US 5,899,268 AGranted

Downhole milling tool

AssigneeBaker Hughes Incorporated

InventorsGerald D. Lynde, Harold H. Harvey

Life of this patent

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Abstract

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.

Claims11

Dependent claims

A milling 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;
and
a plurality of cutting surfaces at spaced intervals around said tool body;
wherein each said cutting surface comprises a plurality of cutting elements arranged in a predetermined pattern of rows extending generally transversely relative to said axis of rotation, and columns extending generally parallel to said axis of rotation, for presenting at least part of said cutting surface;
wherein each said cutting element is formed of a material harder than the metal to be cut and is of a predetermined size and shape;
wherein each said cutting element is positioned adjacent another said cutting element, and each said cutting element has an exposed cutting face including a first surface irregularity adjacent a lower edge of said cutting element and a second surface irregularity 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 interesting of the turnings;
and
whereby, together, said surface irregularities on said cutting elements cover a significant portion of said cutting surfaces on which the cutting elements are mounted.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/958,829Filed 28 Oct 1997 · continuation
Priority: 6 Jan 1986
Granted: 4 May 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

E21B 29/005
Cutting, e.g. milling, a pipe with a cutter rotating along the circumference of the pipe: with a radially-expansible cutter rotating inside the…
B23B 5/16
Turning-machines or devices specially adapted for particular work; Accessories specially adapted therefor: for bevelling, chamfering, or deburring…
B23B 5/168
Tools for chamfering the ends of bars or tubes: with guiding devices
B23P 15/28
Making specific metal objects by operations not covered by a single other subclass or a group in this subclass: cutting tools

Family

Serial816,287Parent of this continuation-in-part · filed 6 Jan 1986
Serial181,812Parent of this continuation · filed 15 Apr 1988
US 4,796,709 AParent of this continuation-in-part · filed 10 Jan 1989
Serial621,063Parent of this continuation-in-part · filed 3 Dec 1990
US 4,978,260 AParent of this continuation · filed 18 Dec 1990
Serial680,702Parent of this continuation · filed 4 Apr 1991
US 5,058,666 AParent of this continuation-in-part · filed 22 Oct 1991
Serial948,362Parent of this continuation-in-part · filed 21 Sep 1992
US 5,150,755 AParent of this continuation · filed 29 Sep 1992
Serial096,010Parent of this continuation · filed 22 Jul 1993
US 5,297,630 AParent of this continuation-in-part · filed 29 Mar 1994
Serial323,815Parent of this continuation · filed 17 Oct 1994
US 5,373,900 AParent of this continuation · filed 20 Dec 1994
Serial541,551Parent of this continuation · filed 10 Oct 1995
US 5,456,312 AParent of this continuation
US 5,899,268 AThis patent

From the US filing history. Foreign family members aren’t listed.