US3530885A

US3530885A - Wellhead assembly

Info

Publication number: US3530885A
Application number: US587774A
Authority: US
Inventors: John H Fowler
Original assignee: Rockwell Manufacturing Co
Current assignee: Rockwell Manufacturing Co; Smith International Inc
Priority date: 1966-10-19
Filing date: 1966-10-19
Publication date: 1970-09-29
Anticipated expiration: 1987-09-29
Also published as: GB1155797A

Description

United States Patent John H. Fowler Houston, Texas Oct. 19, 1966 Sept. 29, 1970 Rockwell Manufacturing Company, Houston, Tex.,

a corporation of Pennsylvania lnventor Appl. No. Filed Patented Assignee WELLHEAD ASSEMBLY 4 Claims, 3 Drawing Figs.

u.s. Cl 137/608, 137/236 lnl.Cl [52") 41/00 Field ol'SearchW 251/367 (Cursory),

31 (Cursory); 137/608 (Cursm'y); 137/236,

608: 61/(lnquired); 251/57: 63.5. 63.6

References Cited UNITED STATES PATENTS 2,641,280 6/1953 Fleischhauer 137/625 3,2l2,5l6 l0/l965 Natho a ..137/236(OS)UX 3,367,355 2/1968 Anderson r 137/236X 3,400,730 9/1968 Anderson 137/236 Primary ExaminerJohn P. McIntosh Attorneys- Robert W. B. Dickerson, Murray Robinson, Ned

L. Conley and James A. Bargfrede ABSTRACT: An underwater wellhead assembly comprising a plurality of valves connected by an adapter. Each valve has a fluid-actuable operator thereon. A control means in the wellhead controls flow of operating fluid to and from the operators. Passageways are formed in the walls of the adapter, valves and operators connecting the control means to the operators without external conduits.

Patented Sept. 29, 1970 Sheet 1 of 3 (156/7 aw/er INVENTOR.

' i Arromvsr -1 Patented Sept. 29, 1970 t I v 3,530,885

Sheet 2 of 3 J b 20 Fow/sr L ENTOR.

Sheet (fa/2n f'aw/ex' LWENTUR.

WELLHEAD ASSEMBLY This invention relates to fluid operated systems, and more particularly it pertains to hydraulic and pneumatic systems for use with fluid operated equipment on well heads positioned at offshore locations.

In an attempt to locate new oil fields, an increasing amount of well drilling has been conducted at offshore locations such as, for example, off the coasts of Louisiana, Texas and California. Usually the strings of pipe in such offshore wells extend to a point above the surface of the water where they are closed in a conventional manner that is used in land wells with a conventional wellhead assembly being attached to the top of the casing. Recently, however, attempts have been made to provide methods and apparatus for drilling and completing a well wherein both the well casinghead and the wellhead assembly are located under water at a depth sufficient to allow ships to pass over them. Preferably, these pieces of equipment are located close to the ocean floor. Thus it has been necessary to design entirely new equipment for this purpose. Among other equipment, it has been'necessary to design new wellhead assemblies for controlling the flow of fluid from producing wells. As is well known in the art, such assemblies are commonly called Christmas trees".

On land the various components of a wellhead assembly for controlling flow are often manually operated so as to achieve the desired production from the well. However, where the wellhead is positioned under water, such as close to the ocean floor, the various elements of the wellhead assembly are preferably arranged for remote control by electrical, hydraulic or pneumatic systems.

It will be appreciated that two fluid lines will normally be required to operate any single moving element of a fluid operated device in a wellhead. Thus, where a wellhead as sembly contains several hydraulically operated devices, as is usually the case, it is normally necessary to provide a large number of hydraulic lines extending from the wellhead assembly below the water to the operating base above the water. Often as many as or more of such hydraulic lines are required for one wellhead assembly. It will be appreciated that such hydraulic lines must be of flexible construction and of suitable materials to extend from the underwater wellhead to the base located at the surface of the water while at the same time being able to resist deterioration by sea water. Also each connection to the wellhead assembly provides a separate point of possible leakage and/or corrosion by the sea water, and a separate point which might be damaged during the lowering of V I a Christmas tree," for example, into position, and a separate wellhead assembly utilizing only a single exposed fluid line for operation of all fluid operated devices thereon.

Another'object of this invention is to provide a wellhead assembly in which fluid connections between various components of the assembly are enclosed within the components themselves, so that there are no external conduits for conducting operating fluid except those between the Christmas tree and the surface.

Still another object of this invention is to greatly simplify and reduce the time required for positioning a Christmas tree" or other wellhead assembly in place and readying it for operation in an underwater location. 7 For better understanding of the foregoing and other objects of the invention, reference is now made to the accompanying drawings, wherein FIG. I is an elevational view ofa Christmas tree utilizing one embodiment ofthe invention,

FIG. 2 is another view of the Christmas tree" shown in FIG. 1 with parts broken away, and I FIG. 3 is a partially sectioned view of one valve and operator therefor embodying one form of the invention.

The Christmas tree" shown in FIGS. 1 and 2 comprises an assembly of a master valve 14, a swab valve 16 and a wing valve 18 connected together by means of an adapter tee 20 between the swab valve and master valve. The master valve is connected through a clamp 12 to an adapter flange l0 affixed to the top of the well. A valve operator 22 is also connected to the tee 20 and provides means for operating each of the I valves. In the embodiment shown, the valves are connected to the tee by means of clamps 24. Similar clamps 26 connect a production line 28 to the wing valve 18 and a plug 30 to the outlet of swab valve 26.

Valves

14, 16 and 18 each have a through bore, illustrated at 15 in FIG. 3, through which well fluid may flow when the valve is open. Flanges 86 are provided at each end of each flanges brings the facing surfaces of the flanges into sealing abutment with each other.

As shown in FIG. 2, each of the valves is provided with a hydraulic operator 32. It will be appreciated that in readying the well for production or for other operations in the well, it will be necessary to operate the various valves from open to closed and from closed to open from time to time in various combinations. Control means are provided in the copending application of myself and Charles F. Johnson, Ser. No. 587,892, filed Oct. 19, I966 now abandoned, entitled Valve Operator, for operating all of the valves by means of hydraulic fluid supplied from the surface through a single hydraulic line. The unit provided for this purpose in my said copending application is known as a sequencing valve, and such a sequencing valve may be used for the control device 22 shown herein. Other apparatus suitable for controlling flow of fluid to the valve operators may also be used. For example the apparatus described in US. Pat. No. 2,64'l,280,'issued on June 9, 1953 to H. G. Fleischhauer, could easily be adapted to such a use.

In FIG. 3, valve 14 is shown with a form of valve operator 32 which may be used in the wellhead assembly of this invention. It will be appreciated that the structure shown in FIG. 3 is also typical of the structures of

valves

16 and 18 and their operators. As shown, the operator 32 comprises an elongated housing 34 which is connected by means of a coupling 36 to a spacer 38 which also serves as the bonnet for the valve 14. Thus, spacer 38 maybe considered to be a part of the valve or a part of the operator. The spacer 38 is connected to the valve by means'of a clamp 40. A cover 42 closes the outer end of the operator housing 34. The operator housing is provided with a cylindrical bore 44 extending longitudinally thereof to form a cylinder in which a piston 46 is sealingly received,

piston rings

48 and 50 being provided on the piston to form a seal with the cylinder. The piston 46 is fastened to a piston rod 52 by means of a nut 54. The piston rod extends longitudinally through and extends out the lower end of the housing 34 and is connected, as by means of the J-slot connector 56, to the valve stem 58. The valve stem, as is well known in the art, is connected to the gate of the valve, and longitudinal movement of the valve stem serves to open and close the valve by lowering and raising the gate.

In the embodiment shown, the valve is biased toward a closed position by means of the

concentric springs

60 and 62 extending between the piston 46 and a spring washer 64 surrounding the piston rod at the lower end of the cylinder and resting on the end of the spacer 38. Y

A longitudinal passageway 66 is provided in the wall of the housing 34 extending to the upper end of the housing and communicating with a cavity 68 in the cap 42. At the lower end of the housing the passageway 66 is positioned to communicate with a corresponding passageway 70 in the wall of the spacer which extends longitudinally thereof to both ends of the spacer. A connector 72 extends between the abutting flanges and sealingly connects the two passageways 66 and 70 v by means of O-ring seals 74, which are adapted to form seals with enlarged counter bores in the facing ends of the

passageways

66 and 70. At the opposite end of the passageway 70a similar connector 72 is provided to provide communication between the passageway 70 in the spacer and another passageway 76 formed in the wall of the body of valve 14.

To provide actuating fluid to the opposite side of the piston 46 a radial passageway is formed in the wall of the operator housing 34 and is plugged as by means ofa plug 81 at its outer end. An intersecting longitudinal passageway 82 extends from the radial passageway 78 to the lower end of the housing where it is in communication with a longitudinally extending passageway in the spacer which in turn communicates with a passageway similar to passageway 76 in the valve body. Connection between these passageways may be provided similarly as is shown for the

passageways

66, 70 and 76.

A counter bore 84 is provided in the end of the flange 86 of the valve which is received within the clamp 24 shown in H0. 1. This counter bore receives a connector 72 to provide the fluid communication between the valve body and a passageway 88 in the tee (See FIG. 2). The passageway 88 in the wall of the tee 20 extends from a flange corresponding to the flange 86 on the valve 14 to a flange 90 on the tee which is provided for connection thereto of the control device 22. Another connector 72 intermediate the flange 90 and the control device provides communication between the passageway 88 and the control device.

A similar passageway 92 in the opposite side of the tee provides fluid communication with the operator 32 for valve 16. It will be appreciated that two of each of

such passageways

88 and 92 are provided for each valve although not all the passageways are shown on the drawing.

A hydraulic line 94 which leads to the surface of the water is connected into the valve control device at 96. This line may provide hydraulic fluid for operation of all of the valves in the Christmas tree".

It will be appreciated that a Christmas tree of the type shown and described herein may be assembled at the surface and that all connections for operating fluid are automatically made upon the assembling of the various elements together, provided that the connectors 72 are placed in the counter bores provided during the assembly. Upon assembly in this manner all of the fluid lines for conduction of operating fluids are wholly enclosed in the various elements of the Christmas tree and are not exposed to the elements nor need they be serviced in any manner after the Christmas tree is lowered into the water. Thus, the difficulty of lowering, in this case, six hydraulic lines to the wellhead and connecting them to the valves at the desired locations is avoided. Also the problems which are inherent in exposed connections of small high pressure lines are avoided. A wellhead assembly is, therefore, provided in which only a single external connection for actuating fluid is required.

Although a preferred embodiment of the invention has been shown and described herein, it is not intended that the invention be limited to this embodiment since various modifications thereof will be apparent to those skilled in the art. The invention is, therefore, to be limited only in the manner defined by the appended claims.

I claim:

1. A Christmas tree comprising:

a plurality of wellhead valves;

an adapter for connecting said valves together;

said adapter including well-fluid passages therethrough;

fluid-actuable operator means on each valve for operating the valve between open and closed positions;

control meansfor controlling the flow of operating fluid to and from said operator means; and

communicating passageways in the walls of said valves, said operator means, and said adapter connecting said control means to said operator means without external conduits.

2. A Christmas tree as defined by claim 1 wherein: each valve has a surface abutting a surface on an operator means and another surface abutting a surface on said adapter; and

said passageways communicate through said abutting surfaces.

3. A Christmas tree comprising:

a master valve positionable above a well;

a swab valve above and spaced away from said master valve;

aligned well-fluid passageways in said valves;

adapter means intermediate said valves with an aligned well-fluid passageway therethrough;

a side-opening well-fluid passageway in said adapter means;

a wing valve having a well-fluid passageway communicating with said side-opening passageway;

each of said valves and said adapter means having abutting surfaces surrounding said well-fluid passageways;

abutting surfaces between each operator means and the valve which it operates;

control means on said adapter means for controlling the flow of operating fluid to and from said operator means; and

a series of communicating fluid passages from said control means to each operator means formed in the walls of said adaptor means, the valve and said operator means, communication being accomplished across said abutting surfaces.

4. A Christmas tree as defined by claim 3, and including:

connector means for automatically and sealingly connecting said series of communicating fluid passages upon moving said surfaces into abutment.