US2939727A

US2939727A - Wellhead equipment

Info

Publication number: US2939727A
Application number: US615976A
Authority: US
Inventors: Allen Herbert; Marvin R Jones
Original assignee: Cameron Iron Works Inc
Current assignee: Cooper Industries LLC
Priority date: 1956-10-15
Filing date: 1956-10-15
Publication date: 1960-06-07
Anticipated expiration: 1977-06-07

Description

June 7, 1960 H. ALLEN ETAL 2,939,727

WELLHEAD EQUIPMENT Filed 001". l5, 1956 2 Sheets-Sheet 1 Hill jy H' H. ALLEN ET `AL WELLHEAD EQUIPMENT 2 Sheets-Sheet 2 June 7, 1960 Filed 00T.. l5, 1956 WELLHEAD EQUIPMENT `Herbert Allen and Marvin R. Jones, Houston, Tex., as-

signors to Cameron Iron Works, Inc., Houston, Tex., a corporation of Texas Filed Oct. 15, 1956, Ser. No. 615,976

2 Claims. (Cl. 285-96) This invention relates to improved wellhead equipment for suspending a plurality of tubing strings in side-by-side relation within a multiple zone well.

` During-production from multiple zone wells, the tubing strings are suspended from and sealed olf with respect to a Afitting at the wellhead so as to isolate the space about United VStates Patent the strings within the well. For this purpose, it has been Y proposed to seat a bushing within the bore of the iitting or tubi-ng head-subsequent to running drilling and completion .tools therethrough, and then run the strings through openings in the bushing having conical seats for supporting similarly shaped hangers on the strings. The hangers are thus sealed with respect to the bushing and the bushing with respect to the tubing head -so -as to close the bore and thus seal off the space within the well, as above-mentioned.

' 'I 'he principal shortcoming of this earlier equipment is that the openings through the bushing are not large enough to permit the passage of gas lift valves and other auxiliaryparts run on the tubing strings. In a copending application, Serial No. 543,215, tiled October 27, 1955 by Herbert Allen now issued as Patent Number 2,794,505 and assigned to the assignee of the present invention, there is disclosed an assembly in which two hangers of semi-circular shape are seatable on yand between pins iixed -to the b ore of the tubing head for support in side-by-side relation. In this manner, upon removal of the hangers from the bore, a space is provided through the tubing head which is substantially as large as the space within the well casing so as to accommodate the passage of such auxiliary parts on the tubing strings.

Unless these pins are of only relatively short radial extent, they will interfere with the running of the drilling and completion tools. On the other hand, when the radial extent of t-he pi-ns is limited for this purpose, the supports they provide for each hanger are 4so located relative to its weight and the load due to the tubing string suspended therefrom that a moment is induced tending to swing the hanger inwardly of the bore of the tubing into aposition interfering with the placement of a hanger adjacent thereto. This problem becomes especially acute in the case of hangers for wells of three or more zones, since such hangers are of correspondingly smaller sector shapes, and particularly less than semi-circular, whereby the moments become greater and the problem of indexing each hanger into place between appropriate pins becomes more complex.

' vAn object of this invention is to provide wellhead equipment having substantially the advantages of the assembly of the above-mentioned copending application in that hangers are supportable in the bore of a tubing head in a manner to provide, upon their removal therefrom, a space at least substantially no less than the space within the well casing, but in which there is less cause for interference 'with drilling .and completion equipment and wherein the hangers, regardless of size, are more rigidly supported in proper position within the bore of the tubing head. .Thusthe .wellheadmequipment. of `the present inrice vention is particularly well-adapted for use in suspending three or more tubing strings in side-by-side relation within a well casing.

Another object is to provide equipment of the character described in the foregoing object in which each of at least all but one of the hangers is seatable and unseatable with respect to the bore of the tubing head independently of the seating `and unseating, respectively, of another hanger.

Still another object is to provide equipment of the character described in either of the foregoing objects, in which the hangers are sealable with respect to one another as well as with respect to the bore of the tubing head, when all are seated therein, so as to seal oif the space therethrough.

A further object is to provide equipment of the character described in any one of the foregoing objects in `which the hangers are automatically indexed into a predeter-mined rotative position with respect to the bore of the tubing Ihead as they are seated therein.

Other objects, advantages and features of this invention will be apparent to one skilled in the art upon a consideration of the Written specification, the attached claims and the annexed drawings.

In the drawings, wherein like reference characters are used throughout to `designate like parts: I

Fig. 1 is a longitudinal sectional view, taken substan tially along broken line 1-1 of Fig. 2, of an illustrative embodiment of wellhead equipment constructed in accordance with the present invention, and with the hangers thereof supported in the tubing head in tubing suspending position;`

Fig. 2 is a top plan view of the wellhead equipment of Fig. 1, taken substantially along broken line 2 2 thereof;

Fig. 3 is a perspective view of one of the hangers of the wellhead equipment of Figs. 1 and 2 and removed from the tubing head thereof;

Fig. 4 is a perspective view of another illustrative embodiment of the present invention, and with the tubing head broken away in part and one of the hangers in a position just prior to seating within the bore of the tubing head; and

Fig. 5 is aperspective of an integrated hanger and support therefor which may be seated in the bore of the elements corresponding in number to the hangers are removably disposable across the bore in angularly spaced apart relation, and the hangers are seated in side-by-side relationbetween adjacent seating elements and the seat in said bore. Thus, `each space in the bore of the tubing head through which a tubing string must he passed is restricted only by the seating elements upon which the hanger for suspending suchstring is seatable.

This construction accomplishes the more basic objects of the invention since, when the seating elements are disposed across the bore for supporting the hangers, they may be extended a suiiicient radial extent to more rigidly resist any tendency of the hangers to tilt from their supported positions and also provide greater areas of support. On the other hand, when the seating elements hanger is seatable and unseatable independently of the e seating and unseatingepectively, `of the other hangers.A

111 another embodiment, ahanger is secured to the seat "hangers are provided with seal `means 'thereabout for Ysealing each hanger lwith respect `to adjacent hangers and the tubing head bore 'so as to seal 0E the space thereof `when all the hangers are seated. More particularly, it ispreferred .that'the seal means about each hanger'be directly engageable with'the seal means of adjacent hangers and said bore.

In accordance with its .preferred usage, Kthere is shown 'in Figs. 1 and 2 an embodiment of the present invention which includes -a tubing head 16 conventionally secured to a casing head (not shown) above the well casing and a plurality lof hangers '11 supportedin side-by-side relation Within `the bore 12 through the tubing head. Tubingstrings 13 are :threadedly secured to the lower ends of `longitudinal openings 14 `through' said hangers for suspension within the well casing and separate communica 'tion with the production zones of the well, in a manner well known in the art.

Asis also customary in the ant, the tubing head is provided with an annularflange 15 at its upper end, and `a member 16, which may be a valveV or the like, is disposed over and connected to the ange by means of bolts 17. More particularly, each `of the tubing head and :member 16 is provided with oppositely facing

grooves

18 and 19, respectively, Vwhich receive a ring-type sealing 4element 20 therebetween, sothat when -therbolts 17 are `tiglltened up to a desired degree, .the tubing head 'and 'member are sealed with respect to one another 'about the jbodre 12`through 'the head.

The upper ends of the openings 14 through the hangers .11 are yalso tbreadedwfor connection with tubing strings 21 which extend upwardly through openings 22 in the member 16. More particularly, -eaoh hanger is provided with an yupstanding tubular boss 23 surrounding the 'opening therethrough, and having a conical outer surface 24 over which a similarly shaped lower end 25 of the corresponding opening 22 in member 16 is iittable. These bosses are surrounded by a resilient compression gasket -26 lying between the member and upper ends of the hangers inwardly of the seal ring 20. An intermediate portion of the opening 14 through each hanger 11 is threaded as at 27 for'receiving a back pressure valve (not shown), in a manner and for apurpose described in the aforementioned copending application.

j -As will be described more fullyhereinafter, when the hangers 11 are seated in'side-by-side relation Within the bore of the tubing-head lil, as shown in Fig. 1, they are 'sealed o with respect to one another as well as with respect to such tubing head bore. Thus, during produc- `tion from the several zones through the tubing strings 13, the space within the well casing about said strings and below thebangersis sealed off for use in a manner Well known in the ant. Also, with the member 16 and other wellhead equipmentconnected above the tubing head, as shown in Fig. l, suitable control is had over the produc tion `from each zone. f

vEach of the hangers 11 is sector-shaped in crossfsection transversely to the opening 14 therethrough. More particularly, the outer sides 28 thereof are curved substantially concentrically of the bore of .the tubing head and the inner frat sides 29 thereof intersect at approximately the axis ofthe bore and curved sides. The aggregate of the angles described by the at sides of the hangers represents a full circle so that, with all the hangers supported inside-by-side relation within the tubing headbore,.rthefspace across thebore is at least Substantially obstructed. Although in the particular embodimentshown in Figs. land 2- there are three interchangeably `useable lhangers each of which describes a sector tofisubstantiallyflZO degrees, it `should be underaoaa'ra? I f .l

' stood that the invention is not Hunted to such an arrangement. In fact, the concepts of the present invention are broadly applicable to wellhead equipment which includes two or more hangers which may be other than semi-circular in cross-section.

A plurality of seating elements in the form of rams 30 are mounted within .the tubing head 10 for selective extension radially across and retraction from the bore of the tubing head. When the arms are retracted, the bore of the Itubing head is free of any obstructions v'which might interfere with the passage of drilling and completion equipment. More particularly, the seating elements correspond in number tothe lhangers 11 and are radially arranged in a manner to provide spaces between adjacent elements corresponding tothe angular relation of the flat sides of the hangers. The bore of the tubing head is provided with an upwardly lfacing seat thereabout which comprises -a conically tapered bowl 31 on the bore,

-and correspondinglyv tapered vseating 'surfaces k32 are jprovided 4on the lower portions of the hangers beneath and inwardly of the curved-sides 28thereof. The lowerpor- 'tions of the lhangers beneath the at sides 29 'thereof larealso recessed inwardly so that each hangerimay be Y separately lowered into 'tubing suspending Vposition through the appropriate space between the tubing head and the adjacent rams. As can be seen from the drawings, the lower ends of the recessed portions are tapered inwardly at 33 so y'as to assist in placement of the hanger. As each hanger is so lowered, its seating surface 32 `seats upon the bowl 31 and seating surfaces 34 above the tapered portions 33 on the recessed portions below the 'at sides of the hanger are seated upon the adjacent rams 30 so as to support the hanger against movement both downwardly .and radially inwardly. More particularly, -the seating elements 30 are narrow so that each space between adjacent elements is only slightly smaller than the hanger which is supportable therebetween. Furthermore, each ram extends .sufficiently far into the borefso as to resist any tendency of the hangersto tilt out of their supported positions and provide the hangers with a large bearing area.

When all the hangers are so supported, the Vflat sides 29 :thereof above 'the seating surfaces 34 Vare at least closely adjacent the corresponding sides of adjacent hangers, and the outer sides thereof above seatingV surfaces 32 are at least closely adjacentthe-bore of thetubing head. Thus, sealing members 35, in the form of rings of rubber or otherY resilient sealing material anddisposed about theY three sides of the hangers, may be energized into sealing engagement with yone another as well as with the bore of the tubing head. For this purpose, the tubing head -10 is provided with one or more openings 60 extending radially through the anges 15 thereof .and communicable Vwith `the seal rings 35. Thus, the rings may be energized into such sealing engagement by means of-a plastic Vmaterial injected under pressure through said openings. l

More particularly, the openings 60 are threaded to receive .ttings 61 at their outer ends, and connectfwith the upper'ends Aof slots 62 on the periphery of the seated hangers which 'connect -at their lower ends with the grooveswhich receive the seal rings. A ball check `valve 63 is normally urged by a coil spring 64 into seated. .engagement with the inner end of a passage 65 throughlthe fitting k61 of each opening, and a plunger 66 is threadedly received within leach passage outwardly of said innerend thereof. Thus, upon removal of the plunger, asuitable plastic material maybe forced past `the check` valve @63 for energizing .theseal rings. The plunger 66 may then be `replaced and usedfor increasing the pressure .on A,the plasticA to a desired degree.V

It will be appreciated that, in the assemblyabove ide- Y scribed,-the .rams 30not .only-serve to support the hangers but also .tolocatevthem ina predetermined rotative posi# tionwithzrespectfto .the tubing head.V Thus, `.upon place ment of the member 16 over the flange 15, the bolt holes 1n said member will `be automatically aligned with those in the ange of the tubing head and openings 60 will be properly disposed opposite slots 62. It will also be appreciated that each of Ithe hangers is seatable and unseatable within the tubing head independently of the seating and unseating, respectively, of any other hanger. Thus, the hangers may be lowered into and removed from tubing suspending position in any desired sequence.

As `previously indicated, with the hangers removed from the bore of the tubing head, the radially extending rams 30 provide the only obstruction across the bore, so that the space therein available for passing the tubing strings and auxiliary parts at least approximately corresponds to the space within the well tubing. More particularly, the space so provided for each string corresponds at least substantially to the portion of the space within the well casingfor accommodating such strings.

It will further be understood that the ilat sides 29 of the hangers need not necessarily be directly sealable with one another, and that the outer curved sides 28 need not necessarily be directly sealable with the bore i12 of the tubing head, when the hangers are supported in side-byside relation within the tubing head bore. Thus, for example, seal rings about the hangers may be sealable with one or both of the radially extending seat elements and a peripheral seating element intermediate the bore and curved outer sides of the hangers. However, the arrangement shown is preferred as it provides a maximum amount of space through the bore for passing the tubing strings.

As shown in Fig. l, each of the rams 30 is received through a radially extending passage 36 in the tubing head, and is provided with a threaded portion 37 intermediate its length for mating with a threaded portion 38 of the bore. The outer end of each ram is provided with a part 39 for rotating same and thus moving its inner end inwardly or outwardly with respect to the bore 12 of the tubing head. A packing assembly 40 in the passage 36 seals about the ram intermediate its threaded portion 37 and inner end.

, Also mounted within the tubing head'are a plurality of l holddown bolts 41 for preventing movement of the hangers upwardlyfrom their seated positions. These bolts are tln'eadedly received within radial passages 42 in the tubing head for selective movement into or out of engagement within openings 43 in the hangers. As shown in Fig. l, these bolts and matching openings are preferably provided in the upper ends of the tubing head and hangers, respectively. A packing assembly 44 seals about each bolt intermediate its threaded portion and a gland nut 45. An actuating part 46 on the outer end of each bolt permits rotation thereof for imparting the aforesaid inward and outward movement thereto. Any desired number of bolts, such as the three illustrated in Fig. 2, may be provided for holding each hanger down.

After vthe well has been drilled so as to penetrate the multiple zones, it may be completed without a loss of pressure within the well. Thus, upon cementing of the casing in place, the tubing head is connected above the casing head and a blowout preventer or like equipment is connected above the tubing head in the place of the member 16. Packers are then lowered into the well casing and set at levels therein for isolating .the production zones from one another in a manner well known to the art of multiple zone well completion.

For example, a trst packer may be run and set on the drill pipe between the middle and lowermost of the three production zones. Subsequent packers may then be run on .the iirst string of tubing and set between the middle and uppermost zone and above the uppermost zone, respectively. The lower end of this rst string may be received in the iirst packer for communication with the lowermost zone, and the lower end of each of the other two strings received in one of the remaining packers 'for communication with the middle and uppermost zones, respectively.' Obviously, the rams 30 may be retracted during running of the packers on the first string, and then extended ac ross the bore of the tubing head for supporting the hanger 11 for said `string as it is lowercdinto seated position. Alternatively, it may be possible to run land set all of the packers by wire line, `in which case the rams may be extended `into supporting position prior to running of any lof the strings.

rl `h e hangers may be held down in seated positionby the bolts 41 and back-pressure valves (not shown) lowered into nthe hangers and connected to the threads 27 in the openings 14 therethrough. The blowout preventer may 'then Abe removed and replaced by a control valve or suitable flange member, such as indicated at 16 in Fig. l, and various other parts connected above said member to complete the wellhead. Upon removal of the -back pressure valves, the zones of the well may be washed The embodiment of the invention illustrated in Fig. 4 diiers 'from that above-described principally in that the radially extending seat elements removably disposable lacross the bore of the tubing head 10 comprise a spider 47 having seating surfaces 48 on the outer ends of two ofthe legs 49 thereof tapered similarly to the bowl 31 for seating thereon to support the spider in position across the bore of the tubing head. Thus, the tubing head 10 of -this embodiment does not require the rams 30, although it is provided with a vertically extending slot 50 in its bore for receiving an outwardly projecting part 51 on the third leg of the spider so as to automatically index the spider into a predetermined rotative position as it is lowered into the well.

Each of the hangers is provided with tapered seating surfaces 52 on the lower ends of their at sides for seating upon similarly tapered surfaces 53 on the spider legs. In other respects, however, the tubing head and hangers are similar to those of the above-described embodiment. Thus, as the hangers are supported in side-byside relation upon seating between adjacent seating elements and the bore of the tubing head, seal rings 35 about each of the hangers are energized into direct sealing engagement with seal rings on adjacent hangers and the bore 12 of the tubing head so as to seal off the bore. Also, it is obvious that this latter embodiment of the invention permits completion of a well in the manner described above in connection with the embodiment of Figs. l to 3.

Fig. 5 illustrates part of la still further embodiment of the invention, and, more particularly, a modified form of seating elements for supporting the hangers within a tubing head 10 of the type shown in Fig. 4. In this form, a hanger is secured between two of three radially extending and angularly spaced apart seating elements 55 so as to support the hanger in tubing suspended position as the integral member is lowered into the bore of the tubing head and seated upon the bowl 31 thereof. It is obvious from Fig. 5 that the hanger so secured to the seating elements occupies the same position, when so supported, as it would if it were separate from the spider and seatablc between spider legs and the tubing head bore, as in the case of the hanger shown in Fig. 4.

Upon seating of the integral member, the remaining two hangers may be seated in a manner previously described. Obviously, Ialthough each of the latter two hangers is seata-ble and unseatable independently of the seating and unseating, respectively, ofthe hanger secured to the seating surfaces, the latter is the first to be seated and the last to be unseated. Thus, it is desirable during completion of a well with this embodiment of the invention, to run and set packers on this irst string.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together' with other advantages `which' are obvious and which are :inherent to the apparatus.

' It will `be understood that certain features and subcombinations are of utility and may 4be employed Without Areference-to other features and subcombinations. This is contemplated-byand is within the'scope of the'claims.

g As vmany possible embodiments may be'made Vof the invention without departing from the scope thereof, :it is =tohe understood that all vmatter lherein set forth'or shown in the accompanying drawings is "tobe interpreted --as zillustrative and not ina limiting sense.

The invention Yhaving been described,rwhat is claimed is:

1. Wellhead equipment comprising -a `tubing headhavirl-ga Vbore therethrough, at least three 'tubinghangers together forming substantially a cylinder and each having a longitudinal opening therethrough to receive a tube and being substantiallysector-shaped transversely thereof, said 'tubing head and hangers having complemental downwardly tapering seats for supporting said cylinder lin said 'tubinghead and rams corresponding in nunrber to said .hangers and mounted on said head for movement between retracted positions radially outwardly of the minimum diameter of the Abore and extended positions radially inwardly thereof `for supporting each of said hangers between adjacent rams and the bore of the tubing head in `side-by-side relation to the `other hangers, the at sides of each lof :said tubing hangers 'being recessed `upwardly from :the bottom portion to provide downwardly :facing seats which intersect the curved `:side thereof for permitting downward insertion Aof said hangers in said head and lforrseating on seating .surfaces of extended adjacent rams, and said rams being of such size that eachspace Ybetween extended adjacent ramsis only slightly'smaller than that 4portion of the tubing hanger supported between said extended rams Whiehlis above therecessed sidesthereof, each set of said seats'being disposed for substantially simultaneous engagement in assembled position of .said

,cylinder and hangers.

2. Wellhead equipment of the character dened in .claim 1, including, seal Ymeans about ysalid portion of each `tubing hanger above the recessed sides thereof for sealing with respect to said portion of adjacent hangers as well as said bore in the supported position thereof.

References Cited in the le of this patentV UNITED STATES PATENTS