U.S. patent application number 14/396582 was filed with the patent office on 2015-04-23 for slip assembly.
The applicant listed for this patent is McCoy Corporation. Invention is credited to Jonathan Ancelet, Vetsouvanh Malathong.
Application Number | 20150107856 14/396582 |
Document ID | / |
Family ID | 49482068 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150107856 |
Kind Code |
A1 |
Malathong; Vetsouvanh ; et
al. |
April 23, 2015 |
SLIP ASSEMBLY
Abstract
A gripping system is taught for gripping oil well casing, casing
string or other string comprising one or more slips cammed against
one or more inclined recesses when the gripping system is rotated
to maintain gripping engagement of the casing. A further gripping
system is taught for gripping oil well casing, casing string or
other string comprising one or more slips received into one or more
inclined recesses. A method is taught for gripping casing sections
or casing strings. The method comprises the steps of providing a
gripping system comprising one or more recesses and one or more
slips, setting said one or more slips on the casing section and
rotating the gripping system to cam said one or more slips against
said one or more inclined recesses, wherein camming said one or
more slips against said one or more inclined recesses serves to
maintain gripping engagement on the casing. A further method is
taught for gripping casing sections or casing strings. The method
comprises the steps of receiving a slip into each of one or more
inclined recesses of a gripping system, setting said one or more
slips on the casing section and rotating the gripping system.
Inventors: |
Malathong; Vetsouvanh;
(Broussard, LA) ; Ancelet; Jonathan; (Broussard,
LA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
McCoy Corporation |
Edmonton |
|
CA |
|
|
Family ID: |
49482068 |
Appl. No.: |
14/396582 |
Filed: |
April 25, 2013 |
PCT Filed: |
April 25, 2013 |
PCT NO: |
PCT/CA2013/000411 |
371 Date: |
October 23, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61638057 |
Apr 25, 2012 |
|
|
|
Current U.S.
Class: |
166/382 ;
166/75.14 |
Current CPC
Class: |
E21B 34/02 20130101;
E21B 17/042 20130101; E21B 19/06 20130101; E21B 17/046 20130101;
E21B 19/10 20130101; E21B 17/00 20130101; E21B 33/0422 20130101;
E21B 19/07 20130101 |
Class at
Publication: |
166/382 ;
166/75.14 |
International
Class: |
E21B 19/07 20060101
E21B019/07; E21B 33/04 20060101 E21B033/04; E21B 17/00 20060101
E21B017/00 |
Claims
1. A gripping system for gripping oil well casing, casing string or
other string comprising one or more slips cammed against one or
more inclined recesses when the gripping system is rotated to
enhance gripping engagement of the casing.
2. The gripping system of claim 1, wherein the one or more inclined
recesses capture at least a portion of the one or more slips.
3. The gripping system of claim 2, wherein at least an axial
portion of said one or more inclined recesses surrounds greater
than 180 degrees of the one or more slips.
4. The gripping system of claim 3, wherein the one or more slips
have a smaller cross section than said one or more inclined
recesses.
5. The gripping system of claim 4, wherein rotation of the gripping
system serves to rotate a front face of the one or more slips and
to cam a rear face of the one or more slips against the one or more
inclined recesses.
6. The gripping system of claim 2, wherein one or more recesses
have a cross sectional geometry selected from the group consisting
of partial circles, partial rectangles, partial squares, partial
ovals, partial rhomboids and partial triangles.
7. The gripping system of claim 6, wherein at least a portion of
the one or more inclined recesses have a part cylindrical geometry
and at least a portion of the one or more slips have a
corresponding cylindrical geometry.
8. The gripping system of claim 1, wherein the one or more inclined
recesses are housed in a seat.
9. The gripping system of claim 8, wherein the seat has geometry
selected from conical and cylindrical.
10. The gripping systems of claim 9, wherein the one or more
inclined recesses are uniformly spaced around the seat.
11. A gripping system for gripping oil well casing, casing string
or other string comprising one or more slips received into one or
more inclined recesses.
12. The gripping system of claim 11, wherein at least a portion of
the one or more slips are captured by the one or more inclined
recesses.
13. The gripping system of claim 12, wherein the one or more
recesses comprise a cross sectional geometry for at least a portion
of the axial length thereof that surrounds greater than 180 degrees
of the one or more slips.
14. The gripping system of claim 11, wherein the one or more slips
have a smaller cross section than said one or more inclined
recesses.
15. The gripping system of claim 14, wherein rotation of the
gripping system serves to rotate a front face of the one or more
slips and to force a rear face of the one or more slips against the
one or more inclined recesses.
16. The gripping system of claim 11, wherein one or more recesses
have a cross sectional geometry selected from the group consisting
of partial circles, partial rectangles, partial squares, partial
ovals, partial rhomboids and partial triangles.
17. The gripping system of claim 16, wherein at least a portion of
the one or more inclined recesses have a part cylindrical geometry
and at least a portion of the one or more slips have a
corresponding cylindrical geometry.
18. The gripping system of claim 17, wherein at least a portion of
the axial length of the inclined recess has a cross sectional
geometry that is more than a semi-circle.
19. The gripping system of claim 11, wherein the one or more
inclined recesses are housed in a seat.
20. The gripping system of claim 19, wherein the seat has geometry
selected from conical and cylindrical.
21. The gripping systems of claim 20, wherein the one or more
inclined recesses are uniformly spaced around the seat.
22. A method of gripping casing sections or casing strings, said
method comprising the steps of: a) providing a gripping system
comprising one or more recesses and one or more slips; b) setting
said one or more slips on the casing section; and c) rotating the
gripping system to cam said one or more slips against said one or
more inclined recesses, wherein camming said one or more slips
against said one or more inclined recesses serves to enhance
gripping engagement on the casing.
23. The method of claim 22, wherein the one or more slips are at
least partially captured by the one or more inclined recesses.
24. The method of claim 23, wherein the one or more recesses
comprise a cross sectional geometry on at least a portion of the
axial length thereof that surrounds greater than 180 degrees of the
one or more slips.
25. The method of claim 24, wherein the one or more slips are
cylindrical and wherein at least a portion of the axial length of
the one or more inclined recesses has a cross sectional geometry
that is more than a semi-circle.
26. The method of claim 25, wherein the one or more slips have a
smaller cross section than said one or more inclined recesses.
27. The method of claim 26, wherein rotation of the gripping system
serves to rotate the one or more slips and to cam a rear face of
the one or more slips against the one or more inclined
recesses.
28. A method of gripping casing sections or casing strings, said
method comprising the steps of: a) receiving a slip into each of
one or more inclined recesses of a gripping system; b) setting said
one or more slips on the casing section; and c) rotating the
gripping system.
29. The method of claim 28, wherein the one or more slips are at
least partially captured by the one or more inclined recesses.
30. The method of claim 29, wherein the one or more recesses
comprise a cross sectional geometry on at least a portion of the
axial length thereof that surrounds greater than 180 degrees of an
axial surface of the one or more slips.
31. The method of claim 30, wherein the one or more slips are
cylindrical and wherein at least a portion of the axial length of
the one or more inclined recesses has a cross sectional geometry
that is more than a semi-circle.
32. The method of claim 31, wherein the one or more slips have a
smaller cross section than said one or more inclined recesses.
33. The method of claim 32, wherein rotation of the gripping system
serves to rotate the one or more slips and to cam a rear face of
the one or more slips against the one or more inclined recesses.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a slip assemblies and
methods for gripping casing joints and casing strings.
BACKGROUND
[0002] Slip assemblies are well known in the down-hole drilling and
oil and gas industry. Slip assemblies are used to grip casing
sections or strings, also called tubulars or piping, for a number
of purposes including drilling, making up or breaking out casing
strings and performing operations to produce oil from the well.
Casing strings are made up by connecting multiple threaded casing
sections together and feeding them into the wellbore. Rotation of a
first casing into a second casing is conducted until the thread
male and female ends engage one another.
[0003] The gripping mechanism of the slip assembly must be able to
carry large loads and in certain operations including make up or
break out operations do so while rotationally gripping the casing
section or casing string. The components of the slip assembly must
also cooperate to set and unset with ease and to maintain a fully
set position on the casing section or casing string during
torqueing and rotation.
[0004] While a number of prior art patents including U.S. Pat No.
6,631,792, U.S. Pat. No. 7,891,469 and U.S. Pat. No. 7,775,270
teach slip assemblies with means of guiding a slip into engagement
with a casing section. However these patents do not address means
of maintaining gripping of the casing during rotation and torqueing
of the slip assembly for any number of operations including casing
make up and break out or any operation involving rotation and
torqueing where axial loads may exist.
[0005] A need and interest therefore exists in the art to develop
improved slip assemblies and gripping systems and methods for
making up casing strings.
SUMMARY
[0006] A gripping system is taught for gripping oil well casing,
casing string or other string comprising one or more slips cammed
against one or more inclined recesses when the gripping system is
rotated to enhance gripping engagement of the casing.
[0007] A further gripping system is taught for gripping oil well
casing, casing string or other string comprising one or more slips
received into one or more inclined recesses.
[0008] A method is taught for gripping casing sections or casing
strings. The method comprises the steps of providing a gripping
system comprising one or more recesses and one or more slips,
setting said one or more slips on the casing section and rotating
the gripping system to cam said one or more slips against said one
or more inclined recesses, wherein camming said one or more slips
against said one or more inclined recesses serves to enhance
gripping engagement on the casing.
[0009] A further method is taught for gripping casing sections or
casing strings. The method comprises the steps of receiving a slip
into each of one or more inclined recesses of a gripping system,
setting said one or more slips on the casing section and rotating
the gripping system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will now be described in greater
detail, with reference to the following drawings, in which:
[0011] FIG. 1 is an isometric view of a part of the slip assembly
of the present invention;
[0012] FIG. 2 is an isometric view of further parts of the slip
assembly of the present invention;
[0013] FIG. 3 is an isometric view of yet further parts of the slip
assembly of the present invention;
[0014] FIG. 4 is an isometric view of yet further parts of the slip
assembly of the present invention; and
[0015] FIG. 5 is a top plan view of one embodiment of the present
slip assembly.
DESCRIPTION OF THE INVENTION
[0016] The slip assembly of the present invention, also called a
gripping system can be used in conjunction with a number of tools
known in the field of oil well completion and production. These
tools include but are not limited to elevators, spiders, flush
mount spiders, snubbing tools, bucking units and back up tongs. The
present slip assemblies can be used in relation to any operations
involving hoisting and rotation of a casing string or casing
section or in any operation in which a casing string, casing
section or tubular of any kind is torqued or rotated while under
axial loading forces. These operations include but are not limited
to casing make up or break out "drilling with casing", snubbing
operations and horizontal wellbore operations.
[0017] The slip assemblies of the present invention are preferably
actuated by one or more cylinders (not shown) that extend to set
one or more gripping members of the slip assembly and retract to
release said gripping members. Other means of actuation are also
possible and would be understood by a person of skill in the art to
be encompassed by the scope of the present invention
[0018] The present slip assembly or gripping system 14 is now
described with references to FIGS. 1 to 5.
[0019] The seat 16 of the gripping system 14 preferably comprises
an array of one or more separate inclined elements 30 for receiving
slips 18.
[0020] In a further preferred embodiment, the inclined elements 30
comprise one or more integral or non-integral means of laterally
retaining the slips 18 in the inclined elements 30, in such a way
that the slips 18 are prevented from falling or tipping towards a
central bore of the casing gripping system 14. Examples of
non-integral retaining means include but are not limited to strips,
plates, clips, cages, bars, tabs and rings that can be removably
attached to at least a portion of the slip 18 and at least a
portion of the seat 16 to laterally retain the slip 18 to the
inclined element 30. Integral retaining means can include but are
not limited to mating profiles on at least a portion of the slip 18
and on at least a portion of the inclined elements 30 that connect
to hold the slip 18 to the inclined element 30; such mating
profiles can include shiplap profiles, tongue-and-groove profiles,
dovetail profiles or other profiles well known in the art.
[0021] As seen in FIGS. 1 and 2, the inclined elements 30 can more
preferably be in the form of an array of one or more inclined
recesses 90 that correspond to a rear face 32 of the slips 18,
thereby generating radially inward movement of the slips 18 to grip
the casing joint 10 as the slips 18 are disposed longitudinally
within inclined recesses 90, without the need for separate tracks,
cam followers, springs or other means.
[0022] Preferably, the inclined recesses 90 have a cylindrical
geometry and part-circular cross section to match a cylindrical
geometry and part circular cross section of the slips 18. It is
also possible for the inclined recesses 90 and slips 18 to have
cross sections that are partial rectangles, partial squares,
partial ovals, partial rhomboids and partial triangles or other
cross-sectional geometries.
[0023] In a preferred embodiment, the inclined recesses 90 can
comprise an integral retaining means along at least a portion of
the axial length of the inclined recess 90. In one example, at
least a portion of longitudinal edges 92 of the inclined recesses
90 comprise an integral throat, tab or strip that act to restrict
the size of the mouth 94 of the inclined recess 90, to thereby
capture slips 18 and laterally retain slips 18 from falling or
tipping into the central bore of the seat 16.
[0024] In a further preferred embodiment, the inclined recesses 90
are machined to a cross sectional geometry that restricts the mouth
94 of the inclined recesses 90 to be smaller than the widest cross
section of the slip 18. In this embodiment the recesses 90 function
to partially circumferentially capture the slips 18. To effect this
embodiment, at least a portion of the axial length of the inclined
recesses 90 is machined such that the desired cross sectional
geometry converges to restrict mouth 94. In the preferred case of a
partial circle cross-section, at least a portion of the axial
length of the inclined recess 90 is formed as more than half of a
circle, otherwise put, more than a semi-circle, to provide a
restriction to mouth 94 such that the slip 18 cannot fall into the
central bore of the seat 16.
[0025] In a preferred embodiment of the present invention, the
slips 18 and the recesses 90 interact in such a way as to enhance
gripping forces on the casing section 10 during rotation. In a
preferred embodiment, the slips 18 are caused to cam or wedge into
the recesses 90 to thereby maintain a firm penetration of the dies
20 in the slips 18 and a firm grip of the outer surface of the
casing section 10 by the dies 20 during casing make up or break out
operations.
[0026] Most preferably slips 18 are nominally smaller in cross
section than inclined recesses 90. When the slips 18 and dies 20 of
the present gripping system 14 are set on the casing section 10 to
be made up, the top drive is rotated to rotate gripping system 14.
During rotation, gripping torque causes the slightly smaller slip
18 to advantageously rotate slightly. This results in a line of
force in which the dies 20 are forced into a front face 36 of the
slips 18, in turn forcing a rear face 32 of the slip to cam into
and against the inclined recesses 90. This serves to further
frictionally arrest the dies 20 into the slips 18, and the slips 18
into the inclined recesses 90, and thereby enhances frictional
engagement of the dies to the casing section 10 during make up and
break out operations.
[0027] Although present seat 16 is preferably shown as having a
conical form, it would be well understood by a person of skill in
the art that numerous alternative forms of seats 16 are possible
that would cause the slips 18 to bias radially inwardly as they
move axially down the seat 16. For example, the seat 16 may
alternatively have a cylindrical form comprised of one or more
inclined elements 30.
[0028] Preferably, the inclined recesses 90 are uniformly spaced
around the seat 16. Most preferably, the inclined recesses 90 are
arranged in diametrically opposing pairs.
[0029] The dies 20 of the present invention are illustrated in a
preferred embodiment in FIGS. 2 and 3. Most preferably each slip 18
comprises three dies 20 arranged axially along the slip 18. Support
means are provided to support the dies 20 on the slips 18. A most
preferred embodiment of dies 20 and slips 18 is depicted in FIGS. 3
and 4, in which independent axial load transfer keys or tongues 34
are formed on a front face 36 of the slip 18 that are received in
corresponding load transfer grooves 38 formed on a rear face 40 of
the dies 20. A front face 42 of the dies 20 can have any number of
profiles and gripping surfaces well known in the art to engage and
grip a range of casing joint diameters. The profile may be concave
or may be any suitable profile to capture a tubular member when the
die 20 comes in contact with such member. Examples of such profiles
are well known in the art and would be understood by a skilled
practitioner to be included in the scope of the present invention.
If concave, the profile of the front face 42 of the dies 20 may
preferably have a singular radius of curvature, or a compound
radial profile comprising one or more profile sections each having
the same or different radii of curvature with either the same or
different centers. The surface of the front face 42 of the die 20
may be smooth or may be textured, scored, etched or ridged to
provide further gripping of the casing joint 10.
[0030] In the foregoing specification, the invention has been
described with a specific embodiment thereof; however, it will be
evident that various modifications and changes may be made thereto
without departing from the broader spirit and scope of the
invention.
* * * * *