CORE RECOVERY TOOL Russian patent published in 2006 - IPC E21B25/08 

FIELD: mining, particularly well drilling with core recovery and formation medium conservation.

SUBSTANCE: tool comprises body with connection sub, drilling head, core separation unit adapted to separate core from face; core lifter having closed top and suspended to frictionless bearing so that the core lifter may rotate. The frictionless bearing is covered with bell-shaped case filled with consistent grease. The core lifter is aligned inside the body by means of ball centrators. Plastic insert filled with thermoplastic insulating material, for instance with paraffin, is located inside the core lifter. Core separation unit comprises collet and lever-type corers, as well as corer case provided with outer annular grooves, which form labyrinth packing along with drilling head interior.

EFFECT: possibility to obtain core without contact thereof with flushing liquid, not contaminated with hydrocarbons and containing the most of formation fluids up to core removal from insert and cleaning of paraffin, reduced labor inputs and simplified tool structure.

2 cl, 2 dwg