GB2493180A - Valve housing arrangement - Google Patents

Abstract

A valve, such as a ball valve 24 defining a subsea test tree of a landing string, comprises a valve mechanism ball seat 42 and ball member 44 located within a housing arrangement 40 comprising a structural outer housing 60 configured to be mechanically secured with a fluid conduit system, and an inner housing 62 located within the outer housing and configured to contain pressure. The ball 44 may have a cutting region to shear through tubing. The outer housing 60 may be longitudinally split into two hinged segments and may have a non-cylindrical, or oval, outer profile.

Description

VALVE

HELD OF THE iNVENTION The present invention relates to a valve, and in particular, but not exclusively, to a valve for use in a landing string anangement, for example for use within a subsea test tree.

BACKGROUND TO THE INVENTION

Landing strings are used in the oil and gas industry for throughriser deployment of equipment, such as completion architecture, well testing equipment, intervention tooilng and the like into a subses well from a surface vesseL When in a deployed configuration the landing string extends between the surface vessel and the weilhead, for example a wellhead Blow Out Preventor (BOP). While deployed the landing string provides many functions, induding permitting the safe deployment of wireline or coiled tubing equipment through the landing string and into the wail, providing the necessary primary we control barriers and perrnitung emergency disconnect while isolating both the well and landing string.

Wireline or coiled tubing deployment may be facilitated via a lubricator valve which is located proximate the surface vessel, for example below a rig floor.

Well control and isolation in the event of an emergency disconnect is provided by a suite of valves which are located at a lower and of the landing string. normally positioned inside the central bore of the BOP. The BOP therefore restrids the maximum size of such vaives. The valve suite includes a lower valve assembly called the subsea test tree (SSTT) which provides a safety baffler to contain weil pressure, and an upper valve assembly called the retainer valve which isolates the landing string contents and can be used to vent trapped pessure from between the retainer valve and SSTT. A shear sub component extends between the retainer valve and SSTT which is capable of being sheared by the BOP if required.

As noted above, the landing string may accommodate wireline and/or coiled tubing deployed tools. In this respect the various valve assemblies, such as in the SSTT, must define sufficiently large internal diameters to permit unrestricted passage therethrough. However, the valve assemblies also have outer diameter limitations, for example as they must be locatable within the wellhead BOP, Such conflicting design requirements may create difficulty in, for example, achieving appropriate valve sealing, running desired tooling through the valves and the like.

Furthermore. the anthng string must be capabe of cutting any wirene or coied tubing which extends therethrough in the event of an emergency disconnect. It is known n the art to use one or more of the valves to shear through the wireline or coiled tubing upon closure. However, providing a vave with the necessary cutting capacity may be difficult to achieve within the geometric design constramts associated with the landing string. For exampie, the valve actuators must be of sufficient size to provide the necessary closing/cutting forces, which may be difficult to accommodate within the restricted available size.

The landing string must also be designed to accommodate the significant in service loadings, such as the global tension from a supported dower string (eg, a test string, completion or the Hke), bending loads, valve actuation loading, internal and ex.tern pressures and the ke. As the industry continues to move into fields with increasing formation and water depths, the resulting structural demands on the landing string also become more extreme. For earnpIe, landing string global tension recuirements farm excess of &5MN (1000,000 lbf) and welibore pressures which can exceed 690 bar (10,000 psi) are typicaL Such loadings must be accommodated across regions including the various valve assembHes. such as the SSTT. It is therefore necessary to design the valve housings and appropriate end connections to be capable of accommodating the global appiled tension, bending loads, valve actuation loading and pressures. This recuRs in the use of thick walled valve housings, which can compromise the achievable valve internal diameters and seailng integrity.

Furthermore, current industry standards call for all connections through such landing string valve assemblles to be configured to avoid separation during use to improve fatigue perlbrmance. Such connections may include bolted connectons of the valve housings into the landing string. This typicafly requfres significant upsizing of the connections and estabkhes further dtl1cu ties in achieving sufficiently large internal diameters within the outer diameter constraints, such as dictated by the BOP.

Issues such as those described above are not unique to valves within landing string applications. For example, there is a general desire in the art to minimise the size of valves, for example to provide minimal valve housing dimensions while stilt maximising the inner diameter to accommodate appropriate valve mechanisms and the like.

SUMMARY OF THE INVENTION

According to a first aspect of the presenL invention there is provided a valve comprising a valve mechanism located within a housing arrangement, wherein the houng arrangement comprises an outer houng configured to be mechanicaUy secured with a fluid conduit system, and an inner housing located within the outer housing and configured to contain pressure.

In use, the outer housing may permit the valve to be secured with a fluid conduit system whe the inner housing provides an appropriate pressure barrier for pressure internaHy and/or externally of the valve/fluid conduit system, wherein the valve mechanism pennds control of flow along the fluid conduit system, The outer housing may be configured to be secured inUne with a fluid conduit system.

The valve may be configured to form part of a fluid conduit system.

The fluid conduit system may be defined by one or more tubing components, flow equipment such as other valves, flow meters, sheaNsub components or the like, The valve may have numerous appcations as might readily be understood by those of skill in the art. In some embodiments the valve may be configured for use within a landing string assembly. For example, the valve may define or form pad of a Subsea Test Tree (SSTT), a retainer valve, a lubricator valve or the ike. In such an arrangement a landing string may define a fluid conduit system.

The outer housing may be defined as a structural housing. That is, the outer housing may be provided primarily to accommodate mechanical forces, such as axial and bending forces, associated with the fluid conduit system while providing minimal or no pressure containment, for example of internal and/or external pressures. The inner housing may he defined as a pressure housing. That is, the inner housing may be provided primarily for pressure containment, for example of internal and/or external pressures, while providing minimal or no contribution to accommodating mechanical loading associated with the fluid conduit system This arrangement may permit each individual housing to be designed and/or selected to meet more focussed or specific operational requirements.

These divided roles of the outer and inner housings may provide a number of advantages, such as reduction in wall thickness, weight, costs and the like. In particular, the provision of an outer structural housing and a separnte pressure containing inner housing may permit a reduction in the global housing wall thickness to be achieved. That is, as the outer housing is not intended to be pressure containing, the waD thickness of this can be significantly reduced. Furthermore, as the inner housing is intended for pressure containment, and not, for example. to accommodate significant tensUe and bending loads, this too can have a minimal wall thickness for its Hmited function. As such, the combined wall thickness can be reduced relative to a single structure which is designed to be exposed to both mechanical and pressure hading.

Reducing the overall wall thickness of the housing may permit a larger housing inner diameter to be avaDable. This may provide a number of advantages, such as assisting to maximise the viable size of the valve mechanism, permitting larger equipment to be deployed through the valve, valve seaUng area and the like.

Furthermore, such dimensional advantages may be achieved without increasing, or without significantly increasing rnateri usage. For example, being able to provide a thinner global waU thickness across separate outer and inner housings relative to a single housing design may permit an increased inner diameter to be achieved without also requiring an increased outer diameter. This may have advantage in applications in which the valve must be located wfthin an outer constraining structure, such as a pipeDne, txwehole, casing string, weDbore, riser, SOP or the like.

By the outer housing being mechanically secured, for example in4ine, with a fluid conduit system mechanical forces, such as tensile forces and bending forces, may be transmitted across the outer housing. Such mechanical forces may originate from the fluid conduit system, such as from the weight of the fluid conduit system or the ike.

The outer housing may comprise a connection arrangement for permitting mechanical connection with a fluid conduit system. The connection arrangement may comprise first and second connectors for securing with a fluid conduit system, for example iniine with a fluid conduit system. The first and second connectors may be configured to be secured to similar components, such as tubing, for example. The first and second connectors may he configured La be secured to different components. For example, one connector may be configured to be secured to tubing, and one connector may be configured to be secured to flow equipment such as another valve, flow meter, tubing hanger, choke, manifold, or the ike.

At least one of the first and second connectors may comprise a flange connector.

At least one of the first and second connectors may define a preloaded connector. Such prelcading may be achieved by use of one or more preloaded bolt connections, clamp assemblies or the like. Such preloading may permit the point of connection from separating during use, for example due to axial and bending forces.

As the inner housing is located internally within the outer housing and does not include any direct mechanical connection with the fluid condtht system, any requirement to provide such a preloaded connector with the inner housing is eHminated. That is, only the connection between the outer housing and the fluid conduit system may require pr&oading, for example to meet required or preferred industry standards.

The inner housing may be aSHy contained within the outer housing, In such an arrangement any axial loading experienced by the inner housing, for example due to internal pressures, valve actuation forces and the like may be transferred to the outer housing. The inner housing may be aSHy contained between first and second connectors of the outer housing. At east a portion of the valve mechanism may be axiay ocated, for example secured, between the outer and inner housings. For example, at least a portion of the valve mechanism may be secured between one of the first and second connectors and the inner housing, for example an axial end face of the inner housing.

The outer housing may comprise an axiaHy extending waU section configured to encapsulate the inner housing. As pressure forces are contained primarHy by the inner housing, the wall thickness of the axially extending wall section ci the outer housing may be minimised.

The outer housing may define a barrel-type housing.

The outer housing may be split to permit access to nstaU, remove, replace, inspect or the like the inner housing and/or the valve mechanism. In one embodiment the outer housing may be longitudinally split, that is, split along its length. The outer housing may comprise at least two housing segments. The housing segments may be hingedly connected together. The housing segments may be conflgured to be secured together when in a closed configuration. For example, the housing segments may be secured together in a closed configuration when the outer housing is secured to a fluid conduit system, for example via first and second connectors. The housing segments may be secured along a length of separation, for example along the length of the split defined between the different segments. This arrangement may provide or establish appropriate hoop stiffness within the outer housing which may be required to resist bending forces for example.

The housing segments may be secured together by a bolting arrangement. The bolting arrangement may be provided along one or more sides or regions of separation between different segments.

The housing segments may be secured together via one or more tangential bos.

Adjacent housing segments may comprise one or more connecting portions extending at least partiaVy along the length of split defined between the adjacent 6 segments, wherem opposing connecting portons of each segment may be secured together, for exampe via bolting. A plurality of connecting portions may be provided on each adjacent segment. AxiaUy adjacent connecting porfions on a single segment may be separated by a &otted region, such as a laterally extending slot. Such separation between axiaUy adjacent connecting portions may permit appropriate redirection of stress, for example due to tensile oading, around and across this area of connection between segments.

The housing segments may be secured together via one or more axiay extending connecting members, such as a connecting rod, bolt or the like. In such an arrangement adjacent housing segments may comprise interleaving portions which are held together via such an axially extending connectng member.

As the outer housing is not intended to be pressure containing any sealing, or at east any significant sealing arrangements. may not be required between individual housing segments when secured together. However, in some embodiments a sealing arrangement may be provided between different segments of the outer housing. in other embodiments no sealing arrangement between different segments may be provided. This may permit equalisation of pressure internaUy and externally of the outer housing, thus assisting to eminate or minimise any stress, for example hoop stress, applied via effects of pressure.

At east a portion of the outer housing may define a generaHy cylindrical outer profile.

At east a portion of the outer housing may define a generally noncylindrical outer profile having different dimensions in mutually perpendicular lateral directions.

For example, at least a portion of the outer housing may define a generally oval outer profile, elliptical outer profile or the like. Such an arrangement may permit umbllicals or the Uke to he accommodated between the valve housing and an outer constr&ning structure, such as an outer pipeUnc, borehole, casing section, riser, SOP or the like.

In some embodiments a connection awangement, such as a flange connection arrangemertt of the outer housing may define a noncyndrical profile.

At east a portion of the outer housing may define a generally cylindrical inner profile.

The outer housing may define one or more axial holes, such as gun dried holes, which may accommodate fluid communication, for example across the entire length of the housing, to provide hydrauc power to the vve mechanism or the Uke.

The inner housing may define a generaUy cylindrical profile.

The Inner housing may be isolated from mechanical connection with a fluid conduit system. For example, the inner housing not be exposed, or may be exposed to a far lower proportion of mechanical loading associated with the fluid conduit system as the outer housing. This lack of connection thus eliminates any requirement for a pr&oaded connection with the fluid conduit system, for example as may be required or pr&én'ed by industry standards, This permiLs space savthg to be achieved, for example in terms of available internal diameter thus allowing a larger valve mechanism to be utiHsed.

The inner housing may be defined by a pressure containing sleeve.

At least a portion of the valve mechanism may define part of tie inner housing.

Any suitable valve mechanism as would reathly be selected by a person of skill in the art may be utilised. Such valve mechanisms may comprise, for example, a bali valve, butterfly valve, poppet valve, needle valve, check valve, choke valve, gate valve.

piston valve or the like. The valve mechanism may generally compnsa a valve seat and a valve member configured to cooperate with the valve seat to provide flow control.

The valve mechanism may comprise an actuator, for example an actuator to displace a valve body. The actuator may comprise a hydraulic actuator, electrical actuator, mechanical actuator, thermal actuator, pressure differential actuator or the like, The actuator may comprise a piston arrangement.

The valve mechanism may be configured to cut a body extending at least partially through the valve. This arrangement may permit full closure of the valve mechanism to be achieved without impedance From the body. Further, such cutting may be provided not only where full closure is required. For example, the valve mechanism may he utilised to cut a body and then return to an open conlguration thereafter.

The valve mechanism may be configured to cut an elongate body, such as tubing, coiled tubIng, wireline, slickline, a tool string or the like.

The abity to maxirnise the inner diameter of the housing by use of separate housing components may permit the valve mechanism to be appropriately configured, for example in terms of size, avaUable cutting force and the like, to cut through a body.

In one embodiment the valve mechanism may comprise a ball vah'e mochansm which includes a ball seat and a ball member, wherein the ball member is rotatable reiative to the ball seat to provide flow control.

The ball seat may be axially contained between the inner housing, for example an axial end or the inner housing, and the outer housing, for example a connecting portion of the outer housing. Such an arrangement may provide a simple modular construction, permitting ease of assembly while ensuring sufficient retention of the bali seat within the ball valve. Furthermore, such an arrangement may eliminate the requirement to provide a mechanica connection of the ball seat within the ball valve providing advantages in terms of, icr example, space saving.

The ball seat and ball member may define respective through bores each having a bore edge.

The respective through bores of the ball seat and ball member may define a flow'path through the v&ve. The ball member may be rotated relative to the ball seat to misalign the respective through bores to prevent or restrict flow through the valve, and may be rotated relative to the ball seat to align, for example coaxially align, the respective through bores to permit or increase tow through the valve.

The bore edge of at east one of the ball seat anc ball member may be configured [a cut a body extending at east partially through the valve upon closure of the ball member.

The bore edge of at least one of the ball seat arid ball member may define a recessed cutting region for culling a body.

Both the ball seat and ball member may define a recessed cutting region. In such an arrangement the respective recessed cutting regions may be configured similarly, or differently. Respective recessed cutting regions of the ball seat and ball member may be generally aligned with each other. Such alignment may be considered to exist in a plane which is perpendicular to a rotationa' axis of the ball member. In other embodiments the respective recessed cutting regions of the ball seat and ball member may be misaligned.

Only one of the ball seat and ball member may define a recessed cutting region. This arrangement may be advantageous in that the component which does not comprise a cutting recess may hold the body being cut in a more central position relative to the ball seat and ball member, presenting the body in a better position to he cut. In one embodiment only the ball member may define a recessed cuffing region.

A recessed cutting region may be recessed reative to an associated through beta That is, the recessed cutting region may be outwardly recessed relative to an associate through bore.

A recessed cuffing region may be configured to at least parfially receive a body to be cut. The recessed cuffing region may be configured to entirely receive a body to be cut. In some embodiments, large bodies, for example large diameter bodies may only partially be received within the recessed cutting region.

A recessed cutting region may be provided in a leading edge of one or both of the ball seat and ball member. In this respect the leading edges of the ball seat and ball member may be considered to be those edges of the respective through bores which initially pass each other upon closure of the ball member relative to the seat.

Upon closure of the ball member the bore edge of the ball member through bore may engage and displace a body which at least parfially extends through the vaive until said body is engaged between the ball member bore edge and the ball seat bore edge and at least partially received within a recessed cutting region, such that further rotational movement of the ball member towards a closed position permits cutting of the body, typically by a shearing action, by the recessed cutting region.

A recessed cutfing region may define a cutting edge. The cuffing edge may be formed continuously with the edge of an associated through bore edge.

A recessed cuffing region may define at least two cuffing edges configured to permit simultaneous cuffing into separate regions of a body, for example upon initial contact with the body. A recessed cutting region may be arranged to define at least two points of cutting contact with a body during cutting thereof. During initial contact with the body duhng cuffing thereof the at least two points of cutting contact may be offset from a central region of the body. During initial contact with the body the at least two points of cutting contact may be offset from a central region of the recessed culling region. This arrangement may permit the Force of cutting to he dMded between the different points of cutting contact, assisting to prevent adverse compression, collapsing or the like of the body. Furthermore., this arrangement may prevent large cutting forces being applied initially centrally of a body which may assist to prevent collapse of the body, for example, Also, this arrangement may require less torque through the ball member to cut the body. Such reduced loading is anticipated to reduce damage to the components of the ball valve which may assist in preventing or redudng any damage to sealing regions. During cutting of a body, the at least two points of cutting contact with the body may converge together. That is, the at least two points of cuthng contact may propagate relative to the body until converged together.

The at least two cuffing edges may be defined by two disunct cutting edges. in some embodfrnents the at least two cutting edges cray be defined by separate regions of a single cutting edge.

The at least Iwo cutting edges may be agned substanfiaHy obquely relative to a rotation axis of the bafi member.

At least one cuthng edge may be generay straight. At least one cutting edge may be curved, for example arcuate.

A recessed cutting region may be defined by a notch extending into the edge region of an associated through hors.

A recessed cutting region may be generally vshaped, for example defined by a v.shaped notch.

A recessed cutting region may be arcuate, for example, The bore edge of at east one of the vve seat and baH member may define a single recessed cuffing region. The bore edge of at east one of th.e valve seat and baU member may define at least two recessed cutting regions. In such an arrangement at east two cutting negions may be separated from each other. At least two cutting regions may merge or overlap each other.

A recessed cutting region may comprise a projection, for example a central projection, which may function to pierce the body, for example centrally oF the body.

A recessed cutting region may comprise a serrated edge.

The baU valve may comprise one or more inserts located within a recessed cutting region. The insert may define a cutting edge. Such an insert may facilitate easier maintenance and the like. For example, to re**estabsh a sufficient cutting edge only the insert need be replaced, rather than the entire ball.

The ball member may define a sealing area which cooperates with an appropriate sealing area of the bail seat, at least when the valve is in a closed configuration. The baH seal area is rotationay offset from the ball through bore. The recessed cutting region may be defined within the ball member, wherein said cutting region is recessed towards the sealing area According to a second aspect of the present invenhon there is provided a method of controHing flow along a fluid conduit system, comprising: securing a valve housing arrangement to a fluid conduit system, wherein the valve housing arrangement includes an outer housing which provides mechanical connection to the fluid conduit system and an inner housing located within the outer housing and which contains pressure; and controlling flow along the fluid conduit using a valve mechanism located within the valve housing.

According to a third aspect of the present invention there is provided a sub sea test tree comprising: a housing arrangement; and a vaive mechanism located within a housing arrangement, wherein the housing arrangement comprises an outer housing configured to be mechanically secured with a fluid conduit system, and an inner housing ocated within the outer housing and configured to contain pressure.

The housing arrangement may be configured to he located within a Blow Out Preventor (BOP).

According to a fourth aspect of the present invention there is provided a landing string assembly comprising a valve, wherein the valve comprises: a housing arrangement; and a valve mechanism located within a housing arrangement, wherein the housing arrangement comp1ses an outer housing configured to be mechanicafly secured with a landing string fluid conduit system, and an inner housing located within the outer housing and configured to contain pressure.

The valve may define a sub sea test tree.

The outer housing may be mechanically secured iNline with a fluid conduit system.

Features defined in relation to one aspect defined above may be associated with any other aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will now be described, by way of example only. with reference to the accompanying drawings, in which: Figure 1 illustrates a landing string arrangement which includes features according to embodiments of aspects of the present invention; Figure 2 is a cross-sectional view ol a ball valve in accordance with an embodiment of the present invention; Figure 3 is a perspective view of a bail member which may be utilised in the ball valve of Figure 2, in accortance with an embodiment of the present invention; Figure 4 is a crosssectionai view of the ball member of Figure 3 shown in combination with an associated bail seat; Figure 5 is an top etevaU.onal view of the bail member, bail seat and coiled tubing shown in Figure 4; Figure 6 is a perspective view of a ba member and bail seat of a bail valve according to a modUied embodiment of the present inventIon; Figures 7 and B are top &evadonal views of alternative embodiments of a hail member according to the present invention; Figure 9 is a perspective view of a split outer housing component of a valve according to an embodiment of the present invention, wherein the spilt housing component is shown in a dosed configuration and coupled within a Bowline; Figure 10 is a crosssectional view of a valve assembly which incorporates the split outer housing of Figure 9; Figure 11 is a perspective view of a split outer housing component of a valve 16 according to an alternative embodiment of the present invention, wherein the spilt housing component is shown in an open configuration; and Figure 12 is a top elevational view of a ball valve shown located within a riser, in accordance with a modtfied embodiment of the present invenflon.

DETAILED DESCRIPIION OF THE DRAWINGS

Aspects of the present invention relate to a valve. Such a valve may be used in numerous applications. However, one specific exemplary application will be described below.

A landing string assembly 10 is diagrammatically illustrated in Figure 1, shown in use within a riser 12 and extending between a surface vessel 14 and a subsea weilhead assembly 16 which includes a SOP 16 mounted on a wellhead 20. The use and functionality of landing strings are well known in the art for throughriser deployment of equipmenL such as completion architecture, well testing equipment, intervention tooling and the like into a subsea well from a surface vessel, When in a deployed configuration the landing string 10 extends through the riser 12 and into the SOP 16. While deployed the landing string 10 provides many functions, including permitting the safe deployment of wireline or coiled tubing equipment (not shown) through the landing string and into the well, providing the necessary primary well control barriers and permitting emergency disconnect while isolating both the well and landing string 10.

WireHne or coded tubing deployment may be facifliated via a lubricator valve 22 which is located proximate the surface vessel 14.

WeD control and isolation in the event of an emergency disconnect is provided by a suite of valves which are located at a lower end of the landing string 10 inside the GOP 18. The valve Ste includes a lower valve assembly ca fled the subsea test tree (SSTT) 24 which provides a safety barrier to contain weD pressure. and also funcfions cut any wirene or co&i tubing which. extends through the landing string 10. The valve suite also includes an upper valve assembly called the retainer valve 2$ which isolates the landing string contents and can be used to vent trapped pressure from between the retainer valve 26 and SST'T 24. A shear sub compcnant 28 extends between the retainer valve 26 and SSTT 24 which is capable of being sheared by shear rams 30 of the GOP 18 ft required. A sck joint 32 extends below the SSTT 24 which facilitates engagement with GOP pipe rams 34.

The landing string 10 may include an interface arrangement for interfacing with other oil filed equipment. For example, in the present embodiment the landing string includes a tubing hanger 3$ at its owermost end which engages with a corresponding tubing hanger 38 provided in the wellhead 20. When the landing string is fully deployed and the corresponding tubing hangers 36, 33 are engaged, the weight of the lower siring (such as a completion, workover string or the like which extends into the well and thus not illustrated) becomes supported through the wefihead 20. However, during deployment of the lower string through the riser 12 cli the weight and other forces associated with the lower string must be entirely supported through the landing string 10, Furthermore, when deployed a degree of tension is conventionaDy appiled to the landing sIring 10, for example to prevent adverse compressive forces being applied, for example due to the weight of the landing string 10, which can be significant in deep water, The landing string 10 must thus be designed to accommodate significant inseMce loadings, such as the global tension and bending loads from a supported lower string. Such inservice loadings, which may also include valve actuation loading, internal and external pressures and the like, must be accommodated across the various valve assemblies, such as the SSTT 24. it is therefore necessary to design the valve housings and approDriate end connections to he capable of accommodating the global applied tension, bending loads, valve actuation loading, pressures and the like.

A cross sectional view of a valve in accordance with an embodiment of the present invention is shown in Figure 2. The valve, which in the current embodiment is a ba valve, may be provided for various functions, but for the purposes of the present description the bafi valve may define a SSTT 24 of the landing string 10 shown in Figure 1. it should be noted that although the SSTT 24 is iUustrated in Figure 1 as a dual baH valve, the arrangement shown in Figure 2 is a single bed valve assembly for purposes of clarity.

The bed valve 24 includes a housing arrangement, generedy identified by reference numeral 40 which is secured between the upper shear sub component 28 and the lower sck joint 32. As such, the bed valve 24 is instaUed inne with the landing string 10 which can be considered to be a fluid conduit system. The housing 40 accommodates a valve mechanism which comprises a ball seat 42 and a ball member 44, wherein the bed member 44 is rotatable about axis 46 to selectively close the ball valve 24 and control flow through the anding string, ln the embodiment shown the bed member 44 is rotatable in the direction of arrow 48 to close the bed valve 24.

The bed seat 42 and ball member 44 define respective through bores 50, 52 which when edgned define a flow path through the valve 24 and when misaligned (as shown in Figure 2) prevent or restrict Flow through the v&ve. When the ball member 44 is closed a sealing area 54 is defined between the ball seal 42 and ball member 44.

As will be discussed in further detail below, a leading edge 56 of the ball member 44 and/or ball seat 42 is configured to cut through a body (not shown), such as wireline, coiled tubing or the like which extends through the valve 24 and landing string 10 (Figure 1) upon closure of the haD member 44.

As wi also be discussed in further detail below, the housing arrangement 40 comprises an outer housing 60 configured to be mechanically secured inline with the landing string 10 (Figure 1), and an inner housing 62 located within the outer housing 60 and which is configured to contain pressure. The outer housing comoonent 60 comprises a thinwalled, nonpressure containing cylindrical portion 63 which extends between axially opposing end flange connectors 64, 66 which are configured to be secured to flange components 68, 70 of the shear sub 28 and slick joint 32, respectively. In such an arrangement the outer housing 60 may be defined as a structural housing. That is, the outer houng 60 may he proided primarily to accommodate mechanical forces, sich as axial and bending forces, associated with the landing string 10 and any supported lower string while providing minimal or no pressure containment, for example of internal and/or external pressures.

The inner housing 62 comprises a generally cylindrical portion or sleeve and does not include any mechanical connection to the landing string 10 (Figure 1). In such an arrangement the inner housing 52 may be defined as a pressure housing.

That is, the inner housing 62 may be provided primarlly for pressure containment, for example of internal and/or external pressures, whfle providing minimal or no contribution to accommodaing mechanical loading associated with the landing string 10 and/or supported lower string.

This spllt role arrangement may permit each individual housing 60, 62 to be deffigned and/or selected to meet more focussed or specific operational requfrements, providing a number of advantages, such as permithng a reduction in the global wa thickness of the housing which can increase the avallable internal housing diameter.

The vSve mechanism further includes an actuator assembly, generally identified by reference numeral 72 for use in actuating the ball member 44 to rotate relative to the ball seat 42 between open and closed positions. In the present example the actuator assembly 72 comprises a piston arrangement.

Various forms of ball member 44 and ball seat 42 may be provided within the scope of the present invention. Some exernpary embodiments are described below with reference to Figures 3 to 8.

Reference is initially made to Figures 3 and 4. Figure 3 shows a perspective view of a bell member, in this case identified by reference numeral 44a, according to an exemplary embodiment of the present invention, and Figure 4 shown a crosssectional view of the ball member 44a of Figure 3 in combination with an embodiment of a ball seat, in this case identiFied by reference numeral 42a. Ball member 44a and seat 42a have many features in common with ball member 44 and seat 42 shown in Figure 2 and as such. like features share like reference numerals, suffixed with the letter a".

The ball member 44a defines a through bore 52a having a bore edge 74, wherein a leading edge 56a defines a recessed cutting region 76 which is configured to receive and cut through a body, such as coiled tubing 78, shown in broken outline in Figure 4 extending through the through bore 52a of the ball member 44a and a through bore 50a of the ball seat 42a. That is, rotation of the bali member 44a towards a closed position causes the coiled tubing 78 to become engaged between the edge oF the ball seat 42a and the recessed cutting region 76 of the ball member 44& with Further rotation effecting cutting of the coiled tubing 78 primarlly by a shearing action.

The ball member 44a includes a slotted region 80 which accommodates the lower portion of the coiled tubing 78 during rotation oF the ball member 44a.

The recessed cutting region 76 encroaches into the sealing area 54a which is defined between the ball member 44a and ball seat 42a. In some embodiments the recessed cutting region may define a relatively shedow recess such that seang area 54a may not be compromised. However, in other embodiments the ability to utise a thinner waned housing arrangement 40 by use of separate outer and inner housinos 60, 62 (having different roles, namely structural and pressure containing) facilitates use of a larger baH member Ma and ball seat 42a such that even with the presence of the recessed cutUng region 76 the seaUng area 54a may be sufficienfly large to retain sealing integrity.

In the present embodiment the recessed cutting region 76 is generaUy v shaped. Such a vshaped cuthng region. 76 is also shown in Figure 5 (reference to which is also made) which is a top elevation view of the ba seat 42a and ba member 44a. Such a profile defines two cutting edges 82, 84 which provide simuRaneous iniUsl cutting into separate regions of the tubing 78. In this way, during initial contact two points of cutting contact are created which are ofiedt from a central region ci the tubing 78 and which propagate together as cutting continues. This arrangement may permit the force of cutting to be divided between the different points of cutting contact provided by each cuthng edge 82, 84, assisting to prevent coHapsing of the tubing 78 which the present inventors have discovered can render cutting very difficult. Also, this arrangement may require less torque through the bail member 44a to cut the tubing 78.

Such reduced loading is anticipated to reduce damage to the components of the bail valve which may assist in preventing or reducing any damage to sealing regions, such as sealing area 54a.

As iUustrated most dearly in Figure 5, in the present embodiment, the leading edge 86 of the ball seat 42a does not include any recessed region. However, in other embodiments, the ball seat may also (or alternatively) include a recessed region. Such an embodiment is illustrated in Figure 6 which is a perspective view, from below, of a ba seat 42b and ball member 44b which both include recessed cutting regions 88, 90.

In the exemplary embodiments described above the recessed cutting region is generally vshaped, However, other arrangements are possible. For example, a ball member 44c (or a corresponding ball seat) may include a generally arcuate recessed region 92 as shown in Figure 7. Furthermore, in the exemplary embodiments described above a single recessed cutting region is provided. However, in other arrangements multiple recessed regions may be provided. For example, a ball member 44c (or corresponding ball seat) may include a pair of (or more) recessed regions 94 as shown in Figure 8. In such an embodiment a prcection 96 may be defined between each recessed region 94 which may function to pierce a body, such as colied tubing, to assist ri initiating cutting whlie minimising adverse coliapse or the ike, Such a projecfion may be provided within embodiments induding a single recess.

A perspective view of the bali valve 24 iliustrated in Figure 2 is shown in Figure 9, reference to which is now made, along with Figure 10 which shows a further cross sectional view of the bali valve 24 with the SI member 44 and actuator 72 removed for darity.

As descdbed above, the housing arrangement 40 of the valve 24 includes an outer housing 60 end a separate inner housing 62, wherein the outer housing 60 includes oppo&ng flange connectors 64, 66 which are secured to the respective flange components 68, 70 of the shear sub 28 and slick joint 32. Each flange connection 64, 68 and 66, 70 is made via a plurality of bolts 100, wherein one or more of the bolts 100 may be pre4ensbned to provide a degree of preloading through the connecflons, The inner housing 62 is axiafly retained between the flange connectors 64, 66 of the outer housing 60. Furthermore, the bali seat 42 is interposed between the upper flange connector 64 and the upper end of the inner housing 62.

The inner housin.g 62 defines a unitary cyndrical component, whereas the outer housing 60 is iongitudinaliy split along a line of separation 102 such that the outer housing 60 is formed from two half segments 104, 106. Referring also to Figure Ii.

this split arrangement permits the outer housing 60 to be opened to provide access to insta, inspect, repair, replace or the like the inner housing 62 and other components, such as the bali seat 42. Splitting a housing of a valve is generafly not attempted in the art. However, the present invention permits the outer housing 60 to be split as this does not need to provide any sealing or pressure retaining function, which instead is provided by the unitary inner housing 62.

The segments 104, 106 are hinged together along one side 108 and once dosed may be retained closed upon connection of the respective flange connectors 64, 66 to the flange components 68, 70 of the shear sub 28 and slick joint 32. Additionally, a longitudinal connecting arrangement 110 is provided which longitudinally secures the segments 104, 106 together when closed. In an alternative embodiment no hinge connection may be provided and instead both sides may be bolted to secure together the different segments 104, 106. Providing such a longitudinal connection arrangement 110 establishes appropriate hoop stiffness within the outer housing 60 which may be required to resist bending forces, for example.

The longitudinal connection arrangement 110 may be provided in a number of forms. In this respect one such form is illustrated in Figure 9 (identified by reference numeral 11 Ga), whereas an alternative form is Hiustrated in Figure 11 (identified by relerence numeral 1 lOb), The longitudinal connection arrangement I iDa of Figure 9 comprises a pluraifty of tangentiakype bofta or cap screws 112 which extend through respective flange fingers or ribs 114 on one housing segment 106 and engage threaded holes (not iflustrated) in the opposing housing segment 104, Each adjacent flange finger or rib 114 is separated by a &otted regbn 116. This geometry assist to redirect stress along this region of connection to, for example, prevent high stresses at the locations of the cap screws 112 during tensUe loading.

The longitudinal connection &rangernent 11Gb illustrated in Figure 11 comprises a plurality of interleaving components 118 on each segment which are intaricaved with each other when the segment halves 104, 106 are closed. Each interleaving component 118 comprises an axiay extending bore 120 which become agned when the segment halves 104, 106 are closed. An elongate connecting member 122 is provided which is received within the &igned bores 120 to thus secure the seoment halves 104, 106 together.

hi the embodiments described above, such as with reference to Figures 2 and 9 to 11, the outer housing defines a generally cyndrical outer profile. However, in other embodiments a noNoylindrical outer proffle may be provided, as iustrated in Figure 12. In this embodiment a valve, generay identified by reference numeral 124, includes a split outer housing 160 and a unitary inner housing 162, in a similar manner to the embodiments described above for simfiar reasons, However, in the present embodiment the outer housing 160 defines a generally oval outer profile. This arrangement permits other components, such as the iHustra(ed umbilica' 123 to be accommodated beieen the valve 24 and an outer constraining component, such as a riser 12.

It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing form the scope of the present invention. For example, the disclosed valve embodiments are not solely for use within a landing string, and may be used in many other applications as would be understood by a person of skifl in the art. Furthermore, the multiple component housing arrangement may also be used in combination with different valve types, and is not limited solely for use in ball vale applications.

Claims (1)

1. <claim-text>CLAIMS: 1. A valve comprising a valve mechanism located within a housing arrangement, wherein the housing arrangement comprises an outer housing configured to be S mechanically secured with a fluid conduit system, and an inner housing located within the outer housing and configured to contain pressure.</claim-text> <claim-text>2. The valve according to claim I wherein the outer housing is configured to be secured nllne with a fluid conduit system.</claim-text> <claim-text>3. The valve according to claim I or 2, del ning or forming part of at least one of a Subsea Test Tree (SSTT), a retainer vve and a lubricator valve, 4, The valve according to any preceding claim, wherein the outer housing comprises a connecdon arrangement for permitting mechanical connection with a fluid conduit system.5. The valve according to claim 4, wherein the connection arrangement comprises first and second connectors for securing with a fluid conduit system.6. The valve according to claim 5, where!n at least one of the first and second connectors comprises a flange connector.7. The valve according to claim 5 or 6, wherein at least one of the first and second connectors defines a pr&oaded connector.8. The valve according to any preceding caim, wherein the inner housing is axiay contained within the outer housing.9. The valve accodin to claim 8, when dependent on any one of dairns 5, 6 or 7, wherein the inner housing is axially contained between the first and second connectors of the outer housing.10. The valve according to any preceding claim, wherein at least a portion of the valve mechanism is axially located between the outer and inner housings.11. The vve according to any preceding dairn, wherein the outer housing comprises an axiay extending wafl section conflgured to encapsulate the inner housing.12. The valve according to any preceding claim, wherein the outer housing is spt.13. The valve according to any preceding claim, wherein the outer housing is longitudinally split.14. The valve according to any preceding claim, wherein the outer housing comprises at east two housing segments.15. The valve according to claim 14, wherein the housing segments are hingedly 1 5 connected together 16. The valve according to daim 14 or 15. wherein the houng segments are configured to be secured together when the outer housing is secured to a fluid conduit system.17. The valve according to claim 14, 15 or 16, wherein the housing segments are secured along a length of separation, for example along the length of the split defined between the difFerent segments.18. The valve according to any one of claims 14 to 17, wherein the housing segments are secured together by a bolting arrangement.19. The vaive according to claim 18 wherein the bolting arrangement a provided along one or more sides or regions of separation between different segments.20. The valve according to any one of claims 14 to 19, wherein the housing segments are secured together via one or more tangential bolts.21. The valve according to any one of claims 14 to 20, wherein adjacent housing segments comprise one or more connecting portions extending at least partially along the length of spht defined between the adjacent aegments, wherein opposing connecting portions of each segment are arranged to be secured together.22. The valve according to daim 21, wherein a pluraUty of connecting portions are provided on each adjacent segment.23. The valve according to dairn 22, wherein axiaUy adjacent connecting portions on a single segment are separated by a oUed region.24. The valve according to any preceding claim, wherein at least a portion of the outer housLng defines a generaUy cyUndrical outer proflle.25. The valve according to any preceding claim, wherein at east a portion of the outer housing defines a generay noncylindhcel outer profile having different dimensions in mutually perpendicular lateral directions.26. The valve according to any preceding daim, wherdn the inner housing is isolated from mechanical connection with a fluid conduit system.27. The valve according to any preceding claim, wherein the inner housing is defined by a pressure containing sleeve.28. The valve according to any preceding claim, wherein at least a portbri of the valve mechanism may define part of the inner housing.29. The valve according to any preceding claim, wherein the valve mechanism comprises a bafl valve mechanism.30. Thee valve according to any preceding claim, wherein the valve mechanism is configured to cut a body extending at east partially through the valve.31. The v&ve according to any preceding claim, wherein the valve mechanism is configured to cut an ebngate body including at least one of tubing, coiled tubing, wireline, slickline and a tool string.32. The valve accordh'ig to any preceding claim, wherein the valve mechanism comprises a ball valve mechanism which includes a baH seat and a bafl member, wherein the ha member is rotatable relative to the baU seat to provide flow controL 33. The valve according to claim 32, wherein the baU seat and ball member define respectwe through bores each having a bore edge and the bore edge of at east one of the ba seat and baU member is contigured to cut a body extending at least partially through the valve upon closure of the bail member.34. The valve according to caim 33, wherein the hare edge of at least one of the ball seat and ball member defines a recessed cutting region for cutting a body.35, A method of controlling flow along a fluid conduit system, comprising: securng a valve housing arrangement to a fluid conduit syster., wherein the valve housing arrangement includes an outer housing which provides mechanical connecfion to the fluid conduit system and an inner housing located within the outer housing and which contains pressure; and controlling flow along the fluid conduit using a valve mechanism located within the valve housing.36. A sub sea test tree comprising: a housing arrangement; and a valve mechanism located within a housing arrangement, wherein the housing arrangement comprises an outer housing configured to be mechanicaliy secured with a fluid conduit system, and an inner housing located within the outer housing and configured to contain pressure.</claim-text>