NON-ROTATING MECHANICALLY ENHANCED AND PASSIVELY PRELOADED CONNECTION FOR OILFIELD EQUIPMENT

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This Non-Provisional patent application is related to and claims the benefit of priority from U.S. Provisional Application No. 63/439,996, titled “NON-ROTATING MECHANICALLY ENHANCED AND PASSIVELY PRELOADED CONNECTION FOR OILFIELD EQUIPMENT,” filed on Jan. 19, 2023, and incorporated by reference herein in its entirety for all intents and purposes.

BACKGROUND

1. Technical Field

This disclosure relates generally to oilfield equipment and more particularly to systems and methods for tubular coupling associated with non-rotating, mechanically enhanced, and passively preloaded connection for oilfield equipment.

2. Description of the Prior Art

Oilfield equipment, such as a wellhead for methane hydrate exploration and production may be associated with features to suspend tubing, such as production tubing. A connection profile may need to be machined within a restricted region on a bottom of a wellhead adapter that is associated with the wellhead and that is for suspending the production tubing. The connection profile may use a premium threading geometry, such as from a premium connection, that may be complex to machine. The complexity is even more the case because of the features to enable such a connection profile being recessed within a large diameter block of the wellhead adapter where there may be limited real-estate due to close proximity restrictions to accommodate other features. Further, the connection profile may require a predetermined torque and/or rotational process to achieve a required graphing characteristics, which may be used to verify an acceptable connection. Still further, the torque requirement may pertain to weight and physical geometry limitations of the equipment to be torqued.

SUMMARY

In at least one embodiment, a system for oilfield equipment includes a wellhead adapter to be associated with a wellhead of the oilfield equipment and to include a tapered spool having thereon a tapered sleeve that is secured on the tapered spool by a retention mechanism. The tapered sleeve is to be loaded between the tapered spool and the wellhead adapter. The tapered spool is to enable coupling of a tubing to the wellhead adapter.

In at least one embodiment, a method to couple tubing in oilfield equipment includes providing a wellhead adapter to be associated with a wellhead of the oilfield equipment and to comprise a tapered spool having thereon a tapered sleeve that is secured on the tapered spool by a retention mechanism. The method includes installing the tapered spool within the wellhead adapter with the tapered sleeve loaded between the tapered spool and the wellhead adapter, where the tapered spool includes a tubing coupled thereto.

BRIEF DESCRIPTION OF DRAWINGS

Some of the features and benefits of the present disclosure having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of certain oilfield equipment that is subject to systems and methods for coupling of tubing therein, in accordance with at least one embodiment.

FIG. 2 is a cross-section view of aspects of a system for coupling of tubing in oilfield equipment, in accordance with at least one embodiment.

FIG. 3 is a cross-section detail view of further aspects of a system for coupling of tubing in oilfield equipment, in accordance with at least one embodiment.

FIG. 4 is a cross-section view of aspects of a tapered spool with a tapered sleeve and a retention mechanism prior to engagement of such features for coupling of tubing in oilfield equipment, in accordance with at least one embodiment.

FIG. 5 illustrates cross-section view of further aspects of a tapered spool with a tapered sleeve and a retention mechanism for coupling of tubing in oilfield equipment, in accordance with at least one embodiment.

FIG. 6 is a flow diagram of a method for a system that is described at least in FIGS. 1-5 herein, in accordance with at least one embodiment.

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

DETAILED DESCRIPTION

The foregoing aspects, features and advantages of the present technology will be further appreciated when considered with reference to the following description of preferred embodiments and accompanying drawings, wherein like reference numerals represent like elements. In describing the preferred embodiments of the technology illustrated in the appended drawings, specific terminology will be used for the sake of clarity. The present technology, however, is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.

In at least one embodiment, to resolve issues described above to improve reliability of systems and methods for coupling of tubing in oilfield equipment, a non-rotational passive preload connection is described that enables production tubing, casing, or other tubular sections to be assembled in oilfield equipment with low torque. Further, the low torque is only applied to a retention mechanism of the system herein, in part, during installation of the system. In at least one embodiment, low torque as used herein may be in reference to a range of torque required to account for different tubing sizes and material grades. In at least one embodiment, a range from about 300 to about 1,200 foot-pounds (ft. lbs) of torque represents a low torque used for the retention mechanism of the system herein, whereas a range of about 4,000 to about 50,000 ft. lbs of torque is required for premium connections.

The passive preload applied to the system herein is optimized further during application of an axial or internal pressure load, so as to provide a second preload that will be higher than a first preload applied during, in part, the installation of the system. In at least one embodiment, a primary resolved load that is part of a first preload may be reacted through a main body of the system to minimize radial deflections in the system that may be caused by sectional bulk at a connection location. In one example, a ‘socketing’ action for the connection can optimize bending loads of a spool that may react through the connection in the wellhead adapter.

In at least one embodiment, the system herein can address issues previously noted, such to removal of a need for premium connections that are proprietary connections. Such premium connections may require thread-machining that may be complex and limited to number of times a system having such premium connections may be assembled or disassembled prior to requiring recuts, repair, or scrapping of one of more components.

In at least one embodiment, the system herein allows for multiple assembly and disassembly to be achieved due to individual machined components having tapered interfacing surfaces that may be installed together and that may be disassembled for reuse. Further, the use of individual machined components themselves lends a benefit of ease of replacement of one or more of such individual machined components, if any become unserviceable.

In at least one embodiment, mechanical advantages are also offered by the system herein via at least a tapered interface between a tapered sleeve and a tapered spool. The tapered interface allows a passive preload over an initial preload, as the system is loaded and at least as the tapered sleeve is loaded. In at least one embodiment, additional features of the system herein that may be from the tapered interface include a self-locking characteristic using an initial preload that is sufficient for retention of the tapered sleeve and tapered spool within the system. This can enhance connection fatigue performance that such components may endure.

In at least one embodiment, approaches using the system herein can address issues of applying full preload to a connection during initial assembly itself and, thereafter, relying on preload retention to mitigate separation. The system herein may also incorporate a wicker profile to one or more of the tapered interfaces to provide additional axial load capacity and incorporation of metal to metal (MS) sealing. In at least one embodiment, an anti-rotation feature of the tapered spool is provided to be within a receiving feature of the wellhead adapter to prevent rotation of the tapered spool when coupling further tubing to the tapered spool. Therefore, the system herein provides a non-rotating, mechanically enhanced, and passively preloaded connection for oilfield equipment.

In at least one embodiment, the system herein addresses issues from machining requirements of the premium connection that was required in a wellhead adapter and, instead, uses a spool (also referred to herein as a production spool piece) that can be secured within the wellhead adapter by an industry standard (non-premium) thread and allows coupling of tubing to the spool. In at least one embodiment, the system herein therefore also removes high torqueing requirement at installation time for the spool, where the high torqueing applied to installation of the spool to the wellhead adapter. Furthermore, thread repair or recuts and recesses of a connection made using the high torqueing requirement are addressed by the system herein. Instead, the spool of the system herein can be torqued up to a saver sub using standard (non-premium connections) and using standard (non-premium) capabilities of torqueing tools prior to assembly into the wellhead adapter.

In at least one embodiment, the saver sub contains premium connections. The saver sub may be made up to a bottom end of the tapered spool prior to assembly into the wellhead adapter. This enables the saver sub to be a lowest premium connection to be made up to the production tubing or casing and can save multiple assembly or disassembly requirements otherwise if the tapered spool were to be provided with a premium connection to the saver sub. Additionally, thread repair is more affordable using the approaches herein due to smaller diameter geometry of the saver sub.

In at least one embodiment, the system and method herein may be used on a wellhead adapter or in other applications requiring replacement of a premium connection that is associated with a tubular connection and that therefore requires rotational assembly. For example, the system and method herein may be used in tubing hangers, casing hangers, and riser joints, where some of these aspects may be suspended within a subsea tree, a wellhead, a tubing spool, or a rig, to provide a replacement for a respective premium connection therein.

FIG. 1 is a block diagram of certain oilfield equipment 100 that is subject to systems and methods for coupling of tubing therein, in accordance with at least one embodiment. The oilfield equipment 100 may include a Christmas tree 130 over a wellhead 120 located at or about a surface or subsea layer 140. Valves for operations to be performed for the wellhead 120 and for the underlying conductor string 114 may be included on one or more branches 102 of the oilfield equipment 100. The valves may control the production tubing 118B or annulus between the production tubing 118B and an outer tubing 118A. However, the system and method for coupling tubing may be used within the Christmas tree 130 instead of a wellhead adapter 110, within a tubing hanger suspended within a bore of the Christmas tree 130, or within a subsea wellhead or tubing spool.

Further, as illustrated in FIG. 1, the oilfield equipment 100 may include a top connector 112 that is connected at a top of a studded cross 104. There may be multiple flow line gate valves and multiple kill line gate valves, generally illustrated as valves 106. These valves 106 may be on opposite sides of a studded cross 104. Further, the oilfield equipment 100 may include one or more master gate valves 108, such as an upper and a lower master gate valve. A wellhead adapter 110 may be connected between the studded cross 104 and at least one of the master gate valves 108. In at least one embodiment, there may be multiple casings or tubing 116, 118 within the bore 114 that may be subject a system and method for coupling within the oilfield equipment 100 herein.

FIG. 2 is a cross-section view of aspects 200 of a system for coupling of tubing in oilfield equipment, in accordance with at least one embodiment. The system for oilfield equipment 100 includes wellhead adapter 110 that is to be associated with a wellhead 120 of the oilfield equipment 100. The system including the wellhead adapter 110 allows for coupling of a production tubing 118B therefrom using a saver sub 204 that is coupled to a tapered spool 208 using a coupling 206. In at least one embodiment, an isolation sleeve is associated with the wellhead adapter 110. The isolation sleeve seals on an internal diameter of the wellhead and provides a secondary barrier during usage of the system in the oilfield equipment, which is described further in connection with FIG. 3.

In at least one embodiment, an isolation sleeve can be retained within the wellhead adapter 110. A passive preload connection interface may be provided within the tapered spool 302, thereby negating a requirement for a further premium thread connection. The wellhead adapter 110 includes an axial passage 202. In at least one embodiment, the components herein, unless stated otherwise, such as the tapered spool 208, the tapered sleeve 304, and the retention mechanism 306 are annular features around the axial passage 202. The tapered sleeve 304 may be a tapered collet that is either a single piece construction or an individual tapered collet.

FIG. 3 cross-section detail view of further aspects 300 of a system for coupling of tubing in oilfield equipment, in accordance with at least one embodiment. In FIG. 3, the system for coupling a tubing 118B is coupled to a tapered spool 302 that further includes thereon a tapered sleeve 304. The tapered sleeve 304 is secured on the tapered spool 302 by a retention mechanism 306. The retention mechanism 306 may be a barrel nut that is threaded on an outside to interface with the wellhead adapter 110. Retention mechanism (barrel nut) 306 slides axially on the tapered production spool 302. In at least one embodiment, when the retention mechanism 306 is a barrel nut, the barrel nut includes threading on its outer diameter to engage into a body of the wellhead adapter 110. Further, an isolation sleeve may be provided in the system. The isolation sleeve may be a larger diameter sleeve to provide a larger through-bore with an additional pressure retaining boundary prior to a primary pressure-containing seal between a wellhead adapter or Christmas tree and the wellhead.

In at least one embodiment, the tapered spool 302 may be installed within the wellhead adapter 110. The tapered sleeve 304 can be loaded between the tapered spool 302 and the wellhead adapter 110. For example, the load is an axial load from passive preloading of the system. Separately, the load is additionally an axial or internal pressure load of the system in operation with the wellhead 120. For example, the internal pressure load is contained within the production tubing and/or contained within the wellhead casing strings. Further, a primary resolved load from the passive preloading is reacted through the wellhead adapter 110 and minimizes radial deflections that may otherwise occur in the system. In at least one embodiment, the tapered spool 302 enables coupling of tubing 118B from the wellhead adapter 110.

FIG. 3 also illustrates that a first portion 302A of the tapered spool 302 can be within the wellhead adapter 110. However, a second portion 302B of the tapered spool 302 can protrude from the wellhead adapter 110. The saver sub 204 may be associated with the second portion 302B of the tapered spool 302 via a coupling 206. At least one tubing 118B may be suspended or coupled to a lowest connection point 212 of the saver sub 206. In at least one embodiment, FIG. 3 also illustrates that independent seals 308 provided between the wellhead adapter 110 and the tapered spool 302. Non-premium threading is provided on the retention mechanism 306 to engage with the wellhead adapter 110 when the tapered spool 302 is installed in the wellhead adapter 110. This enables installing of the tapered spool 302 within the wellhead adapter 110 with its first portion 302A within the wellhead adapter 110.

In at least one embodiment, an anti-rotation feature 310 of the tapered spool is provided to be within a receiving feature 312 of the wellhead adapter 110. For example, the anti-rotation feature 310 is one or more protrusions that extend into one or more spaces, where the spaces collectively represent the receiving feature 312. The anti-rotation feature 310 of the tapered spool 302 can prevent rotation of the tapered spool 301 during installation of the wellhead adapter and the tubing. In at least one embodiment, tapped holes 314 can facilitate removal of a tapered sleeve 304 if a resistance to disassembly occurs in the system.

In at least one embodiment, FIG. 3 illustrates that texture or textured surface may be provided on an outside circumference 316 of the tapered sleeve 304. The texture may be wicker geometry on the tapered sleeve 304. In at least one embodiment, the texture can provide additional axial capacity for the system for coupling a tubing but can also support incorporation of a metal-to-metal seal having wicker geometry to create metal-to-metal seal. The texture can engage an inner surface of the wellhead adapter 110.

In at least one embodiment, FIG. 3 illustrates that a gap 320 may be provided between a top of the tapered sleeve 304 and a shoulder portion of the wellhead adapter 110. For example, the gap 320 supports axial translation, while accommodating machining tolerances. The gap 320 ensures that the tapered spool 302 can bottom-out or mate with a shoulder on the wellhead adapter 110. The gap 320 can enable the tapered sleeve 304 to be disassembled from the wellhead adapter 110 when disconnecting the tapered sleeve 304 in the system for coupling of the tubing in the oilfield equipment. In at least one embodiment, the isolation sleeve is associated with the wellhead adapter 110 by a flange or other coupling between the two.

In at least one embodiment, FIG. 4 is a cross-section view of aspects 400 of a tapered spool with a tapered sleeve and a retention mechanism prior to engagement of such features for coupling of tubing in oilfield equipment, in accordance with at least one embodiment. FIG. 4 illustrates that the retention mechanism 306 is associated with the tapered sleeve 304 on the tapered spool 302 before the tapered spool 302 is made up in the wellhead adapter 110.

FIG. 4 illustrates that a tapered spool 302 may have a tapered portion 402B having tapered outer surface 402 and may have a linear portion 402A, 402C. Further, FIG. 4 illustrates that the tapered spool 302 includes a shoulder 404 to engage with a mating surface of the wellhead adapter 110, as illustrated in part in FIG. 3. At least one of the liner portions, such as the top portion 402A may be a plain section for sealing purposes. Further, non-premium threading may be provided on the retention mechanism 306 to enable the securing of the first portion 302A of the tapered spool within the wellhead adapter 110, with a remaining (second) portion 302B protruding from the wellhead adapter 110.

FIG. 5 illustrates cross-section view of further aspects 500 of a tapered spool 302 with a tapered sleeve 304 and a retention mechanism 306 for coupling of tubing in oilfield equipment, in accordance with at least one embodiment. The aspects 500 include that the tapered spool 302 includes a tapered portion 402B and a linear portion 402C, both illustrated in part in FIG. 5. Further, the aspects 500 include slots 502 on the tapered sleeve 304 to allow elastic deflection of the tapered sleeve 304. For example, the elastic deflection may be based in part on the tapered sleeve 304 being under loads between the tapered spool 302 and the wellhead adapter 110. For example, the tapered spool 302 is to receive a first preload during installation and is to receive a second preload during operation, where the second preload is higher than the first preload.

In at least one embodiment, a tapered inner surface 504 of the tapered sleeve 304 forms a tapered interface with the tapered outer surface 402 of the tapered spool 302. In at least one embodiment, a retention mechanism 306 may be a barrel nut that may include external threads and allows the barrel nut to be threaded against threads on an inside of the wellhead adapter 110. This allows the tapered sleeve 304 to be located as far up 506 the tapered spool 302, with the barrel nut threaded up 508 to secure the tapered sleeve 304 in its position once the position is reached within the wellhead adapter 110. In at least one embodiment, the end of a threading on the wellhead adapter 110 defines a limit for movement of the retention mechanism 306.

With the tapered sleeve 304 and securing mechanism 306 in position, a saver sub or other crossover adapter 204 may be associated with the tapered spool 302 for coupling of tubing 118B from the tapered spool 302. The tapered spool 302 with its tubing 118B may be made up within the wellhead adapter 110. Further, with the wellhead adapter 110 made up, an isolation sleeve may be added for usage of the system having all such aspects in the oilfield equipment.

FIG. 6 is a flow diagram of a method 600 for a system that is described at least in FIGS. 1-5 herein, in accordance with at least one embodiment. The method 600 is for coupling tubing in oilfield equipment. The method 600 includes providing (602) a wellhead adapter to be associated with a wellhead of the oilfield equipment. The method 600 includes enabling (604) a tapered spool be within the wellhead adapter and to include thereon a tapered sleeve that is secured on the tapered spool by a retention mechanism. The enabling (604) step may include threading a retention mechanism within the wellhead adapter to initially preload the tapered surfaces of the tapered spool and the tapered sleeve, for instance. For example, the tapered sleeve translates vertically and is free to slide until contacting a mating surface, linear or tapered surface, of the tapered spool. Separately, retention of the tapered sleeve in the tapered spool may be achieved during assembly of the tapered spool with the tapered sleeve in the wellhead adapter.

A verification (606) may be performed to ensure that the tapered sleeve is ready for installation in the wellhead adapter. In at least one embodiment, the verification (606) may include ensuring that a predetermined position for the retention mechanism is reached or that a predetermined first (or initial) preload for the tapered sleeve is reached. The method 600 includes installing (608) the tapered spool within the wellhead adapter, with the tapered sleeve loaded between the tapered spool and the wellhead adapter, wherein the tapered spool includes at least one tubing coupled thereto.

In at least one embodiment, the at least one tubing may be coupled to the tapered spool via the saver sub in the method 600. Such a tubing may be coupled to the tapered spool via a saver sub that is therefore between the tapered spool and the tubing where a requirement for the tubing coupled to the tapered spool may be part of the verification (606) before the tapered spool can be installed in the wellhead adapter. However, the use of the tapered spool and tapered sleeve allows for coupling of tubing after the tapered spool is installed in the wellhead adapter via the saver sub, so long as the saver sub extends from the isolation sleeve.

In at least one embodiment, the method 600 includes providing a first portion of the tapered sleeve to be within the wellhead adapter. The method 600 includes a further step or sub-step for allowing a second portion of the tapered sleeve to protrude from the wellhead adapter. The saver sub can be associated with the second portion of the tapered sleeve. The method 600 includes a further step or sub-step for providing non-premium threading on the retention mechanism to enable the securing of the first portion of the spool within the wellhead adapter.

The method 600 includes a further step or sub-step for providing slots on the tapered sleeve to allow an elastic deflection the tapered sleeve. The elastic deflection may be based in part on the tapered sleeve being under loads between the tapered spool and the wellhead adapter. The method 600 includes a further step or sub-step for providing an anti-rotation feature of the tapered spool to be within a receiving feature of the wellhead adapter. The anti-rotation feature of the tapered spool can prevent rotation of the tapered spool during installation of the wellhead adapter and the tubing. The method 600 includes a further step or sub-step for providing texture on an outside circumference of the tapered sleeve to allow the tapered sleeve to engage an inner surface of the wellhead adapter.

The method 600 includes a further step or sub-step for providing a gap between a top of the tapered sleeve a shoulder portion of the wellhead adapter. The gap can enable the tapered sleeve to be disassembled from the wellhead adapter during changing out any of the components used in the system herein. The method 600 includes a further step or sub-step for associating an isolation sleeve with the wellhead adapter. The method 600 includes a further step or sub-step for providing the tapered spool with a first preload during installation. The method 600 includes a further step or sub-step for allowing the tapered spool to receive a second preload during operation. The second preload may be higher than the first preload.

While techniques herein may be subject to modifications and alternative constructions, these variations are within spirit of present disclosure. As such, certain illustrated embodiments are shown in drawings and have been described above in detail, but these are not limiting disclosure to specific form or forms disclosed; and instead, cover all modifications, alternative constructions, and equivalents falling within spirit and scope of disclosure, as defined in appended claims.

When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments. Additionally, it should be understood that references to “one embodiment”, “an embodiment”, “certain embodiments,” or “other embodiments” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, reference to terms such as “above,” “below,” “upper”, “lower”, “side”, “front,” “back,” or other terms regarding orientation are made with reference to the illustrated embodiments and are not intended to be limiting or exclude other orientations.

Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within range, unless otherwise indicated herein and each separate value is incorporated into specification as if it were individually recited herein. In at least one embodiment, use of a term, such as a set (for a set of items) or subset unless otherwise noted or contradicted by context, is understood to be nonempty collection including one or more members. Further, unless otherwise noted or contradicted by context, term subset of a corresponding set does not necessarily denote a proper subset of corresponding set, but subset and corresponding set may be equal.

Conjunctive language, such as phrases of form, at least one of A, B, and C, or at least one of A, B and C, unless specifically stated otherwise or otherwise clearly contradicted by context, is otherwise understood with context as used in general to present that an item, term, etc., may be either A or B or C, or any nonempty subset of set of A and B and C. In at least one embodiment of a set having three members, conjunctive phrases, such as at least one of A, B, and C and at least one of A, B and C refer to any of following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of A, at least one of B and at least one of C each to be present. In addition, unless otherwise noted or contradicted by context, terms such as plurality, indicates a state of being plural (such as, a plurality of items indicates multiple items). In at least one embodiment, a number of items in a plurality is at least two but can be more when so indicated either explicitly or by context. Further, unless stated otherwise or otherwise clear from context, phrases such as based on means based at least in part on and not based solely on.

In at least one embodiment, even though the above discussion provides at least one embodiment having implementations of described techniques, other architectures may be used to implement described functionality, and are intended to be within scope of this disclosure. In addition, although specific responsibilities may be distributed to components and processes, they are defined above for purposes of discussion, and various functions and responsibilities might be distributed and divided in different ways, depending on circumstances.

In at least one embodiment, although subject matter has been described in language specific to structures and/or methods or processes, it is to be understood that subject matter claimed in appended claims is not limited to specific structures or methods described. Instead, specific structures or methods are disclosed as example forms of how a claim may be implemented.

From all the above, a person of ordinary skill would readily understand that the tool of the present disclosure provides numerous technical and commercial advantages and can be used in a variety of applications. Various embodiments may be combined or modified based in part on the present disclosure, which is readily understood to support such combination and modifications to achieve the benefits described above.

It should be appreciated that embodiments herein may utilize one or more values that may be experimentally determined or correlated to certain performance characteristics based on operating conditions under similar or different conditions. The present disclosure described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the disclosure has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art and are intended to be encompassed within the spirit of the present disclosure disclosed herein and the scope of the appended claims.