ROTATING CONTROL DEVICE WITH ROTARY LATCH
TECHNICAL FIELD
This disclosure relates generally to equipment utilized
and operations performed in conjunction with a subterranean
well and, in one example described below, more particularly
provides a rotating control device with a rotary latch.
BACKGROUND
A rotating control device (RCD, also known as a
rotating head, rotating blowout preventer and rotating
diverter) is used to seal off an annulus about a rotatable
tubular (such as, part of a drill string or other tubular
string) at or near the earth's surface. For this purpose,
the rotating control device includes an annular seal, which
may rotate with the tubular. Bearings can be used to allow
the seal to rotate relative to an outer housing of the
rotating control device.
It is beneficial to be able to releasably latch the
seal and/or bearings relative to the outer housing, so that
the seal and/or bearings could be conveniently installed and
removed when desired. Thus, it will be appreciated that
improvements are continually needed in the arts of
constructing and operating latches for rotating control
devices .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a representative cross-sectional view of a
well system and associated method which can embody
principles of this disclosure.
FIG. 2 is a representative cross-sectional view of the
well system and method of FIG. 1 , with a seal and bearing
assembly latched into a rotating control device outer
housing .
FIG. 3 is an enlarged scale representative perspective
view of an engagement member of a rotary latch of the
rotating control device.
FIGS. 4A & B are representative cross-sectional views
of the latch in respective unlatched and latched
configurations .
FIG. 5 is a representative perspective view of cam
profiles of the rotary latch.
FIG. 6 is a representative cross-sectional view of
another example of the rotary latch.
FIG. 7 is a representative cross-sectional view of the
rotating control device.
FIG. 8 is a representative cross-sectional view of a
manual rotation mechanism of the rotary latch.
FIG. 9 is a representative cross-sectional view of the
rotating control device, taken along line 9-9 of FIG. 7 .
FIG. 10 is a representative cross-sectional view of the
rotating control device, taken along line 10-10 of FIG. 7 .
DETAILED DESCRIPTION
FIG. 1 is a representative cross-sectional view of a
well system 10 and associated method which can embody
principles of this disclosure. However, it should be clearly
understood that the system 10 and method are merely one
example of an application of the principles of this
disclosure in practice, and a wide variety of other examples
are possible. Therefore, the scope of this disclosure is not
limited at all to the details of the system 10 and method
described herein and/or depicted in the drawings.
In the FIG. 1 example, a rotating control device (RCD)
12 is connected as part of a riser string 14, so that a flow
passage 16 of the riser string extends longitudinally
through the RCD. The RCD 12 is connected between an annular
blowout preventer (BOP) 18 and a diverter tie-back 20.
However, in other examples, the RCD 12 is not necessarily
connected as part of a riser string (e.g., the RCD could be
used with a land-based rig), and the RCD is not necessarily
connected between any particular well tools or components.
The BOP 18 can be connected to various types of
structures 22 (for example, a tensioner ring of the riser
string 14, a wellhead or a lower marine riser package
(LMRP)), so that the passage 16 is in communication with a
wellbore (not shown). The diverter tie-back 20 can be
connected to a rig diverter (not shown) of a floating or
jack-up drilling rig. However, the scope of this disclosure
is not limited to use of the RCD 12 with any particular type
of drilling rig, or to any particular arrangement or
configuration of components or well tools above or below the
RCD.
The RCD 12 includes a rotary latch 24 for releasably
securing a seal and bearing assembly (see FIG. 2 ) in an
outer housing 26 of the RCD. In FIG. 1 , it can be seen that
the latch 24 includes multiple engagement members 28 that
are circumf erentially distributed in the outer housing 26.
FIG. 2 is a representative cross-sectional view of the
well system 10 and method of FIG. 1 , with a seal and bearing
assembly 30 latched into the rotating control device outer
housing 26. In this configuration, an annular seal 32 of the
assembly 30 can sealingly engage an exterior of a tubular 34
(such as a drill pipe) inserted in the passage 16.
The assembly 30 includes bearings 36, which permit the
seal 32 to rotate relative to the outer housing 26. In this
manner, the seal 32 can rotate with the tubular 34 while
sealing off an annular space 38 formed radially between the
tubular and the outer housing 26. The latch 24 releasably
secures the assembly 30 against removal from the outer
housing 26.
In the FIGS. 1 & 2 example, the latch 24 releasably
secures both the seal 32 and the bearings 36 against removal
from the RCD 12. However, in other examples, the latch 24
could releasably secure only the seal 32, or only the
bearings 36 (e.g., if the seal is separately removable from
the outer housing 26). Thus, the scope of this disclosure is
not limited to use of any particular type of seal and
bearing assembly, or to use of an assembly which includes
both a seal and bearings.
Only one seal 32 is depicted in FIG. 2 , and the seal is
illustrated as being of the type known to those skilled in
the art as a "passive" seal. However, in other examples,
multiple seals could be used, and some or all of the seals
could be "active" seals. The seal 32 is not necessarily
positioned within the outer housing 26. Thus, it will be
appreciated that the scope of this disclosure is not limited
to use of any particular number, position or type(s) of
annular seals.
As described more fully below, the latch engagement
members 28 can be displaced radially relative to the outer
housing 26 between a position in which removal of the seal
and bearing assembly 30 from the RCD 12 is prevented, and a
position in which the seal and bearing assembly can be
inserted into or removed from the outer housing 26.
FIG. 3 is an enlarged scale representative perspective
view of one engagement member 28 of the rotary latch 24 of
the rotating control device 12. In this view, it can be
clearly seen that the member 28 includes a generally Tshaped
recess 40 and a concave curved engagement face 42.
The recess 40 is configured for connecting the
engagement member 28 to another member described below (see
FIGS. 4A & B ). The engagement face 42 is configured to
complementarily engage an annular recess (see FIGS. 4A & B )
formed on the seal and bearing assembly 30.
However, in other examples, the engagement member 28
could be otherwise configured. For example, the engagement
member 28 could be threaded or otherwise connected to
another member, or the engagement member could be integrally
formed with such other member. The curved engagement face 42
could instead be planar, straight or convex. Thus, the scope
of this disclosure is not limited to any particular
configuration of the engagement member 28.
FIGS. 4A & B are representative cross-sectional views
of the latch 24 in respective unlatched and latched
configurations. In FIG. 4A the engagement member 28 is
displaced radially outward by a rotary cam 44 of the latch
24, and in FIG. 4B the engagement member is displaced
radially inward by the rotary cam into engagement with an
annular recess 46 on the seal and bearing assembly 30.
The seal and bearing assembly 30 can be inserted into
or removed from the RCD 12 when the engagement member 28 is
in the position depicted in FIG. 4A. The seal and bearing
assembly 30 is prevented from being removed from the RCD 12
when the engagement member 28 is in the position depicted in
FIG. 4B.
The engagement member 28 is connected to a rod 48 that
is sealingly and slidingly received in an opening 50 formed
radially through the outer housing 26. The rod 48 includes a
head 52 shaped for complementary engagement with the recess
40 in the engagement member 28.
In other examples, the engagement member 28 and rod 48
could be otherwise connected, or they could be integrally
formed. Thus, the scope of this disclosure is not limited to
any particular configuration of the rod 48, or to any
particular manner of connecting the rod to the engagement
member 28.
The member 28 and rod 48 are displaced radially inward
and outward relative to the outer housing 26 by means of cam
profiles 54, 56, 58 formed in the rotary cam 44. When the
cam 44 is rotated in one direction, the profiles 54 displace
the member 28 and rod 48 radially outward to the FIG. 4A
position. When the cam 44 is rotated in an opposite
direction, the profiles 56, 58 displace the member 28 and
rod 48 radially inward to the FIG. 4B position.
Cam followers 60 are connected to the rod 48 for
engaging the cam profiles 54, 58. However, in other
examples, the rod 48 and cam followers 60 could be
integrally formed, or could be connected to each other by
various means (such as, threads or welding). Thus, the scope
of this disclosure is not limited to any particular
configuration of the rod 48 and cam followers 60.
Although only one set of the engagement member 28, rod
48, cam profiles 54, 56, 58 and cam followers 60 is depicted
in FIGS. 4A & B , multiple such sets are circumf erentially
distributed relative to the outer housing 26. The rotary cam
44 is used to displace these multiple engagement members 28,
rods 48 and cam followers 60 radially inward and outward,
using the respective multiple sets of cam profiles 54, 56,
58.
FIG. 5 is a representative perspective view of the cam
profiles 54, 56, 58 of the rotary latch 24. An upper portion
of the rotary cam 44 has been removed, so that the cam
profiles 54, 56, 58 therein can be seen.
Each of the cam profiles 54, 56, 58 is inclined
radially so that, as the cam 44 is rotated, the rod 48
and/or cam followers 60 are biased by the cam profiles to
displace radially inward or outward (depending on the
direction of rotation of the cam) . Note that the cam profile
56 is configured so that it engages an end of the rod 48.
In addition, note that each of the cam profiles 56, 58
is configured so that, when the engagement member 28 (see
FIGS. 4A & B ) is engaged with the seal and bearing assembly
30, the rod 48 and cam followers 60 do not contact radially
inclined portions of the cam profiles 56, 58. This prevents
outward biasing of the rod 48 (for example, due to pressure
in an interior of the RCD 12) from causing rotation of the
cam 44, which could otherwise be caused by contact of the
rod and/or cam followers 60 with radially inclined portions
of the cam profiles 56, 58.
FIG. 6 is a representative cross-sectional view of
another example of the rotary latch 2 4 . In this example, a
biasing device 6 2 (such as a compression spring) is used to
displace the engagement member 2 8 and rod 4 8 radially
outward. The cam profile 5 4 is not used to outwardly
displace the member 2 8 and rod 4 8 . Thus, the scope of this
disclosure is not limited to use of any particular number or
arrangement of cam profiles in the rotary latch 2 4 .
FIG. 7 is a representative cross-sectional view of the
rotating control device 12 . In this view, it may be seen
that multiple motors 6 4 can be used to rotate the rotary cam
4 4 .
In this example, the motors 6 4 are mounted to the outer
housing 2 6 and each of the motors has a pinion gear 6 6 on
its shaft. The pinion gears 6 6 engage a ring gear 6 8 mounted
on the rotary cam 4 4 . Thus, the motors 6 4 rotate the pinion
gears 6 6 , which rotate the ring gear 6 8 , and this causes the
rotary cam 4 4 to rotate.
The motors 6 4 can be any type of motors suitable for
causing rotation of the cam 4 4 . For example, electrical,
pneumatic or hydraulic motors could be used.
In other examples, devices other than motors (such as,
hydraulically or pneumatically actuated pistons and
cylinders acting through a lever arm to rotate the cam 4 4 ,
or other types of actuators) could be used to rotate the cam
4 4 . Thus, the scope of this disclosure is not limited to use
of any particular means for rotating the cam 4 4 .
FIG. 8 is a representative cross-sectional view of a
manual rotation mechanism 7 0 of the rotary latch 2 4 . The
manual rotation mechanism 7 0 permits the cam 4 4 to be
rotated by hand, for example, if the motors 6 4 are not
functional (e.g., due to loss of electrical, pneumatic or
hydraulic power) . Multiple manual rotation mechanisms 70 may
be provided, if desired.
The manual rotation mechanism 70 includes a shaft 72
having one of the pinion gears 66 secured thereon. The shaft
72 is rotatably secured to the outer housing 26 .
The pinion gear 66 engages the ring gear 68 , as
described above for rotation of the cam 44 using the motors
64 . However, in the FIG. 8 example, the pinion gear 66 can
be rotated by hand using, for example, a socket 74 formed in
an end of the shaft 72 . The socket 74 can be engaged with a
suitably configured hand tool (not shown).
FIG. 9 is a representative cross-sectional view of the
rotating control device 12 , taken along line 9-9 of FIG. 7.
In this view, the manner in which the pinion gears 66 are
distributed about the ring gear 68 can be clearly seen. In
addition, it may be seen that two of the manual rotation
mechanisms 70 are used in this example.
FIG. 10 is a representative cross-sectional view of the
rotating control device 12 , taken along line 10-10 of FIG.
7. In this view, the manner in which the engagement members
28 , rods 48 and cam profiles 54 , 56 , 58 are
circumf erentially distributed relative to the outer housing
26 can be clearly seen.
All of the engagement members 28 can be conveniently
displaced linearly and radially inward and outward by
rotation of the rotary cam 44 using the motors 64 , or using
the manual rotation mechanisms 70 (see FIG. 8) . However,
other means of displacing and directions of displacing the
engagement members 28 could be used, if desired. For
example, it is not necessary for the rods 48 to be radially
arranged, or for the engagement members 28 to displace only
radially. Thus, the scope of this disclosure is not limited
to any particular direction of displacement of particular
components of the RCD 12 .
It may now be fully appreciated that the above
disclosure provides significant advancements to the arts of
constructing and operating rotating control devices. In
examples described above, the seal and bearing assembly 3 0
can be conveniently secured to and released from the RCD 12
using the rotary latch 2 4 . In these examples, the rotary
latch 2 4 includes the rotary cam 4 4 , which translates
rotation of the cam into radial displacement of the
engagement members 2 8 .
The above disclosure provides to the art a rotating
control device 12 which, in one example, includes an outer
housing 2 6 , at least one annular seal 3 2 rotatable relative
to the outer housing 2 6 , and a latch 2 4 including at least
one rotary cam 4 4 and at least one engagement member 2 8
which releasably secures relative to the outer housing 2 6 at
least one of the annular seal 3 2 and a bearing 3 6 . Rotation
of the rotary cam 4 4 relative to the outer housing 2 6
displaces the engagement member 2 8 .
The annular seal 3 2 may be rotatable relative to the
outer housing 2 6 when the annular seal 3 2 is secured by the
latch 2 4 against removal from the outer housing 2 6 .
The rotating control device 12 can comprise a seal and
bearing assembly 3 0 which includes the annular seal 3 2 and
the bearing 3 6 . Removal of the seal and bearing assembly 3 0
from the outer housing 2 6 may be prevented by the latch 2 4 .
The latch 2 4 may include a motor 6 4 which rotates the
rotary cam 4 4 . The latch 2 4 can further include a gear 6 8
connected to the rotary cam 4 4 , the gear 6 8 being driven by
the motor 6 4 .
The engagement member 28 may displace radially and/or
linearly relative to the outer housing 26 in response to
rotation of the rotary cam 44.
The latch 24 can include a rod 48 that displaces
through the outer housing 26 in response to rotation of the
rotary cam 44.
The engagement member 28 may be displaced outward
relative to the outer housing 26, and removal of the annular
seal 32 and/or bearing 36 from the outer housing 26 can be
permitted, in response to rotation of the rotary cam 44.
The at least one engagement member 28 may comprise
multiple engagement members 28 circumferentially distributed
in the outer housing 26.
A method of releasably latching at least one annular
seal 32 relative to an outer housing 26 of a rotating
control device 12 is also described above. In one example,
the method comprises: rotating a rotary cam 44, thereby
linearly displacing an engagement member 28 that releasably
secures the annular seal 32 relative to the outer housing
26. Rotation of the annular seal 32 relative to the outer
housing 26 is permitted when the engagement member 28 is
displaced to a position in which removal of the annular seal
32 is prevented.
The rotating step can comprise rotating the rotary cam
44 by hand and/or with a motor 64. The rotating step can
comprise rotating a gear 68 with the motor 64. The gear 68
may be connected to the rotary cam 44 and encircle the outer
housing 26.
The rotating control device 12 can comprise a bearing
36. Removal of the bearing 36 from the outer housing 26 may
be prevented when the engagement member 28 is displaced to a
- ¬
position in which removal of the annular seal 3 2 is
prevented.
The engagement member 2 8 may displace radially relative
to the outer housing 2 6 in response to the rotating step. A
rod 4 8 may displace through the outer housing 2 6 in response
to the rotating step.
The rotating step can comprise displacing the
engagement member 2 8 outward relative to the outer housing
2 6 , thereby permitting removal of the annular seal 3 2 from
the outer housing 2 6 .
Also described above is a rotating control device 12
which, in one example, includes an outer housing 2 6 , at
least one annular seal 3 2 rotatable relative to the outer
housing 2 6 , and a latch 2 4 including at least one rotary cam
4 4 and multiple separate engagement members 2 8 disposed in
the outer housing 2 6 . Rotation of the rotary cam 4 4 relative
to the outer housing 2 6 displaces the engagement members 2 8
in the outer housing 2 6 .
The latch 2 4 can include multiple rods 4 8 that displace
through the outer housing 2 6 in response to rotation of the
rotary cam 4 4 . The engagement members 2 8 may be displaced by
multiple respective cam profiles 5 4 , 5 6 , 5 8 formed on the
rotary cam 4 4 .
Although various examples have been described above,
with each example having certain features, it should be
understood that it is not necessary for a particular feature
of one example to be used exclusively with that example.
Instead, any of the features described above and/or depicted
in the drawings can be combined with any of the examples, in
addition to or in substitution for any of the other features
of those examples. One example's features are not mutually
exclusive to another example's features. Instead, the scope
of this disclosure encompasses any combination of any of the
features .
Although each example described above includes a
certain combination of features, it should be understood
that it is not necessary for all features of an example to
be used. Instead, any of the features described above can be
used, without any other particular feature or features also
being used.
It should be understood that the various embodiments
described herein may be utilized in various orientations,
such as inclined, inverted, horizontal, vertical, etc., and
in various configurations, without departing from the
principles of this disclosure. The embodiments are described
merely as examples of useful applications of the principles
of the disclosure, which is not limited to any specific
details of these embodiments.
In the above description of the representative
examples, directional terms (such as "above," "below,"
"upper," "lower," etc.) are used for convenience in
referring to the accompanying drawings. However, it should
be clearly understood that the scope of this disclosure is
not limited to any particular directions described herein.
The terms "including," "includes," "comprising,"
"comprises," and similar terms are used in a non-limiting
sense in this specification. For example, if a system,
method, apparatus, device, etc., is described as "including"
a certain feature or element, the system, method, apparatus,
device, etc., can include that feature or element, and can
also include other features or elements. Similarly, the term
"comprises" is considered to mean "comprises, but is not
limited to."
Of course, a person skilled in the art would, upon a
careful consideration of the above description of
representative embodiments of the disclosure, readily
appreciate that many modifications, additions,
substitutions, deletions, and other changes may be made to
the specific embodiments, and such changes are contemplated
by the principles of this disclosure. For example,
structures disclosed as being separately formed can, in
other examples, be integrally formed and vice versa.
Accordingly, the foregoing detailed description is to be
clearly understood as being given by way of illustration and
example only, the spirit and scope of the invention being
limited solely by the appended claims and their equivalents.

WHAT IS CLAIMED IS:
1 . A rotating control device, comprising:
an outer housing;
least one annular seal; and
a latch including at least one rotary cam and at least
one engagement member which releasably secures relative to
the outer housing at least one of a group comprising the
annular seal and a bearing, wherein rotation of the rotary
cam relative to the outer housing displaces the engagement
member .
2 . The rotating control device of claim 1 , wherein
the annular seal is rotatable relative to the outer housing
when the annular seal is secured by the latch against
removal from the outer housing.
3 . The rotating control device of claim 1 , further
comprising a seal and bearing assembly which includes the
annular seal and the bearing, and wherein removal of the
seal and bearing assembly from the outer housing is
prevented by the latch.
4 . The rotating control device of claim 1 , whe
the latch includes a motor which rotates the rotary cam.
5 . The rotating control device of claim 4 , wherein
the latch further includes a gear connected to the rotary
cam, the gear being driven by the motor.
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6 . The rotating control device o f claim 1 , wherein
the engagement member displaces radially relative to the
outer housing in response to rotation o f the rotary cam.
7 . The rotating control device o f claim 1 , wherein
the engagement member is displaced outward relative to the
outer housing, and removal o f the at least one o f the group
comprising the annular seal and the bearing from the outer
housing is permitted, in response to rotation o f the rotary
cam.
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8 . A method of releasably latching at least one
annular seal relative to an outer housing of a rotating
control device, the method comprising:
rotating a rotary cam, thereby linearly displacing an
engagement member that releasably secures the annular seal
relative to the outer housing,
wherein rotation of the annular seal relative to the
outer housing is permitted when the engagement member is
displaced to a position in which removal of the annular seal
from the outer housing is prevented.
9 . The method of claim 8 , wherein the rotating
further comprises rotating the rotary cam with a motor.
10. The method of claim 9 , wherein the rotating
further comprises rotating a gear with the motor.
11. The method of claim 8 , wherein the rotating
control device comprises a bearing, and wherein removal of
the bearing from the outer housing is prevented when the
engagement member is displaced to a position in which
removal of the annular seal is prevented.
12. The method of claim 8 , wherein the engagement
member displaces radially relative to the outer housing in
response to the rotating.
13. The method of claim 8 , wherein the rotating
further comprises displacing the engagement member outward
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relative to the outer housing, thereby permitting removal of
the annular seal from the outer housing.
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14. A rotating control device, comprising:
an outer housing;
at least one annular seal; and
a latch including at least one rotary cam and multiple
separate engagement members disposed in the outer housing,
wherein rotation of the rotary cam relative to the
outer housing displaces the engagement members in the outer
housing .
15. The rotating control device of claim 14, wherein
the annular seal is rotatable relative to the outer housing
when the annular seal is secured by the latch against
removal .
16. The rotating control device of claim 14, further
comprising a bearing, and wherein removal of the bearing
from the outer housing is prevented by the latch.
17. The rotating control device of claim 14, wherein
the latch includes at least one motor which rotates the
rotary cam.
18. The rotating control device of claim 14, wherein
the engagement members displace radially relative to the
outer housing in response to rotation of the rotary cam.
19. The rotating control device of claim 14, wherein
the engagement members displace linearly relative to the
outer housing in response to rotation of the rotary cam.
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20. The rotating control device of claim 14, wherein
the engagement members are displaced by multiple respective
cam profiles formed on the rotary cam.