Hanger assembly

Abstract

A hanger assembly and a method for supporting a string of tubular members in a wellhead assembly are disclosed wherein the hanger assembly is supported within the wellhead assembly by a single landing shoulder in the wellhead assembly and a seal member is independently, sealingly engaged with a portion of the string of tubular members.

Description

BACKGROUND OF THE INVENTION

1. RELATED APPLICATION

[0001] This application claims the benefit of Provisional Patent Application Serial No. 60/302,241, filed Jun. 29, 2001.

[0002] 2. Field of the Invention

[0003] The invention relates to a hanger assembly for supporting a string of tubular members, such as casing pipe or production tubing, in a wellhead assembly.

[0004] 3. Description of Related Art

[0005] Various types of hanger assemblies have been proposed for supporting a string of tubular members, such as casing pipe or production tubing, within a wellhead used in connection with the drilling and/or production of hydrocarbons. One type of hanger assembly is configured so as to be supported in the wellhead assembly by at least two inwardly extending landing shoulders formed in the wellhead assembly. It would be advantageous to have a hanger assembly which is configured so as to only require a single inwardly extending landing shoulder formed in the wellhead assembly. Additionally, because of increased loads and pressures to be supported and contained by the hanger assembly, improvements are necessary in prior art hanger assemblies. Furthermore, increased temperature differentials encountered by hanger assemblies in use, such as −20° F. to 350° F., require improved performance of seals and other components in conventional hanger assemblies, to resist and/or restrict damage by extrusion of the seal members used in the hanger assemblies.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a perspective view of a hanger assembly in accordance with the present invention;

[0007] FIG. 2 is a partial cross-sectional view taken along line 2-2 of FIG. 1;

[0008] FIG. 3 is a partial cross-sectional view taken along line 3-3 of FIG. 1;

[0009] FIG. 4 is a top view of a casing hanger slip bowl in accordance with the present invention;

[0010] FIG. 5 is a partial cross-sectional view of the casing hanger slip bowl of FIG. 4 taken along line 5-5 of FIG. 4;

[0011] FIG. 6 is a top view of a casing hanger slip bowl housing in accordance with the present invention;

[0012] FIG. 7 is a partial cross-sectional view of the casing hanger slip bowl housing of FIG. 6 taken along line 7-7 of FIG. 6;

[0013] FIG. 8 is a top view of the slips of the hanger assembly of the present invention;

[0014] FIG. 9 is a partial cross-sectional view of a the slips of FIG. 8, taken along line 9-9 of FIG. 8;

[0015] FIG. 10 is a top view of an upper support plate in accordance with the present invention;

[0016] FIG. 10A is a partial cross-sectional view of the upper support plate taken along line 10A-10A;

[0017] FIG. 11 is a partial cross-sectional view of the upper support plate of FIG. 10 taken along line 11-11 of FIG. 10;

[0018] FIG. 12 is a top view of a lower support plate in accordance with the present invention;

[0019] FIG. 13 is a partial cross-sectional view of the lower support plate of FIG. 12 taken along line 13-13 of FIG. 12;

[0020] FIG. 14 is a partial cross-sectional view of an anti-extrusion ring for use in the present invention;

[0021] FIG. 15 is a top view of a seal member for use in the present invention; and

[0022] FIG. 16 is a partial cross-sectional view of the seal member of FIG. 15 taken along line 16-16 of FIG. 15.

[0023] While the invention will be described in connection with the preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and the scope of the invention as defined by the appended claims.

SUMMARY OF THE INVENTION

[0024] In accordance with the invention the foregoing advantages have been achieved through the present hanger assembly for use in a wellhead assembly, or system. The hanger assembly of the present invention is believed to be capable of supporting very high loads, and containing high pressures, and further is believed to be capable of being operable over wide temperature differentials, such as −20° F. to 350° F.

DETAILED DESCRIPTION OF THE INVENTION AND SPECIFIC EMBODIMENTS

[0025] With reference to FIGS. 1-3, a hanger assembly 20 in accordance with the present invention is shown supported in a conventional wellhead housing, or bowl, 21 (FIG. 2), and generally includes: a plurality of slips 22 in contact with a portion of a string of tubular members 23; a casing hanger slip bowl housing, or housing 24; casing hanger slip bowl, or bowl 25; a casing hanger seal member upper support plate, or upper support plate, 26; a casing hanger seal member lower support plate, or lower support plate, 27; and a seal member 28.

[0026] Hanger assembly 20 is of a conventional split bowl construction, as shown at line 30 of FIG. 1, and includes a lower beveled surface 31 adapted for abutting engagement with the single landing shoulder 32 of wellhead housing, or wellhead housing bowl, 21. A plurality of cap screws 33 are illustrated disposed in openings 34 in FIG. 1; however, cap screws 33 are only used for installation purposes and when the hanger assembly 20 is disposed within wellhead housing 21 as shown in FIG. 2, the cap screws 33 have been previously removed.

[0027] Still with reference to FIGS. 1-3, it is seen that the outer wall surface 35 of hanger assembly 20 is substantially smooth, having a substantially cylindrical cross-sectional configuration with only one lower beveled surface 31 for abutting engagement with landing shoulder 32 of wellhead housing 21. The outer wall surfaces of the casing hanger slip bowl housing 24, upper and lower support plates 26, 27, and the seal member 28, which comprise the outer wall surface 35 of hanger assembly 20, are all substantially coplanar with each other as shown in FIGS. 1 and 2. If desired the outer wall surfaces of upper and lower support plates 26, 27 and seal member 28 could be spaced inwardly of the outer wall surface of hanger slip bowl housing 24. Thus hanger assembly 20 does not include a second beveled surface for engagement with another landing shoulder formed in wellhead casing 21, as used in prior art devices. Hanger assembly 20 may be used to support a string of tubular members 23, and the use of the term “string of tubular members” is intended to include both casing pipe, as well as production tubing, as are both known in the art. A plurality of cap screws, or bolts, 40 (16 bolts being illustrated for illustrative purposes only), pass through upper support plate 26, seal member 28, and lower support plate 27, and are threadedly received within the upper end of casing hanger slip bowl 25, as shown in FIGS. 1, 2, and 5. Slip bowl 25 is provided with a plurality of threaded openings 41 (FIG. 5) for receipt of the bolts 40.

[0028] As seen in FIGS. 2, 3, and 7, casing hanger slip bowl housing 24 includes an inwardly extending ledge portion 45, which restrains downward movement of slip bowl 25 within slip bowl housing 24, with a gap 47 (FIGS. 2 and 3) initially provided between housing 24 and the lower end of slip bowl 25. Slip bowl 25 is provided with a reduced diameter portion 100 at the lower end of slip bowl 25, which provides a radial shoulder 101, which may abut ledge portion 45 of slip bowl housing 24. Housing 24 may further have an enlarged interior diameter as shown at 46. Slip bowl housing 24 has a generally cylindrical cross-sectional configuration with an interior wall surface 48 for receipt of the outer surface 49 of casing hanger slip bowl 25.

[0029] As shown in FIGS. 2, 3, and 9, the plurality of slips 22 have a substantially smooth outer wall surface 50 which slopes inwardly and is matingly received within the substantially smooth, inner wall surface 42 (FIG. 5) of casing hanger slip bowl 25. The inner wall surface 51 of slips 22 are provided with a plurality of gripping teeth 52, as are known in the art, for engagement with the outer surface of the upper end of the string of tubular members 23. Preferably, four slip members, or slips, 22, are provided although a lesser or greater number of slip members can be provided as is known in the art.

[0030] As seen in FIGS. 2, 3, 10, and 11, upper support plate 26 has a generally cylindrical, annular configuration with a plurality of openings 60 disposed therein for receipt of the plurality of bolts 40. Upper plate member 26 has a downwardly extending, annular shaped ridge member 61 for engagement with a correspondingly shaped, annular groove 81 (FIG. 16), formed in the upper surface of seal member 28. Lower support plate 27, FIGS. 12 and 13, also has a plurality of openings 70 formed therein for passage therethrough of bolts 40, as well as an upwardly extending, annular shaped ridge member 72 which is matingly received in a corresponding annular shaped groove 82 formed in the lower surface of seal member 28 (FIG. 16). Similarly, seal member 28 is provided with a plurality of openings 80 through which the corresponding number of cap screws, or bolts, 40 may also pass. Upper support plate 26, lower support plate 27, and seal, or packing member, 28 may be formed in two or more sections to permit assembly of the hanger assembly 20 about the upper end of the string of tubular members 23, as is known in the art. Lower support plate 27 is supported upon the upper end 49 of slip bowl housing 24 in an abutting relationship.

[0031] Seal member 28 may be made of any suitable elastomeric material having the requisite strength and temperature resistance characteristics so as to be utilized in a conventional wellhead assembly. The corners of the seal member 28 may be reinforced by the use of a suitable anti-extrusion material, such as kevlar rope 83. Preferably, and in particular for high temperature conditions, an anti-extrusion ring 90 (FIG. 14) is disposed about each bolt 40, overlying the openings 80 formed in seal member 28. An anti-extrusion ring 90 would be disposed about bolts 40 in engagement with the upper and lower grooved surfaces 81, 82, of seal member 28, as shown in FIG. 2. Openings 60 and 80 in upper and lower support plates 26, 27 are each preferably provided with a small annular shaped, beveled, countersink, or beveled counterbore, 63 (FIG. 10A), 73 (FIG. 13) for mating engagement with the tapered outer surface 91 of each extrusion ring 90. Upon an energizing force being exerted upon upper and lower support plates 26, 27, by threading cap screws, or bolts, 40 into casing hanger slip bowl 25, the anti-extrusion rings 90 prevent the portions of seal member 28 disposed adjacent openings 80 in seal member 28 from being extruded, or forced into, openings 60, 70, of upper and lower seal plates 26, 27.

[0032] In operation, after hanger assembly 20 is mounted about the upper end of the string of tubular members 23 and disposed within wellhead housing 21, the weight of the string of tubular members 23 causes the slips 22 to slide downwardly within slip bowl 25. The mating inner tapered surface 42 of slip bowl 25 and the outer tapered wall surface 50 of slips 22 cause the gripping teeth 52 of the slips 22 to be forced inwardly into the string of tubular members 23, as the inner diameter of the slip is reduced. Either simultaneously with such movement of slips 22, or thereafter, a pulling force is created by threading bolts 40 into the threaded openings 41 and the upper end of casing hanger slip bowl 25, whereby the seal member 28 is activated to sealingly engage about the upper end of the string of tubular members 23. The inwardly threading of bolts 40 serves to pull the upper support plate 26 toward the lower support plate 27, which is supported upon the upper end 49 of slip bowl housing, thereby compressing seal member 28 and forcing the interior surface 85 (FIG. 16) into contact with the upper outer wall surface of the string of tubular members 23. In contrast to prior art hanger assemblies, wherein the seal member is compressed by abutting engagement of a portion of the hanger assembly with a second landing shoulder formed in the wellhead housing, the actuation and compression of seal member 28 of the present invention is controlled by the amount of the pulling force exerted upon the seal member 28 via the threading of bolts 40, and the gap 47 between slip bowl housing 24 and slip bowl 25 assists in controlling the energizing force upon seal member 28.

[0033] It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiment shown and described, as obvious modifications and equivalents will be apparent to one skilled in the art. Accordingly, the invention is therefore to be limited only by the scope of the claims.

Claims

1. A hanger assembly for use in a wellhead housing and for supporting a string of tubular members, the hanger assembly comprising:

a hanger slip bowl housing, having an upper end, a lower end, and an outer wall surface, adapted to be supported by a portion of the wellhead housing;

a hanger slip bowl, having an upper end and a lower end, disposed within the hanger slip bowl housing;

at least one slip disposed within the hanger slip bowl and adapted for contacting a portion of the string of tubular members;

at least one seal member adapted to sealingly engage about a portion of the string of tubular members, the at least one seal member having an upper surface, a lower surface, and an outer wall surface, the outer wall surface being substantially coplanar with the outer wall surface of the hanger slip bowl housing; and

the hanger slip bowl housing having a substantially cylindrical cross-sectional configuration with only one beveled surface provided at the lower end of the hanger slip bowl housing, the only one beveled surface adapted for engagement with a single mating, inwardly extending, landing shoulder provided in the wellhead housing, whereby the wellhead housing requires only a single landing shoulder to support the hanger assembly and the string of tubular members.

2. The hanger assembly of claim 1, including a casing hanger seal member upper support plate provided above the at least one seal member, and a casing hanger seal member lower support plate provided below the at least one seal member, the upper and lower support plates each having an outer wall surface, and the outer wall surfaces of each support plate are substantially coplanar with the outer wall surface of the hanger slip bowl housing.

3. The hanger assembly of claim 2, wherein the lower support plate is supported upon the upper end of the slip bowl housing.

4. The hanger assembly of claim 3, wherein the lower support plate is in an abutting relationship with the upper end of the slip bowl housing.

5. The hanger assembly of claim 2, wherein the upper and lower support plates and the at least one seal member are each provided with at least one opening, the at least one opening of each of the upper and lower support plates and the at least one seal member, mating with adjacent openings to provide at least one passageway, through which each at least one passageway a bolt is passed; the bolt having an end threadedly received within the hanger assembly, whereby upon the bolt being threaded into the hanger assembly, the at least one seal member is compressed into sealing engagement about a portion of the string of tubular members.

6. The hanger assembly of claim 5, wherein the bolt has an upper end and a lower end, the upper end being received within the upper support plate, and the lower end is threadedly received within the hanger assembly.

7. The hanger assembly of claim 6, wherein the lower end of the bolt is threadedly received within the upper end of the hanger slip bowl.

8. The hanger assembly of claim 1, wherein the hanger slip bowl housing has an interior wall surface and the hanger slip bowl has an outer wall surface, and a portion of the outer wall surface of the hanger slip bowl is in sliding engagement with a portion of the interior wall surface of the hanger slip bowl housing.

9. The hanger assembly of claim 8, wherein the lower end of the hanger slip bowl housing has an inwardly extending ledge portion which restrains downward movement of the hanger slip bowl within hanger slip bowl housing.

10. The hanger assembly of claim 9, wherein the lower end of the hanger slip bowl has a reduced diameter portion which provides a radial shoulder formed in the outer wall surface of the hanger slip bowl, whereby downward movement of the hanger slip bowl within hanger slip bowl housing is restrained by the radial shoulder abutting the ledge portion of the hanger slip bowl housing.

11. The hanger assembly of claim 5 wherein an anti-extrusion ring is disposed about each bolt, and the anti-extrusion ring overlies each of the at least one openings formed in the at least one seal member.

12. The hanger assembly of claim 11, wherein two anti-extrusion ring are disposed about each bolt with an anti-extrusion ring in engagement with the upper surface of the at least one seal member and an anti-extrusion ring is in engagement with the lower surface of the at least one seal member.

13. The hanger assembly of claim 2, wherein the upper and lower support plates each have annular shaped ridge member which are matingly received by corresponding annular shaped grooves found in the upper and lower surfaces of the at least one seal member.

14. The casing hanger of claim 1, wherein downward movement of the string of tubular members within hanger slip bowl does not automatically cause compression of the at one least seal member.

15. A method for supporting a string of tubular members in a wellhead assembly having at least one landing shoulder, comprising the steps of:

providing a hanger assembly having a hanger slip bowl housing with an outer wall surface, a hanger slip bowl, at least one slip disposed within the hanger slip bowl, and at least one seal member with an outer wall surface;

disposing a portion of the string of tubular members within the hanger assembly;

disposing and supporting the hanger assembly within the wellhead assembly by placing the hanger assembly in abutting engagement with only one landing shoulder of the wellhead assembly;

permitting downward movement of the at least one slip member within the hanger slip bowl to cause the at least one slip member to be forced inwardly to grip a portion of the string of tubular members; and

compressing the at least one seal member by exerting a compressive force upon the at least one seal member to cause it to sealingly engage about a portion of the string of tubular members.

16. The method of claim 15, wherein the compressive force to the at least one seal member is provided by threading at least one bolt into the hanger assembly, the bolt being operatively associated with the at least one seal member.

17. The method of claim 16, including the step of associating at least one anti-extrusion ring with the at least one bolt.

18. The method of claim 15, including the step of disposing the outer wall surfaces of the hanger slip bowl housing and the at least one seal member substantially co-planar to each other.