US3268242A

US3268242A - Wellhead assemblies

Info

Publication number: US3268242A
Application number: US302937A
Authority: US
Inventors: Bishop Robert; Jr William W Word
Original assignee: Armco Inc
Current assignee: Armco Inc
Priority date: 1963-08-19
Filing date: 1963-08-19
Publication date: 1966-08-23
Anticipated expiration: 1983-08-23
Also published as: GB1076765A

Description

Aug. 23, 1966 R. BISHOP ETAL WELLHEAD ASSEMBLIES Filed Aug. 19, 1963 2 Sheets-Sheet l 2 INVENTORS ROBERT ESHOP WILLIAM W. WORD, JR.

BY M l/ ATTORNEYS 1966 R. BISIHOP ETAL 3,268,242

WELLHEAD ASSEMBLIES Filed Aug. 19, 1963 2 Sheets-Sheet 2 FIG.3.

INVENTORS ROBERT BISHOP WILLIAM W, WORD JR.

BYM @La *M ATTORNEYS United States Patent 3,268,242 WELLHEAD ASSEMBLIES Robert Bishop and William W. Word, .liu, Houston, Tex., assignors to Armco Steel Corporation, Middletown, Ohio, a corporation of Ohio Filed Aug. 19, 1963, Ser. No. 302,937 3 Claims. (Cl. 285-142) This invention relates to wellhead apparatus, and more particularly to wellhead assemblies installed at underwater locations remote from the floating vessel or like support from which drilling and completion of the well are accomplished.

In underwater wellhead installations, the problem of providing for return flow from the space surrounding a casing string which is being cemented frequently presents severe diffculties arising both because of the need of physically accommodating the return flow within the wellhead and because of the requirement that the flow path for the return flow must be sealed after cementing of the casing has been completed. It has heretofore been proposed that underwater wellheads employ ported hanger structures for supporting casing strings which must be cemented, the ports in the hanger accommodating the return flow during cementing and being sealed ofi after the cementing operation has been completed. One successful construction of this type is disclosed in copending application Serial Number 192,174, filed May 3, 1962, by Charles M. Cole, Paul E. Bickel, and William W. Word, ]r., now Patent 3,171,489, issued March 2, 1965. Though the use of ported hangers has proved to be an advantageous and successful expedient in underwater wellhead installations, numerous problems have remained, particularly including the problem of providing a suitable remotely manipulated device for closing the ports in the hanger at the desired time.

A general object of this invention is to provide an improved underwater wellhead assembly having provision for satisfactorily accommodating the return flow during cementing of a casing string, and for satisfactorily sealing off the return flow area once cementing has been completed.

Another object is to provide such a wellhead assembly comprising a ported hanger and, in conjunction therewith, a sealing or pack off device which is simple and effective in its operation and can be installed from a remote location with certainty, dependability and relative ease.

A further object is to devise a wellhead assembly of the type described which includes a hanger and sealing device both of which can be installed by simple straightline movements, without depending upon such relatively complex manipulations as the making up of a threaded joint.

Another object is to provide a wellhead assembly for underwater installation which comprises a ported casing hanger and a seal device arranged to seal off above the ports of the hanger, both the hanger and the seal device being effective in combination as 'load bearing elements to support the Weight of internal wellhead devices installed thereabove.

In order that the manner in which these and other objects are obtained in accordance with the invention can be understood in detail, reference is had to the accompan'ying drawings, which form a part of this specification, and wherein:

FIG. 1 is a vertical sectional view of a well head assembly constructed in accordance with one embodiment of the invention;

FIG. 2 is a transverse sectional view taken on line 2-2, FIG. 1; and

FIG. 3 is a view, partly in vertical section and partly Patented August 23, 1966 ice in elevation, of a seal device employed in the wellhead assembly of FIG. 1.

Referring now to the drawings in detail, FIGS. 1 and 2 illustrate a wellhead assembly in accordance with the invention and comprising a base structure including a landing plate 1 seated on outer casing 2 and rigidly carrying a stub body 3 from which the conductor casing 4 depends.

Seated on the base structure and rigidly clamped and sealed to body 3 is an elongated upright body member 5 having an upright passage indicated generally at 6. Body 3 has a fiat transverse annular upper end face 7 and a peripheral flange 8. The lower end of :body member 5 has a flat transverse annular face 9, which directly engages face 7, and a peripheral flange 10. Body member 5 is secured by a conventional ring clamp 11 engaging flanges 8 and 10. Body 3 has a central passage 12 with which passage 6 is aligned, passage 12 being surrounded by an annular projection defined by the wall of the passage and a downwardly and outwardly slanting frustoconical surface 13. At its lower end, body member 5 has a downwardly opening recess defined by a doWn wardly and outwardly slanting surface 14 which is slightly larger than and concentric with surface 13,

surfaces

13 and 14 converging downwardly. A metal sealing ring 15 of such trapezoidal cross-section as to be wedged between

surfaces

13 and 14 under the axial clamping force applied by clamp 11 is disposed between the two frusto-conical surfaces.

Passage 6 is cylindrical and includes a short lower portion 16 and an elongated upper portion 17, portion 17 being of slightly larger diameter than is portion 16. The two passage portions are joined by a transverse annular upwardly directed shoulder 18 which serves as a seat for rigidly supporting the casing hanger 19 against downward movement.

Described in detail and claimed in copending application Serial Number 302,994, filed concurrently herewith by Edward A. Castor, Claude R. Neilon, Michael A. Walker, and William W. Word, Jr., hanger 19 is latched in place by latching segments 20 engaged in a transverse inwardly opening groove 21 in body member 5, and carries a weight-actuated, pressure-energized seal 22 to preclude passage of fluid in either direction axially of the hanger.

As described and claimed in copending application Serial Number 302,974, filed concurrently herewith by William W. Word, In, body member 5 is equipped with a plurality of by-pass flow ducts 23 communicating between the space around the surface casing string below hanger 19 and the space above the hanger, the by-pass flow ducts allowing upward passage of the return flow during cementing of the surface casing. After this cementing operation, a seal sleeve 24 is installed, seating on the upper end of hanger 19 and extending above the upper end of the by-pass ducts 23. Described and claimed in the aforementioned copending application Serial Number 302,994, sleeve 24 forms a fluid tight seal with the wall of passage 6 both above and below the upper end of the by-pass ducts 23, and also serves to support the internal wellhead elements installed thereabove.

At its upper end, the seal sleeve 24 presents upwardly facing shoulders on which the mandrel 25, for supporting inter-mediate casing string 26, is landed. This shoulder means includes an upper, downwardly and in- Wardly slanting frusto-conical surface 27 and a lower, fiat, transverse annular surface 28,

surfaces

27 and 28 being joined by a cylindrical surface 29. Mandrel 25 has a main body portion provided with a downwardly and inwardly slanting shoulder 30 and a flat bottom face 31 for engagement with

shoulders

27 and 28, respectively. Body 5 is provided with a groove 32 disposed above the upper end of sealing device 24, when the latter has been landed, actuated and latched in place. Mandrel has a plurality of outwardly opening recesses disposed to face groove 32 when the mandrel is seated, each such recess retaining an outwardly biased shear pin 33 in such fashion that, when the mandrel 25 reaches its proper position, shear pins 33 engage in groove 32 to latch the mandrel against upward movement.

Mandrel 25 includes a centrally disposed dependent tubular portion 34 which is suitably threaded at its lower end for connection to casing string 26. Since portion 34 has the same diameter as the casing string to which it is connected, the main body portion of the mandrel projects laterally from portion 34 and occupies a substantial space at the upper end of the annulus around casing 26. Ac cordingly, mandrel 25 can be ported to accommodate the return flow which occurs during cementing of casing 26. Thus, a plurality of grooves or notches 35 are cut in the main body of mandrel 25, each groove or notch extending completely through the mandrel body portion so as to place the annulus around casing 26 in direct communication with the space above mandrel 25.

It will be understood that landing of mandrel 25 can be accomplished with a suitable handling string (not shown), and cementing of the intermediate casing string 26 can then be accomplished, with the return flow during cementing passing upwardly through mandrel 25 via ports or grooves 35. When the cementing operation has been completed, the handling string is removed and assembly of the wellhead is continued by installation of the mandrel sealing device 36.

In this regard, it will be noted that mandrel 25 includes an upwardly projecting tubular portion 37 which has an outer cylindrical surface spaced inwardly from the surrounding wall of passage 6, so that the sealing device 36 can be seated on the upper face of the main body of mandrel 25 and fills the space between the wall of passage 6 and the outer surface of mandrel portion 37.

Seal device 36 includes a tubular upper body 38, an intermediate sealing ring 39, and a lower ring 40. Body 38 presents, at its lower end, an outer downwardly and inwardly tapering frusto-conical face 41 the upper edge of which is defined by the downwardly directed transverse annular shoulder 42. Body 38 also presents an inner, downwardly and outwardly slanting frusto-conical face 43, the upper edge of which is defined by a transverse annular downwardly directed shoulder 44. A downwardly opening annular groove 45, of rectangular transverse cross-section, is provided in the lower end portion of body 38, being disposed between

faces

42 and 43. Groove 45 is substantially narrower than the space between the lower edges of

faces

42 and 44, so that the body 38 also presents downwardly directed

end face portions

46 and 47.

At its upper end, ring 40 presents a configuration which is completely complementary to that just described for the lower end portion of body 38. Thus, ring 40 has an upwardly and inwardly slanting outer frusto-conical face 48 and an upwardly and outwardly slanting inner frustoconical face 49. A transverse annular upwardly directed shoulder 50 is provided at the lower edge of face 48 and an inner transverse annular upwardly directed shoulder 51 is provided at the lower edge of face 49. An upwardly opening annular groove 52 is cut into ring 40, groove 52 having the same cross-sectional shape and dimensions as groove 45. Groove 52 divides the upper end face of ring 40 into outer and inner portions 53 and 54, respectively. The bottom end face 55 of ring 40 is so dimensioned as to be disposed for direct flush engagement with the flat upper face of the main body portion of mandrel 25.

Sealing ring 39 includes a rigid supporting annulus 56, an outer resiliently flexible sealing ring 57 and an inner resiliently flexible sealing ring 58. Supporting annulus 56 has an intermediate body portion from which project an upwardly extending annular flange 59 and a downwardly extending flange 60. At the base of flange 59, support 56 presents an outer upwardly directed annular face 61. Flange 59 is dimensioned to project within groove 45 and is of such length, axially, that the upper end face 63 of the flange can come into engagement with the corresponding wall of groove 45 simultaneously with engagement of face 61 with face 46. Flange is dimensioned to be received within groove 52 and has a lower end face 64. The main portion of supporting annulus 56 presents, at the base of flange 60, an outer downwardly directed annular face 65. The dimensions of flange 68 are such that faces 64 and 65 can come into simultaneous engagement, respectively, with the bottom wall of groove 52 and face Formed of synthetic rubber or like resilient flexible material, and molded directly on the outer surface of the main portion of supporting annulus 56, sealing ring 57 includes an upper lip 67 and a lower lip 68. The normal or relaxed condition of ring 57 is such that the

lips

67 and 68 slant inwardly respectively toward

faces

41 and 48 so that, when the parts of the seal device are related as seen in FIG. 3, the

lips

67 and 68 are displaced inwardly from the outer cylindrical surfaces of body 38 and ring 40 and are therefore protected against engagement with any surrounding well ele-ment during descent of the seal device toward its final position of installation. Sealing element 58 similarly includes an upper lip 69 and a lower lip 70, the relaxed or normal condition of element 58 being such that the lips slant inwardly respectively toward

faces

43 and 49 when the parts of the seal device are in the positions shown in FIG. 3.

Body 38 carries at least one set screw 71 which extends into frictional engagement with the outer surface of flange 59. Ring 40 correspondingly carries at least one set screw 72 extending into engagement with the outer surface of flange 60. Set screws 71 and 72 serve to hold body 38, ring 39 and ring 40 in the relative positions seen in FIG. 3, preparatory to installation of a plurality of shear pins 73 and 74. Shear pins 73 serve to retain the illustrated relative positions between body 38 and ring 39, while shear pins 74 serve to retain the initial relative positions, as seen in FIG. 3, between ring 39 and ring 40.

Body 38 has an outwardly opening transverse annular groove 75 which accommodates an annular series of latching segments 76. A transverse annular inwardly opening groove 77 is provided in the wall of passage 6 at such a location that, when the seal device 36 has been properly landed on mandrel 25 and fully weight-actuated to the condition shown in FIG. 1, segments 76, being springbiased outwardly, will snap into engagement in groove 77 to restrain seal device 36 against upward movement. Segments 76 have upwardly directed, downwardly and outwardly slanting cam faces 78 which extend across the annular space between the upper portion of body 38 and the surrounding wall of passage 6 when the segments are engaged in groove 77. Body 38 carries an actuating sleeve 79 which can be employed to act on cam faces 78 and cam the segments 76 inwardly to disengaged position, preparatory to retrieval of the seal device 36, as described in detail in copending application Serial Number '3 02,83 6, filed concurrently herewith by Robert Bishop, Edward E. Castor, Michael A. Walker and William W. Wond, Jr.

In addition to effecting a fluid-tight seal between the wall of passage 6 and portion 37 of mandrel 25, the seal device 36, once fully weight-actuated, serves to support the hanger 80 from which the tubing string 81 is suspended. Hanger 80 is described (in detail) and claimed in the aforementioned copending application Serial Number 302,994.

Elements of the wellhead installed above body member 5 have been ignored in the foregoing description, since the nature of such elements is not pertinent to this invention. In general, however, the blow out preventers and Christmas tree are secured to the top of body member 5 by a remotely actuated coupling such as that described and claimed in copending application Serial Number 264,195, filed March 11, 1963 by Claude R. Neilon, Michael A. Walker and William W. Word, I r. R will be understood that the elements of the base structure, and body member 5, are assembled with the aid of a suitable guide system (not shown) which can be of the type described in US. Patent 2,808,229, issued October 1, r1957, to Robert F. Bauer et a1. and that the internal components of the well-head usually are installed via a riser pipe extending from the wellhead to surface of the body of water in which the installation is being made.

while specific embodiments of the invention have been chosen for illustrative purposes, it will be understood that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.

What is claimed is: 1. In an underwater wellhead assembly, the combination of a wellhead member having an upright passage, upwardly facing shoulder means within said passage, and a transverse annular groove opening inwardly into said passage; a hanger disposed in said passage and comprising downwardly directed shoulder means opposed to said upwardly facing shoulder means, said hanger being rigidly supported by said upwardly facing shoulder means, means for attaching a dependent string of well pipe to said hanger, a body portion filling said passage, and an upwardly projecting portion spaced radially inwardly from the surrounding wall of said passage above said body portion, said body portion being formed with at least one flow Opening for communication between the space surrounding said well pipe and the space between said upwardly projecting portion and the wall of said passage; an annular seal device disposed between said upwardly projecting portion of said hanger and the wall of said passage, said seal device comprising an upper annular metal body having an outwardly opening recess opening toward the wall of said passage, a latch element disposed in said recess, and means biasing said latch element outwardly, an intermediate metal ring, and a lower annular metal body, said upper annular metal body and said intermediate ring having cooperating generally axially directed abutment surfaces, said lower annular metal body and said intermediate ring having cooperating generally axially directed abutment surfaces, said lower annular metal body being seated on said body portion of said hanger; said abutment surfaces of said upper annular body, said intermediate ring, and said lower annular body being in series metal-tometal axial engagement; said recess in said upper annular body opening toward said inwardly opening groove in said wellhead member, and said biasing means unging said latching element outwardly into latching engagement in said groove to restrain said seal device against upward movement relative to said wellhead member, said seal device further comprising an inner flexible sealing ring carried by said intermediate metal ring, and an outer flexible sealing ring carried by said intermediate metal ring, said inner sealing ring and said outer seal-ing ring being urged respectively into sealing engagement with said upwardly projecting portion of said hanger and the wall of said passage below said inwardly opening groove by engagement with said upper and lower annular metal bodies. 2. In an underwater Wellhead assembly, the combination of a wellhead member having an upright passage and upwardly facing shoulder means within said passage; a hanger disposed in said passage and comprising downwardly directed shoulder means opposed to said upwardly facing shoulder means, said hanger being rigidly supported by said upwardly facing shoulder means, means for attaching a dependent string of well pipe to said hanger, a body portion filling said passage, and an upwardly projecting portion spaced radially inwardly from the surrounding wall of said passage above said body portion, said body portion being formed with at least one flow opening for communication between the space surrounding said well pipe and the space between said upwardly projecting portion and the wall of said passage; an annular seal device disposed between said upwardly projecting portion of said hanger and the wall of said passage,

said seal device being seated on said body portion of said hanger, said wellhead member having a transverse groove located above said body portion of said hanger and opening inwardly into said passage and toward said upwardly projecting portion of said hanger, said seal device having an outwardly opening recess opening toward said groove, a latch element disposed in said recess, and means biasing said latch element outwardly into engagement in said groove to restrain said seal device against upward movement relative to said wellhead member, said seal device including seal means operatively engaging said upwardly projecting portion of said hanger and the wall of said passage to seal off above said at least one flow opening; and means carried by said seal device above said recess and movable axially downwardly, between said seal device and the surrounding wall of said passage, into engagement with a camming surface on said latch element to force said latch element radially inwardly out of said groove preparatory to retrieval of said seal device. 3. In an underwater Wellhead assembly, the combination of a wellhead member having an upright passage and upwardly facing shoulder means within said passage; a hanger disposed in said passage and comprising downwardly directed shoulder means opposed to said upwardly facing shoulder means, said hanger being rigidly supported by said upwardly facing shoulder means, means for attaching a dependent string of well pipe to said hanger, a body portion filling said passage, and an upwardly projecting portion spaced radially inwardly from the surrounding wall of said passage above said body portion, said body portion being formed with an least one flow opening for communication between the space surrounding said well pipe and the space between said upwardly projecting portion and the wall of said passage; an annular seal device disposed between said upwardly projecting portion of said hanger and the wall of said passage and comprising '2 8 a plurality of telescopically related annular metal seal device against upward movement relative to bodies, the lower one of said annular metal said wellhead member, and bodies being seated on said body portion of another hanger member disposed in said passage and said hanger, said annular metal bodies having seated on said upwardly directed supporting shoulder cooperating generally axially directed abutment D of said uppermost one of said annular metal bodies of faces disposed in engagement, the uppermost said seal device. one of said annular metal bodies having at its upper end an upwardly directed transverse References Cited y the Examine! armularsupportine'shoulder, and UNITED STATES PATENTS inner and outer fleidble sealing rings carried by 10 1,845,396 2/1932 Bums one of sal'd P metal Podles and seallflgly 1 97 991 10 1934 D fl 2 5 139 X engaged respectively with said upwardly PI'OJCCt- 2,244 13 5 6/1941 Wallace 277 235 X ing POItiOH Of Said hanger and the wall Of said 2 337:221 12 1943 Allen 2 5 passage to seal off above said at least one flow 2 34 0 4 1944 Yeatman 2 1 X Opening, 2,471,658 5/1949 Shaiifer 285140 said wellhead member having a transverse inwardly 2,617,4 5 11 1952 t h 2 5 14 opening groove located above said body portion 2,707,998 5/ 1955 Baker 166125 of said hanger, 3,051,513 8/1962 Watts -Q 285146 lsaid uppermost one of said annular metal bodies 3,134,610 5/ l964 Muslof 285133 X having a recess opening outwardly toward said ,1 9, 19 Jones 2 5 6 groove, a latch element disposed in said recess, and means biasin g said latch element outwardly CARL TQMLIN P "nary Exammer' into engagement in said groove to restrain said S. R. MILLER, R. GIANGIORGI, Assistant Examiners.

Claims

1. IN A UNDERWATER WELLHEAD ASSEMBLY, THE COMBINATION A WELLHEAD MEMBER HAVING AN UPRIGHT PASSAGE, UPWARDLY FACING SHOULDER MEANS WITHIN SAID PASSAGE, AND A TRANSVERSE ANNULAR GROOVE OPENING INWARDLY INTO SAID PASSAGE; A HANGER DISPOSED IN SAID PASSAGE AND COMPRISING DOWNWARDLY DIRECTED SHOULDER MEANS OPPOSED TO SAID UPWARDLY FACING SHOULDER MEANS, SAID HANGER BEING RIGIDLY SUPPORTED BY SAID UPWARDLY FACING SHOULDER MEANS, MEANS FOR ATTACHING A DEPENDENT STRING OF WELL PIPE TO SAID HANGER, A BODY PORTION FILLING SAID PASSAGE, AND AN INWARDLY PROJECTING PORTION SPACED RADIALLY INWARDLY FROM THE SURROUNDING WALL OF SAID PASSAGE ABOVE SAID BODY PORTION, SAID BODY PORTION BEING FORMED WITH AT LEAST ONE FLOW OPENING FOR COMMUNICATION BETWEEN THE SPACE SURROUNDING SAID WELL PIPE AND THE SPACE BETWEEN SAID UPWARDLY PROJECTING PORTION AND THE WALL OF SAID PASSAGE; AN ANNULAR SEAL DEVICE DISPOSED BETWEEN SAID UPWARDLY PROJECTING PORTION OF SAID HANGER AND THE WALL OF SAID PASSAGE, SAID SEAL DEVICE COMPRISING