CA2865382A1 - Coil tubing hanger - Google Patents
Coil tubing hanger Download PDFInfo
- Publication number
- CA2865382A1 CA2865382A1 CA2865382A CA2865382A CA2865382A1 CA 2865382 A1 CA2865382 A1 CA 2865382A1 CA 2865382 A CA2865382 A CA 2865382A CA 2865382 A CA2865382 A CA 2865382A CA 2865382 A1 CA2865382 A1 CA 2865382A1
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- Prior art keywords
- tubing
- coil
- tubing hanger
- hanger body
- slip
- Prior art date
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Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/20—Flexible or articulated drilling pipes, e.g. flexible or articulated rods, pipes or cables
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
- E21B19/22—Handling reeled pipe or rod units, e.g. flexible drilling pipes
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/02—Surface sealing or packing
- E21B33/03—Well heads; Setting-up thereof
- E21B33/04—Casing heads; Suspending casings or tubings in well heads
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Mechanical Engineering (AREA)
- Earth Drilling (AREA)
Abstract
A coil tubing hanger includes a tubing hanger body shaped to fit between a tubing head and tubing-head adapter. The tubing hanger body is supported by an inside surface of the tubing head. Opposing slip assemblies are situated inside the tubing hanger body to carry weight of the coil tubing and resist up-hole forces, which may result from pressure or thermal expansion of the coil tubing. A gland nut compresses the slip assemblies to grip the coil tubing. A coil-tubing seal is located down-hole of the slip assemblies and may be urged into sealing contact with the coil tubing by weight of the coil tubing, tightening of the gland nut, and hydraulic pressure. Various embodiments with all or some of these features are disclosed.
Description
ATTORNEY DOCKET NO. HP76-002 COIL TUBING HANGER
= Technical Field [0001] This disclosure relates in general to well equipment and, in particular, to an improved coil tubing hanger.
Background of the Disclosure
= Technical Field [0001] This disclosure relates in general to well equipment and, in particular, to an improved coil tubing hanger.
Background of the Disclosure
[0002] Coil tubing (also known as coiled tubing) is used in oil and gas wells for various purposes, such as circulation, pumping, drilling, logging, perforating, and production.
[0003] Coil tubing is often hung and landed within the wellhead Christmas tree. A threaded or flanged tubing hanger is commonly situated above the tubing-head adapter. Such tubing hangers can disadvantageously add height and cost to the tree. Moreover, conventional tubing hangers are designed to support the coil tubing in the well and provide little restraint to upwards vertical forces, such as those resulting from pressure or thermal expansion of the coil.
[0004] In addition, the Christmas tree bore is often a reduced diameter with respect to the full bore of the well casing or tubing head. Thus, the full diameter of the wellbore is not available unless the reduced-bore components of the tree are removed. This can cause unsafe conditions before coil tubing is run or after coil tubing is pulled from the well, in that the reduced-bore components often need added time and special equipment to be removed before pressure control or other intervention can be applied to the full bore.
[0005] Known coil tubing hangers may suffer from the above disadvantages as well as other problems.
, Summary
, Summary
[0006] In a first aspect, there is provided a coil tubing hanger including a tubing hanger body including an axial bore for receiving a length of coil tubing that is to extend into a wellbore. The coil tubing hanger further includes a first slip assembly disposed within the axial bore of the tubing hanger body. The first slip assembly is oriented to restrain movement of the length of coil tubing in a down-hole direction. The coil tubing hanger further includes a second slip assembly disposed within the axial bore of the tubing hanger body. The second slip assembly is oriented to restrain movement of the length of coil tubing in an up-hole direction.
[0007] The coil tubing hanger may have the advantage of restraining the coil tubing against both weight of the coil tubing in the wellbore and against up-hole force, such as force due to pressure or thermal expansion of the coil tubing.
[0008] In certain embodiments, the coil tubing hanger further includes a junk ring positioned between the first slip assembly and the second slip assembly. The junk ring is for distributing force between the first slip assembly and the second slip assembly.
[0009] In other certain embodiments, the coil tubing hanger further includes a coil-tubing seal disposed within the axial bore of the tubing hanger body at a location down-hole of the first and second slip assemblies. The coil-tubing seal is for sealing against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing.
[0010] In yet another embodiment, the coil tubing hanger further includes a first slip bowl positioned to receive the first slip assembly. The first slip bowl is aligned with the coil-tubing seal for transferring compressive force to the coil-tubing seal to urge the coil-tubing seal into sealing contact with the length of coil tubing.
[0011] In still another embodiment, the coil tubing hanger further includes a gland nut threadably connectable to the tubing hanger body at a position up-hole of the first and second slip assemblies. The gland nut is for applying compressive force to at least the second slip assembly to cause the second slip assembly to grip the length of coil tubing.
[0012] In still another embodiment, the coil tubing hanger further includes a second slip bowl positioned to receive the second slip assembly and to receive the compressive force from the gland nut.
[0013] In still another embodiment, the second slip assembly is disposed within the tubing hanger body at a position up-hole of the first slip assembly.
[0014] In still another embodiment, the tubing hanger body is shaped to be received in a flanged tubing head of a wellhead of the wellbore.
[0015] In still another embodiment, the tubing hanger body includes an exterior bearing surface shaped to bear against an interior frustoconical surface of the flanged tubing head.
[0016] In still another embodiment, the exterior bearing surface of the tubing hanger body is shaped to accommodate a tubing-head seal for sealing with the flanged tubing head.
[0017] In still another embodiment, the tubing hanger body includes an elongated neck. The elongated neck includes a surface that is shaped to accommodate a tubing-head-adapter seal for sealing with a tubing-head adapter.
[0018] In a second aspect, there is provided a coil tubing hanger including a tubing hanger body including an axial bore for receiving at least one slip assembly for gripping a length of coil tubing that is to extend into a wellbore. The axial bore is further for receiving a coil-tubing seal for sealing against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing. The tubing hanger body is shaped to be received in a flanged tubing head of a wellhead of the wellbore. The tubing hanger body includes an exterior bearing surface shaped to bear against an interior frustoconical surface of the flanged tubing head to transfer weight of the coil tubing to the flanged tubing head.
[0019] The coil tubing hanger may have one or more of the advantages of reducing an overall height and complexity of a wellhead assembly and allowing quicker and safer access to the full diameter of the wellbore if, for example, well control intervention is required.
[0020] In certain embodiments, the exterior bearing surface of the tubing hanger body includes at least one groove to accommodate a tubing-head seal for sealing with the interior frustoconical surface of the flanged tubing head.
[0021] In other certain embodiments, the exterior bearing surface is frustoconical in shape.
[0022] In yet another embodiment, the tubing hanger body further includes an elongated neck extending opposite the exterior bearing surface. The elongated neck includes a surface including at least one groove to accommodate a tubing-head-adapter seal for sealing with a tubing-head adapter.
[0023] In still another embodiment, the tubing hanger body is shaped to receive two opposing slip assemblies and two respective slip bowls.
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[0024] In still another embodiment, an up-hole end of the tubing hanger body includes a thread for receiving a gland nut and a down-hole end of the tubing hanger body includes a shoulder for seating the coil-tubing seal.
[0025] In a third aspect, there is provided a coil tubing hanger including a tubing hanger body including an up-hole end, a down-hole end, and axial bore for receiving a length of coil tubing that is to extend into a wellbore. The tubing hanger body is shaped to be received in a flanged tubing head of a wellhead of the wellbore and including an exterior surface for bearing against and sealing with an interior frustoconical surface of the flanged tubing head.
The tubing hanger body further includes an elongated neck at the up-hole end for sealing with a tubing-head adapter. The tubing hanger body further includes a shoulder inside the axial bore at the down-hole end. The coil tubing hanger further includes a first slip assembly disposed within the axial bore. The first slip assembly is oriented to restrain movement of the length of coil tubing in a down-hole direction. The coil tubing hanger further includes a first slip bowl positioned in the axial bore to receive the first slip assembly. The coil tubing hanger further includes a second slip assembly disposed within the axial bore at a position up-hole of the first slip assembly and aligned with the first slip assembly. The second slip assembly is oriented to restrain movement of the length of coil tubing in an up-hole direction. The coil tubing hanger further includes a second slip bowl positioned in the axial bore to receive the second slip assembly.
The coil tubing hanger further includes a junk ring positioned between the first slip assembly and the second slip assembly. The coil tubing hanger further includes a coil-tubing seal disposed within the axial bore of the tubing hanger body and seated against the shoulder at a location down-hole of the first and second slip assemblies in alignment with the first and second slip assemblies. The coil-tubing seal is positioned to receive a compressive force from the first slip assembly due to weight of the coil tubing acting on the first slip assembly. The compressive force causes the coil-tubing seal to deform to seal against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing. The coil tubing hanger further includes a gland nut threadably connected to the tubing hanger body at a position up-hole of the first and second slip assemblies. The gland nut is for applying compressive force to cause at least the second slip assembly to grip the length of coil tubing.
100261 The coil tubing hanger may have the advantage of restraining the coil tubing against both weight of the coil tubing in the wellbore and against up-hole force, such as force due to pressure or thermal expansion of the coil tubing. The coil tubing hanger may further have one or more of the advantages of reducing an overall height and complexity of a wellhead assembly and allowing quicker and safer access to the full diameter of the wellbore if, for example, well control intervention is required.
100271 In certain embodiments, the coil tubing hanger further includes an end piece engaged with the coil-tubing seal. The end piece directly abuts the shoulder to seat and support the coil-tubing seal.
10028] In other certain embodiments, the tubing hanger body further includes at least one fluid channel in fluid communication with a space behind the coil-tubing seal for pressurizing the coil-tubing seal against the coil tubing.
10029] In a fourth aspect, there is provided a method of running coil tubing into a wellbore.
The method includes inserting a tubing hanger body into a flanged tubing head of a wellhead of the well, running the coil tubing through an axial bore of the tubing hanger body and into the wellbore, and providing two opposing slip assemblies around a length of the coil tubing inside the tubing hanger body. The method further includes threading a gland nut into the tubing hanger body to compress at least one slip assembly of the two opposing slip assemblies to grip the length of the coil tubing. The at least one slip assembly is oriented to restrain movement of the coil tubing in an up-hole direction.
[0030] The method may have the advantage of restraining the coil tubing against both weight of the coil tubing in the wellbore and against up-hole force, such as force due to pressure or thermal expansion of the coil tubing. The method may further have one or more of the advantages of reducing an overall height and complexity of a wellhead assembly and allowing quicker and safer access to the full diameter of the wellbore if, for example, well control intervention is required.
[0031] In certain embodiments, the method further includes the gland nut compressing the two opposing slip assemblies and compressing a coil-tubing seal axially aligned with the two opposing slip assemblies.
[0032] In other certain embodiments, inserting the tubing hanger body into the flanged tubing head includes landing an exterior bearing surface of the tubing hanger body against an interior frustoconical surface of the flanged tubing head.
[0033] In yet another embodiment, the method further includes connecting a tubing-head adapter to the flanged tubing head to form a seal between the tubing-head adapter and the flanged tubing head. The tubing-head adapter further seals with an elongated neck of the tubing hanger body.
[0034]
Other aspects, features, and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of the inventions disclosed.
Description of the Figures [0035] The accompanying drawings facilitate an understanding of the various embodiments.
[0036] FIG. 1 is a partial cross-sectional elevation view of a wellhead assembly having a coil tubing hanger in accordance with this disclosure.
[0037] FIG. 2 is a cross-sectional side view of the coil tubing hanger.
[0038] FIG. 3 is an exploded perspective view of the coil tubing hanger.
[0039] FIG. 4 is a partial cross-sectional view showing insertion of the tubing hanger body into the tubing head.
[0040] FIG. 5 is a partial cross-sectional view showing insertion of a length of coil tubing and the first slip assembly into the tubing hanger body.
[0041] FIG. 6 is a partial cross-sectional view showing completing the assembly of the coil tubing hanger.
[0042] FIG. 7 is a partial cross-sectional view showing the completely installed coil tubing hanger and forces acting on the coil tubing.
[0043] FIG. 8 is a cross-sectional side view of another coil tubing hanger in accordance with this disclosure.
[0044] FIG. 9 is a cross-sectional side view of a portion of yet another coil tubing hanger in accordance with this disclosure.
[0045] FIG. 10 is a cross-sectional side view of a portion of yet another coil tubing hanger in accordance with this disclosure.
[0046] FIG. 11 is a cross-sectional side view of a portion of yet another coil tubing hanger in accordance with this disclosure.
Detailed Description [0047] FIG. 1 shows a wellhead assembly 10 that includes a wellhead 12 and a Christmas tree 14. The wellhead assembly 10 is merely one example of an apparatus suitable for use with the principles described herein, and other wellhead assemblies having other configurations may also be suitable.
[0048] The wellhead 12 serves as a surface access point to an oil, gas, or other type of well.
The wellhead 12 terminates a casing string 16 and includes a tubing head 18 and a tubing-head adapter 20. Various other casing strings may also be present at the wellhead 12. The tubing head 18 and tubing-head adapter 20 have flanges 22, 24 that are bolted together to removably connect the tubing-head adapter 20 to the tubing head 18. A seal 26 is installed between the flanges 22, 24 to seal against leakage of Well fluid (e.g., crude oil, natural gas) to outside the wellhead 12.
The tubing head 18 further incudes lock screws 28 that extend through the flange 22. The wellhead 12 further includes valves 29 for access to inside the casing 16 to, for example, monitor and control any pressure between the coil tubing 32 and the casing 16.
[0049] A coil tubing hanger 30 is disposed between the tubing head 18 and tubing-head adapter 20. The coil tubing hanger 30 supports at least some of the weight of a string of coil tubing 32 within the wellbore 34 and transfers such weight to the tubing head 18. After the lock screws 28 are engaged, the coil tubing hanger 30 further resists up-hole force on the coil tubing 32, such as force resulting from well pressure or thermal expansion of the coil tubing 32. A
tubing-head seal 36 is provided between the coil tubing hanger 30 and the tubing head 18 and a tubing-head-adapter seal 38 is provided between the coil tubing hanger 30 and the tubing-head adapter 20. The seals 36, 38 seal against leakage of well fluid past the coil tubing hanger 30.
[0050] The Christmas tree 14 is an assembly of valves, spools, pressure gauges, and/or chokes fitted to the wellhead 12 to control production. The Christmas tree 14 includes one or more master valves 40 situated up-hole of the coil tubing hanger 30. Christmas trees, of which the Christmas tree 14 is an example, typically have an inside diameter smaller than the inside diameter of the tubing head 18.
[0051] As shown in FIG. 2, the coil tubing hanger 30 includes a tubing hanger body 50 having an axial bore 52. The axial bore 52 serves to receive a length of the coil tubing 32 that is to extend into the wellbore 34 (FIG. I). The tubing hanger body 50 is generally axially symmetric about the central axis of the axial bore 52 and is shaped to be received in the tubing head 18. The overall diameter D of the tubing hanger body 50 is less than the inner diameter of the entryway of the flanged tubing head 18, so that at least a portion of the tubing hanger body 50 is accommodated inside the tubing head 18. The tubing hanger body 50 is made of low-alloy steel.
Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
Further, the tubing hanger body 50 is made from a unitary piece of material.
However, the tubing hanger body 50 may be made up of several distinct pieces that are permanently or removably connected.
[0052] The tubing hanger body 50 lacks a thread, which is typically an external thread, for thread-connecting to a component of the Christmas tree 14, such as the master valve 40. The tubing hanger body 50 also lacks a flange for bolt-connecting to a component of the Christmas tree 14. Lack of such a thread and flange may advantageously reduce the complexity of the tubing hanger body 50 and may reduce make-up time required at the well-site.
While such a thread or flange may still be provided to the tubing hanger body 50, such thread or flange is not required, as will be apparent from this disclosure.
[0053] The tubing hanger body 50 includes a seal-carrying portion 54, a support portion 56, and an elongated neck 58. The seal-carrying portion 54 is situated at the down-hole end of tubing hanger body 50, the elongated neck 58 is situated at the up-hole end opposite the down-hole end, and the support portion 56 is located between the seal-carrying portion 54 and the elongated neck 58. The term "end" designates a general location and is not limited to an extremity. Further, while the terms "down-hole" and "up-hole" refer to directions apparent when the coil tubing hanger is installed on a wellhead, these terms are equally applicable when the coil tubing hanger or components thereof are removed from the wellhead and/or loose and unassembled, such as in a shop environment. The terms "down-hole" and "up-hole" are not otherwise limiting.
[0054] The seal-carrying portion 54 is narrow enough to extend as far into the tubing head 18 and into the wellhead as needed, and the elongated neck 58 is narrow enough to fit within the tubing-head adapter 20. The support portion 56 is wider than each of the seal-carrying portion 54 and the elongated neck 58, and defines the overall diameter D of the tubing hanger body 50.
[0055] The seal-carrying portion 54 accommodates a coil-tubing seal 60 that will be discussed in detail below.
[0056] The support portion 56 includes an exterior bearing surface 62 that is shaped to bear against an interior frustoconical surface 64 of the tubing head 18. The exterior bearing surface 62 is frustoconical in shape, converging in the down-hole direction, and transfers weight of the coil tubing 32 from the tubing hanger body 50 to the tubing head 18. The exterior bearing surface 62 may have other shapes that are capable of bearing onto the down-hole converging interior frustoconical surface 64 of the tubing head 18. The exterior bearing surface 62 is also shaped to accommodate the tubing-head seal 36 to provide for sealing contact with the interior surface 64 of the flanged tubing head 18. The tubing-head seal 36 includes one or more 0-rings 66 positioned in grooves 68 formed in the exterior bearing surface 62. In addition to or as an alternative to 0-rings, another type of seal and seal material may be used. In addition, the exterior bearing surface 62 is a uniform surface that serves both bearing and seal-carrying functions. However, any shape of exterior surface may be provided to the tubing hanger body 50 to serve these functions, including a surface having discrete changes in shape or curvature (e.g., two adjacent frustoconical surfaces having different slopes). Moreover, a separate sealing surface may be used, so that the exterior bearing surface 62 is not used for sealing (see FIG. 10).
[0057] An up-hole end of the support portion 56 includes one to more contact surfaces 70 for abutting the ends of the engaged lock screws 28, which securely hold the tubing hanger body 50 in the tubing head 18 against up-hole forces. The one to more contact surfaces 70 include a frustoconical surface of shape complementary to the shape of the ends of the lock screws 28. The tubing hanger body 50 and thus the coil tubing hanger 30 can be removed from the tubing head 18 when the lock screws 28 are disengaged. The one to more contact surfaces 70 may have other shapes, such as recesses shaped to fit the ends of the lock screws 28.
[0058] The elongated neck 58 of the tubing hanger body 50 has a sealing surface 72 and extends from the support portion 56 in an up-hole direction that is opposite the exterior bearing surface 62 and seal-carrying portion 54. The elongated neck 58 and sealing surface 72 are shaped to accommodate the tubing-head-adapter seal 38 for sealing contact with the tubing-head adapter 20. The tubing-head-adapter seal 38 includes one or more 0-rings 74 positioned in grooves 76 formed in the sealing surface 72 of the elongated neck 58. In addition to or as an alternative to 0-rings, another type of seal and seal material may be used.
[0059] The coil tubing hanger 30 further includes two opposing slip assemblies 80, 90 disposed within the axial bore 52 of the tubing hanger body 50. The slip assemblies 80, 90 are opposed in the sense that one of the slip assemblies 80, 90 is oriented to restrain movement of coil tubing in a down-hole direction, while the oppositely oriented other of the slip assemblies 80, 90 restrains movement of coil tubing in an up-hole direction. The slip assemblies 80, 90 are otherwise identical. However, the slip assemblies 80, 90 may be different.
[0060] The two opposing slip assemblies 80, 90 include a first slip assembly 80 and a second slip assembly 90. The second slip assembly 90 is disposed within the tubing hanger body 50 at a position up-hole of the first slip assembly 80. However, the second slip assembly 90 may be located down-hole of the first slip assembly 80. Each of the slip assemblies 80, 90 is engaged by contact with a respective slip bowl 88, 98 that receives the slip assembly 80, 90. The slip assemblies 80, 90 and slip bowls 88, 98 are made of low-alloy steel. Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
[0061] The first slip assembly 80 includes a plurality of slip pieces 82. Each slip piece 82 has an exterior slip surface in the shape of a frustoconical sector. The exterior slip surfaces of the slip pieces 82 contact a complementary surface 100 of the inside of the first slip bowl 88. Axial compressive force acting on of the slip pieces 82 is translated into lateral force by the first slip bowl 88, so as to urge interior teeth 84 of each slip piece 82 to bite into the outside of the length of coil tubing extending through the bore 52. The slip pieces 82 are held together by cap screws 86, which permit limited lateral movement of the slip pieces 82 with respect to each other. The slip pieces 82 are oriented to bite into the length of coil tubing 32 to restrain movement of the length of coil tubing 32 in the down-hole direction.
[0062] Similarly, the second slip assembly 90 includes a plurality of slip pieces 92. Each slip piece 92 has an exterior slip surface in the shape of a frustoconical sector.
The exterior slip surfaces of the slip pieces 92 contact a complementary surface 102 of the inside of the second slip bowl 98. Axial compressive force acting on of the slip pieces 92 is translated into lateral force by the second slip bowl 98, so as to urge interior teeth 94 of each slip piece 92 to bite into the outside of the length of coil tubing extending through the bore 52. The slip pieces 92 are held together by cap screws 96, which permit limited lateral movement of the slip pieces 92 with respect to each other. The slip pieces 92 are oriented to bite into the length of coil tubing 32 to restrain movement of the length of coil tubing 32 in the up-hole direction.
[0063]
The opposing first and second slip assemblies 80, 90 can advantageously restrain the coil tubing 32 against both weight of the coil tubing 32 in the wellbore and against up-hole force, such as force due to pressure or thermal expansion of the coil tubing 32.
[0064] The coil tubing hanger 30 further includes a junk ring 110 positioned between the first slip assembly 80 and the second slip assembly 90. Each slip piece 82, 92 has a back surface 111, 113 shaped as an annular segment. The junk ring 110 distributes force between the back surfaces 111 of the first slip pieces 82 and the back surfaces 113 of the second slip pieces 92 allowing force to be transmitted between the first and second slip assemblies 80, 90.
The junk ring 110 is made of low-alloy steel. Other suitable material, such as high-alloy steel, polymer, or ceramic, may additionally or alternatively be used.
[0065] The coil-tubing seal 60 is disposed within the axial bore 52 of the tubing hanger body 50 at a location down-hole of the first and second slip assemblies 80, 90. The coil-tubing seal 60 is a resiliently deformable elastomer. The coil-tubing seal 60 is made from synthetic rubber (e.g., butyl rubber, nitrile rubber, etc.). The coil-tubing seal 60 is generally shaped as a hollow cylinder and has an inside surface 112 that acts to seal against leakage of wellbore fluid between the tubing hanger body 50 and the length of coil tubing 32. The coil-tubing seal 60 may additionally or alternatively be made from natural rubber, silicone rubber, or similar material.
[0066] The coil-tubing seal 60 is aligned with the first slip bowl 88 and abuts the first slip bowl 88, which allows transfer of axially compressive force from the first slip bowl 88 to the coil-tubing seal 60 to urge the coil-tubing seal 60 into sealing contact with the length of coil tubing 32. Thus, at least a portion of the weight of the coil tubing 32 is carried by the first slip assembly 80 and transferred to the first slip bowl 88 and further to the coil-tubing seal 60, which deforms into sealing contact with the length of coil tubing 32. For assembly purposes, an up-hole end of the coil-tubing seal 60 engages a back end of the first slip bowl 88 with a mating ring 114 fitted into complementary detents in overlapping diameters of the coil-tubing seal 60 and the back end of the first slip bowl 88.
[0067] A hollow cylindrical end piece 116 engages with a down-hole end of the coil-tubing seal 60 with a mating ring 118 fitted into complementary detents in overlapping diameters of the down-hole end of the coil-tubing seal 60 and the cylindrical end piece 116.
The end piece 116 directly abuts a shoulder 120 inside the tubing hanger body 50 to support the coil-tubing seal 60 against weight of the coil tubing 32 as transferred from the first slip assembly 80 and the first slip bowl 88. That is, the coil-tubing seal 60 is seated against the shoulder 120 by way of the end piece 116. The cylindrical end piece 116 is made of low-alloy steel. Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
[0068] The tubing hanger body 50 includes one or more fluid channels 124 to distribute pressure supplied by hydraulic fluid to an outside surface 128 of the coil-tubing seal 60 to assist in deforming the coil-tubing seal 60 into sealing contact with the coil tubing 32. The one or more fluid channels 124 are in fluid communication with a space behind the coil-tubing seal 60 and have ports that are closed by plugs 126 when not in use. A hydraulic pump or other apparatus can be connected to one or more of the ports to pressurize the coil-tubing seal 60 to supplement any sealing effect attained from weight of the coil tubing 32.
[0069] Sealing against leakage behind the coil-tubing seal 60 is realized by a seal between the first slip bowl 88 and the inside surface 130 of the tubing hanger body 50 and a seal between the cylindrical end piece 116 and the inside surface 130 of the tubing hanger body 50. Such seals include 0-rings 132, 134 disposed in grooves of external surfaces of the first slip bowl 88 and cylindrical end piece 116. In addition to or as an alternative to 0-rings, another type of seal and seal material may be used.
100701 The coil tubing hanger 30 further includes a gland nut 140 that is threadably connectable to the tubing hanger body 50 via mating threads 142. The gland nut 140 is located at a position up-hole of the first and second slip assemblies 80, 90. The gland nut 140 includes an end surface 144 that contacts a back surface 146 of the first slip bowl 88 to apply compressive force when the gland nut 140 is tightened. The compressive force is transmitted to the second slip assembly 90 to cause the second slip assembly 90 to grip the length of coil tubing to restrain the coil tubing against up-hole forces. Compressive force from the gland nut 140 is further transmitted from the second slip assembly 90 to the first slip assembly 80 to increase the grip of the first slip assembly 80 onto the coil tubing 32 to supplement any coil weight-induced gripping effect. Compressive force from the gland nut 140 is also further transmitted from the first slip assembly 80 to the coil-tubing seal 60 to supplement any coil weight-induced sealing effect of the coil-tubing seal 60. That is, the gland nut 140 axially compresses the axially aligned first and second slip assemblies 80, 90 and coil-tubing seal 60 to provide or increase gripping and sealing of the coil tubing 32.
100711 The first slip bowl 88, the coil-tubing seal 60, and the end piece 116 are axially aligned and mutually connected into a seal assembly is held in position inside the tubing hanger body 50 by a snap-ring 148.
100721 As shown in the exploded view of FIG. 3, the seal assembly 150 is pre-assembled before insertion into the tubing hanger body 50. Pre-assembling the first slip bowl 88, the coil-tubing seal 60, and the end piece 116 into the seal assembly 150 can reduce the time require for installation at the well-site and can also protect the coil-tubing seal 60 from damage.
[0073] Also shown in FIG. 3 is one of the flat contact surfaces 152 of the junk ring 110 that contacts respective back surfaces 111, 113 of the first and second slip assemblies 80, 90.
[0074] FIGs. 4 ¨ 7 show a method of running coil tubing into a well using the coil tubing hanger 30.
[0075] As shown in FIG. 4, the lock screws 28 of the flanged tubing head 18 are retracted. Then, the tubing hanger body 50, with the seal assembly 150 installed, is inserted into the flanged tubing head 18 using, for example, a hydraulic press having a threaded lifting pipe 160 that threads into the tubing hanger body 50. The tubing hanger body 50 is lowered into the flanged tubing head 18 to seat the seal 36 and support the tubing hanger body 50 by landing the exterior bearing surface 62 of the tubing hanger body 50 against the interior frustoconical surface 64 of the flanged tubing head 18.
[0076] As shown in FIG. 5, the lock screws 28 are actuated to secure the tubing hanger body 50 in the flanged tubing head 18. Coil tubing 32 is run through the axial bore of the tubing hanger body 50 and into the well. The first slip assembly 80 is installed around the exposed upper portion of the length of coil tubing 32. The coil tubing 32 with installed first slip assembly 80 is then lowered into the tubing hanger body 50 to land the first slip assembly 80 into the first slip bowl 88, so that the first slip assembly 80 bites into the coil tubing 32 to transfer weight of the coil tubing 32 to the tubing hanger body 50 and thus to the flanged tubing head 18. Weight of the coil tubing 32 also deforms the coil-tubing seal 60 to urge the coil-tubing seal 60 into sealing contact with the coil tubing 32. An installation gland nut, similar to the gland nut 140 (FIG. 2) but with a longer neck, is threaded into the tubing hanger body 50 and tightened to a predetermined torque (e.g., 375 ft-lbs or 508 Nm) to set the coil-tubing seal 60 to a predetermined sealing pressure (e.g., 2000 psi or 13.8 MPa). The installation gland nut is then removed. An example of a gland nut with a lengthened neck for use as the installation gland nut is shown at 172 in FIG. 8.
[0077] As shown in FIG. 6, the junk ring 110 is slid over the upper end of the coil tubing 32, the second slip assembly 90 is installed around the exposed upper portion of the length of coil tubing 32 above the junk ring 110, and the second slip bowl 98 is slid over the upper end of the coil tubing 32. The junk ring 110, second slip assembly 90, and the second slip bowl 98 are lowered into the tubing hanger body 50. The gland nut 140 is slid over the upper end of the coil tubing 32, threaded into the tubing hanger body 50, and tightened so as to compress the second slip assembly 90 to bite into the length of coil tubing, to further compress the first slip assembly 80, and to supplement any weight-induced sealing effect of the coil-tubing seal 60. The gland nut 140 is tightened to a predetermined torque (e.g., 375 ft-lbs or 508 Nm) to ensure that the coil-tubing seal 60 remains at the predetermined sealing pressure (e.g., 2000 psi or 13.8 MPa).
[0078] As shown in FIG. 7, the upper end of the coil tubing 32 is then cut and dressed, and the seal 26 is set into the tubing head 18. The tubing-head adapter 20 is lowered over the elongated neck 58 to effect the seal 38 there-between. The tubing-head adapter 20 is then bolted to the tubing head 18. The space between the seals 26, 36, 38 may then be pressure tested.
[0079] The completed assembly, as shown in FIG. 7, secures the coil tubing 32 against downward force W acting on the coil tubing 32, such as some or all of the weight of the coil tubing 32, as well as up-hole force F acting on the coil tubing 32, such as forces resulting from pressure or thermal expansion of the coil tubing 32.
[0080] The coil tubing hanger 30 fitting within the tubing head 18 and tubing-head adapter 20 may advantageously reduce an overall height of the wellhead assembly. For instance, the Christmas tree 14 (FIG. 1) need not have a separate coil tubing hanger, which conventionally adds to its height. Further, quicker and safer access to the full diameter of the wellbore may be possible. If, for example, well-control intervention is required while the coil tubing 32 is being run into the well, the full diameter of the wellbore is available (e.g., to run plugs, etc.) after lifting the coil tubing hanger 30 from the tubing head 18. Since, the Christmas tree 14 is not yet installed it does not need to be removed, which traditionally takes added time and may require special equipment. Hence, well-site safety can also be improved, in that pressure-control or other intervention can be performed with less delay and with access to the full diameter of the wellbore.
[0081] FIG. 8 shows another coil tubing hanger 170. The coil tubing hanger 170 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 170 and the coil tubing hanger 30 will be discussed in detail.
[0082] The coil tubing hanger 170 includes a gland nut 172. The neck of the gland nut 172 is longer than that of the gland nut 140 (FIG. 2) and terminates at an end surface 144. The coil tubing hanger 170 includes the first slip assembly 80, and omits a second slip assembly, second slip bowl, and junk ring. The end surface 144 of the gland nut 172 bears onto the back surface 111 of the first slip assembly 80.
[0083] The coil tubing hanger 170 holds the coil tubing 32 against its weight, provides a seal against the coil tubing 32, and fits within the tubing head 18 and tubing-head adapter 20. Hence, while the coil tubing hanger 170 is less complex and has fewer parts than the coil tubing hanger 30, the coil tubing hanger 170 retains some of the advantages of the coil tubing hanger 30.
[0084] FIG. 9 shows a portion of yet another coil tubing hanger 180. The coil tubing hanger 180 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 180 and the coil tubing hanger 30 will be discussed in detail.
[0085] Instead of a junk ring, the coil tubing hanger 180 includes a snap ring 182 that fits into a complementary recess 184 in a tubing hanger body 186. The tubing hanger body 186 is otherwise the same as the tubing hanger body 50 (FIG. 2). The snap ring 182 is installed after insertion of the first slip assembly 80 into the tubing hanger body 186. The second slip assembly 90 is installed up-hole of the snap ring 182 and rests on the snap ring 182.
Each opposing face 188 of the snap ring 182 abuts respective back surfaces 111, 113 of the first and second slip assemblies 80, 90 to hold the first and second slip assemblies 80, 90 in place. The snap ring 182 supports compressive force received from the second slip assembly 90, but does not transmit a significant amount of such compressive force to the first slip assembly 80.
Hence, the snap ring 182 isolates forces between the first and second slip assemblies 80, 90. The second slip assembly 90 is set using the gland nut 140 (FIG. 2), and the first slip assembly 80 and coil-tubing seal 60 are set by weight of the coil tubing 32.
[0086] The snap ring 182 is made of low-alloy steel. Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
[0087] The coil tubing hanger 180 holds the coil tubing 32 against its weight and against up-hole force, provides a seal against the coil tubing 32, and fits within the tubing head 18 and tubing-head adapter 20. Hence, the coil tubing hanger 180 retains at least some of the advantages of the coil tubing hanger 30.
[0088] FIG. 10 shows a portion of yet another coil tubing hanger 190. The coil tubing hanger 190 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 190 and the coil tubing hanger 30 will be discussed in detail.
[0089] The coil tubing hanger 190 includes a tubing hanger body 192 having a frustoconical exterior bearing surface 62 that is supported by the interior frustoconical surface 64 of the tubing head 18, as discussed above. A seal 194 is provided between a cylindrical outside surface 196 of the tubing hanger body 192 up-hole of the exterior bearing surface 62. The seal 194 is in sealing contact with a cylindrical inside surface 198 of the tubing head 18, so as to seal against leakage of well fluids up-hole. The seal 194 is made from synthetic rubber (e.g., butyl rubber, nitrile rubber, etc.). However, the seal 194 may alternatively or additionally be made from other material. Further, the seal 194 may take another shape, such as an 0-ring or similar, and may be located in a groove in the outside surface 196. The seal 194 serves the same purpose as the seal 36 (FIG. 2), but at a location different from the exterior bearing surface 62.
[0090] FIG. 11 shows a portion of yet another coil tubing hanger 200. The coil tubing hanger 200 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 200 and the coil tubing hanger 30 will be discussed in detail.
[0091] The coil tubing hanger 200 includes a tubing hanger body 202 having a frustoconical exterior bearing surface 62 that is supported by the interior frustoconical surface 64 of the tubing head 18, as discussed above. Two 0-rings 204 are provided within respective grooves 205 in a cylindrical outside surface 206 of the tubing hanger body 202 up-hole of the exterior bearing surface 62. Each groove 205 has an entryway that is narrower than the interior, so as to retain the 0-ring 204. The 0-rings 204 are in sealing contact with a cylindrical inside surface 208 of the tubing head 18 to seal against leakage of well fluids up-hole. The 0-rings 204 are made from synthetic rubber (e.g., butyl rubber, nitrile rubber, etc.). However, the 0-rings 204 may alternatively or additionally be made from other material or be another type of seal. A number other than two 0-rings 204 and grooves 205 may be provided (e.g., one, three, etc.). The 0-rings 204 serve the same purpose as the seal 36 (FIG. 2), but at a location different from the exterior bearing surface 62.
[0092] As described above, various improved coil tubing hangers are disclosed to overcome drawbacks in the art. The improved coil tubing hangers may have advantages over the prior art, such as resistance to up-hole forces, faster installation, safer installation, reduced wellhead assembly height, and reduced complexity.
[0093] In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "left" and right", "front" and "rear", "above" and "below" and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.
[0094] In this specification, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of'. A corresponding meaning is to be attributed to the corresponding words "comprise", "comprised" and "comprises" where they appear.
[0095] In addition, the foregoing describes only some embodiments of the invention(s), and alterations, modifications, additions and/or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive.
[0096] Furthermore, invention(s) have described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention(s). Also, the various embodiments described above may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments. Further, each independent feature or component of any given assembly may constitute an additional embodiment.
The tubing hanger body further includes an elongated neck at the up-hole end for sealing with a tubing-head adapter. The tubing hanger body further includes a shoulder inside the axial bore at the down-hole end. The coil tubing hanger further includes a first slip assembly disposed within the axial bore. The first slip assembly is oriented to restrain movement of the length of coil tubing in a down-hole direction. The coil tubing hanger further includes a first slip bowl positioned in the axial bore to receive the first slip assembly. The coil tubing hanger further includes a second slip assembly disposed within the axial bore at a position up-hole of the first slip assembly and aligned with the first slip assembly. The second slip assembly is oriented to restrain movement of the length of coil tubing in an up-hole direction. The coil tubing hanger further includes a second slip bowl positioned in the axial bore to receive the second slip assembly.
The coil tubing hanger further includes a junk ring positioned between the first slip assembly and the second slip assembly. The coil tubing hanger further includes a coil-tubing seal disposed within the axial bore of the tubing hanger body and seated against the shoulder at a location down-hole of the first and second slip assemblies in alignment with the first and second slip assemblies. The coil-tubing seal is positioned to receive a compressive force from the first slip assembly due to weight of the coil tubing acting on the first slip assembly. The compressive force causes the coil-tubing seal to deform to seal against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing. The coil tubing hanger further includes a gland nut threadably connected to the tubing hanger body at a position up-hole of the first and second slip assemblies. The gland nut is for applying compressive force to cause at least the second slip assembly to grip the length of coil tubing.
100261 The coil tubing hanger may have the advantage of restraining the coil tubing against both weight of the coil tubing in the wellbore and against up-hole force, such as force due to pressure or thermal expansion of the coil tubing. The coil tubing hanger may further have one or more of the advantages of reducing an overall height and complexity of a wellhead assembly and allowing quicker and safer access to the full diameter of the wellbore if, for example, well control intervention is required.
100271 In certain embodiments, the coil tubing hanger further includes an end piece engaged with the coil-tubing seal. The end piece directly abuts the shoulder to seat and support the coil-tubing seal.
10028] In other certain embodiments, the tubing hanger body further includes at least one fluid channel in fluid communication with a space behind the coil-tubing seal for pressurizing the coil-tubing seal against the coil tubing.
10029] In a fourth aspect, there is provided a method of running coil tubing into a wellbore.
The method includes inserting a tubing hanger body into a flanged tubing head of a wellhead of the well, running the coil tubing through an axial bore of the tubing hanger body and into the wellbore, and providing two opposing slip assemblies around a length of the coil tubing inside the tubing hanger body. The method further includes threading a gland nut into the tubing hanger body to compress at least one slip assembly of the two opposing slip assemblies to grip the length of the coil tubing. The at least one slip assembly is oriented to restrain movement of the coil tubing in an up-hole direction.
[0030] The method may have the advantage of restraining the coil tubing against both weight of the coil tubing in the wellbore and against up-hole force, such as force due to pressure or thermal expansion of the coil tubing. The method may further have one or more of the advantages of reducing an overall height and complexity of a wellhead assembly and allowing quicker and safer access to the full diameter of the wellbore if, for example, well control intervention is required.
[0031] In certain embodiments, the method further includes the gland nut compressing the two opposing slip assemblies and compressing a coil-tubing seal axially aligned with the two opposing slip assemblies.
[0032] In other certain embodiments, inserting the tubing hanger body into the flanged tubing head includes landing an exterior bearing surface of the tubing hanger body against an interior frustoconical surface of the flanged tubing head.
[0033] In yet another embodiment, the method further includes connecting a tubing-head adapter to the flanged tubing head to form a seal between the tubing-head adapter and the flanged tubing head. The tubing-head adapter further seals with an elongated neck of the tubing hanger body.
[0034]
Other aspects, features, and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of the inventions disclosed.
Description of the Figures [0035] The accompanying drawings facilitate an understanding of the various embodiments.
[0036] FIG. 1 is a partial cross-sectional elevation view of a wellhead assembly having a coil tubing hanger in accordance with this disclosure.
[0037] FIG. 2 is a cross-sectional side view of the coil tubing hanger.
[0038] FIG. 3 is an exploded perspective view of the coil tubing hanger.
[0039] FIG. 4 is a partial cross-sectional view showing insertion of the tubing hanger body into the tubing head.
[0040] FIG. 5 is a partial cross-sectional view showing insertion of a length of coil tubing and the first slip assembly into the tubing hanger body.
[0041] FIG. 6 is a partial cross-sectional view showing completing the assembly of the coil tubing hanger.
[0042] FIG. 7 is a partial cross-sectional view showing the completely installed coil tubing hanger and forces acting on the coil tubing.
[0043] FIG. 8 is a cross-sectional side view of another coil tubing hanger in accordance with this disclosure.
[0044] FIG. 9 is a cross-sectional side view of a portion of yet another coil tubing hanger in accordance with this disclosure.
[0045] FIG. 10 is a cross-sectional side view of a portion of yet another coil tubing hanger in accordance with this disclosure.
[0046] FIG. 11 is a cross-sectional side view of a portion of yet another coil tubing hanger in accordance with this disclosure.
Detailed Description [0047] FIG. 1 shows a wellhead assembly 10 that includes a wellhead 12 and a Christmas tree 14. The wellhead assembly 10 is merely one example of an apparatus suitable for use with the principles described herein, and other wellhead assemblies having other configurations may also be suitable.
[0048] The wellhead 12 serves as a surface access point to an oil, gas, or other type of well.
The wellhead 12 terminates a casing string 16 and includes a tubing head 18 and a tubing-head adapter 20. Various other casing strings may also be present at the wellhead 12. The tubing head 18 and tubing-head adapter 20 have flanges 22, 24 that are bolted together to removably connect the tubing-head adapter 20 to the tubing head 18. A seal 26 is installed between the flanges 22, 24 to seal against leakage of Well fluid (e.g., crude oil, natural gas) to outside the wellhead 12.
The tubing head 18 further incudes lock screws 28 that extend through the flange 22. The wellhead 12 further includes valves 29 for access to inside the casing 16 to, for example, monitor and control any pressure between the coil tubing 32 and the casing 16.
[0049] A coil tubing hanger 30 is disposed between the tubing head 18 and tubing-head adapter 20. The coil tubing hanger 30 supports at least some of the weight of a string of coil tubing 32 within the wellbore 34 and transfers such weight to the tubing head 18. After the lock screws 28 are engaged, the coil tubing hanger 30 further resists up-hole force on the coil tubing 32, such as force resulting from well pressure or thermal expansion of the coil tubing 32. A
tubing-head seal 36 is provided between the coil tubing hanger 30 and the tubing head 18 and a tubing-head-adapter seal 38 is provided between the coil tubing hanger 30 and the tubing-head adapter 20. The seals 36, 38 seal against leakage of well fluid past the coil tubing hanger 30.
[0050] The Christmas tree 14 is an assembly of valves, spools, pressure gauges, and/or chokes fitted to the wellhead 12 to control production. The Christmas tree 14 includes one or more master valves 40 situated up-hole of the coil tubing hanger 30. Christmas trees, of which the Christmas tree 14 is an example, typically have an inside diameter smaller than the inside diameter of the tubing head 18.
[0051] As shown in FIG. 2, the coil tubing hanger 30 includes a tubing hanger body 50 having an axial bore 52. The axial bore 52 serves to receive a length of the coil tubing 32 that is to extend into the wellbore 34 (FIG. I). The tubing hanger body 50 is generally axially symmetric about the central axis of the axial bore 52 and is shaped to be received in the tubing head 18. The overall diameter D of the tubing hanger body 50 is less than the inner diameter of the entryway of the flanged tubing head 18, so that at least a portion of the tubing hanger body 50 is accommodated inside the tubing head 18. The tubing hanger body 50 is made of low-alloy steel.
Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
Further, the tubing hanger body 50 is made from a unitary piece of material.
However, the tubing hanger body 50 may be made up of several distinct pieces that are permanently or removably connected.
[0052] The tubing hanger body 50 lacks a thread, which is typically an external thread, for thread-connecting to a component of the Christmas tree 14, such as the master valve 40. The tubing hanger body 50 also lacks a flange for bolt-connecting to a component of the Christmas tree 14. Lack of such a thread and flange may advantageously reduce the complexity of the tubing hanger body 50 and may reduce make-up time required at the well-site.
While such a thread or flange may still be provided to the tubing hanger body 50, such thread or flange is not required, as will be apparent from this disclosure.
[0053] The tubing hanger body 50 includes a seal-carrying portion 54, a support portion 56, and an elongated neck 58. The seal-carrying portion 54 is situated at the down-hole end of tubing hanger body 50, the elongated neck 58 is situated at the up-hole end opposite the down-hole end, and the support portion 56 is located between the seal-carrying portion 54 and the elongated neck 58. The term "end" designates a general location and is not limited to an extremity. Further, while the terms "down-hole" and "up-hole" refer to directions apparent when the coil tubing hanger is installed on a wellhead, these terms are equally applicable when the coil tubing hanger or components thereof are removed from the wellhead and/or loose and unassembled, such as in a shop environment. The terms "down-hole" and "up-hole" are not otherwise limiting.
[0054] The seal-carrying portion 54 is narrow enough to extend as far into the tubing head 18 and into the wellhead as needed, and the elongated neck 58 is narrow enough to fit within the tubing-head adapter 20. The support portion 56 is wider than each of the seal-carrying portion 54 and the elongated neck 58, and defines the overall diameter D of the tubing hanger body 50.
[0055] The seal-carrying portion 54 accommodates a coil-tubing seal 60 that will be discussed in detail below.
[0056] The support portion 56 includes an exterior bearing surface 62 that is shaped to bear against an interior frustoconical surface 64 of the tubing head 18. The exterior bearing surface 62 is frustoconical in shape, converging in the down-hole direction, and transfers weight of the coil tubing 32 from the tubing hanger body 50 to the tubing head 18. The exterior bearing surface 62 may have other shapes that are capable of bearing onto the down-hole converging interior frustoconical surface 64 of the tubing head 18. The exterior bearing surface 62 is also shaped to accommodate the tubing-head seal 36 to provide for sealing contact with the interior surface 64 of the flanged tubing head 18. The tubing-head seal 36 includes one or more 0-rings 66 positioned in grooves 68 formed in the exterior bearing surface 62. In addition to or as an alternative to 0-rings, another type of seal and seal material may be used. In addition, the exterior bearing surface 62 is a uniform surface that serves both bearing and seal-carrying functions. However, any shape of exterior surface may be provided to the tubing hanger body 50 to serve these functions, including a surface having discrete changes in shape or curvature (e.g., two adjacent frustoconical surfaces having different slopes). Moreover, a separate sealing surface may be used, so that the exterior bearing surface 62 is not used for sealing (see FIG. 10).
[0057] An up-hole end of the support portion 56 includes one to more contact surfaces 70 for abutting the ends of the engaged lock screws 28, which securely hold the tubing hanger body 50 in the tubing head 18 against up-hole forces. The one to more contact surfaces 70 include a frustoconical surface of shape complementary to the shape of the ends of the lock screws 28. The tubing hanger body 50 and thus the coil tubing hanger 30 can be removed from the tubing head 18 when the lock screws 28 are disengaged. The one to more contact surfaces 70 may have other shapes, such as recesses shaped to fit the ends of the lock screws 28.
[0058] The elongated neck 58 of the tubing hanger body 50 has a sealing surface 72 and extends from the support portion 56 in an up-hole direction that is opposite the exterior bearing surface 62 and seal-carrying portion 54. The elongated neck 58 and sealing surface 72 are shaped to accommodate the tubing-head-adapter seal 38 for sealing contact with the tubing-head adapter 20. The tubing-head-adapter seal 38 includes one or more 0-rings 74 positioned in grooves 76 formed in the sealing surface 72 of the elongated neck 58. In addition to or as an alternative to 0-rings, another type of seal and seal material may be used.
[0059] The coil tubing hanger 30 further includes two opposing slip assemblies 80, 90 disposed within the axial bore 52 of the tubing hanger body 50. The slip assemblies 80, 90 are opposed in the sense that one of the slip assemblies 80, 90 is oriented to restrain movement of coil tubing in a down-hole direction, while the oppositely oriented other of the slip assemblies 80, 90 restrains movement of coil tubing in an up-hole direction. The slip assemblies 80, 90 are otherwise identical. However, the slip assemblies 80, 90 may be different.
[0060] The two opposing slip assemblies 80, 90 include a first slip assembly 80 and a second slip assembly 90. The second slip assembly 90 is disposed within the tubing hanger body 50 at a position up-hole of the first slip assembly 80. However, the second slip assembly 90 may be located down-hole of the first slip assembly 80. Each of the slip assemblies 80, 90 is engaged by contact with a respective slip bowl 88, 98 that receives the slip assembly 80, 90. The slip assemblies 80, 90 and slip bowls 88, 98 are made of low-alloy steel. Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
[0061] The first slip assembly 80 includes a plurality of slip pieces 82. Each slip piece 82 has an exterior slip surface in the shape of a frustoconical sector. The exterior slip surfaces of the slip pieces 82 contact a complementary surface 100 of the inside of the first slip bowl 88. Axial compressive force acting on of the slip pieces 82 is translated into lateral force by the first slip bowl 88, so as to urge interior teeth 84 of each slip piece 82 to bite into the outside of the length of coil tubing extending through the bore 52. The slip pieces 82 are held together by cap screws 86, which permit limited lateral movement of the slip pieces 82 with respect to each other. The slip pieces 82 are oriented to bite into the length of coil tubing 32 to restrain movement of the length of coil tubing 32 in the down-hole direction.
[0062] Similarly, the second slip assembly 90 includes a plurality of slip pieces 92. Each slip piece 92 has an exterior slip surface in the shape of a frustoconical sector.
The exterior slip surfaces of the slip pieces 92 contact a complementary surface 102 of the inside of the second slip bowl 98. Axial compressive force acting on of the slip pieces 92 is translated into lateral force by the second slip bowl 98, so as to urge interior teeth 94 of each slip piece 92 to bite into the outside of the length of coil tubing extending through the bore 52. The slip pieces 92 are held together by cap screws 96, which permit limited lateral movement of the slip pieces 92 with respect to each other. The slip pieces 92 are oriented to bite into the length of coil tubing 32 to restrain movement of the length of coil tubing 32 in the up-hole direction.
[0063]
The opposing first and second slip assemblies 80, 90 can advantageously restrain the coil tubing 32 against both weight of the coil tubing 32 in the wellbore and against up-hole force, such as force due to pressure or thermal expansion of the coil tubing 32.
[0064] The coil tubing hanger 30 further includes a junk ring 110 positioned between the first slip assembly 80 and the second slip assembly 90. Each slip piece 82, 92 has a back surface 111, 113 shaped as an annular segment. The junk ring 110 distributes force between the back surfaces 111 of the first slip pieces 82 and the back surfaces 113 of the second slip pieces 92 allowing force to be transmitted between the first and second slip assemblies 80, 90.
The junk ring 110 is made of low-alloy steel. Other suitable material, such as high-alloy steel, polymer, or ceramic, may additionally or alternatively be used.
[0065] The coil-tubing seal 60 is disposed within the axial bore 52 of the tubing hanger body 50 at a location down-hole of the first and second slip assemblies 80, 90. The coil-tubing seal 60 is a resiliently deformable elastomer. The coil-tubing seal 60 is made from synthetic rubber (e.g., butyl rubber, nitrile rubber, etc.). The coil-tubing seal 60 is generally shaped as a hollow cylinder and has an inside surface 112 that acts to seal against leakage of wellbore fluid between the tubing hanger body 50 and the length of coil tubing 32. The coil-tubing seal 60 may additionally or alternatively be made from natural rubber, silicone rubber, or similar material.
[0066] The coil-tubing seal 60 is aligned with the first slip bowl 88 and abuts the first slip bowl 88, which allows transfer of axially compressive force from the first slip bowl 88 to the coil-tubing seal 60 to urge the coil-tubing seal 60 into sealing contact with the length of coil tubing 32. Thus, at least a portion of the weight of the coil tubing 32 is carried by the first slip assembly 80 and transferred to the first slip bowl 88 and further to the coil-tubing seal 60, which deforms into sealing contact with the length of coil tubing 32. For assembly purposes, an up-hole end of the coil-tubing seal 60 engages a back end of the first slip bowl 88 with a mating ring 114 fitted into complementary detents in overlapping diameters of the coil-tubing seal 60 and the back end of the first slip bowl 88.
[0067] A hollow cylindrical end piece 116 engages with a down-hole end of the coil-tubing seal 60 with a mating ring 118 fitted into complementary detents in overlapping diameters of the down-hole end of the coil-tubing seal 60 and the cylindrical end piece 116.
The end piece 116 directly abuts a shoulder 120 inside the tubing hanger body 50 to support the coil-tubing seal 60 against weight of the coil tubing 32 as transferred from the first slip assembly 80 and the first slip bowl 88. That is, the coil-tubing seal 60 is seated against the shoulder 120 by way of the end piece 116. The cylindrical end piece 116 is made of low-alloy steel. Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
[0068] The tubing hanger body 50 includes one or more fluid channels 124 to distribute pressure supplied by hydraulic fluid to an outside surface 128 of the coil-tubing seal 60 to assist in deforming the coil-tubing seal 60 into sealing contact with the coil tubing 32. The one or more fluid channels 124 are in fluid communication with a space behind the coil-tubing seal 60 and have ports that are closed by plugs 126 when not in use. A hydraulic pump or other apparatus can be connected to one or more of the ports to pressurize the coil-tubing seal 60 to supplement any sealing effect attained from weight of the coil tubing 32.
[0069] Sealing against leakage behind the coil-tubing seal 60 is realized by a seal between the first slip bowl 88 and the inside surface 130 of the tubing hanger body 50 and a seal between the cylindrical end piece 116 and the inside surface 130 of the tubing hanger body 50. Such seals include 0-rings 132, 134 disposed in grooves of external surfaces of the first slip bowl 88 and cylindrical end piece 116. In addition to or as an alternative to 0-rings, another type of seal and seal material may be used.
100701 The coil tubing hanger 30 further includes a gland nut 140 that is threadably connectable to the tubing hanger body 50 via mating threads 142. The gland nut 140 is located at a position up-hole of the first and second slip assemblies 80, 90. The gland nut 140 includes an end surface 144 that contacts a back surface 146 of the first slip bowl 88 to apply compressive force when the gland nut 140 is tightened. The compressive force is transmitted to the second slip assembly 90 to cause the second slip assembly 90 to grip the length of coil tubing to restrain the coil tubing against up-hole forces. Compressive force from the gland nut 140 is further transmitted from the second slip assembly 90 to the first slip assembly 80 to increase the grip of the first slip assembly 80 onto the coil tubing 32 to supplement any coil weight-induced gripping effect. Compressive force from the gland nut 140 is also further transmitted from the first slip assembly 80 to the coil-tubing seal 60 to supplement any coil weight-induced sealing effect of the coil-tubing seal 60. That is, the gland nut 140 axially compresses the axially aligned first and second slip assemblies 80, 90 and coil-tubing seal 60 to provide or increase gripping and sealing of the coil tubing 32.
100711 The first slip bowl 88, the coil-tubing seal 60, and the end piece 116 are axially aligned and mutually connected into a seal assembly is held in position inside the tubing hanger body 50 by a snap-ring 148.
100721 As shown in the exploded view of FIG. 3, the seal assembly 150 is pre-assembled before insertion into the tubing hanger body 50. Pre-assembling the first slip bowl 88, the coil-tubing seal 60, and the end piece 116 into the seal assembly 150 can reduce the time require for installation at the well-site and can also protect the coil-tubing seal 60 from damage.
[0073] Also shown in FIG. 3 is one of the flat contact surfaces 152 of the junk ring 110 that contacts respective back surfaces 111, 113 of the first and second slip assemblies 80, 90.
[0074] FIGs. 4 ¨ 7 show a method of running coil tubing into a well using the coil tubing hanger 30.
[0075] As shown in FIG. 4, the lock screws 28 of the flanged tubing head 18 are retracted. Then, the tubing hanger body 50, with the seal assembly 150 installed, is inserted into the flanged tubing head 18 using, for example, a hydraulic press having a threaded lifting pipe 160 that threads into the tubing hanger body 50. The tubing hanger body 50 is lowered into the flanged tubing head 18 to seat the seal 36 and support the tubing hanger body 50 by landing the exterior bearing surface 62 of the tubing hanger body 50 against the interior frustoconical surface 64 of the flanged tubing head 18.
[0076] As shown in FIG. 5, the lock screws 28 are actuated to secure the tubing hanger body 50 in the flanged tubing head 18. Coil tubing 32 is run through the axial bore of the tubing hanger body 50 and into the well. The first slip assembly 80 is installed around the exposed upper portion of the length of coil tubing 32. The coil tubing 32 with installed first slip assembly 80 is then lowered into the tubing hanger body 50 to land the first slip assembly 80 into the first slip bowl 88, so that the first slip assembly 80 bites into the coil tubing 32 to transfer weight of the coil tubing 32 to the tubing hanger body 50 and thus to the flanged tubing head 18. Weight of the coil tubing 32 also deforms the coil-tubing seal 60 to urge the coil-tubing seal 60 into sealing contact with the coil tubing 32. An installation gland nut, similar to the gland nut 140 (FIG. 2) but with a longer neck, is threaded into the tubing hanger body 50 and tightened to a predetermined torque (e.g., 375 ft-lbs or 508 Nm) to set the coil-tubing seal 60 to a predetermined sealing pressure (e.g., 2000 psi or 13.8 MPa). The installation gland nut is then removed. An example of a gland nut with a lengthened neck for use as the installation gland nut is shown at 172 in FIG. 8.
[0077] As shown in FIG. 6, the junk ring 110 is slid over the upper end of the coil tubing 32, the second slip assembly 90 is installed around the exposed upper portion of the length of coil tubing 32 above the junk ring 110, and the second slip bowl 98 is slid over the upper end of the coil tubing 32. The junk ring 110, second slip assembly 90, and the second slip bowl 98 are lowered into the tubing hanger body 50. The gland nut 140 is slid over the upper end of the coil tubing 32, threaded into the tubing hanger body 50, and tightened so as to compress the second slip assembly 90 to bite into the length of coil tubing, to further compress the first slip assembly 80, and to supplement any weight-induced sealing effect of the coil-tubing seal 60. The gland nut 140 is tightened to a predetermined torque (e.g., 375 ft-lbs or 508 Nm) to ensure that the coil-tubing seal 60 remains at the predetermined sealing pressure (e.g., 2000 psi or 13.8 MPa).
[0078] As shown in FIG. 7, the upper end of the coil tubing 32 is then cut and dressed, and the seal 26 is set into the tubing head 18. The tubing-head adapter 20 is lowered over the elongated neck 58 to effect the seal 38 there-between. The tubing-head adapter 20 is then bolted to the tubing head 18. The space between the seals 26, 36, 38 may then be pressure tested.
[0079] The completed assembly, as shown in FIG. 7, secures the coil tubing 32 against downward force W acting on the coil tubing 32, such as some or all of the weight of the coil tubing 32, as well as up-hole force F acting on the coil tubing 32, such as forces resulting from pressure or thermal expansion of the coil tubing 32.
[0080] The coil tubing hanger 30 fitting within the tubing head 18 and tubing-head adapter 20 may advantageously reduce an overall height of the wellhead assembly. For instance, the Christmas tree 14 (FIG. 1) need not have a separate coil tubing hanger, which conventionally adds to its height. Further, quicker and safer access to the full diameter of the wellbore may be possible. If, for example, well-control intervention is required while the coil tubing 32 is being run into the well, the full diameter of the wellbore is available (e.g., to run plugs, etc.) after lifting the coil tubing hanger 30 from the tubing head 18. Since, the Christmas tree 14 is not yet installed it does not need to be removed, which traditionally takes added time and may require special equipment. Hence, well-site safety can also be improved, in that pressure-control or other intervention can be performed with less delay and with access to the full diameter of the wellbore.
[0081] FIG. 8 shows another coil tubing hanger 170. The coil tubing hanger 170 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 170 and the coil tubing hanger 30 will be discussed in detail.
[0082] The coil tubing hanger 170 includes a gland nut 172. The neck of the gland nut 172 is longer than that of the gland nut 140 (FIG. 2) and terminates at an end surface 144. The coil tubing hanger 170 includes the first slip assembly 80, and omits a second slip assembly, second slip bowl, and junk ring. The end surface 144 of the gland nut 172 bears onto the back surface 111 of the first slip assembly 80.
[0083] The coil tubing hanger 170 holds the coil tubing 32 against its weight, provides a seal against the coil tubing 32, and fits within the tubing head 18 and tubing-head adapter 20. Hence, while the coil tubing hanger 170 is less complex and has fewer parts than the coil tubing hanger 30, the coil tubing hanger 170 retains some of the advantages of the coil tubing hanger 30.
[0084] FIG. 9 shows a portion of yet another coil tubing hanger 180. The coil tubing hanger 180 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 180 and the coil tubing hanger 30 will be discussed in detail.
[0085] Instead of a junk ring, the coil tubing hanger 180 includes a snap ring 182 that fits into a complementary recess 184 in a tubing hanger body 186. The tubing hanger body 186 is otherwise the same as the tubing hanger body 50 (FIG. 2). The snap ring 182 is installed after insertion of the first slip assembly 80 into the tubing hanger body 186. The second slip assembly 90 is installed up-hole of the snap ring 182 and rests on the snap ring 182.
Each opposing face 188 of the snap ring 182 abuts respective back surfaces 111, 113 of the first and second slip assemblies 80, 90 to hold the first and second slip assemblies 80, 90 in place. The snap ring 182 supports compressive force received from the second slip assembly 90, but does not transmit a significant amount of such compressive force to the first slip assembly 80.
Hence, the snap ring 182 isolates forces between the first and second slip assemblies 80, 90. The second slip assembly 90 is set using the gland nut 140 (FIG. 2), and the first slip assembly 80 and coil-tubing seal 60 are set by weight of the coil tubing 32.
[0086] The snap ring 182 is made of low-alloy steel. Other suitable material, such as high-alloy steel, may additionally or alternatively be used.
[0087] The coil tubing hanger 180 holds the coil tubing 32 against its weight and against up-hole force, provides a seal against the coil tubing 32, and fits within the tubing head 18 and tubing-head adapter 20. Hence, the coil tubing hanger 180 retains at least some of the advantages of the coil tubing hanger 30.
[0088] FIG. 10 shows a portion of yet another coil tubing hanger 190. The coil tubing hanger 190 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 190 and the coil tubing hanger 30 will be discussed in detail.
[0089] The coil tubing hanger 190 includes a tubing hanger body 192 having a frustoconical exterior bearing surface 62 that is supported by the interior frustoconical surface 64 of the tubing head 18, as discussed above. A seal 194 is provided between a cylindrical outside surface 196 of the tubing hanger body 192 up-hole of the exterior bearing surface 62. The seal 194 is in sealing contact with a cylindrical inside surface 198 of the tubing head 18, so as to seal against leakage of well fluids up-hole. The seal 194 is made from synthetic rubber (e.g., butyl rubber, nitrile rubber, etc.). However, the seal 194 may alternatively or additionally be made from other material. Further, the seal 194 may take another shape, such as an 0-ring or similar, and may be located in a groove in the outside surface 196. The seal 194 serves the same purpose as the seal 36 (FIG. 2), but at a location different from the exterior bearing surface 62.
[0090] FIG. 11 shows a portion of yet another coil tubing hanger 200. The coil tubing hanger 200 is similar to the coil tubing hanger 30 discussed above. Like reference numerals designate like parts. Only differences between the coil tubing hanger 200 and the coil tubing hanger 30 will be discussed in detail.
[0091] The coil tubing hanger 200 includes a tubing hanger body 202 having a frustoconical exterior bearing surface 62 that is supported by the interior frustoconical surface 64 of the tubing head 18, as discussed above. Two 0-rings 204 are provided within respective grooves 205 in a cylindrical outside surface 206 of the tubing hanger body 202 up-hole of the exterior bearing surface 62. Each groove 205 has an entryway that is narrower than the interior, so as to retain the 0-ring 204. The 0-rings 204 are in sealing contact with a cylindrical inside surface 208 of the tubing head 18 to seal against leakage of well fluids up-hole. The 0-rings 204 are made from synthetic rubber (e.g., butyl rubber, nitrile rubber, etc.). However, the 0-rings 204 may alternatively or additionally be made from other material or be another type of seal. A number other than two 0-rings 204 and grooves 205 may be provided (e.g., one, three, etc.). The 0-rings 204 serve the same purpose as the seal 36 (FIG. 2), but at a location different from the exterior bearing surface 62.
[0092] As described above, various improved coil tubing hangers are disclosed to overcome drawbacks in the art. The improved coil tubing hangers may have advantages over the prior art, such as resistance to up-hole forces, faster installation, safer installation, reduced wellhead assembly height, and reduced complexity.
[0093] In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "left" and right", "front" and "rear", "above" and "below" and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.
[0094] In this specification, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of'. A corresponding meaning is to be attributed to the corresponding words "comprise", "comprised" and "comprises" where they appear.
[0095] In addition, the foregoing describes only some embodiments of the invention(s), and alterations, modifications, additions and/or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive.
[0096] Furthermore, invention(s) have described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention(s). Also, the various embodiments described above may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments. Further, each independent feature or component of any given assembly may constitute an additional embodiment.
Claims (24)
1. A coil tubing hanger comprising:
a tubing hanger body including an axial bore for receiving a length of coil tubing that is to extend into a wellbore;
a first slip assembly disposed within the axial bore of the tubing hanger body, the first slip assembly oriented to restrain movement of the length of coil tubing in a down-hole direction;
and a second slip assembly disposed within the axial bore of the tubing hanger body, the second slip assembly oriented to restrain movement of the length of coil tubing in an up-hole direction.
a tubing hanger body including an axial bore for receiving a length of coil tubing that is to extend into a wellbore;
a first slip assembly disposed within the axial bore of the tubing hanger body, the first slip assembly oriented to restrain movement of the length of coil tubing in a down-hole direction;
and a second slip assembly disposed within the axial bore of the tubing hanger body, the second slip assembly oriented to restrain movement of the length of coil tubing in an up-hole direction.
2. The coil tubing hanger of claim 1 further comprising a junk ring positioned between the first slip assembly and the second slip assembly, the junk ring for distributing force between the first slip assembly and the second slip assembly.
3. The coil tubing hanger of claim 1 or 2 further comprising a coil-tubing seal disposed within the axial bore of the tubing hanger body at a location down-hole of the first and second slip assemblies, the coil-tubing seal for sealing against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing.
4. The coil tubing hanger of claim 3 further comprising a first slip bowl positioned to receive the first slip assembly, the first slip bowl aligned with the coil-tubing seal for transferring compressive force to the coil-tubing seal to urge the coil-tubing seal into sealing contact with the length of coil tubing.
5. The coil tubing hanger of any one of claims 1 to 4 further comprising a gland nut threadably connectable to the tubing hanger body at a position up-hole of the first and second slip assemblies, the gland nut for applying compressive force to at least the second slip assembly to cause the second slip assembly to grip the length of coil tubing.
6. The coil tubing hanger of claim 5 further comprising a second slip bowl positioned to receive the second slip assembly and to receive the compressive force from the gland nut.
7. The coil tubing hanger of any one of claims 1 to 6 wherein the second slip assembly is disposed within the tubing hanger body at a position up-hole of the first slip assembly.
8. The coil tubing hanger of any one of claims 1 to 7 wherein the tubing hanger body is shaped to be received in a flanged tubing head of a wellhead of the wellbore.
9. The coil tubing hanger of claim 8 wherein the tubing hanger body includes an exterior bearing surface shaped to bear against an interior frustoconical surface of the flanged tubing head.
10. The coil tubing hanger of claim 9, wherein the exterior bearing surface of the tubing hanger body is shaped to accommodate a tubing-head seal for sealing with the flanged tubing head.
11. The coil tubing hanger of claim 9, wherein the tubing hanger body includes an elongated neck, the elongated neck including a surface that is shaped to accommodate a tubing-head-adapter seal for sealing with a tubing-head adapter.
12. A coil tubing hanger comprising:
a tubing hanger body including an axial bore for receiving at least one slip assembly for gripping a length of coil tubing that is to extend into a wellbore, the axial bore further for receiving a coil-tubing seal for sealing against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing;
the tubing hanger body being shaped to be received in a flanged tubing head of a wellhead of the wellbore, the tubing hanger body including an exterior bearing surface shaped to bear against an interior frustoconical surface of the flanged tubing head to transfer weight of the coil tubing to the flanged tubing head.
a tubing hanger body including an axial bore for receiving at least one slip assembly for gripping a length of coil tubing that is to extend into a wellbore, the axial bore further for receiving a coil-tubing seal for sealing against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing;
the tubing hanger body being shaped to be received in a flanged tubing head of a wellhead of the wellbore, the tubing hanger body including an exterior bearing surface shaped to bear against an interior frustoconical surface of the flanged tubing head to transfer weight of the coil tubing to the flanged tubing head.
13. The coil tubing hanger of claim 12 wherein the exterior bearing surface of the tubing hanger body includes at least one groove to accommodate a tubing-head seal for sealing with the interior frustoconical surface of the flanged tubing head.
14. The coil tubing hanger of claim 12 or 13 wherein the exterior bearing surface is frustoconical in shape.
15. The coil tubing hanger of any one of claims 12 to 14 wherein the tubing hanger body further includes an elongated neck extending opposite the exterior bearing surface, the elongated neck including a surface including at least one groove to accommodate a tubing-head-adapter seal for sealing with a tubing-head adapter.
16. The coil tubing hanger of any one of claims 12 to 15 wherein the tubing hanger body is shaped to receive two opposing slip assemblies and two respective slip bowls.
17. The coil tubing hanger of any one of claims 12 to 16 wherein an up-hole end of the tubing hanger body includes a thread for receiving a gland nut and a down-hole end of the tubing hanger body includes a shoulder for seating the coil-tubing seal.
18. A coil tubing hanger comprising:
a tubing hanger body including an up-hole end, a down-hole end, and axial bore for receiving a length of coil tubing that is to extend into a wellbore, the tubing hanger body being shaped to be received in a flanged tubing head of a wellhead of the wellbore and including an exterior surface for bearing against and sealing with an interior frustoconical surface of the flanged tubing head, the tubing hanger body further including an elongated neck at the up-hole end for sealing with a tubing-head adapter, the tubing hanger body further including a shoulder inside the axial bore at the down-hole end;
a first slip assembly disposed within the axial bore, the first slip assembly oriented to restrain movement of the length of coil tubing in a down-hole direction;
a first slip bowl positioned in the axial bore to receive the first slip assembly;
a second slip assembly disposed within the axial bore at a position up-hole of the first slip assembly and aligned with the first slip assembly, the second slip assembly oriented to restrain movement of the length of coil tubing in an up-hole direction;
a second slip bowl positioned in the axial bore to receive the second slip assembly;
a junk ring positioned between the first slip assembly and the second slip assembly;
a coil-tubing seal disposed within the axial bore of the tubing hanger body and seated against the shoulder at a location down-hole of the first and second slip assemblies in alignment with the first and second slip assemblies, the coil-tubing seal positioned to receive a compressive force from the first slip assembly due to weight of the coil tubing acting on the first slip assembly, the compressive force causing the coil-tubing seal to deform to seal against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing;
and a gland nut threadably connected to the tubing hanger body at a position up-hole of the first and second slip assemblies, the gland nut for applying compressive force to cause at least the second slip assembly to grip the length of coil tubing.
a tubing hanger body including an up-hole end, a down-hole end, and axial bore for receiving a length of coil tubing that is to extend into a wellbore, the tubing hanger body being shaped to be received in a flanged tubing head of a wellhead of the wellbore and including an exterior surface for bearing against and sealing with an interior frustoconical surface of the flanged tubing head, the tubing hanger body further including an elongated neck at the up-hole end for sealing with a tubing-head adapter, the tubing hanger body further including a shoulder inside the axial bore at the down-hole end;
a first slip assembly disposed within the axial bore, the first slip assembly oriented to restrain movement of the length of coil tubing in a down-hole direction;
a first slip bowl positioned in the axial bore to receive the first slip assembly;
a second slip assembly disposed within the axial bore at a position up-hole of the first slip assembly and aligned with the first slip assembly, the second slip assembly oriented to restrain movement of the length of coil tubing in an up-hole direction;
a second slip bowl positioned in the axial bore to receive the second slip assembly;
a junk ring positioned between the first slip assembly and the second slip assembly;
a coil-tubing seal disposed within the axial bore of the tubing hanger body and seated against the shoulder at a location down-hole of the first and second slip assemblies in alignment with the first and second slip assemblies, the coil-tubing seal positioned to receive a compressive force from the first slip assembly due to weight of the coil tubing acting on the first slip assembly, the compressive force causing the coil-tubing seal to deform to seal against leakage of wellbore fluid between the tubing hanger body and the length of coil tubing;
and a gland nut threadably connected to the tubing hanger body at a position up-hole of the first and second slip assemblies, the gland nut for applying compressive force to cause at least the second slip assembly to grip the length of coil tubing.
19. The coil tubing hanger of claim 18 further comprising an end piece engaged with the coil-tubing seal, the end piece directly abutting the shoulder to seat and support the coil-tubing seal.
20. The coil tubing hanger of claim 18 or 19 wherein the tubing hanger body further comprises at least one fluid channel in fluid communication with a space behind the coil-tubing seal for pressurizing the coil-tubing seal against the coil tubing.
21. A method of running coil tubing into a wellbore, the method comprising:
inserting a tubing hanger body into a flanged tubing head of a wellhead of the well;
running the coil tubing through an axial bore of the tubing hanger body and into a wellbore;
providing two opposing slip assemblies around a length of the coil tubing inside the tubing hanger body; and threading a gland nut into the tubing hanger body to compress at least one slip assembly of the two opposing slip assemblies to grip the length of the coil tubing, the at least one slip assembly being oriented to restrain movement of the coil tubing in an up-hole direction.
inserting a tubing hanger body into a flanged tubing head of a wellhead of the well;
running the coil tubing through an axial bore of the tubing hanger body and into a wellbore;
providing two opposing slip assemblies around a length of the coil tubing inside the tubing hanger body; and threading a gland nut into the tubing hanger body to compress at least one slip assembly of the two opposing slip assemblies to grip the length of the coil tubing, the at least one slip assembly being oriented to restrain movement of the coil tubing in an up-hole direction.
22. The method of claim 21 further comprising the gland nut compressing the two opposing slip assemblies and compressing a coil-tubing seal axially aligned with the two opposing slip assemblies.
23. The method of claim 21 or 22 wherein inserting the tubing hanger body into the flanged tubing head comprises landing an exterior bearing surface of the tubing hanger body against an interior frustoconical surface of the flanged tubing head.
24. The method of any one of claims 21 to 23 further comprising connecting a tubing-head adapter to the flanged tubing head to form a seal between the tubing-head adapter and the flanged tubing head, the tubing-head adapter further sealing with an elongated neck of the tubing hanger body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2865382A CA2865382C (en) | 2014-09-26 | 2014-09-26 | Coil tubing hanger |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2865382A CA2865382C (en) | 2014-09-26 | 2014-09-26 | Coil tubing hanger |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2865382A1 true CA2865382A1 (en) | 2016-03-26 |
| CA2865382C CA2865382C (en) | 2020-09-01 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2865382A Active CA2865382C (en) | 2014-09-26 | 2014-09-26 | Coil tubing hanger |
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| Country | Link |
|---|---|
| CA (1) | CA2865382C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107989566A (en) * | 2018-01-12 | 2018-05-04 | 科莱斯（天津）电热科技有限公司 | A kind of high-pressure well mouth T cables hanger sealing connection mechanism |
| CN108086937A (en) * | 2018-01-12 | 2018-05-29 | 科莱斯（天津）电热科技有限公司 | A kind of high-pressure well mouth hanger controls total valve gear |
| CN117328826A (en) * | 2023-12-01 | 2024-01-02 | 大庆辰平钻井技术服务有限公司 | Pipeline well dropping prevention device and ultra-short radius horizontal well completion method |
| CN117684905A (en) * | 2023-12-27 | 2024-03-12 | 廊坊市长青石油管件有限公司 | Oil head pipe four-way joint and wellhead device |
-
2014
- 2014-09-26 CA CA2865382A patent/CA2865382C/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107989566A (en) * | 2018-01-12 | 2018-05-04 | 科莱斯（天津）电热科技有限公司 | A kind of high-pressure well mouth T cables hanger sealing connection mechanism |
| CN108086937A (en) * | 2018-01-12 | 2018-05-29 | 科莱斯（天津）电热科技有限公司 | A kind of high-pressure well mouth hanger controls total valve gear |
| CN117328826A (en) * | 2023-12-01 | 2024-01-02 | 大庆辰平钻井技术服务有限公司 | Pipeline well dropping prevention device and ultra-short radius horizontal well completion method |
| CN117328826B (en) * | 2023-12-01 | 2024-02-20 | 大庆辰平钻井技术服务有限公司 | Pipeline well dropping prevention device and ultra-short radius horizontal well completion method |
| CN117684905A (en) * | 2023-12-27 | 2024-03-12 | 廊坊市长青石油管件有限公司 | Oil head pipe four-way joint and wellhead device |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2865382C (en) | 2020-09-01 |
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| EEER | Examination request |
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