BLADE REAMER Russian patent published in 2009 - IPC E21B7/28 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to drilling. It can be used for borehole or gas well calibration. The blade reamer consists of integral body with attaching tool-joint threads, and slave unit including four blades and sludge-discharge notches between the blades. Hard-alloy inserts are fixed in the blades. The body is integral with the blades. Along blades there are provided dovetail grooves. They contain preloaded, though reciprocating when fixed in grooves, set of profiled spring-elastic segments with trapezoidal cross-section. Lateral faces of the segments have shaped through-holes formed symmetrically by both sides from trapeze base. Upper part of the segment is provided with V-shaped conic grooves. The segment contains at least three circular cylinder hard-alloy inserts. Shaped through-hole in the segment is generated with: trapeze base and scallops of various circle radiuses. Hard-alloy inserts are mounted on trapeze base in the segment and snugly embraced with scallops in the shaped hole, soldered in the segments and blade grooves to working surface of the blade. Besides hard-alloy inserts, working surface of the blades is provided with antifriction coating flush with hard-alloy inserts.

EFFECT: higher performance, extended application, enhanced calibration and higher development rate.

8 dwg