CA1242970A - Metal-to-metal seal casing hanger - Google Patents
Metal-to-metal seal casing hangerInfo
- Publication number
- CA1242970A CA1242970A CA000502437A CA502437A CA1242970A CA 1242970 A CA1242970 A CA 1242970A CA 000502437 A CA000502437 A CA 000502437A CA 502437 A CA502437 A CA 502437A CA 1242970 A CA1242970 A CA 1242970A
- Authority
- CA
- Canada
- Prior art keywords
- bore
- wickers
- ring
- hanger
- seal ring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Earth Drilling (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A hanger for hanging a string of conduit within a wellhead has a metal-to-metal seal. The hanger has a body that locates within the wellhead and provides an annular clearance between the body and the wellhead. A
locking device fits within this clearance to lock the hanger against axial movement. The metal-to-metal seal is an annular ring with inner and outer cylindrical sidewalls. The seal has a cavity into which a wedge ring is driven to urge the sidewalls apart to embed within the hanger body and wellhead bore. The locking device has reacting wedges that urge a split ring outward into engagement with the wellhead. A retaining mechanism is then moved downwardly with the seal to retain the split ring in locking engagement.
A hanger for hanging a string of conduit within a wellhead has a metal-to-metal seal. The hanger has a body that locates within the wellhead and provides an annular clearance between the body and the wellhead. A
locking device fits within this clearance to lock the hanger against axial movement. The metal-to-metal seal is an annular ring with inner and outer cylindrical sidewalls. The seal has a cavity into which a wedge ring is driven to urge the sidewalls apart to embed within the hanger body and wellhead bore. The locking device has reacting wedges that urge a split ring outward into engagement with the wellhead. A retaining mechanism is then moved downwardly with the seal to retain the split ring in locking engagement.
Description
1 BACKGROUND OF T~E INVENTION
3 1. Field of the Invention:
This invention relates in general to subsea wellhead 6 equipment, and in particular to a casing or tubing hanger 7 having a me-tal-to-metal seal.
9 2. Description of the Prior Art:
11 A typical subsea wellhead assembly includes a 12 wellhead housing mounted within a temporary guide base 13 that is supported on the ocean floor. Large diameter 14 conductor pipe is secured to the wellhead housing and extends downward into the earth a short distance. A
16 wellhead is mounted inside the wellhead housing and to a 17 permanent guide base which mounts on top of the temporary 18 guide base. Surface casing secured to the wellhead 19 extends a few hundred feet down into the well. The top of the wellhead is connected to pressure equipment and 21 risers that e~tend to a drilling vessel at the surface.
22 As the well is drilled deeper, a first string of casing 23 may be set to a certain depth. Subse~uently, a second 24 string of casing may be set.
26 In a typical installation, the casing hanger 27 includes a casing hanger body which is secured to the 28 upper end of the casiny string. The body is supported on 29 an annular shoulder in the wellhead. After cementing, a seal and locking means is lowered into an annular 31 clearance between the casing hanger body and wellhead 32 bore. The seal normally includes an elastomeric ring 33 which is compressed by compression rings between the 34 casing hanger body and the wellhead bore. The locking ~ i -4~
1 means includes a split ring and various wedges, which are
3 1. Field of the Invention:
This invention relates in general to subsea wellhead 6 equipment, and in particular to a casing or tubing hanger 7 having a me-tal-to-metal seal.
9 2. Description of the Prior Art:
11 A typical subsea wellhead assembly includes a 12 wellhead housing mounted within a temporary guide base 13 that is supported on the ocean floor. Large diameter 14 conductor pipe is secured to the wellhead housing and extends downward into the earth a short distance. A
16 wellhead is mounted inside the wellhead housing and to a 17 permanent guide base which mounts on top of the temporary 18 guide base. Surface casing secured to the wellhead 19 extends a few hundred feet down into the well. The top of the wellhead is connected to pressure equipment and 21 risers that e~tend to a drilling vessel at the surface.
22 As the well is drilled deeper, a first string of casing 23 may be set to a certain depth. Subse~uently, a second 24 string of casing may be set.
26 In a typical installation, the casing hanger 27 includes a casing hanger body which is secured to the 28 upper end of the casiny string. The body is supported on 29 an annular shoulder in the wellhead. After cementing, a seal and locking means is lowered into an annular 31 clearance between the casing hanger body and wellhead 32 bore. The seal normally includes an elastomeric ring 33 which is compressed by compression rings between the 34 casing hanger body and the wellhead bore. The locking ~ i -4~
1 means includes a split ring and various wedges, which are
2 actuated by rotation of a running tool to lock the
3 elastomeric seal in compression and to lock the casing
4 hanger in the wellhead. Wickers, which are small parallel grooves, may be located in the wellhead bore for 6 engagement by the split ring.
8 While successful~ elastomeric seals may not have as 9 long of a life as a metal-to-me-tal seal, particularly if subjected to heat. Metal seals, and combinations of 11 metal and rubber seals, are commercially available.
12 Improvements, however, are desirable.
18 `
~2 SUMM~RY OF THE INVENTION
3 In this invention, a casing or tubing hanger is 4 provided with a metal-to-metal seal. The casing hanger
8 While successful~ elastomeric seals may not have as 9 long of a life as a metal-to-me-tal seal, particularly if subjected to heat. Metal seals, and combinations of 11 metal and rubber seals, are commercially available.
12 Improvements, however, are desirable.
18 `
~2 SUMM~RY OF THE INVENTION
3 In this invention, a casing or tubing hanger is 4 provided with a metal-to-metal seal. The casing hanger
5 has a body whi,ch is dimensioned to define an annular
6 clearance between the we]lhead and the body. Locking
7 means is positionable in the annular clearance for
8 locking the body to the wellhead, A deformable metal
9 seal ring is also positioned in the clearance for sealing
10 between the hanger body and the wellhead. The seal ring
11 has inner and outer sidewalls that are cylindrical.
12 Wedge means urges these sidewalls radially apar~ to seal
13 the body to the wellhead.
14
15 In the preferred embodiment, the seal ring is "U"
16 shaped, having an upwardly facing cavity between the
17 inner and outer sidewalls. A metal wedge ring, when
18 pressed into the cavity, urges the sidewalls apart.
19 Wickers are preferably formed on the casing hanger body
20 and on the wellhead bore. The metal seal ring embeds
21 into the wickers to provide sealins.
22
23 Preferably, the locking means has a split rlng that
24 engages another set of wickers in the bore. Wedges move A 25 the ring out into engagement. Wedge fingers movably 26 mounted to the hanger body retain the split ring in 27 locking engagement. The wedge fingers are moved into 28 locking engagement by contact with -the metal seal ring 29 prior to its deforma-tion.
3 Fig. 1 is a partial vertical sectional view of a 4 casing hanger constructed in accordance with this invention and shown prior to setting.
7 Fig, Z is a view of the casing hanger of Fig. 1, 8 taken from a different vertical section than in Fig. 1 9 and shown with the locking means set and the seal means prior to setting.
12 Fig. 3 is a view of the casing hanger of Fig. 1, 13 taken along the same vertical section as in Fig. 2 and 14 showing the seal means and the locking means in the set position.
3 Referring to Fig. 1, casing hanger 11 is shown 4 located within a subsea wellhead 13. Wellhead 13 has a bore 15 with an upwardly facing annular shoulder 17. A
6 lower set of wickers 19 are formed in the bore 15 a short 7 distance above shoulder 17. Wickers 19~ are small 8 parallel and circular grooves formed perpendicular to the 9 axis of bore 15. Preferably there are about eight grooves per inch. An upper set of wickers 21 is located 11 above wickers 19 a selected distance.
13 The casing hanger 11 includes a hanger body 23 that 14 has an axial passage 25 having threads 27 at the lower end for securing to the upper section of a string of 16 casing 29, which could be tubing if hanger 11 is used as 17 a tubing hanger. Body 23 has an exterior flange 31 18 located intermediate the upper and lower ends of the body 19 23. Flange 31 extends radially outward and contacts the wellhead bore 15. Flange 31 has a plurality of vertical 21 slots 32 extending radially outward and spaced 22 circumferentially around the flange. The flange 31 has a 23 reacting surface 33 on the lower side which is inclined 24 so that it faces downwardly and outwardly. The wall of the hanger body 23 above flange 31 and below the reacting 26 surface 33 is cylindrical and spaced inwardly from the 27 bore 15, defining annular clearances between bore 15 and 28 hanger body 23. ~ set of wickers 35 are formed on the 29 upper end of the hanger body 23 on the ex-terior surface in alignmen-t with the wickers 21 formed in the wellhead 31 bore 15. Wickers 35 are of the same size and type as the 32 wickers 21 and 19.
1 Hanger body 23 is supported in the wellhead 13 by a 2 locking means that includes a split ring 37. Split ring 3 37 is a circular ring that will move from a ~adially 4 inward position shown in Fig. 1 to a radially outward position shown in Fig. 2. Passages (not shown) in the 6 split ring 37 allow fluid to flow through the ring. The 7 exterior surface of split ring 37 is cylindrical and 8 contai~s a plurality of wickers 39, which align with the 9 wickers 19 in the wellhead bore 15. A retaining pin 40 (Fig. 2~, orients the split ring 37 with the hanger body 11 23, but allows radial movement with respect thereto.
13 The casing hanger 11 has reacting means for moving 14 the split ring radially outward when the casing hanger 11 is seated upon the wellhead shoulder 17. The reacting 16 means includes the reacting surface 33 and also three 17 wedge shaped rings 41, 43 and 47. The inner ring 41 is lB stationarily carried by the body 23 by means of threads.
19 Inner ring 41 has passages (not shown) that allow fluid to flow upward through ring 41. An outer ring 43 is 21 slidably carried on the cylindrical outer wall of the 22 inner ring 41. Outer ring 43 is secured to the inner 23 ring 41 by means of a shear pin 45. The outer surface of 24 outer ring 43 is cylindrical and contacts the wellhead bore 15. The lower surface of the outer ring 43 is 26 tapered for contacting the tapered shoulder 17. The 27 upper surface of the outer ring 43 is tapered for mating 28 contact with the tapered lower edge of the split ring 37.
As can be seen by comparing Fig's. 2 and 3, the 31 weight of the string 29 will shear the pin 45, causing 32 the hanger body 23 and inner ring 41 to move downward a 33 short distance with respect to the outer ring 43. This 34 downward movement causes the reacting surface 33 and the 2~7~
1 upper edge of the outer ring 43 to urge the split ring 37 2 radially outward for engaging wickers 39 with wickers 19.
3 When moving outwardly, pin 40 (Fig. 2) will move 4 outwardly within its enlarged slot or cavity.
6 The split ring 37 is maintained in the ou-tward 7 position by retaininy ~leans which includes an expandable 8 ring 47 and a plurality of wedging fingers 49.
9 Expandable ring 47 is split to allow radial movement outward as can be séen by comparing Fig's. 1 and 2.
11 Expandable ring 47 has a tapered lower edge carried on a 12 tapered upper edge of inner ring 41 and retained by a pin 13 48. Pin 48 locates in an enlarged slot in inner ring 41 14 to allow radial movement. The upper edge of the expandable ring 47 is tapered and mates slidingly with 16 the lowered tapered edge of the split ring 37.
18 Each wedging finger 49 is integrally formed with a 19 collar 51 at the top. Collar 51 is secured to the hanger body 23 above flange 31 by means of a shear pin 53. Each 21 wedge finger 49 (only one shown) extends through one of 22 the slots 32 spaced around the flange 31. Each wedge 23 finger 49 extends within the inner diameter of split ring 24 37 and is axially movable between the expandable position shown in Fig. 1 and the lower position shown in Fig. 2.
26 Each wedge finger 49 has a tapered su,rface on lts lower 27 end, which slides between the expandable ring 47 and the 28 hanger body 23 when moved to its downward position as 29 shown in Fig. 2. The wedge fingers 49 force the upper ring 47 radlally outward in-to tight contact with the 31 lower edge of the split ring 37, to retain the split ring 32 in the engayed posikion shown in Fig. 2. The fingers 49 33 and upper ring 47 cause the split ring 37 to positively 1 lock the body 23 to the wellhead 13 to prevent any axial 2 movement.
4 The collar 51 and the wedge fingers 49 are moved downwardly by force of a seal ring 55, which also serves 6 to seal the casing hanger ll. Seal ring 55 is a "U"
7 shaped, soft metal ring, which deforms when set to form a 8 metal~to-metal seal. Seal ring 55 is preferably formed 9 of a low carbon steel with a hardness of about 150 Brinnell. Seal ring 55 has inner and outer sidewalls 57 11 and 59 which are cylindrical and concentric with the axis 12 of the wellhead 13. Prior to deformation, the inner and 13 outer sidewalls 57 and 59 are dimensioned such that the 14 seal ring 55 can slide without restriction into the annular space between the hanger body 23 and the bore 15.
16 Seal ring 55 has a closed bottom 61 that is located in a 17 plane perpendicular to the axis of the sidewalls 57 and 18 59. A rectangular cavity 63 is formed in seal ring 55 19 and faces upwardly. Cavity 63 is annular and has a closed bottom defined by bottom 61. Cavity 63 has a 21 tapered and enlarged portion 65 on its upper end.
23 A metal wedge ring 67 has its lower edge carried in 24 the enlarged portion 65 of cavity 63 by means of a shear pin 69. Wedge ring 67 is annular, and will not deform 26 under normal operation, rather serves to deform the seal 27 ring 55. Wedge ring 67 has an inner sidewall 71 and an 28 outer sidewall 73 that are cylindrical, parallel and 29 concentric wi-th the axis of the seal ring 55. The cross-sectional dimension between sidewalls 71 and 73 is 31 greater than the dis-tance across cavity 63. A plurality 32 of passages 75 extend through the top and bottom of the 33 wedge ring 67 to allow the displacement of liquid when 34 the wedge ring is pressed into the cavity 63, as shown in Fig. 3.
Z~7~
1 In operation, the string of casing or tubing will be 2 secured to the lower end of the casing hanger body 23 and 3 lowered through risers (not shown) extending from a 4 drilling vessel into the wellhead 13 by means of a handling tool (not shown). Seal ring 55 and wedge ring 6 67 could be lowered with the same handling tool during 7 the same run, or they could be lowered in a second or 8 subsequent run. When the outer ring 43 contacts the 9 wellhead shoulder 17, further downward movement caused by the weight of string 29 will shear pin 45, causing the 11 split ring 37 to move outward into engagement with the 12 wickers 19. Then, if the string 29 is casing, cement 13 will normally be pumped downward through the passage 25 14 and through the casing 29 to cement the casing 29 into the well. Liquid in the well will be displaced from the 16 annulus between the casing 29 and the wellbore through 17 passages (not shown) located in inner ring 41, upper ring 18 ~7, and split ring 37. The displaced liquid will flow 1~ through the slots 32 and to the surface.
21 Once the cement has set, the handling to~l (not 22 shown), moves the seal 55 downward without rotation, 23 causing its bottom 61 to contact the collar 51, pushing 24 the expandable ring 47 outwardly to retain the split ring 37 in the locked and engaged position. Shear pin 53 will 26 shear at this time. Then, the handling tool applies Z7 force without rotating -to the wedge ring 67. This force 28 deforms the seal ri.ng 55, forcing the inner sidewall 57 29 radially inward and the outer sidewall 59 radially outward. Shear pin 69 will shear. The wedging Eorce 31 will cause the soft metal of the seal ring 55 -to 32 sealingly embed within the wickers 21 and 35. Any fluid 33 that tends to leak past the seal ring 55 will be trapped 34 in the wickers 21 and 35.
1 The invention has significant advantages. The 2 locking portions of the casing hanger assembly positively 3 lock the casing hanger body to the wellhead. This 4 prevents any axial movement of the hanger body relative to the wellhead that might otherwise occur due to the 6 thermal changes. The lack oE movement of the hanger body 7 relative to the wellhead avoids flexing of the metal 8 seal, which could deteriorate the seal. The metal seal 9 has a large cylindrical surface which provides good sealing, enhanced by the wickers. The soft metal seal 11 does not deform the wellhead, enabling the casing hanger 12 to be pulled and another substituted in the same place.
13 The cooperation between the locking means and the seal 14 means enables the casing to be lowered into place, cemented, locked and sealed all in a single run, if 16 desired.
18 While the invention has been shown in only one of 19 its forms, it should be apparent to those skilled in the art that it is not sa limited but is susceptible to 21 various changes without departing from the scope of the 22 invention.
2g
3 Fig. 1 is a partial vertical sectional view of a 4 casing hanger constructed in accordance with this invention and shown prior to setting.
7 Fig, Z is a view of the casing hanger of Fig. 1, 8 taken from a different vertical section than in Fig. 1 9 and shown with the locking means set and the seal means prior to setting.
12 Fig. 3 is a view of the casing hanger of Fig. 1, 13 taken along the same vertical section as in Fig. 2 and 14 showing the seal means and the locking means in the set position.
3 Referring to Fig. 1, casing hanger 11 is shown 4 located within a subsea wellhead 13. Wellhead 13 has a bore 15 with an upwardly facing annular shoulder 17. A
6 lower set of wickers 19 are formed in the bore 15 a short 7 distance above shoulder 17. Wickers 19~ are small 8 parallel and circular grooves formed perpendicular to the 9 axis of bore 15. Preferably there are about eight grooves per inch. An upper set of wickers 21 is located 11 above wickers 19 a selected distance.
13 The casing hanger 11 includes a hanger body 23 that 14 has an axial passage 25 having threads 27 at the lower end for securing to the upper section of a string of 16 casing 29, which could be tubing if hanger 11 is used as 17 a tubing hanger. Body 23 has an exterior flange 31 18 located intermediate the upper and lower ends of the body 19 23. Flange 31 extends radially outward and contacts the wellhead bore 15. Flange 31 has a plurality of vertical 21 slots 32 extending radially outward and spaced 22 circumferentially around the flange. The flange 31 has a 23 reacting surface 33 on the lower side which is inclined 24 so that it faces downwardly and outwardly. The wall of the hanger body 23 above flange 31 and below the reacting 26 surface 33 is cylindrical and spaced inwardly from the 27 bore 15, defining annular clearances between bore 15 and 28 hanger body 23. ~ set of wickers 35 are formed on the 29 upper end of the hanger body 23 on the ex-terior surface in alignmen-t with the wickers 21 formed in the wellhead 31 bore 15. Wickers 35 are of the same size and type as the 32 wickers 21 and 19.
1 Hanger body 23 is supported in the wellhead 13 by a 2 locking means that includes a split ring 37. Split ring 3 37 is a circular ring that will move from a ~adially 4 inward position shown in Fig. 1 to a radially outward position shown in Fig. 2. Passages (not shown) in the 6 split ring 37 allow fluid to flow through the ring. The 7 exterior surface of split ring 37 is cylindrical and 8 contai~s a plurality of wickers 39, which align with the 9 wickers 19 in the wellhead bore 15. A retaining pin 40 (Fig. 2~, orients the split ring 37 with the hanger body 11 23, but allows radial movement with respect thereto.
13 The casing hanger 11 has reacting means for moving 14 the split ring radially outward when the casing hanger 11 is seated upon the wellhead shoulder 17. The reacting 16 means includes the reacting surface 33 and also three 17 wedge shaped rings 41, 43 and 47. The inner ring 41 is lB stationarily carried by the body 23 by means of threads.
19 Inner ring 41 has passages (not shown) that allow fluid to flow upward through ring 41. An outer ring 43 is 21 slidably carried on the cylindrical outer wall of the 22 inner ring 41. Outer ring 43 is secured to the inner 23 ring 41 by means of a shear pin 45. The outer surface of 24 outer ring 43 is cylindrical and contacts the wellhead bore 15. The lower surface of the outer ring 43 is 26 tapered for contacting the tapered shoulder 17. The 27 upper surface of the outer ring 43 is tapered for mating 28 contact with the tapered lower edge of the split ring 37.
As can be seen by comparing Fig's. 2 and 3, the 31 weight of the string 29 will shear the pin 45, causing 32 the hanger body 23 and inner ring 41 to move downward a 33 short distance with respect to the outer ring 43. This 34 downward movement causes the reacting surface 33 and the 2~7~
1 upper edge of the outer ring 43 to urge the split ring 37 2 radially outward for engaging wickers 39 with wickers 19.
3 When moving outwardly, pin 40 (Fig. 2) will move 4 outwardly within its enlarged slot or cavity.
6 The split ring 37 is maintained in the ou-tward 7 position by retaininy ~leans which includes an expandable 8 ring 47 and a plurality of wedging fingers 49.
9 Expandable ring 47 is split to allow radial movement outward as can be séen by comparing Fig's. 1 and 2.
11 Expandable ring 47 has a tapered lower edge carried on a 12 tapered upper edge of inner ring 41 and retained by a pin 13 48. Pin 48 locates in an enlarged slot in inner ring 41 14 to allow radial movement. The upper edge of the expandable ring 47 is tapered and mates slidingly with 16 the lowered tapered edge of the split ring 37.
18 Each wedging finger 49 is integrally formed with a 19 collar 51 at the top. Collar 51 is secured to the hanger body 23 above flange 31 by means of a shear pin 53. Each 21 wedge finger 49 (only one shown) extends through one of 22 the slots 32 spaced around the flange 31. Each wedge 23 finger 49 extends within the inner diameter of split ring 24 37 and is axially movable between the expandable position shown in Fig. 1 and the lower position shown in Fig. 2.
26 Each wedge finger 49 has a tapered su,rface on lts lower 27 end, which slides between the expandable ring 47 and the 28 hanger body 23 when moved to its downward position as 29 shown in Fig. 2. The wedge fingers 49 force the upper ring 47 radlally outward in-to tight contact with the 31 lower edge of the split ring 37, to retain the split ring 32 in the engayed posikion shown in Fig. 2. The fingers 49 33 and upper ring 47 cause the split ring 37 to positively 1 lock the body 23 to the wellhead 13 to prevent any axial 2 movement.
4 The collar 51 and the wedge fingers 49 are moved downwardly by force of a seal ring 55, which also serves 6 to seal the casing hanger ll. Seal ring 55 is a "U"
7 shaped, soft metal ring, which deforms when set to form a 8 metal~to-metal seal. Seal ring 55 is preferably formed 9 of a low carbon steel with a hardness of about 150 Brinnell. Seal ring 55 has inner and outer sidewalls 57 11 and 59 which are cylindrical and concentric with the axis 12 of the wellhead 13. Prior to deformation, the inner and 13 outer sidewalls 57 and 59 are dimensioned such that the 14 seal ring 55 can slide without restriction into the annular space between the hanger body 23 and the bore 15.
16 Seal ring 55 has a closed bottom 61 that is located in a 17 plane perpendicular to the axis of the sidewalls 57 and 18 59. A rectangular cavity 63 is formed in seal ring 55 19 and faces upwardly. Cavity 63 is annular and has a closed bottom defined by bottom 61. Cavity 63 has a 21 tapered and enlarged portion 65 on its upper end.
23 A metal wedge ring 67 has its lower edge carried in 24 the enlarged portion 65 of cavity 63 by means of a shear pin 69. Wedge ring 67 is annular, and will not deform 26 under normal operation, rather serves to deform the seal 27 ring 55. Wedge ring 67 has an inner sidewall 71 and an 28 outer sidewall 73 that are cylindrical, parallel and 29 concentric wi-th the axis of the seal ring 55. The cross-sectional dimension between sidewalls 71 and 73 is 31 greater than the dis-tance across cavity 63. A plurality 32 of passages 75 extend through the top and bottom of the 33 wedge ring 67 to allow the displacement of liquid when 34 the wedge ring is pressed into the cavity 63, as shown in Fig. 3.
Z~7~
1 In operation, the string of casing or tubing will be 2 secured to the lower end of the casing hanger body 23 and 3 lowered through risers (not shown) extending from a 4 drilling vessel into the wellhead 13 by means of a handling tool (not shown). Seal ring 55 and wedge ring 6 67 could be lowered with the same handling tool during 7 the same run, or they could be lowered in a second or 8 subsequent run. When the outer ring 43 contacts the 9 wellhead shoulder 17, further downward movement caused by the weight of string 29 will shear pin 45, causing the 11 split ring 37 to move outward into engagement with the 12 wickers 19. Then, if the string 29 is casing, cement 13 will normally be pumped downward through the passage 25 14 and through the casing 29 to cement the casing 29 into the well. Liquid in the well will be displaced from the 16 annulus between the casing 29 and the wellbore through 17 passages (not shown) located in inner ring 41, upper ring 18 ~7, and split ring 37. The displaced liquid will flow 1~ through the slots 32 and to the surface.
21 Once the cement has set, the handling to~l (not 22 shown), moves the seal 55 downward without rotation, 23 causing its bottom 61 to contact the collar 51, pushing 24 the expandable ring 47 outwardly to retain the split ring 37 in the locked and engaged position. Shear pin 53 will 26 shear at this time. Then, the handling tool applies Z7 force without rotating -to the wedge ring 67. This force 28 deforms the seal ri.ng 55, forcing the inner sidewall 57 29 radially inward and the outer sidewall 59 radially outward. Shear pin 69 will shear. The wedging Eorce 31 will cause the soft metal of the seal ring 55 -to 32 sealingly embed within the wickers 21 and 35. Any fluid 33 that tends to leak past the seal ring 55 will be trapped 34 in the wickers 21 and 35.
1 The invention has significant advantages. The 2 locking portions of the casing hanger assembly positively 3 lock the casing hanger body to the wellhead. This 4 prevents any axial movement of the hanger body relative to the wellhead that might otherwise occur due to the 6 thermal changes. The lack oE movement of the hanger body 7 relative to the wellhead avoids flexing of the metal 8 seal, which could deteriorate the seal. The metal seal 9 has a large cylindrical surface which provides good sealing, enhanced by the wickers. The soft metal seal 11 does not deform the wellhead, enabling the casing hanger 12 to be pulled and another substituted in the same place.
13 The cooperation between the locking means and the seal 14 means enables the casing to be lowered into place, cemented, locked and sealed all in a single run, if 16 desired.
18 While the invention has been shown in only one of 19 its forms, it should be apparent to those skilled in the art that it is not sa limited but is susceptible to 21 various changes without departing from the scope of the 22 invention.
2g
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a hanger for mounting in a wellhead member of the type having a hanger body with a lower end to which a string of conduit is adapted to be secured, the improvement comprising in combination:
locking means adapted to be located in an annular clearance between the wellhead member and the body for locking the body to the wellhead member;
a deformable metal seal ring adapted to be located in the clearance, having inner and outer cylindrical sidewalls separated by an upwardly facing annular cavity; and a metal wedge ring movably carried with the seal ring, the wedge ring having a greater cross-sectional dimension than the cavity, so that downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to seal against the wellhead member and the body.
locking means adapted to be located in an annular clearance between the wellhead member and the body for locking the body to the wellhead member;
a deformable metal seal ring adapted to be located in the clearance, having inner and outer cylindrical sidewalls separated by an upwardly facing annular cavity; and a metal wedge ring movably carried with the seal ring, the wedge ring having a greater cross-sectional dimension than the cavity, so that downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to seal against the wellhead member and the body.
2. For use in a wellhead member having a bore, an improved hanger adapted to be mounted in the bore for supporting a string of conduit, comprising in combination:
a hanger body having a lower end to which the conduit is adapted to be secured;
a plurality of parallel wickers formed on the exterior of the body for alignment with a plurality of parallel wickers formed in the bore;
locking means positionable in an annular clearance provided between the body and the bore for locking the body in the bore;
a deformable metal seal ring positionable in the clearance between the wickers of the bore and wickers of the body, having inner and outer sidewalls; and wedge means for urging the sidewalls radially apart to embed within the wickers of the body and the bore.
a hanger body having a lower end to which the conduit is adapted to be secured;
a plurality of parallel wickers formed on the exterior of the body for alignment with a plurality of parallel wickers formed in the bore;
locking means positionable in an annular clearance provided between the body and the bore for locking the body in the bore;
a deformable metal seal ring positionable in the clearance between the wickers of the bore and wickers of the body, having inner and outer sidewalls; and wedge means for urging the sidewalls radially apart to embed within the wickers of the body and the bore.
3. For use in a wellhead member having a bore, an improved hanger adapted to be mounted in the bore for supporting a string of conduit, comprising in combination:
a hanger body having a lower end to which the string of conduit is adapted to be secured, and a cylindrical wall dimensioned to define an annular clearance between the bore and the body;
a set of wickers formed on the exterior of the body wall in alignment with a set of wickers formed in the bore;
locking means positionable in the annular clearance for locking the body in the bore;
a deformable metal seal ring adapted to be located in the clearance between the sets of wickers of the body and bore, having inner and outer cylindrical sidewalls, separated by an upwardly facing annular cavity; and a wedge ring movably carried with the seal ring, the wedge ring having a greater cross-sectional dimension than the cross-sectional dimension of the cavity, so that downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to embed within the wickers of the body and the bore.
a hanger body having a lower end to which the string of conduit is adapted to be secured, and a cylindrical wall dimensioned to define an annular clearance between the bore and the body;
a set of wickers formed on the exterior of the body wall in alignment with a set of wickers formed in the bore;
locking means positionable in the annular clearance for locking the body in the bore;
a deformable metal seal ring adapted to be located in the clearance between the sets of wickers of the body and bore, having inner and outer cylindrical sidewalls, separated by an upwardly facing annular cavity; and a wedge ring movably carried with the seal ring, the wedge ring having a greater cross-sectional dimension than the cross-sectional dimension of the cavity, so that downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to embed within the wickers of the body and the bore.
4. In a wellhead member having a bore and an upwardly facing shoulder located therein, an improved hanger adapted to be supported to the shoulder for carrying a string of conduit, comprising in combination:
a hanger body having a lower end to which the conduit is adapted to be secured, and a cylindrical wall dimensioned for defining an annular clearance between the bore and the body;
a radially protruding flange located between the ends of the hanger body, defining an upper annular clearance above the flange between the hanger body and the bore, and a lower annular clearance below the flange between the hanger body and bore;
a reacting surface located on the lower side of the flange that is inclined and downwardly facing;
a split ring positionable in the clearance below the reacting surface, having a set of grooves on an outer sidewall for alignment with a set of grooves formed in the bore;
reacting means movably carried by the body below the flange for urging the split ring to slide against the reacting surface outwardly into engagement with the grooves in the bore when the reacting means contacts the shoulder, and the body and string of conduit are moved downwardly relative to the shoulder;
a set of wickers formed on the exterior of the body wall above the flange in alignment with a set of wickers formed in the bore;
a deformable metal seal ring adapted to be located in the clearance above the flange between the wickers of the bore and the wickers of the body, having inner and outer sidewalls separated by an upwardly facing annular cavity; and a wedge ring movably carried with the seal ring, the wedge ring having a greater cross-sectional dimension than the cross-section dimension of the cavity, so that downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to embed within the wickers of the body and the wickers of the bore.
a hanger body having a lower end to which the conduit is adapted to be secured, and a cylindrical wall dimensioned for defining an annular clearance between the bore and the body;
a radially protruding flange located between the ends of the hanger body, defining an upper annular clearance above the flange between the hanger body and the bore, and a lower annular clearance below the flange between the hanger body and bore;
a reacting surface located on the lower side of the flange that is inclined and downwardly facing;
a split ring positionable in the clearance below the reacting surface, having a set of grooves on an outer sidewall for alignment with a set of grooves formed in the bore;
reacting means movably carried by the body below the flange for urging the split ring to slide against the reacting surface outwardly into engagement with the grooves in the bore when the reacting means contacts the shoulder, and the body and string of conduit are moved downwardly relative to the shoulder;
a set of wickers formed on the exterior of the body wall above the flange in alignment with a set of wickers formed in the bore;
a deformable metal seal ring adapted to be located in the clearance above the flange between the wickers of the bore and the wickers of the body, having inner and outer sidewalls separated by an upwardly facing annular cavity; and a wedge ring movably carried with the seal ring, the wedge ring having a greater cross-sectional dimension than the cross-section dimension of the cavity, so that downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to embed within the wickers of the body and the wickers of the bore.
5. In a wellhead member having a bore, an upwardly facing shoulder located therein, an improved hanger adapted to be supported on the shoulder for carrying a string of conduit, comprising in combination:
upper and lower wickers formed in the bore above the shoulder and spaced axially apart;
a hanger body having a lower end to which the conduit is adapted to be secured, and a cylindrical wall dimensioned for defining an annular clearance between the bore and the body;
a set of wickers formed on the exterior of the body wall in alignment with the upper set of wickers formed in the bore;
a split ring positionable in the clearance, having a set of wickers on an outer sidewall in alignment with the lower set of wickers formed in the bore;
reacting means movably carried by the body for forcing the split ring outwardly into engagement with the lower set of wickers upon contact with the shoulder in the bore;
a plurality of wedge finger means carried by the body between the split ring and the body wall for retaining the split ring in engagement with the bore when the wedge finger means is moved downwardly with respect to the split ring;
a deformable metal seal ring adapted to be located in the clearance between the set of wickers of the body and the upper set of wickers of the bore, having inner and outer cylindrical sidewalls separated by an upwardly facing annular cavity;
the seal ring adapted to contact the wedge finger means and move it downwardly with respect to the body when the seal ring is moved downwardly; and a wedge ring movably carried with the seal ring, the wedge ring having a greater cross sectional dimension than the cross-sectional dimension of the cavity, so the downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to embed and seal within the wickers of the body and the bore.
upper and lower wickers formed in the bore above the shoulder and spaced axially apart;
a hanger body having a lower end to which the conduit is adapted to be secured, and a cylindrical wall dimensioned for defining an annular clearance between the bore and the body;
a set of wickers formed on the exterior of the body wall in alignment with the upper set of wickers formed in the bore;
a split ring positionable in the clearance, having a set of wickers on an outer sidewall in alignment with the lower set of wickers formed in the bore;
reacting means movably carried by the body for forcing the split ring outwardly into engagement with the lower set of wickers upon contact with the shoulder in the bore;
a plurality of wedge finger means carried by the body between the split ring and the body wall for retaining the split ring in engagement with the bore when the wedge finger means is moved downwardly with respect to the split ring;
a deformable metal seal ring adapted to be located in the clearance between the set of wickers of the body and the upper set of wickers of the bore, having inner and outer cylindrical sidewalls separated by an upwardly facing annular cavity;
the seal ring adapted to contact the wedge finger means and move it downwardly with respect to the body when the seal ring is moved downwardly; and a wedge ring movably carried with the seal ring, the wedge ring having a greater cross sectional dimension than the cross-sectional dimension of the cavity, so the downward movement of the wedge ring with respect to the seal ring urges the seal ring sidewalls radially apart to embed and seal within the wickers of the body and the bore.
6. In a wellhead member having a bore, an upwardly facing shoulder located therein, and axially spaced-apart upper and lower wickers located above the shoulder, an improved hanger adapted to be supported on the shoulder for carrying a string of conduit, comprising in combination:
a hanger body having a lower end containing threads for threadably receiving the string of conduit, an upper end with a cylindrical exterior, and a radially protruding flange located between the ends and in contact with the bore, defining an upper annular clearance above the flange between the hanger body and bore and a lower annular clearance below the flange between the hanger body and bore;
a split ring carried below the flange by the body within the lower annular clearance;
reacting means carried by the body below the split ring for contact with the shoulder to support the hanger and for urging the split ring radially outward to engage the bore when the hanger body is removed downwardly after contact of the reacting means with the shoulder;
retaining means for retaining the split ring in the engaged position, the retaining means having a plurality of wedge fingers which extend through slots provided in the flange for wedging the split ring in the engaged position when the fingers are moved downwardly with respect to the hanger body, the fingers protruding above the top of the flange;
a deformable metal seal ring adapted to be located in the upper clearance above the flange, having inner and outer sidewalls and a lower edge which is adapted to contact the upper ends of the fingers to move the fingers downwardly when the seal ring is moved downwardly with respect to the hanger body; and wedge means for wedging the sidewalls of the seal ring radially outward to deform against the hanger body and the bore.
a hanger body having a lower end containing threads for threadably receiving the string of conduit, an upper end with a cylindrical exterior, and a radially protruding flange located between the ends and in contact with the bore, defining an upper annular clearance above the flange between the hanger body and bore and a lower annular clearance below the flange between the hanger body and bore;
a split ring carried below the flange by the body within the lower annular clearance;
reacting means carried by the body below the split ring for contact with the shoulder to support the hanger and for urging the split ring radially outward to engage the bore when the hanger body is removed downwardly after contact of the reacting means with the shoulder;
retaining means for retaining the split ring in the engaged position, the retaining means having a plurality of wedge fingers which extend through slots provided in the flange for wedging the split ring in the engaged position when the fingers are moved downwardly with respect to the hanger body, the fingers protruding above the top of the flange;
a deformable metal seal ring adapted to be located in the upper clearance above the flange, having inner and outer sidewalls and a lower edge which is adapted to contact the upper ends of the fingers to move the fingers downwardly when the seal ring is moved downwardly with respect to the hanger body; and wedge means for wedging the sidewalls of the seal ring radially outward to deform against the hanger body and the bore.
7. A method of mounting a hanger body in a bore of a wellhead member which has an upwardly facing shoulder located therein, the method comprising in combination:
securing the lower end of the hanger body to a string of conduit;
mounting a locking means around the hanger body;
lowering the hanger body and the locking means into the bore, and locking the hanger body to the wellhead member with the locking means, the hanger body and wellhead member defining an annular clearance facing upwardly;
providing a set of wickers in the bore of the wellhead member;
providing a set of wickers on the exterior of the hanger body which align with the wickers in the bore when the hanger body is locked to the wellhead member;
lowering a deformable metal seal ring into the annular clearance above the locking means, the seal ring having inner and outer sidewalls separated by an upwardly facing annular cavity; and lowering a metal wedge ring downwardly into the cavity, and wedging the sidewalls outwardly with the wedge ring to cause the sidewalls to embed within the wickers in the hanger body and the bore.
securing the lower end of the hanger body to a string of conduit;
mounting a locking means around the hanger body;
lowering the hanger body and the locking means into the bore, and locking the hanger body to the wellhead member with the locking means, the hanger body and wellhead member defining an annular clearance facing upwardly;
providing a set of wickers in the bore of the wellhead member;
providing a set of wickers on the exterior of the hanger body which align with the wickers in the bore when the hanger body is locked to the wellhead member;
lowering a deformable metal seal ring into the annular clearance above the locking means, the seal ring having inner and outer sidewalls separated by an upwardly facing annular cavity; and lowering a metal wedge ring downwardly into the cavity, and wedging the sidewalls outwardly with the wedge ring to cause the sidewalls to embed within the wickers in the hanger body and the bore.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000502437A CA1242970A (en) | 1986-02-21 | 1986-02-21 | Metal-to-metal seal casing hanger |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000502437A CA1242970A (en) | 1986-02-21 | 1986-02-21 | Metal-to-metal seal casing hanger |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1242970A true CA1242970A (en) | 1988-10-11 |
Family
ID=4132525
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000502437A Expired CA1242970A (en) | 1986-02-21 | 1986-02-21 | Metal-to-metal seal casing hanger |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1242970A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114876399A (en) * | 2022-06-02 | 2022-08-09 | 盐城宝通机械科技有限公司 | Dabber formula casing hanger convenient to maintain |
-
1986
- 1986-02-21 CA CA000502437A patent/CA1242970A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114876399A (en) * | 2022-06-02 | 2022-08-09 | 盐城宝通机械科技有限公司 | Dabber formula casing hanger convenient to maintain |
| CN114876399B (en) * | 2022-06-02 | 2024-05-14 | 盐城宝通机械科技有限公司 | Dabber formula sleeve pipe hanger convenient to maintain |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |