CUTTING TOOL Russian patent published in 2007 - IPC E21B29/06 

FIELD: drilling equipment, particularly cutting tool using whipstock, for example directional window cutters for whipstock operations.

SUBSTANCE: cutting tool has cutting and guiding parts. Cutting part is made as cutter for window forming in casing pipes. Cutting part comprises hollow body with flushing channel extending along body axis and flushing orifices arranged in lower part thereof, as well as side and end working surfaces covered with cutting abrasive covering. Guiding part is made as wedge whipstock having inclined working surface. Cutter body is split and includes upper and lower parts. Lower cutter part has end shaped as regular pyramid with one or two rows of hard-alloy cutting members connected thereto. Cutting abrasive layer is fused on cutting member faces. Upper cutter part has variable cross-section. Upper part end is of cylindrical shape. Body section located over the end is shaped as truncated pyramid provided with cutting abrasive layer applied to faces thereof. Next upper body section is shaped as spherical polyhedron with faces defining irregular trapeze in cross-section. One or two rows of cutting members are secured to lower side surfaces of the faces. Applied over the cutting members is cutting abrasive coating. Upper and lower parts are connected with each other by means of X-shaped spline connection and are retained with bolt inserted in orifice made under flushing channel of lower part. Annular support is created at interface between inner flushing orifice diameter and outer diameter of orifice for bolt receiving. Hollow spring member and T-shaped bolt head are arranged on the support. Vertical part of the head is over horizontal part and has diameter equal to that of bolt body. Flushing orifices are made in upper section. Shear bolt is inserted in threaded orifice between end working cutter surfaces and in intermediate member shaped as bush. One bush section is made as truncated cone with inner thread and projects over wedge whipstock surface.

EFFECT: extended capabilities, simplified assemblage and improved service performance.

11 dwg