US20190145213A1

US20190145213A1 - Positive engagement indicator for remotely operated well pressure control apparatus

Info

Publication number: US20190145213A1
Application number: US16/188,795
Authority: US
Inventors: Matthew Kibler; Kyle Scholl; Keith C. Johansen; Nicolas G. Snoke
Original assignee: FHE USA LLC
Current assignee: FHE USA LLC
Priority date: 2017-11-15
Filing date: 2018-11-13
Publication date: 2019-05-16
Also published as: WO2019099563A1

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.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

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

Not Applicable

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable.

BACKGROUND

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.
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

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.
In some embodiments, the sensor associated with each cam lock comprises a rotary encoder disposed on a cam lock pin.
In some embodiments, the sensor associated with each cam lock comprises a proximity sensor arranged to measured extension of each cam lock piston.
In some embodiments, the sensor associated with each cam lock comprises an accelerometer arranged to measure a rotational orientation of each cam lock.
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.
In some embodiments, the sensor associated with each cam lock comprises a strain gauge.
In some embodiments, the sensor associated with each cam lock comprises an optical sensor.
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.
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
In some embodiments, the sensor associated with the locking ring comprises a proximity sensor.
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.
In some embodiments, the sensor associated with the locking ring comprises a strain gauge.
In some embodiments, the sensor associated with the locking ring comprises an optical sensor.
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.
In some embodiments, the sensor comprises a proximity switch.
In some embodiments, the sensor comprises a limit switch.
In some embodiments, the sensor comprises a linear variable differential transformer.
In some embodiments, the sensor comprises an acoustic range finder.
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.
In some embodiments, the sensor comprises a proximity switch.
In some embodiments, the sensor comprises a limit switch.
In some embodiments, the sensor comprises a linear variable differential transformer.
In some embodiments, the sensor comprises an acoustic range finder.
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.
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.
Other aspects and advantages will be apparent from the description and claims that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

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.

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.

FIG. 11 shows other example embodiments of sensors that can measure parameters related to the amount of closure of the cam locks.

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.

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.

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.

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.

FIG. 18 is an exploded view of the first wedge seal embodiment.

FIG. 19 is a perspective cutaway view of the second wedge seal embodiment.

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.

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.

FIG. 22 is an exploded view of the second wedge seal embodiment.

FIG. 23 shows another possible embodiment of a sensor arrangement to determine status of a lock ring.

FIG. 24 shows a cross-section of the embodiment shown in FIG. 23.

DETAILED DESCRIPTION

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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.

Claims

What is claimed is:

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

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.