U.S. patent application number 16/188795 was filed with the patent office on 2019-05-16 for positive engagement indicator for remotely operated well pressure control apparatus.
The applicant listed for this patent is FHE USA LLC. Invention is credited to Keith C. Johansen, Matthew Kibler, Kyle Scholl, Nicolas G. Snoke.
Application Number | 20190145213 16/188795 |
Document ID | / |
Family ID | 66431953 |
Filed Date | 2019-05-16 |
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United States Patent
Application |
20190145213 |
Kind Code |
A1 |
Kibler; Matthew ; et
al. |
May 16, 2019 |
POSITIVE ENGAGEMENT INDICATOR FOR REMOTELY OPERATED WELL PRESSURE
CONTROL APPARATUS
Abstract
A wellhead pressure control fitting includes a plurality of
locks to engage a mating surface of an adapter sealingly seated in
a receptacle. The locks each comprise a sensor arranged to measure
an amount of movement or rotation of each lock so that full closure
of each lock against the adapter is determinable.
Inventors: |
Kibler; Matthew; (Grand
Junction, CO) ; Scholl; Kyle; (Dunlap, IL) ;
Johansen; Keith C.; (Fruita, CO) ; Snoke; Nicolas
G.; (Grand Junction, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FHE USA LLC |
Fruita |
CO |
US |
|
|
Family ID: |
66431953 |
Appl. No.: |
16/188795 |
Filed: |
November 13, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62586203 |
Nov 15, 2017 |
|
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Current U.S.
Class: |
166/379 |
Current CPC
Class: |
E21B 43/12 20130101;
E21B 19/24 20130101; E21B 33/038 20130101; E21B 34/02 20130101;
E21B 33/04 20130101; E21B 2200/01 20200501 |
International
Class: |
E21B 33/04 20060101
E21B033/04; E21B 34/02 20060101 E21B034/02; E21B 43/12 20060101
E21B043/12 |
Claims
1. A wellhead pressure control fitting, comprising: a generally
tubular Pressure Control Equipment (PCE) adapter assembly; the
generally tubular pressure control assembly configured to mate with
a wellhead and having a plurality of cam locks, each cam lock
configured to rotate; means for rotating the cam locks so as to
urge the adapter into a receptacle in the pressure control assembly
to form a pressure tight seal between the adapter and the assembly;
and a sensor associated with each cam lock, the sensor arranged to
measure a parameter related to an amount of rotation of each cam
lock.
2. The fitting of claim 1 wherein the sensor associated with each
cam lock comprises a rotary encoder disposed on a cam lock pin.
3. The fitting of claim 1 wherein the sensor associated with each
cam lock comprises a proximity sensor arranged to measured
extension of each cam lock piston.
4. The fitting of claim 1 wherein the sensor associated with each
cam lock comprises an accelerometer arranged to measure a
rotational orientation of each cam lock.
5. The fitting of claim 1 wherein the sensor associated with each
cam lock comprises a limit switch arranged to electrically close or
open only when the associated cam lock is fully rotated to a locked
position.
6. The fitting of claim 1 wherein the sensor associated with each
cam lock comprises a strain gauge.
7. The fitting of claim 1 wherein the sensor associated with each
cam lock comprises an optical sensor.
8. The fitting of claim 1 further comprising a locking ring
comprising means to extend and retract the locking ring, wherein
retraction of the locking ring causes the locking ring to move so
as to restrain the cam locks from rotation, and further comprising
a locking ring sensor operatively engaged to the locking ring
whereby measurements made by the locking ring sensor correspond to
full engagement of the locking ring with the cam locks.
9. The fitting of claim 8 wherein the sensor associated with the
locking ring comprises a proximity sensor arranged to measure a
parameter related to extension of the locking. ring
10. The fitting of claim 8 wherein the sensor associated with the
locking ring comprises a proximity sensor.
11. The fitting of claim 8 wherein the sensor associated with the
locking ring comprises a limit switch arranged to electrically
close or open only when the locking ring is fully engaged with the
cam locks.
12. The fitting of claim 8 wherein the sensor associated with the
locking ring comprises a strain gauge.
13. The fitting of claim 8 wherein the sensor associated with the
locking ring comprises an optical sensor.
14. A wellhead pressure control fitting, comprising: a generally
tubular Pressure Control Equipment (PCE) configured to mate with a
pressure control assembly, the pressure control assembly configured
to mate with a wellhead, the adapter further providing a lower
wedge assembly, the lower wedge assembly including a plurality of
lower wedges, each lower wedge having first and second opposing
lower wedge sides, each first lower wedge side providing protruding
top and bottom lower wedge ribs; a generally hollow lower wedge
receptacle, the lower wedge receptacle further providing a
plurality of shaped lower wedge receptacle recesses formed in an
interior thereof wherein axial displacement of the lower wedge
receptacle relative to the lower wedges causes corresponding radial
displacement of the lower wedges; and a sensor arranged to measure
a parameter related to an amount of engagement of the wedges with
the wedge receptacle.
15. The fitting of claim 14 wherein the sensor comprises a
proximity switch.
16. The fitting of claim 14 wherein the sensor comprises a limit
switch.
17. The fitting of claim 14 wherein the sensor comprises a linear
variable differential transformer.
18. The fitting of claim 14 wherein the sensor comprises an
acoustic range finder.
19. A wellhead pressure control fitting, comprising: a generally
tubular Pressure Control Equipment (PCE) adapter having first and
second adapter ends, the first adapter end configured to mate with
pressure control equipment, the adapter providing an annular
adapter rib distal from the first adapter end towards the second
adapter end; a generally tubular pressure control assembly having
first and second assembly ends and a longitudinal centerline, the
centerline defining axial displacement parallel to the centerline
and radial displacement perpendicular to the centerline, the first
assembly end providing a first assembly end interior, the second
assembly end configured to mate with a wellhead; the first assembly
end interior providing a PCE receptacle for receiving the second
adapter end, the second adapter end and the PCE receptacle further
each providing cooperating abutment surfaces, the cooperating
abutment surfaces forming a pressure seal between the second
adapter end and the PCE receptacle when the second adapter end is
received into the PCE receptacle; the first assembly end interior
further providing a wedge assembly, the wedge assembly including: a
plurality of wedges, each wedge having first and second opposing
wedge sides, each first wedge side providing protruding top and
bottom wedge ribs; a generally hollow wedge receptacle, the wedge
receptacle further providing a plurality of shaped wedge receptacle
recesses formed in an interior thereof, one wedge receptacle recess
for each wedge, the wedge receptacle further having first and
second opposing wedge receptacle sides in which the wedge
receptacle recesses define the first wedge receptacle side; and
wherein each wedge is received into a corresponding wedge
receptacle recess so that the first wedge receptacle side and the
second wedge sides provide opposing sloped wedge surfaces, wherein
axial displacement of the upper receptacle relative to the wedges
causes corresponding radial displacement of the wedges; and
wherein, as the second adapter end enters the PCE receptacle and
engages the cooperating abutment surfaces, axial displacement of
the wedge receptacle relative to the wedges causes corresponding
radial constriction of the top and bottom wedge ribs around the
adapter rib, which in turn restrains the adapter from axial
displacement relative to the PCE receptacle; and a sensor arranged
to measure a parameter related to an amount of engagement of the
wedges with the wedge receptacle.
20. The fitting of claim 19 wherein the sensor comprises a
proximity switch.
21. The fitting of claim 19 wherein the sensor comprises a limit
switch.
22. The fitting of claim 19 wherein the sensor comprises a linear
variable differential transformer.
23. The fitting of claim 19 wherein the sensor comprises an
acoustic range finder.
24. A wellhead pressure control fitting, comprising: a generally
tubular Pressure Control Equipment (PCE) adapter configured to mate
with a pressure control assembly, the pressure control assembly
configured to mate with a wellhead, the assembly providing a
plurality of locking elements each disposed to lock the PCE adapter
within the assembly; a locking ring having a plurality of locking
ring actuators extensible to urge the locking ring to an unlocked
position wherein the plurality of locking elements are
disenagageable from the PCE adapter and a locked position wherein
the locking elements retain the PCE adapter within the assembly;
and at least one sensor associated the locking ring, the at least
one sensor arranged to communicate a signal when the locking ring
is in the locked position.
25. The fitting of claim 23 wherein the at least one sensor
comprises a plurality of switches each disposed adjacent to a guide
pin such that full longitudinal retraction of the locking ring
closes all the plurality of switches.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed from U.S. Provisional Application No.
62/586,203 filed Nov. 15, 2017 and which is incorporated herein by
reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable.
BACKGROUND
[0004] This disclosure relates to the field of well pressure
control apparatus. More specifically, the disclosure relates to
apparatus used to lock pressure control devices onto a wellhead or
similar well structure.
[0005] U.S. Pat. No. 9,644,443 issued to Johansen et al. discloses
one example embodiment of a wellhead pressure control fitting
comprising a generally tubular Pressure Control Equipment (PCE)
adapter configured to mate with pressure control equipment at a
first adapter end, and with a receptacle inside a generally tubular
pressure control assembly at a second adapter end. The pressure
control assembly is configured to mate with a wellhead. Cooperating
abutment surfaces form a high pressure seal when the second adapter
end is compressively received into the receptacle. A plurality of
cam locks on the exterior of the pressure control assembly rotate
responsive to extension and retraction of the cam lock pistons. Cam
lock rotation causes perimeter curvatures on the cam locks to bear
down on corresponding curvatures on the second adapter end, which
in turn compresses the second adapter end into the receptacle to
form the seal. A locking ring may restrain the cam locks from
rotation while the seal is enabled. The pressure control fitting
may be operated by a remote control.
SUMMARY
[0006] A wellhead pressure control fitting according to one aspect
of the present disclosure includes a generally tubular Pressure
Control Equipment (PCE) adapter configured to mate with a pressure
control assembly. The generally tubular pressure control assembly
is configured to mate with a wellhead and has a plurality of cam
locks, wherein each cam lock is configured to rotate. Means for
rotating the cam locks is provided so as to urge the adapter into a
receptacle in the pressure control assembly to form a pressure
tight seal between the adapter and the assembly. A sensor is
associated with each cam lock. The sensor is arranged to measure a
parameter related to an amount of rotation of each cam lock.
[0007] In some embodiments, the sensor associated with each cam
lock comprises a rotary encoder disposed on a cam lock pin.
[0008] In some embodiments, the sensor associated with each cam
lock comprises a proximity sensor arranged to measured extension of
each cam lock piston.
[0009] In some embodiments, the sensor associated with each cam
lock comprises an accelerometer arranged to measure a rotational
orientation of each cam lock.
[0010] In some embodiments, the sensor associated with each cam
lock comprises a limit switch arranged to electrically close or
open only when the associated cam lock is fully rotated to a locked
position.
[0011] In some embodiments, the sensor associated with each cam
lock comprises a strain gauge.
[0012] In some embodiments, the sensor associated with each cam
lock comprises an optical sensor.
[0013] Some embodiments further comprise a locking ring comprising
means to extend and retract the locking ring, wherein retraction of
the locking ring causes the locking ring to move so as to restrain
the cam locks from rotation. Some embodiments further comprise a
locking ring sensor operatively engaged to the locking ring whereby
measurements made by the locking ring sensor correspond to full
engagement of the locking ring with the cam locks.
[0014] In some embodiments, the sensor associated with the locking
ring comprises a proximity sensor arranged to measure a parameter
related to extension of the locking. ring
[0015] In some embodiments, the sensor associated with the locking
ring comprises a proximity sensor.
[0016] In some embodiments, the sensor associated with the locking
ring comprises a limit switch arranged to electrically close or
open only when the locking ring is fully engaged with the cam
locks.
[0017] In some embodiments, the sensor associated with the locking
ring comprises a strain gauge.
[0018] In some embodiments, the sensor associated with the locking
ring comprises an optical sensor.
[0019] A wellhead pressure control fitting according to another
aspect of the present disclosure may include a generally tubular
Pressure Control Equipment (PCE) adapter configured to mate with a
pressure control assembly, the pressure control assembly being
configured to mate with a wellhead. The adapter provides a lower
wedge assembly. The lower wedge assembly includes a plurality of
lower wedges, each lower wedge having first and second opposing
lower wedge sides. Each first lower wedge side provides protruding
top and bottom lower wedge ribs and a generally hollow lower wedge
receptacle further providing a plurality of shaped lower wedge
receptacle recesses formed in an interior thereof wherein axial
displacement of the lower wedge receptacle relative to the lower
wedges causes corresponding radial displacement of the lower
wedges. A sensor is arranged to measure a parameter related to an
amount of engagement of the wedges with the wedge receptacle.
[0020] In some embodiments, the sensor comprises a proximity
switch.
[0021] In some embodiments, the sensor comprises a limit
switch.
[0022] In some embodiments, the sensor comprises a linear variable
differential transformer.
[0023] In some embodiments, the sensor comprises an acoustic range
finder.
[0024] A wellhead pressure control fitting according to another
aspect of the present disclosure includes a generally tubular
Pressure Control Equipment (PCE) adapter having first and second
adapter ends. The first adapter end is configured to mate with
pressure control equipment. The adapter provides an annular adapter
rib distal from the first adapter end towards the second adapter
end. A generally tubular pressure control assembly having first and
second assembly ends and a longitudinal centerline defines axial
displacement parallel to the centerline and radial displacement
perpendicular to the centerline. The first assembly end provides a
first assembly end interior, the second assembly end configured to
mate with a wellhead. the first assembly end interior provides a
PCE receptacle for receiving the second adapter end, the second
adapter end and the PCE receptacle further each providing
cooperating abutment surfaces. The cooperating abutment surfaces
form a pressure seal between the second adapter end and the PCE
receptacle when the second adapter end is received into the PCE
receptacle. The first assembly end interior further provides a
wedge assembly. The wedge assembly includes a plurality of wedges,
each wedge having first and second opposing wedge sides, and each
first wedge side providing protruding top and bottom wedge ribs. A
generally hollow wedge receptacle further provides a plurality of
shaped wedge receptacle recesses formed in an interior thereof, one
wedge receptacle recess for each wedge. The wedge receptacle also
has first and second opposing wedge receptacle sides in which the
wedge receptacle recesses define the first wedge receptacle side.
Each wedge is received into a corresponding wedge receptacle recess
so that the first wedge receptacle side and the second wedge sides
provide opposing sloped wedge surfaces, wherein axial displacement
of the upper receptacle relative to the wedges causes corresponding
radial displacement of the wedges. As the second adapter end enters
the PCE receptacle and engages the cooperating abutment surfaces,
axial displacement of the wedge receptacle relative to the wedges
causes corresponding radial constriction of the top and bottom
wedge ribs around the adapter rib, which in turn restrains the
adapter from axial displacement relative to the PCE receptacle. A
sensor is arranged to measure a parameter related to an amount of
engagement of the wedges with the wedge receptacle.
[0025] In some embodiments, the sensor comprises a proximity
switch.
[0026] In some embodiments, the sensor comprises a limit
switch.
[0027] In some embodiments, the sensor comprises a linear variable
differential transformer.
[0028] In some embodiments, the sensor comprises an acoustic range
finder.
[0029] A wellhead pressure control fitting according to another
aspect of the present disclosure comprises a generally tubular
Pressure Control Equipment (PCE) adapter having first and second
adapter ends. The first adapter end is configured to mate with
pressure control equipment. The second adapter end provides a
shaped end including an adapter end curvature. A generally tubular
pressure control assembly has first and second assembly ends. The
first assembly end provides a first assembly end interior and a
first assembly end exterior. The second assembly end is configured
to mate with a wellhead. The first assembly end exterior has an
exterior periphery providing a plurality of locking elements each
disposed to lock the PCE adapter within the first assembly end. A
locking ring has a plurality of locking ring actuators extensible
to urge the locking ring to an unlocked position wherein the
plurality of locking elements are disenagageable from the PCE
adapter and a locked position wherein the locking elements retain
the PCE adapter within the first assembly end. At least one sensor
is associated the locking ring and is arranged to communicate a
signal when the locking ring is in the locked position.
[0030] In some embodiments, the at least one sensor comprises a
plurality of switches each disposed adjacent to a guide pin such
that full longitudinal retraction of the locking ring closes all
the plurality of switches.
[0031] Other aspects and advantages will be apparent from the
description and claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIGS. 1 through 9 show operation of a wellhead pressure
control fitting using cam locks to secure a pressure control
equipment adapter into pressure control equipment that may be
coupled to a wellhead.
[0033] FIG. 10 shows one example embodiment of a sensor that can
measure a parameter related to the amount of closure of a cam lock
onto a pressure control equipment adapter.
[0034] FIG. 11 shows other example embodiments of sensors that can
measure parameters related to the amount of closure of the cam
locks.
[0035] FIGS. 12 through 14 illustrate one embodiment of a
spring-driven ball race seal designed to provide a high pressure
seal for wellhead pressure control fittings, in which FIG. 12 is a
perspective cutaway view, FIGS. 13A and 13B are partial section
views in an unlocked position and a locked position respectively,
and FIG. 14 is an exploded view.
[0036] FIGS. 15 through 22 illustrate two embodiments of a wedge
seal, each also designed to provide a high pressure seal for
wellhead pressure control fittings, in which FIGS. 15 through 18
illustrate a first wedge seal embodiment and FIGS. 19 through 22
illustrate a second wedge seal embodiment. FIG. 15 is a perspective
cutaway view of the first wedge seal embodiment.
[0037] FIGS. 16A and 16B are partial section views of an upper end
of the first wedge seal embodiment in an unlocked position and a
locked position respectively.
[0038] FIGS. 17A and 17B are partial section views of a lower end
of the first wedge seal embodiment in an unlocked position and a
locked position respectively.
[0039] FIG. 18 is an exploded view of the first wedge seal
embodiment.
[0040] FIG. 19 is a perspective cutaway view of the second wedge
seal embodiment.
[0041] FIGS. 20A and 20B are partial section views of an upper end
of the second wedge seal embodiment in an unlocked position and a
locked position respectively.
[0042] FIGS. 21A and 21B are partial section views of a lower end
of the second wedge seal embodiment in an unlocked position and a
locked position respectively.
[0043] FIG. 22 is an exploded view of the second wedge seal
embodiment.
[0044] FIG. 23 shows another possible embodiment of a sensor
arrangement to determine status of a lock ring.
[0045] FIG. 24 shows a cross-section of the embodiment shown in
FIG. 23.
DETAILED DESCRIPTION
[0046] Components and operation of one example embodiment of a
wellhead pressure control fitting will be described with reference
to FIGS. 1 through 9. Such description is related to what is
disclosed in U.S. Pat. No. 9,644,443 issued to Johansen et al.
Example embodiments of a device according to the present disclosure
provide sensors arranged to detect whether such pressure control
fitting as described in the '443 patent is in condition to have
well pressure applied, such that a user can be informed of such
condition remotely without the need for visual observation.
[0047] FIGS. 1 through 9 are a freeze-frame series of illustrations
showing an example embodiment of a pressure control adapter and its
operation. The example embodiment shown in FIGS. 1 through 9 is
only intended to illustrate components that may be used in
accordance with the present disclosure and such illustrated
embodiments is in no way intended to limit the scope of the present
disclosure. In FIG. 1, pressure control equipment ("PCE") is
labeled generally as P, and wellhead is labeled generally as W. A
pressure control assembly 200 may be secured to the wellhead W
using a conventional bolted flange, although the present disclosure
is not limited in this regard. The wellhead end of the pressure
control assembly 200 may advantageously provide a customized
fitting F to connect to the wellhead W. An adapter 250 is secured
to the PCE P using conventional threading, although again this
disclosure is not limited to a threaded connection between PCE P
and adapter 250.
[0048] In FIG. 2, the PCE has been lifted and moved over the
pressure control assembly 200 using, for example, a conventional
crane (not shown). Entry of the adapter 250 into the pressure
control assembly 200 is facilitated by a tulip 201, which is a
conically-shaped piece. For reference, a locking ring 240 and link
arms 235 are also shown in FIG. 2. FIG. 3 is an elevation view of a
top portion of the pressure control assembly 200 in more detail.
The tulip 201, a locking ring 240, link arms 235 and cam locks 220
are shown in FIG. 3. It will be appreciated that in FIG. 3, the
locking ring 240 and cam locks 220 are in their disengaged
position. One of a plurality of locking ring pistons 242 is also
visible in FIG. 3 in a partially extended state. Locking ring
pistons 242 are preferably conventional hydraulic pistons and may
be circumferentially disposed around the PCE.
[0049] FIG. 4 is an elevational view of what is shown in FIG. 3,
except in partial cutaway view to illustrate more clearly the
component parts of pressure control assembly 200. The tulip 201,
the locking ring 240, the cam locks 220, the link arms 235 and the
cam lock pistons 222 are all visible in FIG. 4. It will also be
appreciated that the cam lock pistons 222, link arms 235 and cam
locks 220 together form a pinned linkage in which extension and
retraction of the cam lock pistons 222 will cause cam locks 220
each to rotate about a corresponding cam lock pin 224. Cam lock
pistons 222 are preferably conventional hydraulic pistons.
[0050] FIG. 5 shows the adapter 250 (attached to PCE) entering the
pressure control assembly 200 with the assistance of the tulip 201.
A receptacle 260 for the adapter 250 is also illustrated, waiting
to receive adapter 250. Conventional o-rings 252 are visible on the
adapter 250.
[0051] FIG. 6 is similar to what is shown in FIG. 5 except that the
adapter 250 is shown moving closer to its seat in the receptacle
260. FIGS. 7 through 9 are magnified freeze-frame views as the
adapter 250 engages its seat in the receptacle 260. As will be
described in greater detail, FIGS. 7 and 8 show features regarding
the seating of the adapter 250 in the receptacle 260. First, the
adapter 250 is designed to fit in the receptacle 260 so as to
provide a high pressure seal when the adapter 250 connection to the
receptacle 260 is in compression. Second, a shoulder 254 on the
adapter 250 presents a curvature that is shaped and located to
match a corresponding cam curvature 225 (refer to FIG. 8) on the
cam locks 220. As the cam locks 220 rotate responsive to extension
of the respective cam lock pistons 222, the cam curvatures 225 on
the cam locks 220 engage the shoulder 254 and compress the adapter
250 into the receptacle 260.
[0052] In FIGS. 7 and 8, the locking ring 240 has been moved away
from the cam locks 220 by fully extending the locking ring pistons
242 (pistons 242 are not shown in FIGS. 7 and 8, see FIG. 3
instead). FIGS. 7 and 8 also illustrate the cam lock linkage in
more detail, discussed above with reference to previously described
figures. With particular reference to FIG. 8, it may be observed
that the cam locks 220 are disposed to rotate about corresponding
cam lock pins 224. The cam locks 220 each present cam curvatures
225. The cam locks 220 are each in pinned linkage connection to a
corresponding one of the cam lock pistons 222 via link arms 235,
and first and second linkage pins 236 and 237.
[0053] Referring now to FIG. 7, the cam locks 220 provide cam lock
notches 226 in order to assist capture of the shoulder 254 on the
adapter 250. With reference now to FIGS. 8 and 9, it may be
observed that once the cam lock notches 226 have engaged the
shoulder 254, further rotation of the cam locks 220 around the cam
lock pins 224 encourages snug engagement of the cam curvatures 225
on the shoulder 254 in order to provide a high pressure seal
between the adapter 250 and the receptacle 260. The relative
dimensions, geometries, locations in space, and paths of travel of
the cam lock pistons 222, first and second linkage pins 236 and
237, link arms 235, cam locks 220, cam lock pins 224, cam lock
notches 226 and cam curvatures 225 are all designed to cooperate
with corresponding selections of dimensions and geometries on the
shoulder 254, seat surface 255 and slope surface 256 on the adapter
250 interfacing with the receptacle 260, all to provide a
high-pressure seal by compression of the adapter 250 into the
receptacle 260. In some embodiments, there may be about a
5-thousandths of an inch (0.005'') clearance between the exterior
cylindrical surface of the adapter 250 and the interior cylindrical
surface of the receptacle 260. This clearance allows for a high
pressure seal capability using o-rings 252. Further, as may be
observed in FIGS. 7 through 9, the adapter 250 has machined
surfaces on the seat surface 255 and the slope surface 256. The
receptacle 260 also provides corresponding machined surfaces shaped
to match the seat surface 255 and the slope surface 256.
Compression of the adapter 250 into the receptacle 260 thus enables
a machined surface metal-to-metal seal at the seat surface 255 and
slope surface 256. This metal-to-metal seal is designed to contain
high pressures--up to about 15,000 psi MAWP in some embodiments.
However, with reference to the cooperating abutment surfaces at the
interface of adapter 250 and receptacle 260, it will appreciated
that the scope of this disclosure is not limited to embodiments
providing a machined surface metal-to-metal seal at seat surface
255 and slope surface 256, and that other embodiments may provide
other suitable sealing arrangements.
[0054] Still with reference to FIGS. 7 and 8, and including FIG. 9,
the operation of the cam locks 220 to compress adapter 250 into
receptacle 260 is illustrated, thereby enabling the high pressure
seal discussed above. In FIG. 7, the adapter 250 is entering the
receptacle 260. Cam lock pistons 222 are fully retracted, and cam
curvatures 225 are disengaged. In FIG. 8, extension of cam lock
pistons 222 has begun, causing rotation of cam locks 220 about cam
lock pins 224 such that cam lock notches 226 have assisted capture
of shoulder 254 on adapter 250. In FIG. 9, cam lock pistons 222 are
fully extended. The pinned linkage of cam locks 220 to cam lock
piston 222 (via link arm 235 and first and second linkage pins 236
and 237) may be observed to have translated the extension of cam
lock pistons 222 into rotation of cam locks 220 about cam lock pins
224. Rotation of cam locks 220 about cam lock pins 224 brings cam
curvatures 225 to bear on shoulder 254 on adapter 250. Cooperating
abutment surfaces at the contact interface of adapter 250 and
receptacle 260 are compressed together to form a high pressure
seal.
[0055] In FIG. 9, it may be observed that the linkage between cam
locks 220, link arms 235 and cam lock pistons 222 is configured so
that when cam locks 220 are fully engaged on shoulder 254, locking
ring 240 may be lowered to engage cam locks 220. Engagement of cam
locks 220 by locking ring 240 is via full retraction of locking
ring pistons 242 (pistons 242 are not shown on FIG. 9, see FIG. 3).
Cam locks 220 also provide cam lock tapers 227 in order to assist
capture of cam locks 220 by locking ring 240. With continuing
reference to FIG. 10, it will may be observed that as locking ring
240 is lowered to retain and secure cam locks 220 in an engaged
position on shoulder 254, corresponding locking ring tapers 241 on
locking ring 240 cooperate with cam lock tapers 227 to assist
engagement of locking ring 240 on cam locks 220. In some
embodiments, locking ring 240 may be shaped and sized to provide an
interference fit between itself and cam locks 220 to retain and
secure them once fully engaged on cam locks 220.
[0056] The action of locking ring 240 to secure cam locks 220 is
primarily for safety purposes, to prevent cam locks 220 from
becoming disengaged from shoulder 254 on adapter 250 in the event
of a loss in hydraulic pressure (or otherwise) potentially
compromising the high-pressure seal between adapter 250 and
receptacle 260. However, it will be appreciated from the
immediately preceding paragraphs that the interference fit between
locking ring 240 and cam locks 220 also enables, as a secondary
effect, an additional "squeezing" force on cam locks 220 when fully
engaged on shoulder 254 on adapter 250.
[0057] It will be appreciated that in some embodiments, extension
and retraction of cam lock pistons 222 and locking ring pistons 242
may be done by remote hydraulic operation, fulfilling one of the
technical advantages of the disclosed pressure control apparatus as
discussed earlier in this disclosure. It will be further
appreciated that the "engineered motion and fit" of the cooperating
parts as illustrated on FIGS. 7 through 9 are not limited any
particular embodiment that might generate a high-pressure seal for
a certain size or model of the disclosed pressure control
apparatus. It will be appreciated that, consistent with the scope
of this disclosure, many such "engineered motion and fit"
arrangements may be selected and designed for different sizes or
models in which the disclosed pressure control apparatus may be
embodied.
[0058] Having described a mechanism to sealingly engage the adapter
250 with the receptacle 260, various embodiments will now be
explained of devices to measure whether the cam locks 220 have been
fully engaged to seat the adapter 250 in the receptacle.
[0059] In FIG. 10, one of the cam lock pistons 222 is shown
protruding from the bottom of its cylinder. A disk shaped head 222A
may be disposed on the bottom of each cam lock piston 222 such that
when the cam lock piston 222 is fully extended (see FIG. 9), the
position of the head 222A may be measured by a sensor 10. The
sensor 10 may be, for example, a limit switch that closes or opens
when the head 222A contacts the sensor 10. The sensor 10 may also,
for example, be a proximity sensor such as an electromagnetic or
capacitive proximity sensor. Irrespective of the type of sensor
used for the sensor 10 shown in FIG. 10, the sensor measures a
parameter related to the amount of extension of the associated cam
lock piston 222. A corresponding sensor may be provided for each of
the cam lock pistons 222 on the apparatus explained with reference
to FIGS. 1 through 9. Thus, if any one or more of the sensors 10
indicates that the corresponding cam lock piston 222 is not fully
extended, a signal may be generated and communicated to the
apparatus operator that the one or more cam locks (220 in FIG. 9)
is not fully engaged, and that the adapter (250 in FIG. 9) may not
be fully seated in the receptacle (260 in FIG. 9). In such
instance, the apparatus operator will have warning that opening any
pressure valve in the wellhead (W in FIG. 1) may be unsafe. In such
instance, the cam locks may all be released and the adapter seating
operation may be repeated until all the sensors 10 indicate full
extension of each of the cam lock pistons 222.
[0060] Other example embodiments of sensors that may make
measurements corresponding to the amount of rotation of the cam
locks 220 may be better understood with reference to FIG. 11. For
example, a rotary encoder 16 may be affixed to each cam lock pin
224 to measure the amount of rotation of each cam lock 220. An
accelerometer or level sensor 12 may make measurements related to
the relative orientation of the cam lock 220 with reference to
Earth's gravity, and thus corresponding to the rotational position
of the cam lock 220. Other types of sensors may comprise a spring
loaded limit switch 14 that extends (and thereby opens or closes
electrically) only when the cam lock 220 is rotated to its fully
closed position, that is, fully engaged to the adapter (250 in FIG.
9). Other sensors which may be used in accordance with the present
disclosure include optical sensors such as a lamp or LED and
photoresistor, and force sensitive resistors such as strain
gauges.
[0061] In some embodiments, similar configurations of sensors may
be used in connection with the lock ring (240 in FIG. 7) to measure
whether the lock ring 240 is fully seated against the cam locks
220.
[0062] A fitting and sensor system made in accordance with
principles of the example embodiments described with reference to
FIGS. 1-11 may provide a system user with remote indication of
whether the adapter is fully seated, locked and sealed in the
adapter (or any corresponding structures) prior to opening any well
pressure control devices. Such remote indication may increase the
safety and efficiency with which a system such as described in U.S.
Pat. No. 9,644,443 issued to Johansen et al. may be used.
[0063] FIGS. 12 through 14 illustrate one example embodiment of a
spring-driven ball race seal assembly 700 for providing a high
pressure seal for wellhead pressure control fittings. The
description which follows with reference to FIGS. 12 through 22
similar to what is disclosed in U.S. Pat. No. 9,670,745 issued to
Johansen et al.
[0064] FIGS. 12 through 14 should be viewed together. FIG. 12 is an
isometric section view of ball race seal assembly 700, and FIG. 14
is an exploded view of FIG. 12. FIG. 12 shows a ball race seal
assembly 700 in the locked position. FIGS. 13A and 13B are
freeze-frame views of ball race seal assembly 700 in partial
section, illustrating ball race seal assembly 700 in its unlocked
position (FIG. 13A) and locked position (FIG. 13B). For clarity in
FIGS. 12 through 14, and to reduce clutter in the drawings,
conventional sealing parts such as o-rings are either shown but not
called out as separate parts, or are omitted altogether.
[0065] Referring first to FIG. 12, receptacle 760 is generally
tubular and provides an exterior annular cutout at a first end that
forms an elongate receptacle sealing portion 762 at the first end.
A second end of receptacle 760 provides a flange or other suitable
connection to a wellhead, or to equipment interposed between
receptacle 760 and the wellhead. PCE adapter 750 is also generally
tubular and provides a suitable connection, such as a threaded
connection, to pressure control equipment (PCE) at a first end.
Adapter 750 further provides an interior annular cutout at a second
end that forms an elongate adapter sealing portion 752 at the
second end. Adapter sealing portion 752 and receptacle sealing
portion 762 are shaped and dimensioned such that when adapter
sealing portion 752 is received over receptacle sealing portion 762
and constrained radially outwards, a pressure seal is formed
between adapter sealing portion 752 and receptacle sealing portion
762. O-rings 761 facilitate the seal.
[0066] Lower body 710 is generally tubular, and is received over
and affixed to the exterior of receptacle 760 via threading or
other suitable connection. Lower body 710 has first and second
ends, and is affixed at its second end to receptacle 760. The first
end of lower body 710 extends parallel with receptacle sealing
portion 762 and is positioned to constrain adapter sealing portion
752 radially when adapter sealing portion 752 is in sealing
engagement with receptacle sealing portion 762.
[0067] Referring briefly to FIG. 14, ball race cylinder 720
provides holes 722 to receive ball bearings 721 and retain them
externally. It will be understood that although holes 722 are small
enough to retain ball bearings 721 externally, ball bearings 721
may nonetheless roll freely within holes 722 while protruding
internally through holes 722. Referring once again to FIG. 12, ball
race cylinder has first and second ends. The second end of ball
race cylinder 720 (including ball bearings 721) is positioned at
the first end of lower body 710 such that ball bearings 721, when
protruding internally through holes 722, roll against an exterior
surface of adapter 750 as adapter sealing portion 752 is brought to
engage over receptacle sealing portion 762. The exterior surface of
adapter 750 further provides annular adapter grooves 751 that are
positioned and dimensioned to receive ball bearings 721 (as ball
bearings 721 protrude internally through holes 722) when adapter
sealing portion 752 is fully engaged over receptacle sealing
portion 762. Adapter grooves 751 are further positioned, sized and
shaped such that adapter sealing portion 752 is locked in sealing
engagement with receptacle sealing portion 762 when ball bearings
721 are compressed into adapter grooves 751.
[0068] Floating member 730 is generally tubular and is received
over lower body 710 and ball race cylinder 720. Floating member 730
has first and second ends. The first end of floating member 730
retains ball bearings 721 in holes 722, while the interior of the
second end of floating member 730 is in sealing engagement with the
exterior of lower body 710. The first end of floating member 730
further provides a thickened floating member locking portion 731
which, when engaged on ball bearings 721, compresses ball bearings
721 into adapter grooves 751.
[0069] Sleeve 770 is generally tubular and is received over ball
race cylinder 720, floating member 730 and lower body 710. Sleeve
770 has first and second ends. The second end of sleeve 770 is
affixed to the exterior of the second end of lower body 710 by
threading or other suitable connection. The first end of sleeve 770
is further positioned, dimensioned and shaped to be in sealing
engagement with the first end of ball race cylinder 720.
[0070] With reference now to FIG. 14, sleeve 700 has an interior
annular sleeve cavity 771 formed therein. With reference now to
FIG. 18, floating member 730 resides within sleeve cavity 771 so as
to create a sealed annular upper chamber 740 above the first end of
floating member 730 and a sealed annular lower chamber 745 below
the second end of floating member 730. Upper and lower chamber
ports 741 and 746 are provided in sleeve 770 to supply hydraulic
fluid to and from upper and lower chambers 740 and 745
respectively. Compression spring 735 resides in upper chamber 740
and is biased to encourage floating member 730 to a position
furthest away from the first end of sleeve 770.
[0071] FIGS. 13A and 13B illustrate the operation of ball race seal
assembly 700 from an unlocked position in FIG. 13A to a locked
position in FIG. 13B. In FIG. 13A, hydraulic fluid is introduced
through lower chamber port 746 (and denoted by the large arrow on
FIG. 19A) and pressurizes lower chamber 745, moving floating member
730 towards the first end of sleeve 770 in the direction of the
small vertical arrow on FIG. 13A and against the bias of
compression spring 735. Thickened floating member locking portion
731 of locking member 730 is disengaged from ball bearings 721,
allowing ball bearings 721 to displace radially outwards in the
direction of the small horizontal arrows on FIG. 19A. At this time,
adapter 750 is free to be brought into engagement with receptacle
760, such that adapter sealing portion 752 may form a seal over
receptacle scaling portion 762, while also being constrained
radially by lower body 710.
[0072] Turning now to FIG. 13B, adapter sealing portion 752 is now
fully engaged over receptacle sealing portion, and adapter grooves
751 are now positioned adjacent to ball bearings 721. Hydraulic
fluid is introduced through upper chamber port 741 (and denoted by
the large arrow on FIG. 19B) and pressurizes upper chamber 740,
moving floating member 730 towards the second end of sleeve 770 in
the direction of the small vertical arrow on FIG. 13B and assisted
by the bias of compression spring 735. Thickened floating member
locking portion 731 of locking member 730 engages ball bearings
721, compressing ball bearings 721 into adapter grooves in the
direction of the small horizontal arrows on FIG. 13B, and thereby
locking adapter sealing portion 752 in sealing engagement with
receptacle sealing portion 762.
[0073] FIG. 13B shows a sensor 730A that is arranged to measure a
parameter related to the amount of movement of the locking member
730 toward the bottom of or the second end of the sleeve 770.
Measurements of the parameter related to the amount of movement of
the locking member 730 may be used to determine that the locking
member has moved fully so as to cause engagement of the ball
bearings 721 into the adapter grooves 751 in the adapter 750,
thereby indicating that the adapter 750 is fully engaged with the
receptacle 760. Non-limiting examples of types of sensors that may
be used in various embodiments for the sensor 730A may comprise,
proximity switches, limit switches, linear variable differential
transformers (LVDTs) and acoustic range finders, although the
foregoing examples are not to be construed as limits on the scope
of the present disclosure.
[0074] FIGS. 15 through 22 illustrate two embodiments of a wedge
seal design for providing a high pressure seal for wellhead
pressure control fittings. FIGS. 15 through 18 illustrate a first
embodiment, wedge seal assembly 800, in which opposing sloped sides
of wedges are driven in reciprocating motion directly by hydraulic
fluid pressure. FIGS. 19 through 22 illustrate a second embodiment,
wedge seal assembly 900, in which the opposing sloped sides of the
wedges are driven by hydraulically-actuated pistons.
[0075] Turning first to FIGS. 15 through 18, wedge seal assembly
800 is illustrated for providing a high pressure seal for wellhead
pressure control fittings. FIGS. 15 through 18 should be viewed
together. FIG. 15 is an isometric section view of wedge seal
assembly 800, and FIG. 18 is an exploded view of FIG. 15. FIG. 15
depicts wedge seal assembly 800 in the locked position. FIGS. 16A
and 16B are freeze-frame views of wedge seal assembly 800 in
partial section at the upper end, illustrating engagement of upper
adapter rib 851 on adapter 850. FIG. 16A illustrates wedge seal
assembly 800 in its unlocked position prior to engagement of upper
adapter rib 851 and FIG. 16B illustrates wedge seal assembly 800 in
its locked position over upper adapter rib 851.
[0076] A sensor 825A may be disposed in a wedge receptacle,
explained further below, to make a measurement corresponding to the
amount of compression of the wedge seal assembly. The sensor 825
may be, for example, any of the types of sensors described with
reference to FIG. 13B, and may include, without limitation,
proximity switches, limit switches, linear variable differential
transformers (LVDTs) and acoustic range finders, although the
foregoing examples are not to be construed as limits on the scope
of the present disclosure.
[0077] FIGS. 17A and 17B are freeze-frame views of wedge seal
assembly 800 in partial section at the lower end, illustrating
engagement of lower adapter rib 852 on adapter 850. FIG. 17A
illustrates wedge seal assembly 800 in its unlocked position prior
to engagement of lower adapter rib 852 and FIG. 17B illustrates
wedge seal assembly 800 in its locked position over lower adapter
rib 852. For clarity in FIGS. 15 through 18, and to reduce clutter
in the drawings, conventional sealing parts such as o-rings are
either shown but not called out as separate parts, or are omitted
altogether. Further, not all parts on wedge seal assembly 800 are
shown on freeze-frame FIGS. 16A through 17B. Some parts have been
omitted for clarity in FIGS. 16A through 17B so that the unlocking
and locking mechanisms of wedge seal assembly 800 can be
appreciated more clearly.
[0078] By way of introduction to wedge seal assembly 800 in more
detail, FIGS. 17A and 17B illustrate that the high pressure seal
between adapter 850 and receptacle 860 is functionally analogous to
the high pressure seal between adapter 250 and receptacle 260
described above with reference to FIGS. 6 through 9. Referring to
FIGS. 17A and 17B, adapter 850 provides machined surfaces on seat
surface 855 and slope surface 856. Receptacle 860 also provides
corresponding machined surfaces shaped to match seat surface 855
and slope surface 856 at a first (distal) end 861 thereof. It will
be appreciated compression of adapter 850 into receptacle 860 on
wedge seal assembly 800 as depicted in FIGS. 17A and 17B enables a
machined surface metal-to-metal seal at seat surface 855 and slope
surface 856.
[0079] A primary distinction between the embodiment of wedge seal
assembly 800 (as depicted in FIGS. 17A and 17B) over the embodiment
of pressure control assembly 200 (as depicted in FIGS. 6 through 9)
arises in the mechanism by which wedge seal assembly 800 compresses
adapter 850 into receptacle 860 to form a high pressure seal. With
reference first to FIG. 17B, when adapter 850 is received into seal
engagement with receptacle 860, lower adapter rib 852 is presented
for engagement with lower wedge 840. Lower wedge 840 provides lower
wedge top and bottom ribs 843 and 844. Hydraulic fluid is
introduced under pressure through lower engage port 832 into lower
engage chamber 831, as denoted by the large arrow on FIG. 17B.
Pressurization of lower engage chamber 831 causes movement of lower
wedge receptacle 845 in the direction of the small vertical arrow
on FIG. 17B (i.e., in a direction away from the wellhead), assisted
by the bias of lower compression spring 846. This movement of lower
wedge receptacle 845 compresses lower wedge 840 radially against
the engagement of adapter 850 and receptacle 860, in the direction
of the small horizontal arrows on FIG. 17B. Lower wedge top rib 843
locks over lower adapter rib 852 and lower wedge bottom rib 844
locks into wedge groove 865 provided in receptacle 860.
[0080] Referring again to FIG. 17A, the release of the high
pressure seal enabled by wedge seal assembly 800 is substantially
the reverse of the disclosure immediately above describing FIG.
17B. Hydraulic fluid is introduced under pressure through lower
release port 834 into lower release chamber 833, as denoted by the
large arrow in FIG. 17A. It will be understood that at the same
time, hydraulic fluid pressure is released in lower engage chamber
831 through lower engage port 832. Pressurization of lower release
chamber 833 causes movement of lower wedge receptacle 845 in the
direction of the small vertical arrow on FIG. 17A (i.e., in a
direction towards the wellhead), against the bias of lower
compression spring 846. This movement of lower wedge receptacle 845
releases lower wedge 840 from its engagement of lower adapter rib
852 and wedge groove 865, in the direction of the small horizontal
arrows on FIG. 17A. Adapter 850 and receptacle 860 are now free to
separate, releasing the high pressure seal between them.
[0081] It will be appreciated that first from reference to FIG. 15,
and then to FIGS. 16A and 16B, the high pressure seal provided by
wedge seal assembly 800 is assisted by a locking mechanism further
above the seal, where upper adapter rib 851 is engaged by upper
wedge 820. For the avoidance of doubt, it should be understood that
the engagement of upper adapter rib 851 per FIGS. 16A and 16B is
not a seal, but a lock that holds adapter 850 in sealing engagement
with receptacle 860 as described immediately above with reference
to FIGS. 17A and 17B. It will be therefore necessarily understood
that in the embodiment of wedge seal assembly 800 illustrated on
FIGS. 15 through 18, upper adapter rib 851 may be engaged and
released by upper wedge 820 independently of the engagement and
release of lower adapter rib 852 by lower wedge 840.
[0082] With reference now to FIGS. 16B and 17B, when adapter 850 is
received into seal engagement with receptacle 860, upper adapter
rib 851 is presented for engagement with upper wedge 820. Upper
wedge 820 provides upper wedge top and bottom ribs 823 and 824.
Hydraulic fluid is introduced under pressure through upper engage
port 812 into upper engage chamber 811, as denoted by the large
arrow on FIG. 16B. Pressurization of upper engage chamber 811
causes movement of upper wedge receptacle 825 in the direction of
the small vertical arrow on FIG. 16B (i.e., in a direction away
from the wellhead), assisted by the bias of upper compression
spring 826. This movement of upper wedge receptacle 825 compresses
upper wedge 820 radially against upper adapter rib 851, in the
direction of the small horizontal arrows on FIG. 16B. Upper wedge
top and bottom ribs 823 and 824 lock over upper adapter rib 851 and
further restrain adapter 850 from movement relative to the high
pressure seal below (seal shown on FIG. 17B).
[0083] Referring now to FIG. 16A, the release of the locking
mechanism over upper adapter rib 851 is substantially the reverse
of the disclosure immediately above describing FIG. 16B. Hydraulic
fluid is introduced under pressure through upper release port 814
into upper release chamber 813, as denoted by the large arrow on
FIG. 16A. It will be understood that at the same time, hydraulic
fluid pressure is released in upper engage chamber 811 through
upper engage port 812. Pressurization of upper release chamber 813
causes movement of upper wedge receptacle 825 in the direction of
the small vertical arrow on FIG. 16A (i.e., in a direction towards
the wellhead), against the bias of upper compression spring 826.
This movement of upper wedge receptacle 825 releases upper wedge
820 from its engagement of upper adapter rib 851, in the direction
of the small horizontal arrows on FIG. 16A.
[0084] Referring once again to FIGS. 15 and 18, wedge seal assembly
800 comprises a generally tubular receptacle 860 that provides an
exterior annular wedge groove 865 at a first end 861 thereof. A
second end of receptacle 860 provides a flange or other suitable
connection to a wellhead, or to equipment interposed between
receptacle 860 and the wellhead. PCE adapter 850 is also generally
tubular and provides a suitable connection, such as a threaded
connection, to pressure control equipment (PCE) at a first end.
Adapter 850 further provides a lower adapter rib 852 at a second
end proximate machined seal surfaces including seat surface 855 and
856. As described above with respect to FIG. 17B, the high pressure
seal between adapter 850 and receptacle 860 is functionally
analogous to the high pressure seal between adapter 250 and
receptacle 260 described above with reference to FIGS. 6 through
9.
[0085] Lower wedge receptacle 845 is generally cylindrical and is
received over the first end 861 of receptacle 860. Lower wedges 840
are received into shaped recesses 845A in lower wedge receptacle
845 and are positioned around the first end 861 of receptacle 860.
Three (3) lower wedges 840 are illustrated on FIGS. 15 and 18,
although the scope of this disclosure is not limited in this
regard. Lower wedges 840 are separated and kept in circumferential
bias by lower wedge separator springs 841. Six (6) lower wedge
separator springs 841 are illustrated in FIGS. 15 and 18, although
again, the scope of this disclosure is not limited in this regard.
Shaped recesses 845A and lower wedges 840 present opposing sloped
surfaces such that lower wedges 840 are caused to constrict and
expand radially within lower wedge receptacle 845 responsive to
axial displacement of lower wedge receptacle 845 relative to lower
wedges 840. Each lower wedge 840 further provides lower wedge top
and bottom ribs 843 and 844. Lower wedge top rib 843 is shaped and
positioned to be received over lower adapter rib 852 when adaptor
850 is sealingly received into receptacle 860. Lower wedge bottom
rib 844 is shaped and positioned to be received into wedge groove
865 on receptacle 860 when adaptor 850 is sealingly received into
receptacle 860.
[0086] Lower compression spring 846 is received over receptacle 860
and interposed between lower wedge receptacle 845 and the second
end of receptacle 860. Lower compression spring 846 is biased to
encourage radial constriction of lower wedges 840 via axial
displacement of lower wedge receptacle 845 relative to lower wedges
840.
[0087] Lower sleeve 804 is generally tubular and is received over
lower wedge receptacle 845 and lower compression spring 846.
Exterior ribs 845B on lower wedge receptacle 845 sealingly engage
with lower sleeve 804. Two (2) exterior ribs 845B are illustrated
on FIGS. 21 and 24, although the scope of this disclosure is not
limited in this regard. Lower sleeve 804 has first and second ends.
The second end of lower sleeve 804 is affixed to the exterior of
the second end of receptacle 860 by threading or other suitable
connection, and is advantageously further secured in place by
securement ring 805. The first end of lower sleeve 804 sealingly
engages with lower roof member 830. Lower roof member 830 also
contacts lower wedge top ribs 843. Lower engage chamber 831 is
formed by lower wedge receptacle 845 (including exterior ribs
845B), lower sleeve 804 and receptacle 860. Lower engage port 832
supplies and drains lower engage chamber 831 with hydraulic fluid.
Lower release chamber 833 is formed by lower wedge receptacle 845
(including exterior ribs 845B), lower sleeve 804 and lower roof
member 830. Lower release port 834 supplies and drains lower
release chamber 833 with hydraulic fluid.
[0088] With continuing reference to FIGS. 15 and 18, compression
spring retainer sleeve 827 is generally cylindrical and has first
and second ends. The second end of compression spring retainer
sleeve 827 is received into an interior annular recess 830A in
lower roof member 830. Upper wedge receptacle 825 is received over
the first end of compression spring retainer sleeve 827. Upper
wedges 820 are received into shaped recesses 825A in upper wedge
receptacle 825. Three (3) upper wedges 820 are illustrated on FIGS.
15 and 18, although the scope of this disclosure is not limited in
this regard. Upper wedges 820 are separated and kept in
circumferential bias by upper wedge separator springs 821. Six (6)
upper wedge separator springs 821 are illustrated in FIGS. 15 and
18, although again, the scope of this disclosure is not limited in
this regard. Shaped recesses 825A and upper wedges 820 present
opposing sloped surfaces such that upper wedges 820 are caused to
constrict and expand radially within upper wedge receptacle 825
responsive to axial displacement of upper wedge receptacle 825
relative to upper wedges 820. Each upper wedge 820 further provides
upper wedge top and bottom ribs 823 and 824. Upper wedge top and
bottom ribs 823 and 824 are shaped and positioned to enable upper
wedges 820 to constrict around and restrain upper adapter rib 851
when adaptor 850 is sealingly received into receptacle 860.
[0089] Upper compression spring 826 is received over compression
spring retainer sleeve 827 and interposed between upper wedge
receptacle 825 and lower roof member 830. Upper compression spring
826 is biased to encourage radial constriction of upper wedges 820
via axial displacement of lower wedge receptacle 825 relative to
lower wedges 820.
[0090] Upper sleeve 803 is generally tubular and is received over
upper wedge receptacle 825 and upper compression spring 826.
Exterior rib 825B on upper wedge receptacle 825 sealingly engages
with upper sleeve 803. One (1) exterior rib 825B is illustrated in
FIGS. 15 and 18, although the scope of this disclosure is not
limited in this regard. Upper sleeve 803 has first and second ends.
The second end of upper sleeve 803 is sealingly affixed to the
exterior of the first end of lower sleeve 804 by threading plus
gasket, or other suitable connection. The first end of upper sleeve
803 is sealingly engaged to upper roof member 810. Upper roof
member 810 also contacts upper wedge top ribs 823. Upper engage
chamber 811 is formed by upper wedge receptacle 825 (including
exterior rib 825B) and upper sleeve 803. Upper engage port 812
supplies and drains upper engage chamber 811 with hydraulic fluid.
Upper release chamber 813 is formed by upper wedge receptacle 825
(including exterior rib 825B), upper sleeve 803 and upper roof
member 810. Upper release port 814 supplies and drains upper
release chamber 813 with hydraulic fluid.
[0091] Upper roof member 810 is affixed to tulip 801. Tulip 801
provides tulip clearance 802 sufficient to allow upper and lower
adapter ribs 851 and 852 on adapter 850 to pass through tulip
801.
[0092] Referring now to FIGS. 19 through 22, wedge seal assembly
900 is illustrated for providing a high pressure seal for wellhead
pressure control fittings. FIGS. 19 through 22 should be viewed
together. FIG. 19 is an isometric section view of wedge seal
assembly 900, and FIG. 22 is an exploded view of FIG. 19. FIG. 19
depicts wedge seal assembly 900 in the locked position. FIGS. 20A
and 20B are freeze-frame views of wedge seal assembly 900 in
partial section at the upper end, illustrating engagement of upper
adapter rib 951 on adapter 950. FIG. 20A illustrates wedge seal
assembly 900 in its unlocked position prior to engagement of upper
adapter rib 951 and FIG. 20B illustrates wedge seal assembly 900 in
its locked position over upper adapter rib 951. FIGS. 21A and 21B
are freeze-frame views of wedge seal assembly 900 in partial
section at the lower end, illustrating engagement of lower adapter
rib 952 on adapter 950. FIG. 21A illustrates wedge seal assembly
900 in its unlocked position prior to engagement of lower adapter
rib 952 and FIG. 21B illustrates wedge seal assembly 900 in its
locked position over lower adapter rib 952. For clarity in FIGS. 19
through 22, and to reduce clutter in the drawings, conventional
sealing parts such as o-rings are either shown but not called out
as separate parts, or are omitted altogether. Further, not all
parts on wedge seal assembly 900 are shown in freeze-frame in FIGS.
20A through 21B. Some parts have been omitted for clarity on FIGS.
20A through 21B so that the unlocking and locking mechanisms of
wedge seal assembly 900 can be understood more clearly.
[0093] FIG. 20B shows an example sensor 925A that may be used to
measure a parameter related to the amount of compression of the
wedge seal assembly 900. For example the sensor 925A may be
proximity switches, limit switches, linear variable differential
transformers (LVDTs) and acoustic range finders, although the
foregoing examples are not to be construed as limits on the scope
of the present disclosure.
[0094] By way of introduction to wedge seal assembly 900 in more
detail, FIGS. 21A and 21B illustrate that the high pressure seal
between adapter 950 and receptacle 960 is functionally analogous to
the high pressure seal between adapter 250 and receptacle 260
described above with reference to FIGS. 6 through 9. Referring to
FIGS. 21A and 21B, adapter 950 provides machined surfaces on seat
surface 955 and slope surface 956. Receptacle 960 also provides
corresponding machined surfaces shaped to match seat surface 955
and slope surface 956 at a first (distal) end 961 thereof. It will
be appreciated that analogous to FIGS. 6 through 9 as described
above for pressure control assembly 200, compression of adapter 950
into receptacle 960 on wedge seal assembly 900 as depicted in FIGS.
21A and 21B enables a machined surface metal-to-metal seal at seat
surface 955 and slope surface 956.
[0095] A primary distinction between the embodiment of wedge seal
assembly 900 (as depicted on FIGS. 21A and 21B) over the embodiment
of pressure control assembly 200 (as depicted on FIGS. 6 through 9)
arises in the mechanism by which wedge seal assembly 900 compresses
adapter 950 into receptacle 960 to form a high pressure seal. With
reference first to FIG. 21B, when adapter 950 is received into seal
engagement with receptacle 960, lower adapter rib 952 is presented
for engagement with lower wedge 940. Lower wedge 940 provides lower
wedge top and bottom ribs 943 and 944. Hydraulic fluid is
introduced to actuate and extend lower piston 975, as denoted by
the large arrow on FIG. 21B. Extension of lower piston 975 causes
movement of lower wedge receptacle 945 in the direction of the
small vertical arrows on FIG. 21B (i.e., in a direction away from
the wellhead), assisted by the bias of lower compression spring
946. This movement of lower wedge receptacle 945 compresses lower
wedge 940 radially against the engagement of adapter 950 and
receptacle 960, in the direction of the small horizontal arrows on
FIG. 21B. Lower wedge top rib 943 locks over lower adapter rib 952
and lower wedge bottom rib 944 locks into wedge groove 965 provided
in receptacle 960.
[0096] Referring now to FIG. 21A, the release of the high pressure
seal enabled by wedge seal assembly 900 is substantially the
reverse of the disclosure immediately above describing FIG. 21B.
Hydraulic fluid is released to retract lower piston 975. Retraction
of lower piston 975 causes movement of lower wedge receptacle 945
in the direction of the small vertical arrows on FIG. 21A (i.e., in
a direction towards the wellhead), against the bias of lower
compression spring 946. This movement of lower wedge receptacle 945
releases lower wedge 940 from its engagement of lower adapter rib
952 and wedge groove 965, in the direction of the small horizontal
arrows on FIG. 21A. Adapter 950 and receptacle 960 are now free to
separate, releasing the high pressure seal between them.
[0097] It will be appreciated that first from reference to FIG. 19,
and then to FIGS. 20A and 20B, the high pressure seal provided by
wedge seal assembly 900 is assisted by a locking mechanism further
above the seal, where upper adapter rib 951 is engaged by upper
wedge 920. For the avoidance of doubt, it should be understood that
the engagement of upper adapter rib 951 per FIGS. 20A and 20B is
not a seal, but a lock that holds adapter 950 in sealing engagement
with receptacle 960 as described immediately above with reference
to FIGS. 21A and 21B. It will be therefore necessarily understood
that in the embodiment of wedge seal assembly 900 illustrated on
FIGS. 19 through 22, upper adapter rib 951 may be engaged and
released by upper wedge 920 independently of the engagement and
release of lower adapter rib 952 by lower wedge 940.
[0098] With reference now to FIG. 20B, when adapter 950 is received
into seal engagement with receptacle 960, upper adapter rib 951 is
presented for engagement with upper wedge 920. Upper wedge 920
provides upper wedge top and bottom ribs 923 and 924. Hydraulic
fluid is introduced to actuate and extend upper piston 970, as
denoted by the large arrow in FIG. 20B. Extension of upper piston
970 causes movement of upper wedge receptacle 925 in the direction
of the small vertical arrows on FIG. 20B (i.e., in a direction away
from the wellhead), assisted by the bias of upper compression
spring 926. This movement of upper wedge receptacle 925 compresses
upper wedge 920 radially against upper adapter rib 951, in the
direction of the small horizontal arrows on FIG. 20B. Upper wedge
top and bottom ribs 923 and 924 lock over upper adapter rib 951 and
further restrain adapter 950 from movement relative to the high
pressure seal below (seal shown on FIG. 21B).
[0099] Referring again to FIG. 20A, the release of the locking
mechanism over upper adapter rib 951 is substantially the reverse
of the disclosure immediately above describing FIG. 20B. Hydraulic
fluid is released to retract upper piston 970. Retraction of upper
piston 970 causes movement of upper wedge receptacle 925 in the
direction of the small vertical arrows on FIG. 20A (i.e., in a
direction towards the wellhead), against the bias of lower
compression spring 946. This movement of upper wedge receptacle 925
releases upper wedge 920 from its engagement of upper adapter rib
951, in the direction of the small horizontal arrows on FIG.
20A.
[0100] Referring again to FIGS. 19 and 22, wedge seal assembly 900
comprises a generally tubular receptacle 960 that provides an
exterior annular wedge groove 965 at a first end 961 thereof. A
second end of receptacle 960 provides a flange or other suitable
connection to a wellhead, or to equipment interposed between
receptacle 960 and the wellhead. PCE adapter 950 is also generally
tubular and provides a suitable connection, such as a threaded
connection, to pressure control equipment (PCE) at a first end.
Adapter 950 further provides a lower adapter rib 952 at a second
end proximate machined seal surfaces including seat surface 955 and
956. As described above with respect to FIG. 21B, the high pressure
seal between adapter 950 and receptacle 960 is functionally
analogous to the high pressure seal between adapter 250 and
receptacle 260 described above with reference to FIGS. 6 through
9.
[0101] Lower wedge receptacle 945 is generally cylindrical and is
received over the first end 961 of receptacle 960. Lower wedges 940
are received into shaped recesses 945A in lower wedge receptacle
945 and are positioned around the first end 961 of receptacle 860.
Three (3) lower wedges 940 are illustrated in FIGS. 19 and 22,
although the scope of this disclosure is not limited in this
regard. Lower wedges 940 are separated and kept in circumferential
bias by lower wedge separator springs 941. Six (6) lower wedge
separator springs 941 are illustrated in FIGS. 19 and 22, although
again, the scope of this disclosure is not limited in this regard.
Shaped recesses 945A and lower wedges 940 present opposing sloped
surfaces such that lower wedges 940 are caused to constrict and
expand radially within lower wedge receptacle 945 responsive to
axial displacement of lower wedge receptacle 945 relative to lower
wedges 940. Each lower wedge 940 further provides lower wedge top
and bottom ribs 943 and 944. Lower wedge top rib 943 is shaped and
positioned to be received over lower adapter rib 952 when adaptor
950 is sealingly received into receptacle 960. Lower wedge bottom
rib 944 is shaped and positioned to be received into wedge groove
965 on receptacle 960 when adaptor 950 is sealingly received into
receptacle 960.
[0102] Lower wedge receptacle 945 is received into lower wedge
receptacle retainer 949, and lower wedge receptacle ring 948
retains lower wedge receptacle 945 in lower wedge receptacle
retainer 949. Lower compression spring 946 is received over
receptacle 960 and interposed between lower wedge receptacle
retainer 949 and the second end of receptacle 960. Lower
compression spring 946 is biased to encourage radial constriction
of lower wedges 940 via axial displacement of lower wedge
receptacle 945 (within lower wedge receptacle retainer 949)
relative to lower wedges 940. Lower compression spring telescoping
retainer sleeves 947A and 947B are received over lower compression
spring 946 and also interposed between lower wedge receptacle
retainer 949 and the second end of receptacle 960. Lower
compression spring telescoping retainer sleeves 947A and 947B
extend and retract in register with extension and retraction of
lower compression spring 946.
[0103] Lower sleeve 904 is generally tubular and is received over
lower wedge receptacle retainer 949, lower compression spring
telescoping retainer sleeves 947A and 947B, and lower compression
spring 946. Lower sleeve 904 has first and second ends. The second
end of lower sleeve 904 is affixed to base ring 907. Base ring 907
is affixed to the exterior of the second end of receptacle 960 by
threading or other suitable connection, and lower sleeve 904 is
advantageously further secured in place on base ring 907 by lower
securement ring 905. The first end of lower sleeve 904 is affixed
to lower roof member 930. Lower roof member 930 also contacts lower
wedge top ribs 943. Lower pistons 975 are positioned in the annular
space between lower sleeve 904 and lower compression spring
telescoping retainer sleeves 947A and 947B, and are advantageously
secured to the exterior of receptacle 960 by bolts or other
suitable fasteners. Lower piston ports 976 supply and drain
hydraulic fluid from lower pistons 975. Two (2) lower pistons 975
are illustrated on FIGS. 19 and 22, although the scope of this
disclosure is not limited in this regard.
[0104] The cylinders of lower pistons 975 are connected to lower
wedge receptacle retainer 949. As noted above in disclosure
describing FIGS. 21A and 21B, extension and retraction of lower
pistons 975 cause radial constriction and expansion of lower wedges
949 via displacement of lower wedge receptacle 945 (as received
inside lower wedge receptacle retainer 949) with respect to lower
wedges 940.
[0105] With continuing reference to FIGS. 19 and 22, upper
compression spring retainer sleeve 927 is generally cylindrical and
has first and second ends. The second end of upper compression
spring retainer sleeve 927 is received into an interior annular
recess 930A in lower roof member 930. Upper wedge receptacle
retainer 929 is received over the first end of compression spring
retainer sleeve 927. Upper wedge receptacle 925 is received into
upper wedge receptacle retainer 929. Upper wedge receptacle ring
928 retains upper wedge receptacle 925 in upper wedge receptacle
retainer 929. The first end of upper compression spring retainer
sleeve 927 contacts upper wedge bottom ribs 924 on upper wedges
920.
[0106] Upper wedges 920 are also received into shaped recesses 925A
in upper wedge receptacle 925. Three (3) upper wedges 920 are
illustrated on FIGS. 19 and 22, although the scope of this
disclosure is not limited in this regard. Upper wedges 920 are
separated and kept in circumferential bias by upper wedge separator
springs 921. Six (6) upper wedge separator springs 921 are
illustrated in FIGS. 19 and 22, although again, the scope of this
disclosure is not limited in this regard. Shaped recesses 925A and
upper wedges 920 present opposing sloped surfaces such that upper
wedges 920 are caused to constrict and expand radially within upper
wedge receptacle 925 responsive to axial displacement of upper
wedge receptacle 925 relative to upper wedges 920. Each upper wedge
890 further provides upper wedge top and bottom ribs 923 and 924.
Upper wedge top and bottom ribs 923 and 924 are shaped and
positioned to enable upper wedges 920 to constrict around and
restrain upper adapter rib 951 when adaptor 950 is sealingly
received into receptacle 960.
[0107] Upper compression spring 926 is received over upper
compression spring retainer sleeve 927 and interposed between upper
wedge receptacle retainer 929 and lower roof member 930. Upper
compression spring 926 is biased to encourage radial constriction
of upper wedges 920 via axial displacement of upper wedge
receptacle 925 (within upper wedge receptacle retainer 929)
relative to upper wedges 920.
[0108] Upper sleeve 903 is generally tubular and is received over
upper wedge receptacle retainer 929 and upper compression spring
926. Upper sleeve 903 has first and second ends. The second end of
upper sleeve 803 is affixed to lower roof member 930 and secured in
place by upper securement ring 906. The first end of upper sleeve
903 is affixed to upper roof member 910. Upper roof member 910 also
contacts upper wedge top ribs 923. Upper pistons 970 are positioned
in the annular space between upper sleeve 903 and upper compression
spring retainer sleeve 927, and are advantageously secured to upper
sleeve 903 by bolts or other suitable fasteners. Upper piston ports
971 supply and drain hydraulic fluid from upper pistons 970. Two
(2) upper pistons 970 are illustrated on FIGS. 19 and 22, although
the scope of this disclosure is not limited in this regard.
[0109] The cylinders of upper pistons 970 are connected to upper
wedge receptacle retainer 929. As noted above in disclosure
describing FIGS. 20A and 20B, extension and retraction of upper
pistons 970 cause radial constriction and expansion of upper wedges
929 via displacement of upper wedge receptacle 925 (as received
inside upper wedge receptacle retainer 929) with respect to upper
wedges 920.
[0110] Upper roof member 910 is affixed to tulip 801. Tulip 901
provides tulip clearance 902 sufficient to allow upper and lower
adapter ribs 951 and 952 on adapter 950 to pass through tulip
901.
[0111] An embodiment of a sensor arrangement for determining
locking or engagement status of a locking ring, such as shown at
240 in FIG. 3 may be better understood with reference to FIG. 23. A
locking ring 2302 may perform a function similar to that explained
with reference to FIG. 3, that is, to hold locking elements in
their locked position. The locking ring 2302 may be moved
longitudinally such as by locking ring clamps 2300 shaped to engage
an exterior surface of the locking ring 2302 when a respective
locking ring actuator 2301 is affixed to the pressure control
assembly housing (e.g., 200 in FIG. 1). In the present example
embodiment there may be three, equally circumferentially spaced
locking ring actuators 2301, however the number of and
circumferential spacing of the locking ring actuators 2301 is not a
limit on the scope of the present disclosure. Each locking ring
actuator 2301 may comprise an hydraulic cylinder and piston 2304
disposed in a respective bore in the locking ring actuator 2301.
Each locking ring actuator may comprise a respective guide pin 2306
that moves longitudinally within the locking ring actuator 2301 as
the locking ring 2302 is moved longitudinally. A locking ring
longitudinal position switch 2308 may be disposed in each locking
ring actuator 2301 as will be further explained with reference to
FIG. 24 such that when all the locking ring actuators 2301 are
fully retracted (downward in FIGS. 23 and 24), a closed circuit is
made such that a signal may be generated in response to such full
retraction.
[0112] In FIG. 24, the respective positions of the hydraulic piston
and cylinders 2304, locking ring clamps 2300 and guide pins 2306A
used to actuate the switches 2308 may be observed in cross section.
When the hydraulic piston and cylinders 2304, locking ring clamps
2300 and guide pins 2306A are fully retracted longitudinally, all
switches 2308 will be closed. The switches 2308 may be connected in
electrical series such that a closed circuit exists when the
locking ring (2302 in FIG. 23) is fully retracted and in its
locking position. Such closed circuit may provide that a signal may
be generated and communicated to the apparatus operator that the
one or more hydraulic cylinders and pistons 2304) and consequently
the locking ring 2302 are not fully retracted, and that the adapter
(250 in FIG. 9) may not be fully seated in the receptacle (260 in
FIG. 9). In such instance, the apparatus operator will have warning
that opening any pressure valve in the wellhead (W in FIG. 1) may
be unsafe. In such instance, the hydraulic cylinders and pistons
2304 may be extended and the adapter seating operation may be
repeated until the switches 2308 all indicated full retraction of
the locking ring (2302 in FIG. 23).
[0113] The example embodiments of sensors described herein measure
a parameter related to longitudinal motion of a wedge or wedge
containing device as a proxy for measurement of the degree of
lateral compression of the wedges into corresponding receptacles.
It will be apparent to those skilled in the art that other types of
sensors may be arranged that more directly measure a parameter
related to lateral compression of the wedges into corresponding
receptacles yet be within the scope of the present disclosure.
[0114] A fitting and sensor system made in accordance with
principles of the example embodiments described with reference to
FIGS. 12-24 may provide a system user with remote indication of
whether the adapter is fully seated, locked and sealed in the
adapter (or any corresponding structures) prior to opening any well
pressure control devices. Such remote indication may increase the
safety and efficiency with which a system such as described in U.S.
Pat. No. 9,670,745 issued to Johansen et al. may be used.
[0115] Although only a few examples have been described in detail
above, those skilled in the art will readily appreciate that many
modifications are possible in the examples. Accordingly, all such
modifications are intended to be included within the scope of this
disclosure as defined in the following claims.
* * * * *