GB2392683A

GB2392683A - A completion having an annulus valve

Info

Publication number: GB2392683A
Application number: GB0220683A
Authority: GB
Inventors: Richard Kent; Steven Malone; Michael Tierney
Original assignee: FMC TECHNOLOGIES; FMC Technologies Inc
Current assignee: FMC TECHNOLOGIES; FMC Technologies Inc
Priority date: 2002-09-05
Filing date: 2002-09-05
Publication date: 2004-03-10
Anticipated expiration: 2022-09-05
Also published as: AU2003260774A1; WO2004022908A1; GB2392683B; GB0220683D0

Abstract

A completion comprises a tubing hanger 13 having a production bore provided with wireline access, an annulus bore 8, and a sleeve valve 20 located between the tubing hanger 13 and a production seal stab 40. The stab 40 has a formation 44 which engages the sleeve valve 20 when the stab 40 is moved downwardly to move the sleeve valve to an open position. Dogs 21 engage in grooves 43 in the stab to lock the sleeve valve and the stab together. To move the sleeve valve to the closed position, the stab 40 is moved upwardly by hydraulic pressure.

Description

ANNULUS VALVE FOR SUBSEA TREE

Background of the Invention

The present invention relates to a flow control valve that can be used in a tubing hanger m a subsea tree system, is compatible with large bore tubing and which may be mechanically actuated via the tubing hanger production bore. For example, it may be actuated through the production bore on a contingency basis if a primary hydraulic actuation mechanism fails.

lo Most conventional tree systems have parallel bore conduits extending through the tree and tubing hanger, one for production flow and one for annulus communication. When a subsea tree Is to be retrieved for repair it is necessary to close the conduits in the tubing hanger Normal practice is to set two plugs run on wireline; one set in the production bore and another set in the annulus bore.

Another known form of completion provides a valve In the annulus bore of the tubing hanger.

This has the dual advantages of saving time by eliminating the requirement to set an annulus plug and by removing the requirement for vertical access to the annulus. This is particularly advantageous when using a monobore riser, or for tree designs which do not permit wireline 20 access to the tubing hanger annulus bore.

A monobore riser is often used for subsea completion and intervention operations. In this case, if the annulus valve fails to operate by its normal (hydraulic) means, then the monobore riser is brought back to the surface and reconfigured to allow the vertical bore of the riser to 25 align with the generally vertical annulus bore in the tree. A contingency tool is then run on warbling to operate the valve. This procedure is compatible with tubing sizes up to about 5 I/" internal diameter. Recent trends in the oil industry have led to a desire to have larger production conduits, for example 7" I.D. To accommodate these, the configuration of the tree and tubing hanger needs to be changed, one such large bore tree and tubing hanger 30 configuration being described in GB 2342668. A problem with such large bore completions is that if the valve actuation mechanism fails, there is no contingency operation available to

( open and close the valve by wireline, since the generally vertical annulus bore m the tree is eliminated. Summary of the Invention

5 'The present invention allows tubing hanger valve actuation by wirelne or simlamllechancal means via the production bore, thereby maintaining the advantages of existing systems, whilst also allowing a larger production conduit. Such valve actuation may be the primary mode ot'operat-,n, or may be used as a backup or contingency mode in case of failure of'the primary valve actuation mec}larlism.

If) Accordingly, the present invention provides a completion comprising a tubing hanger having a production bore provided with wireline access, a passageway in the tubing hanger communicating between a tubing annulus below the tubing hanger and an annulus flow conduit in a (Christmas tree, wherein the tubing hanger comprises a valve closure element 5 which can be moved by a tool received within the production bore, so as to control fluid flow within the passageway.

I'he valve closure element may be a sleeve in the tubing hanger surrounding the production bore, for example sliding on an inner surface of the tubing hanger. 'I'he annulus flow conduit 20 may he separated from the production bore by a seal stab extending between the tubing, hanger and Christmas tree. Conveniently, a movable production seal stab moves the valve closure element. [n this case, the valve closure element may be of the pressure-balanced type. An abutment surface on the seal stain may move the valve closure element in one direction. Locking dogs which selectively secure the valve closure element to the seal stab 25 may be used to cause the closure element to move in the other direction. The seal stain (where present), or the valve closure element, may be moved by hydraulic pressure apphed through a separate line to an hydraulic piston and cylinder. Alternatively the seal stab (where present) or the valve closure element may be moved by pressure in the annulus flow conduit and/or the production bore.

3) In a pT-ef'er ed embodiment, a calve in the tubing han,cr Is arranged concentrically around a production seal stab between the tree and the tubing hanger. It is operated by notion 't'thc

( protection seal stab. In the primary mode, the seal stab is moved by hydraulically operated pistons. 'I'his arrangement is efficient in teens of the use of radial space and also allows the contingency operation of the valve by wireline. Commonly available wireline tools can be run to engage in a dedicated profile m the seal stab to operate the valve should this be 5 rctiuired in contingency.

Further preferred features and advantages of' the invention are In the t'olkwng description of

illustrative ernb<:>diments made with reference to the drawings.

lo Brief description of the Drawings

l;ig.] is a diagrammatic vertical section through a first preferred embodiment of the Invention; Fig. 2 Is a vertical section througl1 a completion showing the overall configuration of a second preferred crnbodment; is laid. 3 is a vertical section showing parts of Fig. 2 in more detail, and Fig 4 shows a modified form of seal stab that may be used in further pret'errcd embodiments of the Invention.

Description of the preferred Embodiments

2() Ref'ening to Fig. 1, a Christmas tree 60 is connected to a welihead 10 by a connector 5(). 'I'he welibead includes a cylindrical welihead housing 11 in which a casing hanger 12 Is kicked.

The casing hanger supports a string of casing 12a extending downwards into the well. A tubing hanger 13 is also locked into the welihead housing I I and supports a stung of tubing 14 extending, down the well. Static seal stabs 40, 140 f'onned with annular sealing elements 2s and/or sealing surfaces 68, 70 extend from the tree 60 and sealingly engage the tubing hanger 13 An annular annulus flow conduit 1 5()d is thereby defiecd between the seal stabs 4(), 14().

A valve closure element in the f'onn of a slcove 20 is slidably received in the production here 10() in the tubing hanger. A passageway 150a extends upwardly through the tubing hanger, t'rom the tubing annulus below. It terminates at a lateral port lSa adjacent to the sleeve 2(').

30 A further passage\\ ay 1 5()b extends from an opposable port l Sb upwartily through the sleeve 2(). A still further passageway lS()c provides fluid communication between the passageway 15()b and the anriulus flow conduit 15(:kl. As shown, the sleeve 2() is in an upward position

( m which the port 18a is opposite a soLd portion of the sleeve 20, between a pair of annular seal elements 23, 24. The passageways 150a-c through the tubing hanger are thereby closed against fund flow. T he sleeve 2() is movable downwardly from the position shown, to bring the ports lea, lSb into alignment, thereby establishing fluid communication from the tubing 5 annulus through the passageways 150a-c to the annulus flow conduit 15()d. A number of sets of passageways 150a-c may be circumferentially distributed around the tubing hanger 13 and sleeve 2(), with the ports Ma, lSh Conning annular galleries. The sleeve 2() is movable between the up and down positions by hydraulic fluid supplied to chambers 12(), 122 defined between the sleeve 20 and the tubing hanger 13 by annular seal elements 23, 62, tS4. Suitable 10 hydraulic lines (not shown) extend through the tree 6() and tubing hanger 13 to the chambers 120, 122. Alternatively, the chambers 120, 122 and hydraulic lines may he omttcd and the slccvc 2() shuttled up by applying fluid pressure to the production bore 1()() (after setting a plug in the tubing hanger 13Or tubing). The sleeve may be shifted down by pressurizing the annulus flow conduit 15()d. In either case, the sleeve may also be shifted by a tool (not 5 shown) lowered down the production bore 100 on wireline, coiled tubing or the like, to engage groove 2()a in the sleeve 2(). Such operation provides a backup to the primary mode of operation of the sleeve 20. Yet alternatively, the sleeve may not be actuated by fluid pressure at all, in which case the tool provides the only mode of operation. Suitable mechanical detents (e.g. spring loaded balls, snap rings or J-slots and locking pins) may be 20 provided to hold the sleeve 2() in its valve open and valve closed positions.

ligures 2 and 3 show a further embodiment, again comprising a wellhead housmg 11, tree 6(), tubing hanger 13 and closure member sleeve 20. The tubing hanger includes a number ot conduits for conveying hydraulic fluids and/or electrical lines clown the well outside the 25 tubing string. These lines are nonnally arranged concentrically around the tubing 14. The hydraulic and electrical lines communicate With the respective lines in the Christmas tree 6() and from there to the outside ot the well. In Fly. 2 only two conduits are shown, an annulus bore 8 for establishing fluid communication with the tubing, annulus below the tubing hanger 13, and bore 7: an hydraulic line for control of a downhole safety valve.

3)

( The tubing hanger has a production bore 100 having a lower section I S with diameter similar to the inner diameter of the tubing string 14 and an upper section 16 with a larger diameter.

Between them they define an annular shoulder 16a.

s Referring to Fig. 3 the tubing hanger annulus bore 8 communicates with a lateral bore 9. A port 18 in tubing hanger section 16 communicates with bore 9. A groove 17 is made in section 16. A number of such bores 8, 9 and portsl 8 may be circumferentially spaced around the tubing hanger.

0 The closure member 20 is a cylindrical sleeve with an outer diameter which is a sliding fit within section 16 of the tubing hanger production bore. Thus the sleeve can slide along inner wall section 16 movable between fist and second positions, the movement bemg limited by the shoulder 16a and a stop ring 27. The sleeve includes seal elements 23, 24, 26 that provide fluid tight seals between the outer wall of the sleeve and the wall of section 16. A 5 series of circumferentially spaced recesses 22 (only one shown) in sleeve 2() house respective outwardly biased dogs 21.

A production seal stab 40 is located in the tubing hanger and extends upwardly into the Christmas tree. The stab includes seal elements 41, 42 that pack off between the stab and the 2) lower section IS of the tubing hanger inner profile, as well as a metal-to-metal sealing lip 42a which seals against a co-operating surface I Sa in the tubing hanger production bore. These isolate the closure member sleeve 20 from well fluids. As can be seen from Fig. 3, the outer wall of the stab and the wall of section IS of the tubing hanger production bore define between them an annular space in which the sleeve 20 is located. The production seal stab 2s further includes a driving formation 44 engaging the sleeve 20.

The annulus valve can be actuated by moving the stab 40 whereby the driving formation 44 will act on the sleeve 20. In its lower position, a port 25 in annular sleeve 20 will align with port 18 in the tubing hanger, allowing access to the annulus. The port 1 S communicates with 0 crcumferentially spaced, longitudinal channels 25a formed in the upper end of the closure member sleeve 20 and with corresponding channels in the driving formation 44. With the

sleeve 20 m the upper position (as shown in Fig. 3), annulus access is closed c,ff by a solid pc,rtc,n of the closure member sleeve 20 lying between the seal elements 23 and 24.

In use, the production seal stab 40 Is actuated by hydraulic pressure via a dedicated circuit in 5 the ('hristnas tree. This connl-,nses a line 102, Fig,. 2, in the tree (,0 communicatin g with a clc-,scd hydraulic chamber 1()4 which is pressurized for downward movement of the production seal stab 4(). Similarly, a line 1()(, communicates with a chamber 1 (')S t'or upward stab,novenent. An annular piston 110 fondled,;,n the production seal stab 4() separates the chambers 104, 108. (The left-hand side of Fig. 2 shows the production seal stab 4() in its t(3 upper, retracted position, and the riL',ht-hand side the extended position).

When the seal stab 40 and the valve sleeve 20 mc,vc down together, the dogs 21 will be orced radially inwards out of Lgrc,c,ve 17 in the tubing, hanger and into,,roc,ve 43 In the seal stab, thus Ic,ckin,, the sleeve 20 and production bore seal stab 40, together. 'T'c, move the s sleeve 2() up to the closed position, the production seal stab is operated by hydraulic pressure via line 106. Due to the action of the dog mechanism, the sleeve 20 is also caused to, move upwards until the point when the dogs again 21 One up with the,,roovc 17 in the tubmg hanger. At this points the seal stab 40 is released from the sleeve 2() and tree (,() can be disconnected f'rc,m the wellhead with the sleeve left in its closed position. 'I'he lock rind, 27 2, acts as a stop rink, to prevent further upward movement of sleeve 20.

If the hydraulic circuit flails, a tool can be run on wireline or the like into the productic,n bore 100 and engaged into a dedicated profile 40a in the seal stab 40. Tlle stab can then be manipulated up or down in order to operate the valve.

2s Various seal element arrangements and/or types can be used. The seals may for instance either be elastoncr or metal seals.

The closure member configuration shown m F{L\,S. 2 and 3 is pressure balanced, so that when So closed it may be p,-cssurised f'r,n1 above or helow without causing, the sleeve 2() c,r seal stain 4() to rnc.,ve. This gives the ability to, test to confirm that the valve is clc,scd by al-,l-, lying pressure t'rom above. In an a,ltemative embodiment shown in fig. 4, a non pressure-balanced

( production bore seal stab 40 is shown. This may be moved downwardly by pressurising the annulus flow conduit 150d from above, or moved upwardly by plugging the tubing hanger or tubing production bore and pressurising the production bore from above. A metal-to-metal seal element provides sealing between the stab 40 and tree 60 body. The tubing hanger and 5 closure member sleeve are substantially similar to those of Figs. 2 and 3 and are therefore not further described or illustrated. Circumferentially spaced stems 160 (only one shown) extending through bonnets 166 in the tree 60 and engageable with detents 162, 164, or similar mechanical devices, can be provided to lock the seal stab 40 in the extended or retracted position. Such stems also provide visual indication of the proper positioning of the lo seal stab 40. For this purpose, detent 162 is deeper (for example a through hole) than detent 164 (for example a blind-ended hole).

The valve may be wholly activated by mechanical means, thus eliminating the hydranhcs. In such a case, the actuating sleeve may be separate from the production sleeve stab, as shown 5 in Fig. 1. This has the advantage that the production seal stab may remain static. The closure member sleeve may be moved by a wireline run tool as described above. Another method of moving the closure member sleeve may be by rotation by a suitable tool lowered into the production bore and engaged with the sleeve. This may cause the sleeve to move up or down on a threaded connection e.g. with the tubing hanger or production seal stab. Alternatively, JO the sleeve may remain vertically fixed relative to the tubing hanger, with such rotation moving ports otherwise similar to ports 18a, 18b into and out of circumferential alignment.

Claims

1. A completion comprising a tithing hanger having a production bore provided with wireline access, a passageway in the tubing hanger communicating between a tubing annulus s below the tubing hanger and an annulus flow conduit in a Christmas tree, wherein the tubing hanger comprises a valve closure element which can be moved by a tool received within the production bore, so as to control fluid flow within the passageway.

2. A completion as defined in claim I wherein the valve closure element comprises a ail sleeve in the tubing hanger surrounding the production bore.

3. A completion as defined in claim I or 2 wherein the valve closure element slides on an inner surface of'the tubing hanger.

5

4. A completion as defined in claim 1, 2 or 3 wherein he annulus flow conduit is separated f'rom the production bore by a seal stab extending between the tubing hanger and (Christmas tree.

5. A completion as defined in any preceding claim wherem a movable production seal 20 stab moves the valve closure element.

6. A completion as defined In Elaine 5, wherein the valve closure element is of'the pressure balanced type.

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7. A completion as defined in claim 5 or 6 wherein an abutment surface on the seal stab removes the valve closure element in one direction.

8. A completion as defined In claim 7 wherein locking dogs which selectively secure the valve closure element to the seal stab cause the closure element to move in the other 3) direction.

9 A completion as defined in any preceding claim, wherein the seal stab (where prcscnt), or the valve closure elenent, is moved by hydrauhc pressure applied through a separate line to an hydraulic piston and cylinder.

s I () A conpletion as defined in any of claims I to 8 wherein the seal stab (where present), or the valve closure element, is moved by pressure in the annulus flow conduit and/or the production bore.

11 A completion substantially as described with reference to or as shown in Figure I or 10 Figures 2 and 3 or Figure 4 of the drawings.

( Amended claims have been filed as followed 1. A completion comprising a tubing hanger having a production bore provided with wireline access. a passageway in the tubing hanger communicating between a tubing annulus 5 below the tubing hanger and an annulus flow conduit in a Christmas tree, the tubing hanger co-operating with a valve closure element which can be moved by a tool received within the production bore. so as to control fluid flow within the passageway, characterised in that the annulus flow conduit is separated from the production bore by a seal stab extending between the tubing hanger and the Christmas tree.

2. A completion as defined in claim I characterised in that the valve closure element comprises a sleeve in the tubing hanger surrounding the production bore.

3. A completion as defined in any preceding claim characterised in that the seal stab is comprises a movable production seal stab.

4. A completion as defined in claim 3 characterised in that the movable production seal stab moves the valve closure element in use.

20 5. A completion as defined in claim 3 or 4, characterised in that the valve closure element is of the pressure balanced type.

6. A completion as defined in any of claims 3-5, characterised in that an abutment surface on the movable production seal stab moves the valve closure element in one 25 direction.

7. A completion as defined in claim 6, characterised in that locking dogs which selectively secure the valve closure element to the movable production seal stab cause the closure element to move in the other direction.

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f 8. A completion as defined in any preceding ciairn. characterized in that the seal stab o.

the valve closure element is moved by hydraulic pressure applied through a separate line to an hvdrauhc Piston and cylinder.

\ completion as defined in any of claiTns 1 to 7 characterized in that the seal stab o.

the valve closure element is moved by pressure in the annulus flow conduit andior the production bore.

10. A completion as defined in any preceding claim. characterized in that the valve lo closure element slides on an inner surface of the tubing hanger and comprises a port selectively alignable with a corresponding port in the tubing hanger inner surface to control the fluid flow within the passageway; the tubing hanger production bore communicating with a seal stab depending from the Christmas tree, the valve closure element remaining accessible from the tubing hanger production bore for such sliding movement when the seal stab is in position.

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