NO854885L

NO854885L - VALVE FOR BROENNHODE.

Info

Publication number: NO854885L
Application number: NO854885A
Authority: NO
Inventors: Tore Nilsson
Original assignee: Asea Atom Ab
Priority date: 1984-12-05
Filing date: 1985-12-04
Publication date: 1986-06-06
Also published as: SE8406161L; SE8406161D0; GB8529865D0; SE445753B; GB2168463A; GB2168463B

Description

Oppfinnelsen angår en ventil for et brønnhode for en oljekilde under vann, omfattende et i hovedsaken T-formet ventilhus med en langstrakt, i hovedsaken horisontalt anordnet ventilsylinder med et første endeparti, et andre endeparti og et mellom de nevnte endepartier beliggende midtparti, og en i hovedsaken vertikalt anordnet tilkoplingsstuss for tilkopling av ventilhuset til brønnhodet, idet den nevnte stuss utgår fra midtpartiet, og det første endeparti er utformet for tilkopling til en produksjonsledning, idet ventilsylinderens innvendige overflater avgrenser et hulrom som langs en større del av ventilsylinderens lengde har en symmetriakse og som inneholder et ventilstempel, midler for definering av en første, en andre og en tredje aksial stilling for ventilstempelet, og midler for overføring av en aksial manøverkraft til ventilstempelet. The invention relates to a valve for a wellhead for an oil source under water, comprising an essentially T-shaped valve housing with an elongated, essentially horizontally arranged valve cylinder with a first end part, a second end part and a middle part situated between the said end parts, and a the main thing is a vertically arranged connection spigot for connecting the valve housing to the wellhead, the aforementioned spigot emanating from the middle part, and the first end part is designed for connection to a production line, the valve cylinder's internal surfaces delimiting a cavity which along a larger part of the valve cylinder's length has an axis of symmetry and which contains a valve piston, means for defining a first, a second and a third axial position for the valve piston, and means for transmitting an axial maneuvering force to the valve piston.

Oljekilder under vann avsluttes oventil med et ventilarrangement (såkalt ventiltre) som skal kunne tillate forskjellige ventilfunksjoner: Underwater oil wells are terminated at the top with a valve arrangement (so-called valve tree) which should be able to allow different valve functions:

- produksjon (PROD)- production (PROD)

- adgang for service (SWAB)- access for service (SWAB)

- boresikringsventil (BOP).- well protection valve (BOP).

Formålet med oppfinnelsen er å kombinere de tilsvarende ventilfunksjoner i en sleideventil på en fra et funksjons- og fremstillingssynspunkt fordelaktig måte. The purpose of the invention is to combine the corresponding valve functions in a slide valve in an advantageous manner from a functional and manufacturing point of view.

Ventilfunksjonen PROD er slik anordnet at strømmen akselereres i en innsnevring før inntredet i ventilkammeret som er utformet som en utvidelse med utløpet i vinkel med innløpet. Akselerasjonen av strømmen medfører at tyngre partikler (sand o.l.) fortsetter rett frem og får sin bevegelsesenergi dempet på grunn av støt mot kammerets tak. Kammerets tak kan i overensstemmelse med formålet være foret med hardt materiale (keramikk) eller mykt materiale (gummi). Sandpartiklene fortsetter siden med lav bevegelsesenergi sammen med olje-gasstrømmen gjennom ventilutløpet. På denne måte reduseres sandpartiklenes erosjon ved omstyringen av strømmen gjennom ventilen. The valve function PROD is arranged in such a way that the flow is accelerated in a constriction before entering the valve chamber, which is designed as an expansion with the outlet at an angle to the inlet. The acceleration of the flow means that heavier particles (sand etc.) continue straight ahead and have their kinetic energy dampened due to impact with the chamber's roof. The roof of the chamber can be lined with hard material (ceramic) or soft material (rubber) depending on the purpose. The sand particles continue on the side with low kinetic energy together with the oil-gas flow through the valve outlet. In this way, the erosion of the sand particles is reduced by the redirection of the flow through the valve.

Ventilfunksjonen SWAB er anordnet som et rett gjennomløp uten skarpe kanter som kan forstyrre innføringen av serviceverktøy. I en ekstrem ytterstilling kan adgangsarealet til kilden økes til et forutbestemt, ønsket areal ved at en uttrekkbar del av ventilhuset demonteres. Dette gjør at ventilhuset kan monteres på et tidlig stadium av klargjø-ringen av kilden og ferdigboringen skje gjennom ventilhuset uten at de endelige tetnings flater skades, og at sleiden kan utformes med en hensiktsmessig mindre diameter. The valve function SWAB is arranged as a straight passage without sharp edges that could interfere with the introduction of service tools. In an extreme extreme position, the access area to the source can be increased to a predetermined, desired area by dismantling a retractable part of the valve housing. This means that the valve housing can be mounted at an early stage of the preparation of the source and that the finished drilling takes place through the valve housing without damaging the final sealing surfaces, and that the slide can be designed with an appropriately smaller diameter.

Ventilfunksjonen BOP er anordnet ytterst og slikThe valve function BOP is arranged at the outer end and so

at det store stempelareal i ventilanordningen utnyttes når ventilen inntar denne stilling. På denne måte kan maksimal kraft utnyttes, og til og med avskjæring av serviceverktøy i SWAB-stilling kan utføres. Ventilstillingen BOP inntas uavhengig av stillingsgiver eller annen kontrollutrustning ettersom ventilstillingen BOP beordres på grunn av trykk-økning i anordningens plusskammer. that the large piston area in the valve arrangement is utilized when the valve assumes this position. In this way, maximum power can be utilized and even cutting off service tools in the SWAB position can be performed. The valve position BOP is taken independently of the position transmitter or other control equipment, as the valve position BOP is ordered due to a pressure increase in the device's plus chamber.

Ventilanordningen er utformet slik at ventilstil-lingene PROD og BOP inntas i ytterstilling, mens SWAB oppnås ved hjelp av passende trykksetting og mekanisk sneppfunksjon i midtstillingen. The valve device is designed so that the valve positions PROD and BOP are taken in the outer position, while SWAB is achieved with the help of suitable pressure setting and mechanical snap function in the middle position.

Ventilstempelet er forsynt med midler med hvis hjelp det sikres at sleiden inntar en orientert stilling i forhold til åpningene i ventilhuset. The valve piston is provided with means with the help of which it is ensured that the slide occupies an oriented position in relation to the openings in the valve housing.

Det som kjennetegner oppfinnelsen, fremgår av de etterfølgende krav. What characterizes the invention is evident from the following claims.

Oppfinnelsen skal beskrives nærmere i det følgende under henvisning til tegningene, der fig. 1 viser en ventil ifølge oppfinnelsen i perspektivriss, idet en horisontal toppring er fjernet for å forenkle fremstillingen, fig. 2, 3 og 4 viser et vertikalsnitt gjennom en på fig. 1 vist, horisontalt forløpende symmetriakse A for et av en ventilsylinder avgrenset hulrom, og viser tre forskjellige ventiltilstander, nemlig henholdsvis "sikringsventil", "adgang for service" og "produksjon", og fig. 5, 6 og 7 viser et vertikalsnitt vinkelrett på aksen A og gjennom den på fig. 1 viste, vertikale midtlinje B, idet disse figurer viser de samme ventiltilstander som på henholdsvis fig. 2, 3 og 4. The invention will be described in more detail below with reference to the drawings, where fig. 1 shows a valve according to the invention in a perspective view, with a horizontal top ring removed to simplify the manufacture, fig. 2, 3 and 4 show a vertical section through one in fig. 1 shown, horizontally extending axis of symmetry A for a cavity delimited by a valve cylinder, and shows three different valve states, namely "safety valve", "access for service" and "production", respectively, and fig. 5, 6 and 7 show a vertical section perpendicular to the axis A and through it in fig. 1, vertical center line B, as these figures show the same valve conditions as in fig. 2, 3 and 4.

På tegningene betegner 1 et i hovedsaken T-formet ventilhus. Ventilhuset 1 har en horisontal eller i hovedsaken horisontal ventilsylinder 2 og en med denne sammen-støpt, i hovedsaken vertikal tilkoplingsstuss 3. Stussen 3 har en flens 4 som er beregnet for tilkopling av ventilhuset 1 til et brønnhode 5 for en oljekilde under vann. Ventilsylinderen 2 har et midtparti 6 og to endepartier 7 og 8. Endepartiet 8 har et fastflenset lokk 9. Endepartiet 7 har en flens 10 for tilkopling til en produksjonsledning. In the drawings, 1 denotes a mainly T-shaped valve housing. The valve housing 1 has a horizontal or mainly horizontal valve cylinder 2 and a molded together with this, mainly vertical connection spigot 3. The spigot 3 has a flange 4 which is intended for connecting the valve housing 1 to a wellhead 5 for an oil source under water. The valve cylinder 2 has a middle part 6 and two end parts 7 and 8. The end part 8 has a fixed flanged cover 9. The end part 7 has a flange 10 for connection to a production line.

Ventilhuset 1 omfatter et uttrekkbart anordnet legeme 11 hvis vertikale, utvendige begrensningsflater ligger i en sirkulær sylinderflate. Dennes midtakse sammenfaller med stussens 3 symmetrilinje B. Legemet 11 er forsynt med et gjennomgående, horisontalt rettet hull hvis begrensningsflate utgjør en del av den indre begrensningsflate i ventilsylinderen 2. Legemet 11 har dessuten et hull 12 ved sin øvre ende og et hull 13 ved sin nedre ende. Hullene 12 og 13 er utført med sirkulært tverrsnitt og deres midtlinjer sammenfaller med stussens 3 midtlinje B. Legemets 11 side-flate er anordnet med meget liten klaring i forhold til nær-liggende, krumme flater av ventilhuset 1. Et antall sirku-lære tetningsringer 14 er anordnet i et antall ringformede, koaksialt i forhold til linjen B utformede spor i legemet 11 og i sirkulærsylindriske overflatepartier som omgir legemet. Legemets 11 nedre endeflate hviler på en ringformet ansats som er utformet i stussen 3. Legemet 11 fastholdes normalt i den viste stilling ved hjelp av en avtagbar toppring 15 som normalt er festet til ventilsylinderens 2 midtparti 6, f.eks. ved hjelp av et antall i dette fastskrudde, vertikale bolter. The valve housing 1 comprises a retractable body 11 whose vertical, external limiting surfaces lie in a circular cylinder surface. Its central axis coincides with the symmetry line B of the nozzle 3. The body 11 is provided with a continuous, horizontally directed hole whose limiting surface forms part of the inner limiting surface in the valve cylinder 2. The body 11 also has a hole 12 at its upper end and a hole 13 at its lower end. The holes 12 and 13 are made with a circular cross-section and their center lines coincide with the center line B of the spigot 3. The side surface of the body 11 is arranged with very little clearance in relation to the nearby, curved surfaces of the valve housing 1. A number of circular sealing rings 14 is arranged in a number of ring-shaped grooves designed coaxially with respect to the line B in the body 11 and in circular-cylindrical surface parts that surround the body. The lower end surface of the body 11 rests on an annular shoulder which is formed in the spigot 3. The body 11 is normally held in the position shown by means of a removable top ring 15 which is normally attached to the central part 6 of the valve cylinder 2, e.g. by means of a number in this fixed, vertical bolts.

Et sirkulærsylindrisk ventilstempel 16 er anordnet i ventilsylinderen 2. Ventilstempelet 16 er via en stempel-stang 17' anordnet i stiv, mekanisk forbindelse med et driv-stempel 17 som kan drives i den ene retning langs symmetri-aksen A ved å tilføre et trykkmiddel via en første fluidumtrykktilkopling 18', og i den andre retning ved å tilføres trykkmiddel via en andre fluidumtrykktilkopling 19'. I en første aksial stilling ligger drivstempelet 17 an mot en ringformet ansatsflate 18, og et første endeparti 19 av ventilstempelet 16 ligger tettende an mot åpningene 12 og 13, hvilket innebærer at ventilen befinner seg i sikringsventil-tilstanden (BOP). A circular cylindrical valve piston 16 is arranged in the valve cylinder 2. The valve piston 16 is via a piston rod 17' arranged in rigid, mechanical connection with a drive piston 17 which can be driven in one direction along the axis of symmetry A by supplying a pressure medium via a first fluid pressure connection 18', and in the other direction by supplying pressure medium via a second fluid pressure connection 19'. In a first axial position, the drive piston 17 rests against an annular abutment surface 18, and a first end part 19 of the valve piston 16 rests tightly against the openings 12 and 13, which means that the valve is in the safety valve state (BOP).

I en andre aksial stilling av ventilstempelet 16 sammenfaller en gjennomgående, i ventilstempelets 16 midtparti utformet og i dennes tverretning forløpende kanal 20 med de radialt rettede hull 12 og 13 i ventilsylinderen 2, hvilket innebærer at ventilen er i tilstanden "adgang for service" (SWAB). Hullet 12 er forsynt med (ikke viste) midler for tilkopling av et servicerør til dette. Den tilsvarende stilling av ventilstempelet 16 er definert ved at en stempelring 21 på drivstempelet 17 i denne stilling griper inn i et ringformet spor 22 i ventilsylinderen 2. Stempel-ringen 21 har sirkulær profil, eller en annen passende profil som tillater fortsatt stempelbevegelse ved moderat, men tyde-lig indikerbar trykkøkning. In a second axial position of the valve piston 16, a continuous channel 20 formed in the central part of the valve piston 16 and extending in its transverse direction coincides with the radially directed holes 12 and 13 in the valve cylinder 2, which means that the valve is in the state "access for service" (SWAB ). The hole 12 is provided with (not shown) means for connecting a service pipe thereto. The corresponding position of the valve piston 16 is defined by a piston ring 21 on the drive piston 17 in this position engaging in an annular groove 22 in the valve cylinder 2. The piston ring 21 has a circular profile, or another suitable profile that allows continued piston movement at moderate, but a clearly identifiable pressure increase.

I en tredje aksial stilling ligger drivstempeletThe drive piston is in a third axial position

17 an mot et aksialt fremspring 23 på lokket 9. Et andre endeparti 24 av ventilstempelet 16 ligger da an mot åpningen 13. Endepartiet 24 har et hulrom 24' med en aksialt rettet utløpsåpning 25 og en radialt rettet innløpsåpning 26 som sammenfaller med åpningen 13, hvilket innebærer at ventilen er i tilstanden "produksjon" (PROD). 17 against an axial projection 23 on the lid 9. A second end part 24 of the valve piston 16 then lies against the opening 13. The end part 24 has a cavity 24' with an axially directed outlet opening 25 and a radially directed inlet opening 26 which coincides with the opening 13, which means that the valve is in the state "production" (PROD).

I denne tilstand komprimeres en fjær 27 som omslut-ter fremspringet 23, idet fjærkraften er rettet mot den aksiale kraft som utøves på ventilstempelet på grunn av olje-strømmens retningsendring - og fortrinnsvis tilsvarer minst 50 % av denne. Fjæren 27 dimensjoneres med fordel på en slik måte at den ved et eventuelt trykkbortfall i de til fluidumtrykktilkoplingene 18' og 19' tilkoplede ledninger kan forflytte ventilstempelet til BOP-stillingen. In this state, a spring 27 which encloses the projection 23 is compressed, the spring force being directed against the axial force exerted on the valve piston due to the oil flow's change of direction - and preferably corresponding to at least 50% of this. The spring 27 is advantageously dimensioned in such a way that, in the event of a loss of pressure in the lines connected to the fluid pressure connections 18' and 19', it can move the valve piston to the BOP position.

En med urundt tverrsnitt utformet teleskopstang 28 er anordnet med den ene ende aksialt bevegelig i et dypt, aksialt rettet, urundt hull 23' i fremspringet 23, mens den andre ende er anordnet på samme måte i et tilsvarende hull i drivstempelet 17. Hensikten er å hindre vridning av ventilstempelet 16 om aksen A. A telescopic rod 28 designed with a non-round cross-section is arranged with one end axially movable in a deep, axially directed, non-round hole 23' in the projection 23, while the other end is arranged in the same way in a corresponding hole in the drive piston 17. The purpose is to prevent rotation of the valve piston 16 about the axis A.

Som nevnt kan adgangsarealet til oljekilden økes ved at en uttrekkbar del av ventilhuset demonteres. Dette kanskje ved at lokket 9 fjernes, hvoretter det på fig. 2-4 viste ventilstempel 16 sammen med drivstempelet 17 forflyttes så langt mot høyre at legemet 11 uhindret av ventilstempelet 16 kan forflyttes vertikalt oppover. Deretter fjernes topp-ringen 15 hvoretter legemet 11 fjernes ved at en oppadrettet trekkraft anvendes på dette. As mentioned, the access area to the oil source can be increased by dismantling a retractable part of the valve housing. This perhaps by removing the lid 9, after which in fig. 2-4, the valve piston 16 together with the drive piston 17 is moved so far to the right that the body 11 can be moved vertically upwards unimpeded by the valve piston 16. Next, the top ring 15 is removed, after which the body 11 is removed by applying an upward pulling force to it.

Claims

1. Valve for a wellhead for an underwater oil source, comprising a generally T-shaped valve body (1) with an elongated, substantially horizontally arranged valve cylinder (2) with a first end portion (7), a second end portion (8) and a middle part (6) located between the mentioned end parts, and a mainly vertically arranged connection spigot (3) for connecting the valve housing (1) to the wellhead (5), the spigot (3) starting from the middle part (6) and the first end part (7) is designed for connection to a production line, as the inner surfaces of the valve cylinder (2) delimit a cavity (2 <1> ) which along a larger part of the length of the valve cylinder has an axis of symmetry (A) and which contains a valve piston (16), means for defining a first, a second and a third axial position for the valve piston (16), and means (17') for transmitting an axial maneuvering force to the valve piston (16), characterized in that the middle part (6) has a lower, radially directed opening (13) which is designed to be able to form a hydraulic connection between the cavity (2') and the connection spigot (3), and an upper radial opening (12) which can be connected to a service pipe, in that the aforementioned radial openings (12, 13) and the connecting piece (3) have a common, essentially vertical center line (B), and that the valve piston (16) has a first part (19) as in the aforementioned, first axial position lies sealingly against the radial openings (12, 13), a second part which contains a continuous, radially directed channel (20) whose radial center line in the second axial position essentially coincides with the aforementioned common center line (B), and a third part (24) with a piston cavity (24') which has an axially directed outlet opening (25) and a radially directed piston opening (26), the piston cavity (24') in the third axial position being arranged in hydraulic connection with the connection spigot (3) via the piston opening (26) and d a lower, radially directed opening (13).

2. Valve according to claim 1, characterized in that the aforementioned, radially directed openings (12, 13) are formed in a pull-out arranged, circular cylindrical body (11) with a center line which coincides with the common center line (B ), the circular cylindrical body (11) being made with a through hole which is directed perpendicular to the said center line (B) and whose limiting surface forms part of the inner limiting surface of the valve cylinder (2).

3. Valve according to claim 1, characterized in that two of the aforementioned first, second and third valve piston positions correspond to axial outer positions of the valve piston (16) and are determined by means of each fixed stop surface (18, 23) in relation to the valve cylinder (2) which in the outer positions forms mechanical contact with respectively a first and a second surface portion fixed in relation to the valve piston (16), and that an intermediate position for the valve piston (16) is determined as a position in which a resilient projection (21) on the valve piston (16) snaps into a corresponding recess (22) in the inner wall surface of the valve cylinder (2) or vice versa.