CORE LIFTER
A core lifter and method for making same for use in a drilling system. The core lifter can include a tubular body having an exterior surface and an interior surface and can have a plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter and extending radially inwardly relative to the central axis of the core lifter. The plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter can extend along at least 50 percent of the length of the core lifter.
1 . A method of forming a core lifter for use in a drilling system, the core lifter having a central axis, the method comprising:
forming a tubular body of the core lifter by stamping a sheet of material; and
forming a plurality of longitudinally-oriented recesses in an exterior surface of the tubular body of the core lifter by stamping the sheet of material, the plurality of longitudinally-oriented recesses extending radially inwardly relative to the central axis,
wherein the core lifter has a length, and wherein the plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter extend along at least 50 percent of the length of the core lifter.
2 . The method as in claim 1 , wherein the sheet of material comprises a metallic sheet.
3 . The method as in claim 1 , further comprising:
forming a plurality of longitudinally-oriented recesses in an interior surface of the tubular body of the core lifter by stamping the sheet of material.
4 . The method as in claim 3 , wherein the core lifter has a corrugated configuration.
5 . The method as in claim 4 , wherein the corrugated configuration of the core lifter is formed by the plurality of longitudinally-oriented recesses formed in the interior surface of the tubular body and the plurality of longitudinally-oriented recesses formed in the interior surface of the tubular body.
6 . The method as in claim 1 , wherein forming a tubular body of the core lifter comprises:
forming a corrugated configuration of the tubular body of the core lifter by stamping the sheet of material.
7 . The method as in claim 1 , wherein the tubular body of the core lifter is tapered.
8 . The method as in claim 1 , wherein the plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter are tapered.
9 . The method as in claim 1 , further comprising:
forming a plurality of longitudinally-oriented projections in the exterior surface of the tubular body of the core lifter.
10 . The method as in claim 9 , wherein the plurality of longitudinally-oriented recesses and projections formed in the exterior surface of the tubular body of the core lifter alternate.
11 . The method as in claim 1 , wherein the plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter extend along at least 80 percent of the length of the core lifter.
12 . The method as in claim 1 , further comprising:
forming at least one of a leading edge or a trailing edge of the core lifter at an oblique angle relative to the central axis of the core lifter.
13 . The method as in claim 1 , further comprising:
forming at least one of a leading edge or a trailing edge of the core lifter at a perpindicular angle relative to the central axis of the core lifter.
14 . The method as in claim 1 , further comprising:
forming a gripping surface on an exterior surface of the tubular body of the core lifter by stamping the sheet of material, the gripping surface being configured to grip a core sample; and
forming a raised contact feature of the core lifter by stamping the sheet of material, the raised contact feature extending inwardly away from the gripping surface.
15 . The method as in claim 14 , further comprising:
forming a flared skirt of the core lifter by stamping the sheet of material, the flared skirt extending outwardly from the raised contact feature, the flared skirt configured to limit movement of the core lifter relative to a core lifter case.
16 . The method as in claim 15 , wherein the flared skirt extends radially outwardly from the raised contact feature.
17 . The method as in claim 15 , wherein the flared skirt is adjacent the raised contact feature.
18 . The method as in claim 17 , wherein the gripping surface has an inner diameter; and
wherein the raised contact feature has an inner diameter that is smaller than the inner diameter of the gripping surface.
19 . The method as in claim 18 , wherein the raised contact feature has a generally rounded shape.
20 . The method as in claim 15 , further comprising:
forming a plurality of slots in the flared skirt to to facilitate resilient compression of the flared skirt and the raised contact feature.
21 . The method as in claim 20 , wherein the slots are configured to facilitate resilient compression of the flared skirt and the raised contact feature when a portion of the core sample is disposed within the core lifter and a tapered inner wall of the core lifter case exerts a force against the core lifter.
22 . A method of forming a core lifter for use in a drilling system, the core lifter having a central axis, the method comprising:
forming a tubular body of the core lifter by stamping a sheet of material;
forming a gripping surface on an exterior surface of the tubular body of the core lifter by stamping the sheet of material, the gripping surface being configured to grip a core sample;
forming a raised contact feature of the core lifter by stamping the sheet of material, the raised contact feature extending inwardly away from the gripping surface; and
forming a flared skirt of the core lifter by stamping the sheet of material, the flared skirt extending outwardly from the raised contact feature, the flared skirt configured to limit movement of the core lifter relative to a core lifter case.
forming a plurality of longitudinally-oriented recesses in an exterior surface of the tubular body of the core lifter by stamping the sheet of material, the plurality of longitudinally-oriented recesses extending radially inwardly relative to the central axis; and
23 . The method as in claim 22 , further comprising:
forming a plurality of longitudinally-oriented recesses in an exterior surface of the tubular body of the core lifter by stamping the sheet of material, the plurality of longitudinally-oriented recesses extending radially inwardly relative to the central axis.
24 . The method as in claim 23 , further comprising:
forming a plurality of longitudinally-oriented recesses in an interior surface of the tubular body of the core lifter by stamping the sheet of material.
25 . The method as in claim 24 , wherein the core lifter has a corrugated configuration.
26 . The method as in claim 25 , wherein the corrugated configuration of the core lifter is formed by the plurality of longitudinally-oriented recesses formed in the interior surface of the tubular body and the plurality of longitudinally-oriented recesses formed in the interior surface of the tubular body.
27 . The method as in claim 23 , wherein the tubular body of the core lifter is tapered.
28 . The method as in claim 23 , wherein the plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter are tapered.
29 . The method as in claim 23 , further comprising:
forming a plurality of longitudinally-oriented projections in the exterior surface of the tubular body of the core lifter.
30 . The method as in claim 23 , wherein the plurality of longitudinally-oriented recesses and projections formed in the exterior surface of the tubular body of the core lifter alternate.
31 . The method as in claim 23 , wherein the plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter extend along at least 50 percent of the length of the core lifter.
32 . The method as in claim 22 , wherein the flared skirt extends radially outwardly from the raised contact feature.
33 . The method as in claim 32 , wherein the flared skirt is adjacent the raised contact feature, and wherein the gripping surface has an inner diameter; and wherein the raised contact feature has an inner diameter that is smaller than the inner diameter of the gripping surface.
34 . The method as in claim 22 , further comprising:
forming a plurality of slots in the flared skirt to to facilitate resilient compression of the flared skirt and the raised contact feature,
wherein the slots are configured to facilitate resilient compression of the flared skirt and the raised contact feature when a portion of the core sample is disposed within the core lifter and a tapered inner wall of the core lifter case exerts a force against the core lifter.