The present disclosure relates generally to wellheads and specifically to sealing devices for wellheads.
When completing a well, a wellhead is positioned at the surface to support and seal against various tools. Typically, a section of liner or casing, known as a tieback string, is positioned into the wellbore coupled between a liner hanger within the wellbore and the wellhead once the liner hanger is installed and cemented. The tieback string is typically sealingly coupled to the wellhead. However, because the tieback string extends at least partially through the wellhead, the seals of the wellhead may be exposed to fluids within the annulus of the wellbore. In some cases, corrosive or otherwise reactive chemicals from within the wellbore may come into contact with the wellhead, potentially damaging components of the wellhead including the wellhead seals. Such damage may necessitate costly repairs or may cause an unsafe environment due to the risk of failure of one or more components of the wellhead.
The present disclosure provides for an isolation sleeve. The isolation sleeve may include a sleeve body and a torque sleeve, the torque sleeve threadedly coupled to the sleeve body. The torque sleeve may include a compression shoulder. The isolation sleeve may further include a compression seal positioned about the torque sleeve between the compression shoulder and the sleeve body. The isolation sleeve may further include a lock ring coupled to the sleeve body. The lock ring may be urged into engagement with the packoff by an energizing ring.
The present disclosure also provides for a wellhead. The wellhead may include a wellhead housing coupled to a wellbore at the surface. The wellhead may further include a casing coupled to the wellhead housing, the casing extending into the wellbore. The wellhead may further include a packoff positioned within the wellhead housing. The wellhead may further include an isolation sleeve. The isolation sleeve may include a sleeve body positioned within the packoff and a torque sleeve, the torque sleeve threadedly coupled to the sleeve body. The torque sleeve may include a compression shoulder. The isolation sleeve may further include a compression seal positioned about the torque sleeve between the compression shoulder and the sleeve body, the compression seal sealingly engaging the casing. The isolation sleeve may further include a lock ring coupled to the sleeve body. The lock ring may engage the packoff and may be urged into engagement with the packoff by an energizing ring.
The present disclosure also provides for an isolation sleeve. The isolation sleeve may include a sleeve body and a torque sleeve, the torque sleeve threadedly coupled to the sleeve body. The torque sleeve may include a compression shoulder. The isolation sleeve may further include a compression seal positioned about the torque sleeve between the compression shoulder and the sleeve body. The isolation sleeve may further include a seal ring positioned about the sleeve body. The isolation sleeve may further include an upper body seal positioned between the seal ring and the sleeve body.
The present disclosure also provides for a wellhead. The wellhead may include a wellhead housing coupled to a wellbore at the surface. The wellhead may further include one or more lockscrews threadedly coupled to and extending radially through the wall of the wellhead housing. The wellhead may further include a casing coupled to the wellhead housing, the casing extending into the wellbore. The wellhead may further include an isolation sleeve. The isolation sleeve may include a sleeve body positioned within the wellhead housing and a torque sleeve, the torque sleeve threadedly coupled to the sleeve body. The torque sleeve may include a compression shoulder. The isolation sleeve may further include a compression seal positioned about the torque sleeve between the compression shoulder and the sleeve body, the compression seal sealingly engaging the casing. The isolation sleeve may further include a seal ring positioned about the sleeve body, the seal ring in engagement with the lockscrews. The isolation sleeve may further include an upper body seal positioned between the seal ring and the sleeve body.
The present disclosure also provides for a method. The method may include positioning a casing within a wellbore, coupling a wellhead housing to the wellbore and to the casing, and providing an isolation sleeve. The isolation sleeve may include a sleeve body positioned within the packoff and a torque sleeve threadedly coupled to the sleeve body. The torque sleeve may include a compression shoulder. The isolation sleeve may include a compression seal positioned about the torque sleeve between the compression shoulder and the sleeve body. The method may further include inserting the isolation sleeve into the wellhead housing such that the compression seal is positioned within the casing, rotating the torque sleeve relative to the sleeve body, and compressing the compression seal along the direction of travel of the torque sleeve.
The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
As shown in
In some embodiments, isolation sleeve 100 may include one or more isolation seals 103 positioned to abut between sleeve body 101 and packoff 35. In other embodiments, one or more isolation seals 103 may be positioned on packoff 35 without deviating from the scope of this disclosure.
Isolation sleeve 100 may include one or more antirotation features positioned to engage with one or more corresponding antirotation features of packoff 35. For example, in some embodiments, isolation sleeve 100 may include one or more antirotation pins 105 positioned to engage slots 36 formed in packoff 35 once isolation sleeve 100 is installed to wellhead 10. Antirotation pins 105 may fit into slots 36 such that rotational forces applied to isolation sleeve 100 are transferred to wellhead 10 via antirotation pins 105, thereby reducing or preventing relative rotation between sleeve body 101 and wellhead 10. In some embodiments, antirotation pins 105 may be spring-loaded.
In some embodiments, isolation sleeve 100 may include compression seal 107. Compression seal 107 may be positioned to seal against the inner surface of casing 45 when actuated as further described herein below. Compression seal 107 may be annular and may be formed from an elastomer.
In some embodiments, isolation sleeve 100 may include torque sleeve 109. Torque sleeve 109 may be tubular or generally tubular and may be used, as described herein below, to set isolation sleeve 100 in the set position. Torque sleeve 109 may threadedly couple to lower end 101b of sleeve body 101. Compression seal 107 may be positioned about torque sleeve 109. Torque sleeve 109 may include compression shoulder 111 positioned to abut compression seal 107. When in a run-in configuration as shown in
In some embodiments, isolation sleeve 100 may include one or more positive stop features 113 positioned to, for example and without limitation, prevent torque sleeve 109 from fully disengaging from sleeve body 101, thereby reducing the likelihood that torque sleeve 109 is inadvertently fully disengaged from sleeve body 101. Positive stop features 113 may include one or more of, for example and without limitation, bolts, pins, protrusions, or detents.
In some embodiments, torque sleeve 109 may include one or more rotation slots 115. Rotation slots 115 may be used to engage torque sleeve 109 to a torque tool as further discussed below such that the torque tool can rotate torque sleeve 109.
In some embodiments, isolation sleeve 100 may include one or more lock features positioned to allow isolation sleeve 100 to be locked to wellhead 10. For example and without limitation, in some embodiments, isolation sleeve 100 may include lock ring 117. Lock ring 117 may be annular and may be coupled to sleeve body 101 such that lock ring 117 corresponds with the position of lock groove 37 of packoff 35 when isolation sleeve 100 is installed to wellhead 10. In some such embodiments, isolation sleeve 100 may further include energizing ring 119. Energizing ring 119 may, during a locking operation as further described herein below, be urged between sleeve body 101 and lock ring 117 such that lock ring 117 is urged radially outward and into engagement with lock groove 37 of packoff 35, thereby retaining isolation sleeve 100 to wellhead 10. In some embodiments, one or more retention features may be positioned between energizing ring 119 and sleeve body 101 to retain energizing ring 119 and lock ring 117 in the unlocked position until locking is desired. For example, in some embodiments, one or more shear pins 121 may be so positioned.
In some embodiments, sleeve body 101 may include upper threaded receiver 123 positioned to allow other tools to threadedly couple to the upper end of isolation sleeve 100. In some embodiments, sleeve body 101 may include landing shoulder 125 positioned to engage with packoff 35 when isolation sleeve 100 is fully inserted into wellhead 10.
In other embodiments, as shown in
Isolation sleeve 100 may be installed to wellhead 10 originally or may be installed to wellhead 10 during an intervention into operations of wellbore 15. For example,
To install isolation sleeve 100 to wellhead 10, wellhead 10 is at least partially dismantled and tieback string 50 is removed therefrom. Depending on the configuration of wellhead 10, the operations required to dismantle wellhead 10 may vary from those discussed herein. The following discussion is intended to be exemplary and other configurations of wellhead 10 are contemplated within the scope of this disclosure.
For example, in some embodiments, during such a replacement operation, back pressure valve (BPV) 52 may be installed to tieback string 50 as shown in
Tieback string 50 may be disengaged from wellhead housing 25. In some embodiments, as shown in
Once tieback lock ring 56 is disengaged from lock groove 37, tieback string 50 may be removed from wellhead 10 and wellbore 15 as shown in
In other embodiments, such as described with respect to wellhead 10′ above, tieback string 50 may be released from wellhead 10′ by disengaging lockscrews 117′ and removing tieback string 50.
In some embodiments, once tieback string 50 is removed from wellhead 10, isolation sleeve 100 may be inserted into wellhead 10 as shown in
In some embodiments, mandrel 153 may include lower threaded connection 161 adapted to threadedly engage tubular members positioned within wellhead 10 including, for example and without limitation, isolation sleeve body 101 such that rotation of mandrel 153 may allow engagement between actuation sleeve 155 and lock ring 117.
As shown in
Isolation sleeve 100 may be inserted into wellhead 10 until landing shoulder 125 engages packoff 35. In some embodiments, isolation sleeve 100 may be locked to wellhead 10. For example, in some embodiments, running tool 151 may be rotated such that mandrel 153 urges actuation sleeve 155 into abutment with energizing ring 119. In some embodiments, rotation of running tool 151 may cause rotation of isolation sleeve 100 relative to wellhead 10. In some such embodiments, isolation sleeve 100 may rotate until antirotation pins 105 engage slots 36, at which point antirotation pins 105 may reduce or prevent further rotation of isolation sleeve 100. Further rotation of running tool 151 may cause energizing ring 119 to move such that lock ring 117 is urged radially outward and into engagement with lock groove 37 of packoff 35 as shown on the left side of
In other embodiments in which isolation sleeve 100′ is locked to wellhead 10′ using lockscrews 117′, isolation sleeve 100′ may be inserted to wellhead 10′ while lockscrews 117′ are in a disengaged position as shown in
Once isolation sleeve 100 is locked to wellhead 10, one or more pressure tests of wellhead 10 may be undertaken including, for example and without limitation, testing of seals 40 and 103 (or 120′).
Compression seal 107 may then be engaged to casing 45. In some embodiments, torque tool 171 may be positioned within isolation sleeve 100 as shown in
As shown in
In some embodiments, each torque dog 177 may include flat sidewall 183. Flat sidewall 183 may be positioned to engage rotation slots 115 of torque sleeve 109 as further discussed below. In some embodiments, each torque dog 177 may include tapered upper surface 185. Tapered upper surface 185 may, for example and without limitation, allow torque dog 177 to be urged radially into torque tool body 175 by torque sleeve 109 as torque tool 171 is moved longitudinally upward and torque dogs 177 move out of alignment with rotation slots 115, thereby allowing torque tool 171 to be removed from isolation sleeve 100 as further discussed below.
With reference to
In some embodiments, as torque sleeve 109 is rotated, torque sleeve 109 is further threadedly engaged to sleeve body 101, causing compression seal 107 to be compressed along the axis of isolation sleeve 100 as shown in
Torque tool 171 may then be removed from isolation sleeve 100 by moving longitudinally upward as tapered upper surface 185 of each torque dog 177 allows torque dogs 177 to be urged radially inward and are thereby allowed to escape from rotation slots 115 of torque sleeve 109. BOP 22 may then be removed and tubing head 20 may be replaced to wellhead housing 25 as shown in
In some embodiments, isolation sleeve 100, 100′ may be adapted to be installed into wellhead 10, 10′ without any other modifications to wellhead 10, 10′, thereby allowing isolation sleeve 100, 100′ to be retrofitted into an existing wellhead 10, 10′.
One of ordinary skill in the art with the benefit of this disclosure will understand that isolation sleeve 100 may be installed to wellhead 10 without having to first remove any components including, for example, tieback string 50. Such operations are merely examples of operations that may be undertaken before isolation sleeve 100 is installed to wellhead 10.
Additionally, in some embodiments, isolation sleeve 100 may be uninstalled from wellhead 10 by, for example and without limitation, substantially reversing the above-described operations.
The foregoing outlines features of several embodiments so that a person of ordinary skill in the art may better understand the aspects of the present disclosure. Such features may be replaced by any one of numerous equivalent alternatives, only some of which are disclosed herein. One of ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. One of ordinary skill in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
This application is a nonprovisional application which claims priority from U.S. provisional application No. 63/013,421, filed Apr. 21, 2020, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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63013421 | Apr 2020 | US |