TAR-PARAFFIN DEPOSIT REMOVAL DEVICE Russian patent published in 2007 - IPC E21B37/02 

FIELD: oil production, particularly equipment adapted to clean inner tubing string surface of paraffin deposits used in wells provided with submersed electric-centrifugal pumps in the case of gaslift or natural flow production.

SUBSTANCE: device comprises body formed of guiding rods and of coaxial annular movement limiters and cleaning means. One movement limiter is bypass valve seat. The cleaning means is installed on the body and may slide between limiters in longitudinal direction. The cleaning means is made as spiral knives having ends fixedly connected to two coaxial annular support bushes. One bush has bypass valve clack. Device additionally has bypass valve clack control mechanism, which reacts on temperature and/or pressure change and includes serially installed longitudinal movement drive and movement direction converter, which are arranged between support bushes of cleaning means. Longitudinal movement drive and movement direction converter are connected with each other and with the body. Longitudinal movement drive is substantially fixedly secured to guiding means. Movement direction converter pivotally cooperates with body guiding means and pivotally connected with support bush provided with valve clack.

EFFECT: increased operational stability.

6 cl, 4 dwg