DEVICE FOR OIL WELL FLOW STRING CLEANING OF PARAFFIN, PISTON AND SCRAPER INCLUDED IN THE DEVICE (VARIANTS) Russian patent published in 2007 - IPC E21B37/00 

FIELD: oil production, particularly methods or apparatus for cleaning boreholes or wells provided with centrifugal electric pumps.

SUBSTANCE: device comprises winch with drum and electric drive, flexible member, namely wire, having scraper at wire end and control system. Another scraper is secured to lower part of the first one to create scraper pair. Weight and another scraper pair are serially arranged one under another and connected to the first scraper pair. Said components create hanged cleaning complex. Cleaning scraper pair, weight, piston and another scraper pair are strung on wire to create flying cleaning complex. Wire passes over control system roller at well outlet and is wound about winch drum. Piston made in accordance with the first embodiment comprises body, labyrinth packing and valve. Labyrinth packing is made as a number of elastomeric sleeves serially installed on hollow body and having T-shaped cross-sections. Valve is made as plate put on thick-walled pipe. Piston formed in accordance with the second embodiment has labyrinth packing made as a row of elastomeric sleeves serially installed on hollow body with cylinder and seat. The sleeves are composite and reinforced with resilient steel wire in meridional direction. Scraper in accordance with the first variant comprises body with connection units, two movable members with blades and four spikes. The body is hollow and has box-like cross-section. Connection units have axial channels. Movable U-shaped members tightly enclose the body by sides thereof and are spring-loaded with respect to the body. Scraper in accordance with the second variant also comprises end plates having four grooves and area parallel to longitudinal scraper axis. The grooves mate the spikes secured to two movable members in pairs. Each movable member is spring-loaded with respect to the body in working scrape stroke direction.

EFFECT: provision of continuous cleaning of total inner flow string surface due to working medium flow usage in flow string, possibility of vibration paraffin layer cutting from inner flow string surface.

10 cl, 18 dwg