U.S. patent application number 15/582201 was filed with the patent office on 2018-11-01 for friction lock assembly and retaining ring for wellhead.
The applicant listed for this patent is Cameron International Corporation. Invention is credited to Hao Bin Huang, Kevin P. Minnock, Kyle A. Sommerfeld.
Application Number | 20180313180 15/582201 |
Document ID | / |
Family ID | 63916488 |
Filed Date | 2018-11-01 |
United States Patent
Application |
20180313180 |
Kind Code |
A1 |
Sommerfeld; Kyle A. ; et
al. |
November 1, 2018 |
FRICTION LOCK ASSEMBLY AND RETAINING RING FOR WELLHEAD
Abstract
A locking assembly and a retaining ring for retaining the
locking assembly within a bore of a wellhead component are
provided. In one embodiment, a system includes an inner component
disposed within a bore of a wellhead component and a locking
assembly disposed within the bore to secure the inner component
within the bore. The locking assembly includes a lock ring that
extends into a recess in a wall of the bore of the wellhead
component and an actuator radially disposed between the inner
component and the lock ring. The system also includes a retaining
ring that limits movement of the actuator along the inner component
and maintains the actuator between the inner component and the lock
ring to retain the lock ring within the recess. The actuator and
the retaining ring have mating tapered surfaces that inhibit
movement of the actuator out of engagement with the lock ring.
Inventors: |
Sommerfeld; Kyle A.;
(Houston, TX) ; Minnock; Kevin P.; (Houston,
TX) ; Huang; Hao Bin; (Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cameron International Corporation |
Houston |
TX |
US |
|
|
Family ID: |
63916488 |
Appl. No.: |
15/582201 |
Filed: |
April 28, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 23/06 20130101;
E21B 23/02 20130101; E21B 43/10 20130101; E21B 33/04 20130101 |
International
Class: |
E21B 23/02 20060101
E21B023/02; E21B 33/04 20060101 E21B033/04 |
Claims
1. A system comprising: a wellhead component having a bore; an
inner component disposed within the bore of the wellhead component;
a locking assembly disposed within the bore between the inner
component and the wellhead component to secure the inner component
within the bore of the wellhead component, the locking assembly
including: a lock ring that extends into a recess in a wall of the
bore of the wellhead component; and an actuator radially disposed
between the inner component and the lock ring; and a retaining ring
positioned within the bore of the wellhead component so as to limit
movement of the actuator along the inner component and maintain the
actuator between the inner component and the lock ring to retain
the lock ring within the recess, wherein the actuator and the
retaining ring have mating tapered surfaces that inhibit movement
of the actuator out of engagement with the lock ring.
2. The system of claim 1, wherein the actuator includes a flange,
and the flange and the retaining ring have the mating tapered
surfaces that inhibit movement of the actuator out of engagement
with the lock ring.
3. The system of claim 1, wherein the retaining ring is a
multi-piece mechanism including an outer sleeve and an inner
sleeve, and the actuator and the inner sleeve of the retaining ring
have the mating tapered surfaces that inhibit movement of the
actuator out of engagement with the lock ring.
4. The system of claim 1, wherein the actuator includes an inner
sleeve radially disposed between the inner component and the lock
ring and an outer ring positioned about the inner sleeve, and the
outer ring and the retaining ring have the mating tapered surfaces
that inhibit movement of the actuator out of engagement with the
lock ring.
5. The system of claim 4, wherein the outer ring is carried on a
shoulder of the inner sleeve.
6. The system of claim 1, wherein the retaining ring is a landing
ring of a packoff.
7. The system of claim 1, wherein the retaining ring is positioned
within the bore on the lock ring of the locking assembly.
8. The system of claim 1, wherein the actuator has an interference
fit with the inner component to inhibit movement of the actuator
between the lock ring and the inner component.
9. The system of claim 1, wherein the inner component is a wellhead
hanger.
10. The system of claim 1, comprising a bearing ring between the
lock ring and a shoulder of the inner component.
11. A system comprising: a locking assembly to secure a device in a
bore of a wellhead component, the locking assembly including: a
lock ring; and an actuator configured to be radially disposed
between the device and the lock ring such that the actuator can be
moved axially in a first direction along the device to drive the
lock ring radially outward to a locked position in which the lock
ring secures the device within the bore of the wellhead component;
and a retaining ring, wherein the retaining ring and the actuator
having mating tapered surfaces that, when installed in the bore of
the wellhead component, limit axial movement of the actuator in
second direction, opposite the first direction, along the device so
as to facilitate retention of the actuator in engagement with the
lock ring in the locked position.
12. The system of claim 11, wherein the mating tapered surfaces
limit axial movement of the actuator in the second direction by
cooperating with one another so as to apply an increasing retention
load on the actuator as the actuator moves in the second
direction.
13. The system of claim 11, wherein the lock ring and the actuator
have additional mating tapered surfaces, and the mating tapered
surface of the actuator and the additional mating tapered surface
of the actuator are tapered in opposite directions.
14. The system of claim 11, wherein the actuator includes an outer
ring carried on an inner sleeve, and the outer ring and the
retaining ring have the mating tapered surfaces such that
engagement of the mating tapered surfaces causes the outer ring to
contract inwardly about the inner sleeve in response to axial
movement of the actuator in the second direction.
15. The system of claim 11, comprising the device, wherein the
device includes a wellhead hanger.
16. A method comprising: running a locking assembly into a bore of
a wellhead component, the locking assembly including a lock ring
and an actuator; driving the lock ring into engagement with the
wellhead component by moving the actuator between the lock ring and
an additional wellhead component to a locked position so as to
secure the additional wellhead component within the bore; lowering
a retaining ring into the bore of the wellhead component; and
positioning the retaining ring along the actuator such that a
tapered interface between the retaining ring and the actuator
opposes movement of the actuator along the additional wellhead
component toward an unlocked position.
17. The method of claim 16, wherein driving the lock ring into
engagement with the wellhead component by moving the actuator
between the lock ring and the additional wellhead component to the
locked position so as to secure the additional wellhead component
within the bore includes wedging the actuator between the lock ring
and the additional wellhead component so as to secure the
additional wellhead component within the bore via an interference
fit of the additional wellhead component with the actuator.
18. The method of claim 16, comprising running the additional
wellhead component into the bore with the locking assembly.
19. The method of claim 18, wherein running the additional wellhead
component into the bore includes running a wellhead hanger carrying
the locking assembly into the bore.
20. The method of claim 16, wherein lowering the retaining ring
into the bore includes lowering a packoff having the retaining ring
into the bore.
Description
BACKGROUND
[0001] This section is intended to introduce the reader to various
aspects of art that may be related to various aspects of the
presently described embodiments. This discussion is believed to be
helpful in providing the reader with background information to
facilitate a better understanding of the various aspects of the
present embodiments. Accordingly, it should be understood that
these statements are to be read in this light, and not as
admissions of prior art.
[0002] In order to meet consumer and industrial demand for natural
resources, companies often invest significant amounts of time and
money in finding and extracting oil, natural gas, and other
subterranean resources from the earth. Particularly, once a desired
subterranean resource such as oil or natural gas is discovered,
drilling and production systems are often employed to access and
extract the resource. These systems may be located onshore or
offshore depending on the location of a desired resource.
[0003] Further, such systems generally include wellhead assemblies
mounted on wells through which resources are accessed or extracted.
Such wellhead assemblies can include a wide variety of components,
such as various spools, casings, valves, pumps, fluid conduits, and
the like, that control drilling or extraction operations. In many
instances, casings are coupled to wellheads via hangers installed
in bores of the wellheads. These hangers and other components
within the bores can be retained in various ways, and sealing
packoffs can be used to seal annular spaces within the bores.
SUMMARY
[0004] Certain aspects of some embodiments disclosed herein are set
forth below. It should be understood that these aspects are
presented merely to provide the reader with a brief summary of
certain forms the invention might take and that these aspects are
not intended to limit the scope of the invention. Indeed, the
invention may encompass a variety of aspects that may not be set
forth below.
[0005] Embodiments of the present disclosure generally relate to
locking assemblies that can be used to secure components in bores
and to retaining rings for retaining the locking assemblies in
locked positions within the bores. In one embodiment, a locking
assembly is used to secure a hanger in a wellhead bore. The locking
assembly includes a lock ring and an actuator that is moved to a
locked position to drive the lock ring into engagement with a
mating surface to secure the hanger in the bore. A retaining ring
is positioned over the locking assembly to inhibit unsetting of the
actuator from the locked position. In at least some instances, the
retaining ring and the actuator have mating tapered surfaces that
cooperate to oppose movement of the actuator out of the locked
position.
[0006] Various refinements of the features noted above may exist in
relation to various aspects of the present embodiments. Further
features may also be incorporated in these various aspects as well.
These refinements and additional features may exist individually or
in any combination. For instance, various features discussed below
in relation to one or more of the illustrated embodiments may be
incorporated into any of the above-described aspects of the present
disclosure alone or in any combination. Again, the brief summary
presented above is intended only to familiarize the reader with
certain aspects and contexts of some embodiments without limitation
to the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features, aspects, and advantages of certain
embodiments will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0008] FIG. 1 is a block diagram of a system having a wellhead with
various components installed at a well in accordance with one
embodiment of the present disclosure;
[0009] FIG. 2 is an exploded view of a wellhead hanger apparatus
including a locking assembly and a retaining ring in accordance
with one embodiment;
[0010] FIGS. 3 and 4 are detail views of the wellhead hanger
apparatus of FIG. 2 installed within a wellhead component in
accordance with one embodiment;
[0011] FIGS. 5 and 6 show a wellhead hanger apparatus having a
retaining ring with inner and outer sleeves installed in the
wellhead component in accordance with one embodiment; and
[0012] FIGS. 7 and 8 depict a wellhead hanger apparatus having a
locking assembly with an actuator having an inner sleeve and an
outer ring installed in the wellhead component in accordance with
one embodiment.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0013] Specific embodiments of the present disclosure are described
below. In an effort to provide a concise description of these
embodiments, all features of an actual implementation may not be
described in the specification. It should be appreciated that in
the development of any such actual implementation, as in any
engineering or design project, numerous implementation-specific
decisions must be made to achieve the developers' specific goals,
such as compliance with system-related and business-related
constraints, which may vary from one implementation to another.
Moreover, it should be appreciated that such a development effort
might be complex and time-consuming, but would nevertheless be a
routine undertaking of design, fabrication, and manufacture for
those of ordinary skill having the benefit of this disclosure.
[0014] When introducing elements of various embodiments, the
articles "a," "an," "the," and "said" are intended to mean that
there are one or more of the elements. The terms "comprising,"
"including," and "having" are intended to be inclusive and mean
that there may be additional elements other than the listed
elements. Moreover, any use of "top," "bottom," "above," "below,"
other directional terms, and variations of these terms is made for
convenience, but does not require any particular orientation of the
components.
[0015] Turning now to the present figures, a system 10 is
illustrated in FIG. 1 by way of example. The system 10 is a
production system that facilitates extraction of a resource, such
as oil or gas, from a reservoir 12 through a well 14. A wellhead 16
is installed on the well (e.g., attached to the top of casing and
tubing strings in the well). As shown here, the wellhead 16
includes at least one tubing head 18 and casing head 20. The
wellhead 16 also includes various inner components 22 inside the
wellhead, such as annular plugs and casing and tubing hangers. The
components 22 inside the wellhead 16 can also include packoffs for
inhibiting fluid leakage within the wellhead 16 and locking
assemblies for securing wellhead hangers (e.g., casing and tubing
hangers), plugs, or other inner components within the wellhead 16.
Certain examples of such locking assemblies are described in
greater detail below. In at least some embodiments, the locking
assemblies are constructed for use in high and low temperatures and
for high pressure within the wellhead 16 exceeding 20 ksi. The
depicted system 10 also includes a tree 24 (e.g., a Christmas tree)
to facilitate resource production from the well 14.
[0016] By way of example, components of an apparatus 40 with a
wellhead hanger 48 and a friction locking assembly 50 for securing
the wellhead hanger 48 within a bore are illustrated in FIGS. 2-4
in accordance with one embodiment. Though shown here with the
wellhead hanger 48, it is noted that the locking assembly 50 could
instead be used to secure plugs or other components within a bore
of a wellhead apparatus. The depicted locking assembly 50 includes
a lock ring 54 and an actuator 56, which is shown in the present
figures in the form of an annular sleeve and may also be referred
to as an energizing ring. In addition to the wellhead hanger 48 and
the locking assembly 50, the apparatus 40 is also shown in FIGS.
2-4 as including a retaining ring 52 and a load ring 58, which may
also be referred to as a bearing ring. The components of the
apparatus 40 can be formed of metal or of any other suitable
material.
[0017] In FIGS. 3 and 4, the apparatus 40 is shown disposed within
a bore of a wellhead component 42, such as a tubing head or casing
head, with the locking assembly 50 installed between an inner
component (here the wellhead hanger 48) and the wellhead component
42. As depicted, the hanger 48 is positioned on a landing shoulder
within the bore of the wellhead component 42. The landing shoulder
can be formed as an integral part of the wellhead component 42,
i.e., as a tapered edge of the bore wall, or can be a separate
component installed within the bore. In at least some instances,
the hanger 48 can be threaded onto (or otherwise coupled to) a plug
or some other component.
[0018] As depicted in FIGS. 3 and 4, the lock ring 54 and the
actuator 56 are positioned about a neck 60 of the hanger 48. The
lock ring 54 includes ridges 62 along its outer circumference. The
bore wall of the wellhead component 42 has mating recesses 64 for
receiving the ridges 62 of the lock ring 54. In the presently
depicted embodiment, the load ring 58 is positioned between the
lock ring 54 and a shoulder of the hanger 48, and includes a recess
70 for receiving a distal end 72 of the actuator 56.
[0019] The actuator 56 can be moved axially along the neck 60 to
lock and unlock the assembly 50. More specifically, the actuator 56
can be wedged between the neck 60 and the lock ring 54 to cause the
lock ring 54 to expand into engagement with the recesses 64, and
the actuator 56 can be at least partially withdrawn from between
the neck 60 and the lock ring 54 to allow the lock ring 54 to
contract and disengage from the recesses 64. In its unlocked state,
the locking assembly 50 can be moved (e.g., carried by the hanger
48) axially within the bore of the wellhead component 42, such as
during installation of the hanger 48 in the bore. Once the locking
assembly 50 and the hanger 48 are axially positioned at their
intended locations within the bore (i.e., with the hanger 48 on the
landing shoulder of the wellhead component 42 and the lock ring 54
adjacent to the recesses 64), the actuator 56 can be pushed axially
downward along the neck 60 toward the landing shoulder so that the
actuator 56 is radially positioned between the lock ring 54 and the
neck 60 of the hanger 48.
[0020] Examples of this locked state are depicted in FIGS. 3 and 4.
It will be appreciated that the axial position of the actuator 56
when in its locked state may vary in different implementations. In
some instances, such variation may be attributable to height and
diametrical dimension tolerance stack-ups or deflections in the
system. This variation is generally depicted in the present
drawings, in which FIG. 3 depicts the actuator 56 in a lower locked
position and FIG. 4 depicts the actuator 56 in a higher locked
position due to differences in tolerance stack-ups and
deflections.
[0021] A tapered interface 68 of the lock ring 54 and the actuator
56 causes the lock ring 54 to expand radially as the actuator 56 is
driven between the lock ring 54 and the neck 60. To facilitate this
radial expansion, the lock ring 54 is provided as a split ring
(e.g., a C-ring) in at least some embodiments. The expansion of the
lock ring 54 results in the movement of the ridges 62 into the
recesses 64, which inhibits axial movement of the hanger 48 within
the bore 42.
[0022] Once run into the bore of the wellhead component 42, the
locking assembly 50 of at least some embodiments can be set using
only axial motion to secure the hanger 48 (or some other component)
inside the bore. Unlike other locking assemblies that require
rotation of an element (such as a threaded ring) within bores to
set the locking assemblies and secure components within the bores,
the presently depicted locking assembly can be set by axially
driving (e.g., with a running tool) the actuator 56 between the
lock ring 54 and the hanger 48 to cause the lock ring 54 to engage
the recesses 64. Rotation of components within a bore can increase
the risk of damage to the bore and other components. By axially
setting the locking assembly 50, such an increased risk of damage
from rotation can be avoided. Axial setting also allows the use of
less complicated tooling in installing the locking assembly 50,
which can reduce installation time and expense. The locking
assembly 50 can also be unlocked via axial force, such as by
engaging an upper end of the actuator 56 with a tool and pulling
the actuator 56 away from the load ring 58 to allow the lock ring
54 to relax and retract from the recesses 64.
[0023] Further, when in its locked position, the locking assembly
50 provides a preload on the hanger 48. This preload in some
instances can be equal to the expected loading on the hanger 48
from wellbore fluids in the wellhead during operation. As depicted
in FIGS. 3 and 4, the ridges 62 and recesses 64 have mating tapered
edges. As the lock ring 54 is driven into engagement with the
recesses 64 by the actuator 56, the mating engagement of the upper
tapered surfaces of the ridges 62 and the recesses 64 cause the
lock ring 54 to be driven downward and to apply a compression force
on the load ring 58, thus applying a preload on the hanger 48. It
will be appreciated that the amount of preload depends on the
geometries of the lock ring 54, the load ring 58, and the recesses
64, which can vary between different embodiments.
[0024] In some prior art designs, locking assemblies in wellheads
are retained by providing devices, such as springs, above the
locking assemblies to load against the locking assemblies and
inhibit axial movement. In other prior art designs, threaded
connections are used to retain locking assemblies at a desired
location. But in contrast to such prior art designs, in at least
some embodiments of the present disclosure friction alone is used
to retain a locking assembly 50 in the locked position without the
need for rotation or other retention mechanisms.
[0025] For example, the actuator 56 of the locking assembly 50
depicted in FIGS. 3 and 4 is installed on the neck 60 of the hanger
48 with an interference fit. More specifically, after the actuator
56 is driven between the lock ring 54 and the neck 60 to cause the
lock ring 54 to engage the wellhead component 42, the actuator 56
can be held in its locked position by friction between the neck 60
and the actuator 56 (along an interface 66 between these two
components) and friction between the actuator 56 and the lock ring
54 (along the tapered interface 68).
[0026] As noted above, stack-up tolerances, deflections, or other
factors can cause variation in the height of the actuator 56 (i.e.,
its position along the neck 60) when set in the locked position.
The steep taper between the actuator 56 and the lock ring 54 at the
tapered interface 68 generally compounds this variation. Because of
the uncertainty of the height position of the actuator 56 in a
given application, verification of the proper setting of the
locking assembly 50 can be difficult. Consequently, in at least
some embodiments the hanger apparatus 40 includes a retaining ring
52 that accommodates variation in the locking position of the
actuator 56.
[0027] As shown in FIGS. 3 and 4, the retaining ring 52 engages the
actuator 56 along a tapered interface 80. The direction of taper of
the interface 80 is the reverse of that of interface 68. That is,
the actuator 56 includes a first tapered surface at interface 68
that tapers toward the lower end of the actuator 56, as well as a
second tapered surface at interface 80 that tapers in the opposite
direction toward the upper end of the actuator 56. This second
tapered surface of the actuator 56 is provided along an outer edge
of an exterior flange of the actuator 56 in the embodiment
illustrated in FIGS. 3 and 4, but is provided in different manners
in other embodiments.
[0028] While the actuator 56 may be primarily retained through
friction along interfaces 66 and 68 (i.e., friction with the neck
60 and the lock ring 54), vibration, shock loads, or other forces
could cause movement of the actuator 56 along the neck 60 away from
the locked position. A secondary retention mechanism, such as the
retaining ring 52, can be used to prevent inadvertent unsetting of
the actuator 56 if friction with the neck 60 and the lock ring 54
is insufficient to hold the actuator 56 in the locked position. In
such an instance, upward movement of the actuator 56 along the neck
60 would increase hoop deflection in the retaining ring 52,
allowing the stiffness of the retaining ring 52 to create an
increasing retention load on the actuator 56 that inhibits movement
of the actuator 56 out of engagement with the lock ring 54. That
is, given the tapered surfaces of the interface 80, the retention
load applied by the retaining ring 52 continues to increase as the
actuator 56 moves upward. In FIGS. 3 and 4, upward movement of the
actuator 56 would increase outward hoop deflection in the retaining
ring 52, though the arrangement of the retaining ring 52 and the
actuator 56 could be reversed at the tapered interface 80 such that
the upward movement of the actuator 56 would instead increase
inward hoop deflection of the retaining ring 52.
[0029] Another example of the retaining ring 52 is depicted in
FIGS. 5 and 6, which show the actuator 56 in its locked state at
lower and upper axial positions, such as described above with
respect to FIGS. 3 and 4. In this additional embodiment, the
retaining ring 52 is provided as a mechanism including an outer
sleeve 86 and an inner sleeve 88, with the tapered interface 80
provided between the inner sleeve 88 and the actuator 56. The inner
sleeve 88 can be provided as a bending ring that deflects in
response to applied force from the actuator 56. In this
arrangement, upward movement of the actuator 56 would be resisted
by increased hoop deflection of the inner sleeve 88 caused by the
movement of the actuator 56. The inner sleeve 88 can be pinned or
threaded to the outer sleeve 86, or can be connected to the outer
sleeve 86 in any other suitable manner.
[0030] An additional example of the actuator 56 in its locked state
at lower and upper axial positions is shown in FIGS. 7 and 8. In
this depicted embodiment, the actuator 56 includes a main body or
inner sleeve 94 and an outer ring 96 (e.g., a C-ring or a solid
ring) that engages the retaining ring 52. The tapered interface 80
is provided between the outer ring 96 and the retaining ring 52.
Moreover, in this embodiment, the tapered interface 80 causes
inward hoop deflection of the outer ring 96 (and an increasing
retention load) in response to upward movement of the actuator 56.
The outer ring 96 is carried on a shoulder of the inner sleeve 94
in at least some instances. Additionally, rather than including a
separate load ring 58, the hanger 48 in FIGS. 7 and 8 is shown as
having an integral load ring 58. But the load ring 58 could be
provided as a separate load ring in the embodiment depicted in
FIGS. 7 and 8. Likewise, instead of having a separate load ring 58,
the embodiments depicted in FIGS. 2-6 could instead include a load
ring 58 that is integral with the hanger 48.
[0031] As will be appreciated, each of the various locking
assemblies 50 described above can be run into the bore of a
wellhead component 42 and, once positioned, the actuator 56 can be
moved to a locked position to drive the lock ring 54 into
engagement with the wellhead component 42 and secure the wellhead
hanger 48 or another component within the bore. In some instances,
the locking assembly 50 is run into the bore with the hanger 48.
The retaining ring 52 can also be lowered into the bore with the
locking assembly 50, or after the locking assembly 50 is run into
the bore, and positioned so that the mating surfaces of the tapered
interface 80 oppose movement of the actuator 56 along the hanger 48
toward an unlocked position.
[0032] A packoff can be installed in the bore above the locking
assembly 50. In the presently depicted embodiments, the retaining
ring 52 is provided as part of such a packoff (i.e., a packoff
landing ring) and the retaining ring 52 is lowered into the bore as
part of the packoff. By omitting a separate retention device
between a packoff and the locking assembly 50, the packoff can be
installed closer to (e.g., in contact with) the locking assembly
50, which enables the use of a shorter wellhead assembly. But the
retaining ring 52 could be provided independent of a packoff in
other embodiments.
[0033] While the aspects of the present disclosure may be
susceptible to various modifications and alternative forms,
specific embodiments have been shown by way of example in the
drawings and have been described in detail herein. But it should be
understood that the invention is not intended to be limited to the
particular forms disclosed. Rather, the invention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the following
appended claims.
* * * * *