EP0353962A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Casing cutters
Assignee: Tri State Oil Tool UK Ltd
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Filing: 1989-07-28
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Granted: —
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Expires: 2009-07-28
Abstract
Abstract There is described a casing cutter of the type having a pivotable milling arm (10) which pivots outwards to trace a substantially conical path during rotation of the cutter. The milling arm is provided with an effective cutting edge (18, 20) which has an offset with respect to a notional axial reference line of the arm which passes through the pivot axis of the arm. The offset of each cutting edge is a distinct combination of circumferential offset and radial offset from the notional axial reference line so that a different effective cutting edge is presented to the casing to be cut when the cutter is used to cut a plurality of concentric casings of different diameters.
Inventors
- 👤 Thomas Doig
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 13:34
CPC Classifications
E; E21; E21B; E21B29/00; E21B29/002; E21B29/005; E21B10/00; E21B10/26; E21B10/32; E21B10/322
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
155 words
A casing cutter of the type comprising at least one milling arm which in use pivots outwards of the cutter about a pivot axis to trace a substantially conical path during rotation of the cutter about a rotation axis, the cone angle of the conical path with respect to the rotation axis increasing with increasing diameter of a casing being cut in use of the cutter, the or each milling arm having a plurality of effective cutting edges each having a respective offset with respect to a notional axial reference line of the arm which passes through the respective pivot axis of that arm, the offset of each effective cutting edge being a distinct combination of circumferential offset and radial offset from the respective notional axial reference line whereby a different effective cutting edge is presented to each casing when the cutter is in use to cut a plurality of concentric casings of different diameters.
Claim 2
Dependent Claim
155 words
A casing cutter of the type comprising at least one milling arm which in use pivots outwards of the cutter about a pivot axis to trace a substantially conical path during rotation of the cutter about a rotation axis, the cone angle of the conical path with respect to the rotation axis increasing with increasing diameter of a casing being cut in use of the cutter, the or each milling arm having a plurality of effective cutting edges each having a respective offset with respect to a notional axial reference line of the arm which passes through the respective pivot axis of that arm, the offset of each effective cutting edge being a distinct combination of circumferential offset and radial offset from the respective notional axial reference line whereby a different effective cutting edge is presented to each casing when the cutter is in use to cut a plurality of concentric casings of different diameters.
Claim 3
Dependent Claim
19 words
A casing cutter as claimed in Claim 1, wherein each effective cutting edge is a substantially continuous cutting edge.
Claim 4
Dependent Claim
36 words
A casing cutter as claimed in Claim 1, wherein each effective cutting edge comprises a number of individual cutters mounted in a row to present respective individual cutting edges which collectively form said effective cutting edge.
Claim 5
Dependent Claim
17 words
A casing cutter as claimed in any preceding claim, wherein the effective casing edge is substantially linear.
Claim 6
Dependent Claim
21 words
A casing cutter as claimed in any preceding claim, wherein the cutter has three milling arms symmetrically arranged on the cutter.
Claim 7
Dependent Claim
31 words
A casing cutter as claimed in any preceding claim, wherein the pivot axes of the milling arms are tangential to a common circle co-axial with the rotation axis of the cutter.
Claim 8
Dependent Claim
59 words
A casing cutter as claimed in any preceding claim, and including a piston axially movable in response to hydraulic pressure within a drill string of which a cutter forms part in use of the cutter, the piston linking with each milling arm so that axial movement of the piston in one direction forces each milling arm to pivot outwards.
References Cited (Backward Citations)
No citation records indexed.
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