METHOD AND DEVICE FOR SLOT HOLE FORMING IN CASING PIPE Russian patent published in 2008 - IPC E21B43/11 

FIELD: oil and gas industry, particularly perforators and permeators.

SUBSTANCE: method involves creating slot in casing pipe wall, in cement ring outside the casing pipe and in productive bed by means of rotary cutting tool by serial cutting tool movement relatively casing pipe correspondingly in radial direction due to metered cutting tool advancing in vertical direction caused by perforator movement. Device comprises body with cutting unit arranged in the body, mechanisms for cutting unit driving and advancing and body support units. Cutting member is supported by axis of two parallel flat rocking-arms to provide cutting member rotation. Advancing mechanism comprises hydraulic cylinder with spring-loaded piston rigidly connected with rod and lever hinged to rod and to flat rocking-arm axis. Support members of the body include two body hydraulic cylinders with spring-loaded leg pistons and two pairs of support rollers. Each hydraulic cylinder and each pair of support rollers are arranged in upper and lower body parts correspondingly. Support rollers of each pair are located from cutting unit side and are equidistant one from another so that the support rollers are spaced predetermined angles from cutting unit plane. Hydraulic cylinders with leg pistons are arranged from opposite side thereof.

EFFECT: increased perforation capability.

2 cl, 3 dwg