WO1984003922A1

WO1984003922A1 - Sub sea production choke and actuator

Info

Publication number: WO1984003922A1
Application number: PCT/US1984/000478
Authority: WO
Inventors: John D Muchow
Original assignee: Hydril LLC
Current assignee: Hydril LLC
Priority date: 1983-04-04
Filing date: 1984-04-02
Publication date: 1984-10-11
Anticipated expiration: 1986-10-02
Also published as: NO844817L; EP0140938A1

Abstract

A multi-position choke-valve assembly comprises: a) a valve body (15) defining an interior chamber (20) and inlet (24) and outlet (26) fluid flow ports communicable with that chamber, b) a tubular carrier (19) received in the chamber to be axially removable therefrom, c) a tubular nozzle (27) retained in the carrier, d) a flow control sleeve (36) axially movable in the carrier relative to the nozzle and in telescopic relation therewith to control fluid flow from the inlet flow port to the outlet port via the nozzle wherein fluid flow energy is dissipated, e) and mechanism for so moving the flow control sleeve. The referenced mechanism may include a linear to rotary actuator.

Description

SUB SEA PRODUCTION CHOKE AND ACTUATOR

This invention relates generally to control valves, and more particularly to chokes which serve to dissipate the energy of high pressure fluid, as for example fluid rising in a well. Choke valves are commonly connected to the well head at the well surface to dissipate the energy of high pressure fluid, the latter commonly entrain¬ ing small particles loosened from the underground well formation. Such material can and does destructive- ly erode the choke valve due to exposure to the fluid flow when the valve is partly open, i.e. in fluid energy dissipating position.

There is need for a multiposition choke valve characterized as operable under water, as for example in off-shore well environments, and by high-reliability; low wear; simplicity as regards structure and opera¬ tion, and by ease of removal of valve parts subjected to wear, for repair. There is also need for an im¬ proved actuator mechanism to operate the valve, i.e. relatively move valve telescoping elements between open and closed positions, with high mechanical ad¬ vantage due to the extremely high fluid flow forces en¬ countered, i.e. resisting valve closure, and in view of the dissipation of flow energy at and within one or both valve elements (sleeve and nozzle elements, for example) .

Basically, the invention aims to provide an improved multiposition choke valve apparatus meeting

- OMPI the above needs.

Basically, the apparatus of the invention in¬ cludes, in combination: a) a valve body defining an interior chamber and inlet and outlet fluid flow parts communicable with that chamber, b) a tubular carrier received in said chamber to be axially removable therefrom, c) a tubular nozzle retained in the carrier, d) a flow control sleeve axially movable in the carrier relative to the nozzle and in telescopic relation therewith to control fluid flow from the inlet flow port to said outlet port via said nozzle wherein fluid flow energy is dissipated, e) and means for so moving said flow control sleeve.

A further feature of the invention relates to providing for he removability of a bonnet and actuator mechanism from the valve body, and at the same time to enable removal of the afore-mentioned b) , c) and d) elements from the body interior and with the bonnet. Further features and advantages of the in¬ vention, as well as the details of a preferred em¬ bodiment, will be more fully understood from the fol- lowing specification and drawings, in which:

Fig. 1 is an elevation showing a production choke valve assembly connected with a well head in¬ stallation;

Fig. 2 is an enlarged plan view taken in sec- tion on lines 2-2 of Fig. 1;

Fig. 3 is an elevation taken in section on lines 3-3 of Fig. 2; showing the valve in open position;

Fig. 4 is an enlarged section in plan view on lines 4-4 of Fig. 3; Fig. 5 is an elevation on lines 5-5 of Fig.

4;

Fig_* 6 is a section in elevation on lines 6-6

Mfi ^* of Fig. 4 ;

Fig. 7 is an elevation in section on lines 7-7 of Fig. 3;

Fig. 8 is a section taken on lines 8-8 of Fig. 7; and

Fig. 9 is a view like Fig. 3, and showing the valve in closed position, and

Fig. 10 is an enlarged view of a portion of Fig. 3. Referring first to Fig. 1, a choke valve 10 is shown as sidewardly mounted at 11 to a well head 12, which may be located sub-surface, as proximate to the ocean floor. The tubing is adapted to receive pressurized production fluid, as for example petroleum or gas typically containing sand, or other abrasive particles. Arrow 14 designates rising pressurized flow passing from the tubing to the production choke valve.

Extending the description to Figs. 3, 4 and 7-9, theillustrated choke valve 10 is shown to include a valve body 15 and body cap or bonnet 16 interfitting the body at 17. A removable C-clamp 18 retains the bonnet to the body, the clamp bridging the body and bonnet flanges 15a. and 16a. A tubular carrier 19 is axially received in cylindrical chamber defined by counterbore 20 formed by the body, as shown. The lowermost or forwardmost extent 19a_ of the carrier is received in or pilots in body bore 21. The uppermost or rearwardmost portion 19b of the carrier is removable attached, as by pins 22 to telescopically interfitting portion 16b of the bonnet, whereby the carrier may be axially removed from the body after release of the clamp 18 and upon axial retraction of the bonnet.

Chamber 20 includes an annular portion 20a. ex¬ tending annularly about an intermediate portion of car- rier 19 that has a number of ports 19£ through its wall. so the fluid received via body side inlet port 24 in body 15 is passed via ports 19c: into the annular in¬ terior space or sub-chamber 25 within the carrier. The latter is communicable via body outlet port 26 to a sump or other area.

A tubular (sliding seat) nozzle 27 is retained on the carrier to pass the flow from annular space 25 into the nozzle interior 28, for subsequent endwise flow to port 26. That nozzle has an annular wall 27a projecting upwardly into space 25, wall 27a_ defining a number of flow passing side openings through the wall, there being a first group of such openings 28 spaced circumferentially about axis 29, and a second group of openings 30 spaced about axis 29 and axially offset from openings 28. These two groups are adapted to pass the flow in streams which are directed radially inwardly to impinge upon one another and dissipate flow energy, within the nozzle interior 28a_. The nozzle is retained as by rings 31-34 to the internal flanged extent 19d_^ of the carrier. An annular seal 35 is carried by the nozzle to protrude or extend for peripheral engagement by a control sleeve (stopper) 36, the non-metallic seal located below or beyond the openings 28 and 30 so as to be out of the direct flow path of the abrasive wall fluid, which typically con¬ tains abrasive cuttings particles, whereby seal life is enhanced. The seal is also located up-stream of the orifice openings 28 and 30, in a low velocity flow area or zone. The nozzle may consist of wear resistant ma¬ terial, such as tungsten carbide.

The flow control sleeve 36 is located for axial movement within space 25 in the carrier, and rela¬ tive to the nozzle, to control well fluid flow from the port 24 to port 26 via the nozzle. The sleeve 36, which may also consist of tungsten carbide, is movable- telescopically relative to the nozzle, and preferably slidably at the outer side of the latter between re¬ tracted or fully open position (as seen in Figs. 3 and 7, and fully advanced or closed position as seen in Fig. 9 and as indicated by broken lines 36^• in Fig. 7). A rearward stop 200 limits sleeve retraction, the stop provided by an annular part 201 in the carrier. A partially advanced position of the sleeve '36 is shown at 36", wherein row of openings 30 remains partly open. In this regard, the sleeve pressurally engages the seal 35 in fully advanced position 36', to close off flow through the nozzle. Note that openings 28 and 30 are sufficiently close to the lowermost extent 25a. of space 25 to cause the flow to create turbulence in that zone 25a_ to flush sand, and other particles therefrom, but at the same time not to cause such a direct flow impingement on the seal as would undesirably quickly wear it away. Note the additional 0-ring seal at 40 carried on the nozzle to wipe against the bore 36a_^ of the slidable sleeve.

Means is also provided to move or displace the sleeve 36 as described, such means typically in¬ cluding a stem 42 projecting beyond (i.e. rearwardly of) the carrier 19, together with threaded structure 43 for effecting endwise advancement and retraction of the stem in response to stem rotation. The stem is attached to the sleeve 36 as via structure 202 associated with reduced diameter cylinder203 slidably guided at 204 in part 201. The stem is guided in tubu¬ lar part 206 carrying lubricated gland 202a. Actuator mechanism is shown at 44 as having operative connection with the stem 42 to so rotate the stem. Such actuator mechanism is shown to include two fluid pressure op- erated linear actuators 50 and 51, together with a linear- to-rotary motion converter 52 operatively coupled between the actuator or actuators, and the stem, to rotate the latter (see Figs. 2 and 4) .

Thus, for example, forward stroking of the piston 50a and shaft 50b of actuator 50, in the direction of arrow 54 causes pawl 55 on shaft extension 56 to move counterclockwise in slot 57 in a flange 58a on a collar 58. This allows a spring 59 in that flange to urge a plunger 60 into a slot 61a in a ratchet wheel 61 centered within the collar (see Fig. 4ji) so that the collar and ratchet wheel become coupled to¬ gether, and are rotated counter-clockwise (in Fig. 4) in response to forward stroking of the actuator 50 as described. (Note that a pin 62 moves at least partly out of a cam groove 63 in the plunger 60, as the pawl moves in slot 57 away from the plunger, and the latter moves toward the ratchet wheel) . As a result, the ratchet wheel rotates the polygonal stem extension 42at and the stem in one rotary direction (counterclockwise) . These described elements form one unit of the converter 52.

Return motion of thepiston and plunger 50a_ and 50b (accompanied by collar 58 over-riding of the ratchet wheel) is aided by a tension spring or springs 55 connected between terminal 56a of shaft extension 56, and a fixed transverse frame 67. Also, fluid pressure may be admitted to the actuator cylinder 50c_.as via piping 68 from an accumulator 69 to aid the return motion. Underwater sea pressure may be admitted via pipe 71 to one side of a bladder 70 in the accumulator, whereby that pressure is transmitted to the working fluid at the opposite side of the bladder, for aiding the return stroking. Numeral 73 in Fig. 2 designates a source of pressurized fluid, and valving, to control application of that pressure via piping 75 to the cylinder 5θ£ to drive the piston and shaft in direction 54. The accumulator 69 is supported at 69a, within the housing 91.

In like manner, the linear-to-rotary motion converter 52 may include means to rotate the. shaft in the opposite rotary direction. Thus for example, forward stroking of the piston 51a and shaft 51b of actuator 51 in direction 74 causes operation of a cor¬ responding pawl, plunger and spring mechanism associated with a flange 78a_ on an associated collar 78, so that collar 78 and a like reversely directed ratchet wheel become coupled together and are rotated clockwise (in Fig. 4). As a result, the stem extension 42a is rotated clockwise. These elements form a second unit of the converter 52. See also stop bolts 110 and 111 limiting return rotation of collars 58 and 78. Return motion of the piston and plunger 51a_ and 51b_ is aided by a tension spring or springs 81 connected between terminal 82b of a shaft extension 82, and fixed frame 67. Also, fluid pressure may be ad¬ mitted to cylinder 5l£ as via piping 68 from the ac- cumulator 69, to aid the retraction. Numeral 84 in Fig. 2 designates a source of pressurized fluid, and valving, to control application of that pressure via piping 85 to the cylinder 5l£, to drive the piston and shaft in direction 74. As the stem extension 42a_ and stem 42 are rotated in one direction they are caused to axially advance by threading 86, for moving the valve control sleeve 36 axially in a closing direction; and as the stem 42 is rotated in the opposite direction, the thread- ing 86 causes the sleeve 36 is moved axially oppositely. Such threading 86 includes external threads 86a_ on the stem 42, and internal threads 86b on annuli 87 and 88. The latter may be carried in a counterbore 89 in cap or bonnet 16. Also provided is means to maintain the fluid pressure within the interior 90 of the enclosing housing

OMFΪ 91 at the same or approximately the same pressure as that of the surrounding environment, such as sub¬ surface sea pressure. In the example shown .in Fig. 2, an accumulator 92 is supported at 92a, and has an inlet 93 exposed to outside or underwater pressure. That pressure is transmitted via pipe 94 to a bladder 95 within the accumulator, for transfer to hyperbaric pressure at the opposite side of the bladder. That side of the accumulator communicates via outlet 96 with the housing interior 90. Accordingly, pressure equal¬ ization between the exterior and interior is achieved. Oil (as for example water soluble oil) may fill in¬ terior 90. Housing 91 attaches at 97 to the bonnet 16. In addition, means is provided to sense the axial position of the stem 42 and stem extension 42a_, whereby the positioning of the sleeve 36 relative to nozzle 27 is determinable. Such means is shown to include a plunger 98 having an end surface or nose 98a. yieldably urged (as by spring 101) against tapered surface 100 on the stem 42 (or 42ci) , whereby the plung¬ er is variably displaced in accordance with stem axial advancement or retraction. Auxiliary means senses plunger variable displacement for producing an output signal corresponding thereto. See for example the housing 102 containing a magnetic sensor 103 (including coil 104 within which the plunger 105 is movable to provide variable impedance to AC) . The potentiometer output signal at 106 is transmitted via cable 107 to output junction 108, for transmission to an indicator, shown schematically at 109 in Fig. 3.

Finally, note stem bearings 110 carried in auxiliary housing structure 111 and 112.

Referring now to Fig. 10, means is shown as- sociated with the stem further extension 42a' to be manually turned for rotating the stem in override mode. and independently of operation of the actuator mech¬ anism 44. The latter is typically in rest position during such manual operation. Such means may take the form of a polygonal head 120 integral with the stem extension 42a_',,- and adapted to be wrench or tool gripped for rotating the stem. Numeral 121 indicates such a tool or wrench.

Also illustrated in Fig. 10 are indicia (see marks 122 on a sleeve 123 connected to the stem extension 42a_') associated with the stem 42 to be ro¬ tated therewith and relative to a non-rotatable marker 124 (on a fixed plate 125) . This provides visual indication of axial positions of the stem and valve sleeve 36 (relative to openings 28 and 30) upon completed incremental strokings of the actuator mechanism. For example, as the actuator is stroked, sleeve 123 may be rotated through an angle α to advance helically spaced markers 122 into successive registra¬ tion with fixed marker 124. Such markers 122 may be labeled or coded as indicated to correspond to axial positions of sleeve 36, the precise closing positions of the sleeve 36 may be ascertained, visually.

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OMPT

Claims

1. A multiposition- choke-valve assembly, characterized by the combination of: a) a valve body defining an interior chamber and inlet and outlet fluid flow ports communicable with that chamber, b) a tubular carrier received in said chamber to be axially removable therefrom, c) a tubular nozzle retained in the carrier, d) a flow control sleeve axially movable in the carrier relative to the nozzle and in tele¬ scopic relation therewith to control fluid flow from the inlet flow port to said outlet port via said noz¬ zle wherein fluid flow energy is dissipated, e) and operating means for so moving said flow control sleeve.

2. The assembly of claim 1, characterized by a tubular bonnet removably retaining said carrier in said chamber, said operating means including a stem projecting within said bonnet, the stem operatively connected to the flow control sleeve to move axially therewith, said b) , c) and d) .elements being removable from the body with the bonnet as the bonnet is removed from the body.

3. The assembly of claim 1, characterized in that the nozzle has an annular wall defining flow passing through openings located to be controlled by said flow control sleeve.

4. The assembly of claim -3, characterized in that the carrier defines an annular sub-chamber within which the flow control sleeve is axially movable at the outer side of said nozzle- and in controlling relation with said nozzle openings.

5. The assembly of claim 1, characterized ^■ in that said operating means includes a stem

GMfl projecting beyond said.carrier and^" threaded structure for effecting endwise advancement and retraction of the stem in response to stem rotation.

6. The assembly of claim 5, characterized by actuator mechanism operatively connected with the stem to so rotate the stem.

7. The assembly of claim 6, characterized by a tubular bonnet removably retaining the carrier in said chamber, said threaded structure including threading on a part in the bonnet meshing with thread¬ ing on the stem.

8. The assembly of claim 6, characterized in that said actuator mechanism includes a fluid pres¬ sure operated linear actuator, and a linear-to-rotary motion converter operatively coupled between the ac¬ tuator and stem to rotate the stem.

9. The assembly of claim 1, characterized by an annular seal carried by the nozzle to be an- nularly engaged by the sleeve in an advanced position of the sleeve relative to the nozzle and in which the nozzle openings are blocked by the sleeve.

10. The assembly of claim 8, characterized in that said converter includes a first rotary ratchet having one part connected to the actuator and another part coupled to a stem extension whereby linear move¬ ment transmitted to said one part is transmitted as rotary one-way motion in one direction to said other part as the actuator is advanced.

11. The assembly of claim 10, characterized in that said parts are de-coupled as the actuator is retracted, and including a fluid pressure source con¬ nected to the actuator to assist in actuator retraction.

12. The assembly of σla^'im 11, characterized in that said fluid pressure source includes an ac¬ cumulator to which underwater sea pressure is transmis¬ sible.

13. The assembly of claim 11, characterized in that said converter includes a second rotary ratchet mechanism coupled between a second actuator and said stem extension, to rotate the stem extension in a one¬ way mode but in the opposite rotary direction, in response to advancement of the second actuator.

14. The assembly of claim 13, characterized in that said fluid pressure source is connected to said second actuator to assist its retraction.

15. The assembly of claim 8, characterized by a housing enclosing said actuator mechanism, and means in the housing for establishing a fluid pres¬ sure level in the housing interior substantially the same as underwater pressure outside the housing.

16. The assembly of claim 5, characterized by sensor means to sense the extent of said stem ad¬ vancement and retraction, for providing an indication of- the position of the sleeve relative to the nozzle.

17. The assembly of claim 16, characterized in that said sensor means includes a plunger having a surface yieldably urged against an axially tapering surface on the stem, whereby the plunger is variably displaced in accordance with stem advancement or re¬ traction, and means sensing said plunger variable dis¬ placement, for producing an output signal correspond¬ ing thereto.

18. Valve operating means for use in a multi¬ position choke valve assembly having a valve body de¬ fining inlet and outlet flow ports, and valve elements within the body, one element axially movable relative to another element to control the flow through said ports, in response to rotation of an extension of said one element, characterized in that said valve operating means comprises actuator -mechanism operatively con-

CV' I nected with said extension to rotate same, said mech— anism including a fluid pressure operated linear ac¬ tuator, and a linear-to-rotary motion converter op¬ eratively coupled between said linear actuator and said extension to rotate same in response to linear displacement of the actutaor, thereby to move said one element axially, and a housing enclosing said mech¬ anism, and means for establishing a fluid pressure level in the housing interior substantially the same as underwater pressure outside the housing.

19. The valve operating means of claim 18, characterized in that said converter includes a first rotary ratchet having one part connected to the ac¬ tuator and another part coupled to a stem associated with said one element, whereby linear movement of said one part is transmitted as rotary one-way motion in one direction to said other part as the actuator is advanced.

20. The valve operating means of claim 19, characterized in that said parts are de-coupled as the actuator is retracted, and including a fluid pressure source connected to the actuator to assist in actuator retraction.

21. The valve operating means of claim 20, characterized in that said fluid pressure source in¬ cludes an accumulator to which underwater sea pres¬ sure is transmissible.

22. The valve operating means of claim 19, characterized in that said converter includes a second rotary ratchet mechanism coupled between a second ac¬ tuator and said stem extension, to rotate the stem extension in a one-way mode but in the opposite ro¬ tary direction, in response to advancement of the second actuator.

23. The valve operating means of claim 22, characterized in that said fluid pressure source is connected to said second actuator to assist its re¬ traction.

24. The device of claim 8 or 18, char¬ acterized by means associated with the stem to be man¬ ually turned for rotating the stem in override mode and independently of operation of said actuator mechanism.

25. The device of claim 8 or 18, char¬ acterized by indicia associated with the stem to be rotated therewith and relative to a non-rotated marker for visually indicating axial positions of the stem upon completed incremental strokings of the actuator mechanism.

26. In combination, a) a vlave body defining a chamber, b) a carrier in said chamber and a bonnet on the body and closing the chamber, the carrier con¬ nected to the . bonnet to be removable from the chamber when the bonnet is removed from the body, c) relatively movable valve control ele¬ ments in said chamber, at least one element being at¬ tached to the carrier to be removable therewith from the body chamber, and d) actuator mechanism operatively connected to said one valve control element and connected to said bonnet.

27. In combination, a) a valve body defining a chamber, b) a bonnet on the body and closing the chamber, c) relatively movable valve control elements in said chamber, at least one element being attached to the bonnet to be removable therewith from the body chamber, the other valve control element operatively connected to the body, and d) actuator mechanism operatively connected to said one valve control element and connected to said foonnp .

28. In combination, a) a valve body defining a chamber, b) a carrier in said chamber and a bonnet on the body and closing the chamber, c) relatively movable valve control elements in said chamber, at least one element being attached to the carrier, and d) actuator mechanism operatively connected to the other valve control element and connected to said bonnet.