초록 ▼

A tool for cutting or milling casing in a well is disclosed. It includes a plurality of blades extending outwardly to a substantially radial position for cutting the walls of casing strings and removing a predetermined length of the casing strings in a cutting action. The blades have cutting element

A tool for cutting or milling casing in a well is disclosed. It includes a plurality of blades extending outwardly to a substantially radial position for cutting the walls of casing strings and removing a predetermined length of the casing strings in a cutting action. The blades have cutting elements positioned on leading faces of the blades to engage the casing strings in a cutting action without tripping or removal from the bore hole. The cutting elements can be arranged in rows and columns. The cutting elements can be shaped to continually present a sharp cutting edge to the object being milled. The cutting elements can be inclined at a negative axial rake angle to cause the metal chips cut from the object being milled to break off at short lengths. The cutting element can also have surface irregularities to cause the metal chips cut from the casings to break off at short lengths. The cutting element can also have stress relieving grooves to prevent the propagation of a crack across the face of the element.

대표청구항 ▼

[ We claim:] [1.] A cutting tool for removing metal from a wellbore, or other tubular bore, comprising:a tool body adapted to be received within the wellbore and to be supported at its upper end for rotation about its longitudinal axis;a plurality of cutting surfaces at spaced intervals around said

[ We claim:] [1.] A cutting tool for removing metal from a wellbore, or other tubular bore, comprising:a tool body adapted to be received within the wellbore and to be supported at its upper end for rotation about its longitudinal axis;a plurality of cutting surfaces at spaced intervals around said tool body;wherein each of said cutting surfaces comprises a plurality of cutting elements arranged in at least one column extending generally along the longitudinal direction of said tool body for presenting at least part of said cutting surface;wherein each of said cutting elements is formed of a material harder than the metal to be cut, is of a predetermined size and shape and is arranged in a predetermined columnar pattern;wherein each of said cutting elements has an exposed cutting face, with each said cutting face including a first groove portion adjacent a lower edge of said cutting element and a second groove portion adjacent an upper edge of said cutting element for directing an extending end portion of a turning cut from the metal to effect a breaking of the turning from the metal being cut in a predetermined manner to minimize internesting of the turnings; andwhereby, together, said cutting elements on each respective cutting surface present a plurality of said groove portions in a columnar pattern on said cutting surface.