US3581815A

US3581815A - Underwater connector with retrievable sealed electrical assembly

Info

Publication number: US3581815A
Application number: US799735A
Authority: US
Inventors: Fernando Murman
Original assignee: Hydril LLC
Current assignee: Hydril LLC
Priority date: 1969-02-17
Filing date: 1969-02-17
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01
Also published as: NL7002219A; DE2007211B2; DE2007211A1; NL160905C; FR2031477A1; BE745996A; NL160905B; JPS505641B1; GB1252235A; FR2031477B1

Abstract

The disclosure concerns unusually advantageous method and apparatus for controlling a stack of underwater wellhead equipment, utilizing a sealed electrically energizable element lowered underwater into operative proximity to a fluid pressure control adapted to be actuated in response to energization of the element.

Description

I Unlted States Patent 1 1 3,58 1,815

[72] Inventor Fernando Murman {56] References Cited Palos Verdes Peninsula, Calif. UNITED STATES PATENTS tf 2 2 2 3.011.753 12 1961 Kroffke 251 129 122] f d e 1 1971 3,098,635 7/1963 Delaporte eta1.. 251 129 35;; g'zf 3,199,595 8/1965 Lafitte 618.1. 166/.6 LosAngeIesCam. 3,480,040 11/1969 Enckson 251/129 Primary Examiner.1ames A. Leppink Att0mey-White & Haefliger [54] UNDERWATER CONNECTOR WITH RETRIEVABLE SEALED ELECTRICAL ASSEMBLY 21 Clams 7Drawmg ABSTRACT: The disclosure concerns unusually ad- [52] U.S.Cl 166/.5, vantageous method and apparatus for controlling a stack of 251/129, 335/260 underwater wellhead equipment, utilizing a sealed electrically [5 I] Int. Cl E2lb 43/01 energizable element lowered underwater into operative prox- [50] Field of Search 166/.5, .6; imity to a fluid pressure control adapted to be actuated in response to energization of the element.

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UNDERWATER CONNECTOR WITH RETRIEVABLE SEALED ELECTRICAL ASSEMBLY BACKGROUND OF THE INVENTION This invention relates generally to the control of underwater wellhead equipment, and more particularly concerns methods and means for controlling such equipment in a stack, using electrical apparatus which is retrievable independently of the stack.

In certain underwater well-drilling or producing operations it is desirable to service the well as by means of a tool or a stack of tools connectable to a projecting well fitting, such as submarine stub casing terminating above the ocean floor. As an example, where well casing has already been sunk in the submarine hole with the free end of the casing projecting above the ocean floor, it is desirable to provide for the controlled operation of well blowout prevention equipment, safety valves, safety joints or connectors, as well as other auxiliary apparatus, typically mounted on a frame and in a stack attached to the projecting well casing, in order to serve the well. Commercial equipment of this nature is generally fluid pressure operated, and it has heretofore been considered necessary to provide a large bundle of separate pressure hoses, each extending from a surface location to a particular tool in the stack so that independent operation of such tools might be achieved as desired. However, where certain equipment in the stack is to be left at the underwater location for relatively long periods of time, say for example where the well is shut in, the continued dangling of the multiple hoses to great depths becomes impractical and a source of major difficulty. Thus, should the hoses deteriorate, or break, or become entangled with other'equipment, the underwater tools may not remain operable with attendant risk of loss of the well including loss to the sea of great quantities of petroleum or gas.

Toward solving the above and other problems associated with servicing of underwater wells, it has been proposed that, after the stack has been lowered to the well head, electrical connection be made with electrical prime movers at the stack, such prime movers in turn operating the stack equipment, thereby obviating the need for such hoses. While this proposal has advantages, the problem of effectively connecting and disconnecting exposed electrical terminals under water remains, such terminals being subject to corrosion and deterioration.

BRIEF SUMMARY OF THE INVENTION It is a major object of the present invention to provide method and apparatus which will further facilitate the operation of underwater wellhead equipment, eliminating the need for long dangling pressure hoses, and at the same time eliminating need to make and break exposed electrical terminals.

Basically, the method involves the steps of providing at the underwater stack a projecting valve-actuating element capable of being displaced in response to magnetic force application thereto, displacement of that element acting to control the valve for controlling pressure application to the valve; lowering to the actuating element a sealed element which is electrically energizable to cooperate magnetically with the actuating element; and transmitting electrical current to the electrically energizable element to energize it to effect displacement of the valve actuating element. As will be seen, the lowering step may include such mechanical intercoupling of the elements as obviates need for electrical terminal interconnection and the disadvantages of the latter at underwater locations. Thereafter, the electrically energizable element may be retrieved to the surface so as not to remain exposed to the sea water, whereby reliability and life of the equipment is substan tially enhanced due to minimum exposure of the electrical unit to the sea water, that unit also being sealed for further reliability.

In its apparatus'aspects, the invention basically comprises, in combination:

a. a fluid pressure control assembly adapted to be presented underwater and in such relation to the stack as to be actuated for altering fluid pressure application;

b. an operating assembly including a sealed electrically energizable element adapted to be lowered under water into operative proximity to the control assembly; and

c. at least one of the assemblies including structure adapted to be displaced in response to energization of the element for actuating the control assembly.

As will be seen, the electrically energizable element may comprise a solenoid coil, and the referred to structure may comprise part adapted to be magnetically displaced in response to coil energiiation. Further, the part is typically carried by the control assembly which also includes a valve element operated by the part. In one form of the invention, the part may comprise a plunger and in addition, there may be advantageously included a guide socket carried by the operating assembly and presented to receive relative penetration of the control assembly whereby the plunger may be guided into the coil.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:

DRAWING DESCRIPTION FIG. 1 is an elevation showing a stack of well-servicing tools at a submarine well head location, together with apparatus permanently and detachably connected with the stack for controlling operation of the stack actuators;

FIG. 2 is an enlarged vertical section showing details of pressure control and operating assemblies embodying the invention, and in disconnected condition;

FIG. 3 is a view like FIG. 2, but showing the assemblies in connected condition;

FIG. 4 is a view of the surface equipment for lowering and elevating the stack and easing or tubing and the control assembly; and

FIGS. 5-7 show other forms of valve-actuating parts.

DESCRIPTION OF PREFERRED EMBODIMENTS In FIG. I a drill hole 10 sunk beneath the ocean floor 11 contains a string of casing 12 cemented or otherwise fixed in position for further suitable drilling or producing operations. Drill pipe or tubing is shown at 13 extending downwardly through the casing string.

The submarine wellhead equipment includes a lower connector unit 14 releasably fastened onto the casing stub 15 projecting upwardly. In sequence above unit 14 are double master gate 16, blowout preventer 17, a pressure-distributing control unit 18, and another connector 19, intermediate tubular stubs or extensions being indicated at 20, 21, 22 and 23. The connectors l4 and 19 are releasably attached to stubs l5 and 23 respectively, and may be of the type disclosed in US. Pat. No. 2,962,096 to Knox; the unit 18 may comprise suitable manifolding; for distributing pressure to the various actuators; and the blowout preventer 17 may be of the type disclosed in US. Pat. No. 2,609,836 to Knox.

Fluid pressure is transmitted from an underwater supply source inthe form of

pressure vessels

24 and 25 to the unit 18 via

lines

26 and 27; and pressure is controllably transmitted from unit 18 to the connector 14 via lines 28, to the master gate 16 via lines 29 and to the preventer 17 via lines 30. Fluid pressure is supplied from the surface source 31 seen in FIG. 4

via hoses 32 to the upper connector unit 19 in the stack, for

operation independently of unit 18 or in combination therewith.

To complete the general description of FIG. I, the numeral 33 designates the base of a frame for the wellhead equipment stack, the frame also including guide lines 34 attached to the base and

transverse members

35 and 36 respectively attached to the lower connector 14 and the top of unit 19, said members interconnecting the guide line at vertically spaced locations. The guide lines 34 extend to the surface, and the

members

35 and 36 have slidable connection therewith at 37 and 38 for guiding the connectors downwardly into position as shown. if the connector 14 is released from the stub 15, it and the equipment thereabove may be elevated to the surface as the casing 39 in the string or stack is run upwardly. Alternatively, if the connector 19 is released from the stub 23, it and the casing 39 may be elevated as the casing 39 is run upwardly, leaving the equipment in the stack therebelow at the wellhead, as for example when the well is shut-in. The casing is run downwardly or upwardly by adding or subtracting casing lengths at the surface, by suitable means generally indicated at 40 in FIG. 4 and on platform or vessel 41.

Extending the description to the remaining FlGS., mounted on the stack, as by elbow 49 in association with unit 18, is a fluid pressure control assembly 50 presented underwater so as to be actuated for altering fluid pressure application, as via unit 18, to the wellhead equipment (such as the preventer, gate, connector, etc.). Also shown is an operating assembly 51 including a sealed electrically energizable element (as for example solenoid coil annulus or annuli 51a) adapted to be lowered underwater (as by cable 52) into operative proximity to the control assembly 50.

At least one of these assemblies also includes structure adapted to be displaced in response to energization of the element 51a for actuating the control assembly. Such structure may for example comprise a part such as a plunger (or plungers) 53 which extends within the magnetic field the coil or coils 51a when the assemblies 50 and 51 extend in operative proximity as in FIG. 3. As is clear from the drawings, plungers 53 are carried by assembly 50 to project upward for initial reception partly into the coils 51a in response to relative movement of the assemblies into operative proximity. Upon energization of coil 51a plunger 53 will be more fully drawn into the coil by magnetic pull, as seen at 53a in FIG. 3.

The control assembly also includes a valve element or elements 54 having operative connection with the plunger or plungers so that the valve elements may be shifted in response to plunger displacement. Housings 55 contain the valve ele ments and are supported on base structure 56 mounted on the stack. Note the ports 57 and 58 in the .valve housings through which pressure fluid flow is controlled, such flow passing via

lines

59 and 60 from and to unit 18 for distribution to the wellhead equipment, the pressure originating at a vessel 24. Plate structure 61 extends at the upper ends of the housings, and is connected to the housings, to seat the lower plate 62 of unit 51 in FIG. 3 position. Plungers 53 project upwardly through openings 63 in plate 61, and through openings 64 in plate 62. Note the provision of tubular protectors 90 closely receiving the plungers and mounted in plate 61 to prevent sea water access to the plungers. Coils 51a are sealed out of communication with the exterior, as by means of the resinous bodies 65 and 165 (forming recesses 66 receiving the coils) and the plate structure 62 capping the undersides of the bodies 165. Note also the tubular metal sleeves 67 integral with plate 62 and received into the coils and sized for receiving the protectors 90, the sleeves being closed at 68.

A further feature of the invention has to do with the provision of guide structure presented to guide the plunger or plungers relatively into the coil or coils in response to underwater lowering of the operating assembly 51 into operative proximity to the control assembly. Such structure may typically include a socket 70 carried by the assembly 51 and presented to receive relative upward penetration of the control assembly. The socket is shown to include a tubular portion 71 and a flared portion 72 operable to guide the assembly 50 upwardly into tubular portion 71 wherein it is centered so that the plungers will align with the coils. Such alignment, about the vertical axis 74 becomes assured by virtue of the tongue and

groove elements

75 and 76 on the assemblies and located to interfit during the relative penetration. Note for example the widened mouth 76a of the slot or groove 76 which loosely receives the tongue or rod 75 and acts to guide it into the guide extent 76b of the slot, for precise alignment. Slot 76!; also serves as a water outlet on makeup.

The method of the invention involves the steps of providing at the stack a projecting valve-actuating element (as for example plunger 53) capable of being displaced in response to magnetic force application thereto, displacement of that element acting to control the valve 54 for controlling pressure application to the apparatus; lowering to the element a sealed element (such as coil 51a) which is electrically energizable to couple and cooperate magnetically with the actuating element; and transmitting electrical current to the element 51a to energize it and effect displacement of the valve actuating element 53. Such current transmission may be effected via lines or cables 80 running to the surface along the lowering cable 52 seen in FIG. 3. Thereafter, the element 51a may be upwardly retrieved for removal from the sea during times when shifting of the positions of the underwater tools is not desired. In this regard, the various valves 54 (typically four-way) may be paired in association with the various underwater tools, in such manner that operation of one valve of a pair shifts a tool piston in one direction, and operation of another valve of a pair shifts the tool piston in the opposite direction. Surface retrieval equipment is indicated at 40 in FIG. 4.

FIG. 5 illustrates a form of this invention wherein this valveactuating part, which is magnetically displaced in response to coil energization, is carried for linear displacement while remaining out of penetrating relation with the coil. For example, part comprises a plate 101 (as for example iron) on a central stem 102 connected at 103 to the valve (not shown). A housing 104 for that part 100 includes a body 105 in which the stem is guided at 106 for linear movement, and a nonmetallic panel 107 sealing the cavity 108 in which plate 101 is received. Operating assembly 109 including coil 110 is shown in operative proximity to the part 100 in the control assembly. Otherwise, the apparatus may be as shown in FIGS. 1-3.

In FIG. 6, the operating assembly includes solenoid coils and 116 about

pole pieces

117 and 118 which, for example may form north and south poles respectively, at a given instant. Spaced from the pole pieces is a valve-actuating part 119 including a plate 120 constructed to rotate when the coils are energized. A housing 121 carries the part 119 for rotation, as shown, and for protection against sea water contamination.

Finally, FIG. 7 shows an operating assembly 122 having a coil 123, forming a bore 124 into which a protective sleeve 125 is received. Coil 123 may cooperate with suitable laminations and bars (identified at 126) to define a motor stator providing a rotating magnetic field when the coil is energized with alternating current. The valve-actuating part here includes a motor rotor 127 in the fluid pressure control as sembly 128, the rotor being relatively receivable into the sleeve 125 when the

assemblies

122 and 128 are brought into operating proximity. A connection to the rotor is shown at 130, for suitably rotating the underwater valve (not shown). A protector 131 extends about the projecting rotor, to protect it from contamination by sea water.

lclaim:

1. ln apparatus of the character described, the combination comprising:

a fluid pressure control assembly to be presented underwater so as to be actuated for altering fluid pressure application,

a cable and an operating assembly including a sealed electrically energizable coil element supported by the cable to be lowered underwater into operative proximity to said control assembly,

at least one of said assemblies including structure adapted to be displaced in response to energization of said element for actuating said control assembly; said assemblies extending in operative proximity with one another and being relatively shiftable into and out of operative proximity in response to vertical displacement of the cable.

2. The combination of claim 1 wherein said structure comprises a part adapted to be magnetically displaced in response to electrical energization of said coil.

3. The combination of claim 2 wherein said part comprises a plunger whichextends within said coil when said assemblies extend in operative proximity.

4. The combination of claim 3 wherein said plunger is carried by said control assembly to project for movement into said coil in response to coil energization, with said assemblies extending in operative proximity.

5. The combination of claim 2 wherein said control assembly includes a valve element having operative connection with said part.

6. The combination of claim 4 including guide structure presented to guide said part relatively into proximity with said coil in response to underwater lowering of said operating assembly into operative proximity to said control assembly.

7. The combination of claim 6 wherein said structure includes a socket carried by said operating assembly and presented to receive relative penetration of said control assembly.

8. The combination of claim 7 wherein said assemblies form tongue and groove elements one of which is on the socket, and located to interflt during said relative penetration.

9. The combination of claim 1 including an underwater wellhead assembly including a fluid responsive actuator operatively coupled to said fluid pressure control assembly.

10. The combination of claim 9 wherein said wellhead assembly supports said control assembly to be presented upwardly for downward seating of said operating assembly.

11. The combination of claim 2 wherein said part is carried for linear displacement in response to coil energization.

12. The combination of claim 2 wherein said part is carried for rotary displacement in response to coil energization.

13. The combination of claim 2 wherein said part is carried for said displacement while remaining out of coil-penetrating relation.

14. ln apparatus of the character described, the combination comprising:

a fluid pressure. control assembly adapted to be presented underwater so as to be actuated for altering fluid pressure application,

a cable and an operating assembly including at least two sealed solenoid coils supported by the cable to be lowered into operative proximity to said control assembly,

at least one of said assemblies including at least two parts,

one adapted to be magnetically displaced in response to energization of one coil and the other adapted to be magnetically displaced in response to energization of the other coil, for actuating said control assembly, said assemblies extending in telescopically interfltting relation and being relative shiftable into and out said relation in response to vertical displacement of the cable.

15. The combination of claim 14 wherein said parts comprise plungers carried by said control assembly to project for reception into hollows formed in said coils.

16. The combination of claim 15 wherein said control assembly includes valve elements having operative connection with said plungers.

17. The combination of claim 15 including guide structure presented to guide said plungers relatively into said soils in response to underwater lowering of said operating assembly into operative proximity to said control assembly.

18. The combination of claim 15 including recessed protectors closely receiving the plungers to block sea water access thereto when said assemblies are spaced apart.

19. In the method of controlling, from the surface, pressureoperable apparatus installed in a stack of underwater wellhead equipment, the steps that include providing at the stack a valve-actuating element capable of being displaced in response to magnetic force application thereto, displacement of said element acting to control the valve for controlling pressure application to said apparatus,

lowering to said actuating element a sealed coil element which is electrically energizable to cooperate magnetically with said actuating element,

bringing said elements into underwater alignment, and

transmitting electrical current to said electrically energizable element to energize same for effecting displacement of said valve actuating element.

20. The method of claim 19 including the further step of retrieving said electrically energizable element by elevating same in the sea relative to said valve-actuating element.

21. The method of claim 19 wherein said lowering step includes effecting intercoupling of said elements.

Claims

1. In apparatus of the character described, the combination comprising: a fluid pressure control assembly to be presented underwater so as to be actuated for altering fluid pressure application, a cable and an operating assembly including a sealed electrically energizable coil element supported by the cable to be lowered underwater into operative proximity to said control assembly, at least one of said assemblies including structure adapted to be displaced in response to energization of said element for actuating said control assembly; said assemblies extending in operative proximity with one another and being relatively shiftable into and out of operative proximity in response to vertical displacement of the cable.

3. The combination of claim 2 wherein said part comprises a plunger which extends within said coil when said assemblies extend in operative proximity.

8. The combination of claim 7 wherein said assemblies form tongue and groove elements one of which is on the socket, and located to interfit during said relative penetration.

14. In apparatus of the character described, the combination comprising: a fluid pressure control assembly adapted to be presented underwater so as to be actuated for altering fluid pressure application, a cable and an operating assembly including at least two sealed solenoid coils supported by the cable to be lowered into operative proximity to said control assembly, at least one of said assemblies including at least two parts, one adapted to be magnetically displaced in response to energization of one coil and the other adapted to be magnetically displaced in response to energization of the other coil, for actuating said control assembly, said assemblies extending in telescopically interfitting relation and being relative shiftable into and out said relation in response to vertical displacement of the cable.

19. In the method of controlling, from the surface, pressure-operable apparatus installed in a stack of underwater wellhead equipment, the steps that include providing at the stack a valve-actuating element capable of being displaced in response to magnetic force application thereto, displacement of said element acting to control the valve for controlling pressure application to said apparatus, lowering to said actuating element a sealed coil element which is electrically energizable to cooperate magnetically with said actuating element, bringing said elements into underwater alignment, and transmitting electrical current to said electrically energizable element to energize same for effecting displacement of said valve actuating element.