GEAR FOR SLIT PERFORATION OF CASED WELLS Russian patent published in 2000 - IPC

FIELD: oil and gas production, drilling and repair of oil and gas wells to create perforation conduits in casing string, cement stone and rock. SUBSTANCE: wt. % gear includes body, extendible cutting tool coming in the form of threading roll, spring-loaded cantilever, link, monitor extension piece, bearing rollers. It has thrust journal that contacts link and is located between link and cantilever joined by axle. Two holes of different diameters are drilled in body of gear. Hole of bigger diameter is fitted with stopper. Wedge-shaped groove is made in body at some angle with regard to its axis. Two separable plates are installed on its edges. They interact with sliders set freely on axle of threading roll between cheeks of link. Axle of roller is step-shaped and has smaller diameter of ends. It is placed in side grooves of body parallel to wedge-shaped groove. EFFECT: simplified design, convenient handling and reliable operation of gear. 2 dwg