U.S. patent application number 11/862295 was filed with the patent office on 2009-04-02 for cast slip with preset carbide buttons.
Invention is credited to John D. Fothergill.
Application Number | 20090084516 11/862295 |
Document ID | / |
Family ID | 40506859 |
Filed Date | 2009-04-02 |
United States Patent
Application |
20090084516 |
Kind Code |
A1 |
Fothergill; John D. |
April 2, 2009 |
Cast Slip with Preset Carbide Buttons
Abstract
A slip for support of a downhole tool is cast with inserts
positioned in the mold. The inserts can have a unique shape to
allow them to be retained in the cast slip while having the proper
position relative to each other and proper extension and
orientation. A placement tool is envisioned to allow sets of
inserts to be initially placed in the mold at one time and released
from the tool.
Inventors: |
Fothergill; John D.;
(Missouri City, TX) |
Correspondence
Address: |
DUANE MORRIS LLP - Houston
3200 SOUTHWEST FREEWAY, SUITE 3150
HOUSTON
TX
77027
US
|
Family ID: |
40506859 |
Appl. No.: |
11/862295 |
Filed: |
September 27, 2007 |
Current U.S.
Class: |
164/110 |
Current CPC
Class: |
B22D 19/00 20130101 |
Class at
Publication: |
164/110 |
International
Class: |
B22D 19/00 20060101
B22D019/00 |
Claims
1. A method of producing a slip with at least one insert for
downhole use, comprising: providing a mold having at least one
opening; placing an insert in said opening so that at least a
portion thereof extends outside said mold; adding material for the
slip into said mold to fixate said insert.
2. The method of claim 1, comprising: supporting said insert from
outside said mold as it extends through said opening.
3. The method of claim 1, comprising: supporting said insert from
inside said mold as it extends through said opening.
4. The method of claim 1, comprising: supporting said insert from
said opening as it extends through said opening.
5. The method of claim 4, comprising: using an interference fit
between said insert and said opening to support said insert during
said adding material.
6. The method of claim 1, comprising: providing an irregular shape
on a portion of said insert disposed in said mold.
7. The method of claim 1, comprising: providing a plurality of
openings in said mold; inserting a plurality of inserts into said
openings at one time.
8. The method of claim 7, comprising: securing a plurality of
inserts to a rack; using said rack to install said inserts
together.
9. The method of claim 8, comprising: releasably mounting said
inserts to said rack; releasing said inserts from said rack after
installing them in said openings.
10. The method of claim 1, comprising: securing the insert to the
slip without welding or brazing.
11. The method of claim 1, comprising: forming said insert into a
t-shape having a transverse member and a shank; extending said
shank through said opening with said transverse member in said
mold.
12. The method of claim 1, comprising: providing a plurality of
openings in said mold; inserting the portion of said inserts that
extend beyond said openings in a mirror image orientation.
Description
FIELD OF THE INVENTION
[0001] The field of this invention is gripping members for downhole
tools and more particularly techniques for manufacturing slips that
have inserts in their grip faces.
BACKGROUND OF THE INVENTION
[0002] Gripping members for downhole tools such as packers have had
hardened inserts in them to enhance grip. The most common way of
building such parts is to fabricate the slip shape and then machine
holes in the manufactured shape. The inserts then are placed by
hand in each opening and secured to the opening usually by a
welding technique. Some examples of this technique can be seen in
U.S. Pat. Nos. 4,212,352; 6,899,183; 6,793,022 (FIGS. 11-13);
6,481,497 (FIG. 3C); 6,164,377, 6,378,606 and 5,984,007.
[0003] The problem with this technique is that it is expensive due
to the significant amount of hand labor and machining involved in
precisely locating the blind bores or through bores in small slips
and then properly fixating the insert in the intended location
while fixating it. This is further made more difficult by the small
size of the slip body and the close quarters mounting of the
inserts on the small body.
[0004] The present invention is a technique for producing such
slips more economically by assembling the inserts into a mold and
casting the slip with the inserts already in place and properly
positioned. The inserts can have unique shape to help retain them
in position during use. To further expedite the process, a fixture
can be used to retain all the inserts for a particular slip and
allow them all to be inserted in a proper placement in the mold.
These and other aspects of the present invention will be more
readily apparent to those skilled in the art from a review of the
detailed description and the associated drawings while recognizing
that the claims present the full scope of the invention.
SUMMARY OF THE INVENTION
[0005] A slip for support of a downhole tool is cast with inserts
positioned in the mold. The inserts can have a unique shape to
allow them to be retained in the cast slip while having the proper
position relative to each other and proper extension and
orientation. A placement tool is envisioned to allow sets of
inserts to be initially placed in the mold at one time and released
from the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a section view in a mold showing the inserts
uniquely configured to be retained in position after the pour;
and
[0007] FIG. 2 is a schematic illustration of the tool to allow
placement of a set of inserts into a mold at the same time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0008] FIG. 1 illustrates a two piece mold 10 and 12 where the
lower piece 12 has openings 14 to accept inserts such as 16 in a
specific orientation. Inserts 16 are preferably made of tungsten
carbide however other hard materials previously used for inserts
could also be used. Symbolically represented is a way to support
the inserts with respect to the mold lower 12 is a support 18 so
that the desired amount of extension of insert 16 is obtained
before the pour through inlet 20. Another way to get proper
extension and orientation is to size openings 14 such that friction
or an interference fit holds the inserts 16 in the proper extension
and orientation until the pour. Alternatively, an internal support
20 can hold each insert 16 at the proper offset from the bottom 24
of the mold lower portion 12. In the preferred embodiment, the
inserts 16 can have an irregular shape such as a larger head 26
that when spaced from the bottom 24 before the pour will result in
the slip being formed all around the head 26 and a portion of the
shank 28 to better fixate the insert 16. Other irregular shapes
that aid in insert 16 retention are contemplated.
[0009] FIG. 2 illustrates a tool 30 with a handle 32 that can grip
a plurality of inserts 16 and selectively release them with a quick
release feature 34 after the insertion into position as shown in
FIG. 1. The tool can be manually operated or manipulated
robotically as part of a mass production assembly when a belt (not
shown) brings the mold lower 12 into alignment with the tool 30.
Continuing the concept of automation, the mold upper 10 can be
joined to the mold lower 12 by another robot and the pour then
follows. The loading of inserts 16 into tools 30 can be done
manually or alternatively that process can also be automated. This
would involve getting the individual inserts 16 into the proper
orientation and grid pattern and engaging the array to a tool 30
that can then be robotically moved to engage a mold lower 12.
[0010] Welding brazing or adhesives do not need to be used in the
method. Various arrays of slips can be used. Arrays with slips
oriented to grip against forces in opposed direction are
contemplated. Mirror image arrays are possible.
[0011] The above description is illustrative of the preferred
embodiment and many modifications may be made by those skilled in
the art without departing from the invention whose scope is to be
determined from the literal and equivalent scope of the claims
below.
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