first inclined knife connects upper end of the first vertical edge of the first vertical knife with lower end of the first vertical edge of the second vertical knife, the second inclined knife connects lower end of the first vertical edge of the second vertical knife with upper end of the second vertical edge of the first vertical knife. According to the second version: each scraper comprises even number of at least four identical vertical knives in the form of half of flat frame having shape of octahedron symmetrical relative to its vertical and horizontal axes. Knives are rigidly fixed to each other by means of welding along vertical axis of scraper to form equal angles between their side surfaces.

EFFECT: increased quality of cleaning.

10 cl, 16 dwg