Patent Publication Number: US-2021189823-A1

Title: Rotational Lock for Mating Wellhead Components

Description:
BACKGROUND OF THE DISCLOSURE 
     Wellheads use casing hangers inside casing heads to support tubing strings in a well. One problem that has existed for some time is how to hold a tubing string and internal features (e.g., hanger, pack-off, etc.) of the wellhead stationary relative to one another during installation operations. Historically, rotational stops have been used to hold the tubing string and internal features in place. The rotational stops include mechanisms such as hardened pins, spring/pawl mechanisms, spring loaded pins, splines, keyways, and threaded connections. All of these mechanisms require the elements to be axially and/or rotationally aligned to function. Any need to make such alignments complicates installation steps in which large components must be lifted and placed to construct the wellhead. 
     The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above. 
     SUMMARY OF THE DISCLOSURE 
     A component of the present disclosure is used for a wellhead having a throughbore with a tubing component disposed therein. The component comprises a body and at least one canted spring. The body positions in the throughbore of the wellhead. The body defines a bore therethrough, and the bore defines at least one groove thereabout. The bore is disposed at least partially on the tubing component. The at least one canted spring is disposed in the at least one groove and is engaged between the at least one groove and the tubing component. The at least one canted spring restricts rotation of the body relative to the tubing in at least one direction. 
     The body can further comprise: an internal seal disposed in the bore and sealing against the tubing component; and an external seal disposed about the body and sealing against the throughbore of the wellhead. The bore can define a shoulder engaging a distal end of the tubing component. For example, the body can comprise a pack-off. Accordingly, the component can further include a slip hanger disposed in the throughbore of the wellhead on the tubing component below the pack-off. 
     The at least one groove can have a number of variations. For example, the groove can define a backwall divided at an angle and engaging coils of the at least one canted spring at two points. The groove can define a groove width configured relative to a coil width to at least partially define the engagement of the at least one canted spring between the at least one groove and the tubing component. The groove can define a groove depth that is configured relative to the internal and outer dimensions of the canted spring to at least partially define the engagement of the at least one canted spring between the at least one groove and the tubing component. 
     In one particular implementation, a component for a wellhead having a throughbore with a tubing component disposed therein comprises a body and first and second canted springs. As before, the body positions in the throughbore of the wellhead and defines a bore therethrough to at least partially position on the tubing component. The bore defines at first and second grooves thereabout in which first and second canted springs are disposed in the first groove. The springs are engaged between the grooves and the tubing component and preventing rotation of the body relative to the tubing component in opposing directions. 
     The coils of the first canted spring can define a first pitch; and the coils of the second canted spring can define a second pitch orientated opposite to the first pitch. The two pitches can be the same or different from one another. 
     According to the present disclosure, a wellhead for tubing comprises a wellhead component defining a throughbore with the tubing passing at partially therethrough. A body with at least one canted spring as details previously can position in the throughbore of the wellhead and can be disposed at least partially on the tubing. 
     According to the present disclosure, an apparatus comprises first and second components and at least one canted spring. The first component has an outer surface, while the second component defines a bore therethrough and positioning at least partially on the outer surface of the first component. Either the outer surface, the bore, or both define at least one groove thereabout for the at least one canted spring. 
     A method is disclosed of assembling a wellhead having tubing inside a throughbore. At least one canted spring is positioned in at least one groove defined in a bore of a wellhead component, and the bore of the wellhead component is positioned at least partially on the tubing inside the throughbore of the wellhead. The at least one canted spring is engaged between the at least one groove and the tubing, and rotation of the wellhead component and the tubing is restricted relative to one another in at least one direction with the engagement of the at least one canted spring. In positioning the bore of the wellhead component at least partially on the tubing, the wellhead component can be positioned regardless of axial and radial alignment relative to the tubing. 
     In positioning the bore of the body at least partially on the tubing, internal and external seals can seal the body against the throughbore of the wellhead. A shoulder defined in the bore can engage against a distal edge of the tubing. 
     The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  illustrates a cross-sectional view of a wellhead having a casing head, casing hangers, a tubing spool, pack-offs and the like, as well as a rotational lock according to the present disclosure. 
         FIG. 1B  illustrates a cross-sectional view of simplified components for a wellhead having a rotational lock according to the present disclosure. 
         FIGS. 2A-2B  illustrate elements of the disclosed rotational lock during stages of assembly. 
         FIGS. 2C-2E  illustrate other arrangements of the disclosed rotational locks. 
         FIG. 3A  illustrates a plan view of a first canted spring of the disclosed rotational lock. 
         FIG. 3B  illustrates a plan view of a second canted spring of the disclosed rotational lock. 
         FIG. 3C  illustrates an elevational view of portion of a coil for the canted springs. 
         FIG. 4  illustrates a schematic view of the elements of the disclosed rotational lock. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
       FIG. 1A  illustrates a cross-sectional view of a wellhead  10  having various components mounted to surface casing  14 . As is typical, a casing head  20  mounts with a landing ring  12  on the surface casing  14 , and a slip hanger  30  landed in the bowl  25  of the casing head  20  supports an inner casing string  16  downhole. A slip pack-off  40  installs in the casing head  20  above the hanger  30  and mounts on the distal end of the inner casing string  16 . The pack-off  40  provides a seal between the casing hanger  30  and the casing head  20 . 
     A tubing spool  50  connects to the casing head  20  with an adapter  24 . The tubing spool  50  includes a mandrel pack-off  60  engaged on the slip pack-off  40 . Another casing slip hanger  70  mounted in the bowl created by the mandrel pack-off  60  in the tubing spool&#39;s bore  52  supports in an inner tubing string  18  on which another slip pack-off  80  installs. Additional components, such as additional tubing spools, blow-out preventer, a tubing head adapter, gate valves of a production tree, and the like, can then install above the tubing spool  50  depending on the current drilling or production stage of the well. 
     The wellhead  10  can have any variety of configurations, and the present example is only meant to be illustrative. Instead of slip hangers  30  and slip pack-off  40 , mandrel hangers can be used with mandrel pack-offs. 
     The pack-off  40  that installs on the distal end of the inner casing string  16  forms a seal between the casing head&#39;s bore  22  and the inner casing  16 . To do this, the pack-off  40  includes external seals  46  for sealing against the bore  22  of the casing head  20  and includes internal seals  44  in the bore  42  of the pack-off  40  for sealing against the casing  16 . 
     To prevent rotation, the pack-off  40  further includes at least one rotational lock  100  according to the present disclosure. The rotational lock  100  is disposed in the bore  42  of the pack-off  40  and engages against the casing string  16 . Although one rotational lock  100  is shown, additional rotational locks  100  can be used on the same pack-off  40 . Additionally, the other pack-off  80  could also include a rotational lock for the inner tubing string  18 . 
     As noted in the background section, there is a need for an engageable rotational locking feature for wellheads or other assemblies to hold the tubing string and installed components stationary during operations. Rather than requiring axial and rotational alignment to function, the rotation lock  100  of the present disclosure allows for components to snap-on/snap-off of tubing with minimal parts and without significant modifications to existing wellhead elements. 
     For simplified description,  FIG. 1B  illustrates a cross-sectional view of simplified components for a wellhead  10  having a rotational lock  100  according to the present disclosure. In this simplification, a casing head  20  mounts on surface casing  14 , and a casing hanger  30  in the head  20  supports an inner tubing string  15 . A pack-off component  40  mounts above the hanger  30  on the distal end of the tubing string  15 . The pack-off component  40  includes internal seals  44  for sealing against the tubing  15  and includes external seals  46  for sealing against the throughbore  22  of the casing head  20 . In general, the casing hanger  30  can be a slip hanger to which the pack-off component  40  may or may not be affixed. 
     Two rotational locks  100 A-B are disposed in the bore  42  of the pack-off component  40  and are engaged with the tubing  15 . Each rotational lock  100 A-B prevents rotation of the pack-off component in opposite directions. In this way, during assembly of the wellhead  20 , the rotational locks  100 A-B prevent the pack-off component  40  from rotating on the distal end of the tubing  15  and likewise prevent the tubing  15  from rotation, as other components are assembled, removed, reassembled, and/or rearranged for the wellhead  10  during any of the various changes made during drilling, completion, and production operations. 
       FIGS. 2A-2B  illustrate elements of the disclosed rotational locks  100 A-B during stages of assembly. The elements include a mating component  200  for fitting on the distal end  214  of a tubing component  210 , which has an internal bore  212 . In general, the mating component  210  can be any internal component of a wellhead or other assembly that mates to tubing. Therefore, the tubing component  210  may be part of or installed on casing or tubing, such as used in a wellhead. Although described in the context of a wellhead, however, the disclosed rotational locks  100 A-B can be used for any suitable mating components in a wellbore environment. 
     As best shown in  FIG. 2A , the mating component  200  includes an inner bore  202  having circumferential grooves  206 A-B defined thereabout. The bore  202  may also include a stop shoulder  204  and may include seals (not shown). The rotational locks  100 A-B include canted springs  110 A-B disposed in opposite orientations in the circumferential grooves  206 A-B. 
     When the mating component  200  installs on the distal end  214  of the tubing component  210  as shown in  FIG. 2B , the stop shoulder  204  can engage the tubing&#39;s edge. To facilitate passage of the springs  110 A-B past the edge of the tubing component  210 , the distal end  214  may define an outer bevel feature. The canted springs  110 A-B of the rotational locks  100 A-B engage between the grooves  206 A-B and the outer surface of the tubing component  210  to prevent rotation of the mating component  200  in opposite directions. In addition to preventing rotation in one or both directions, the canted springs  110 A-B allow free travel axially between the tubing components  200 ,  210 . This means that the rotational lock  200  does not depend on a need for any particular axial or rotational alignment between the components  200 ,  210 . 
     Although shown in the context of using two canted springs  110 A-B oriented in opposite directions, one or more additional canted springs  110  can be used in one or more additional grooves  206 . For example,  FIG. 2C  illustrates four canted springs  110 A-D used between the components  200 ,  210 . The various canted springs  110 A-D can prevent rotation in either one or both of the directions. In this way, two or more canted springs e.g.,  110 A-B can work in tandem in one direction to support additional loading. Additionally or alternatively, two or more other canted springs e.g.,  110 C-D can work in tandem in the opposite direction. Overall, the tandem support can increase the rotational resistance of the lock depending on the application. 
     Although shown in the context of the mating component  200  having a bore  202  (with the grooves  206 A-B and the canted springs  110 A-B) that fits on the cylindrical outer surface of the tubing component  210 , a reverse arrangement could be used. For example,  FIG. 2D  illustrates a tubing component  210 , provided it has a sidewall of significant thickness, that has external grooves  216  in which the canted springs  110 C-D are positioned. The tubing component  210  can then fit at least partially in the mating component&#39;s bore  202  so the canted springs  110 C-D engage against the inner cylindrical surface of the bore  202  to prevent rotation. 
     Moreover, an assembly may use one or more internal canted springs  110 A-B in the bore  202  of the mating component  200  combined with one or more external canted springs  100 C-D on the tubing component  210 . For example,  FIG. 2E  illustrates first canted springs  110 A-B for preventing rotation in a first direction can be used in internal grooves  206  of the mating component  200 , while second canted springs  110 C-D for preventing rotation in an opposite direction can be used on external grooves  216  of the tubing component  210 . Each pair can alternatively prevent rotation in both directions. 
     These and other tandem, reverse, and combined arrangements of  FIGS. 2A-2E  can be used on any of the various arrangements disclosed herein. 
       FIG. 3A  illustrates a plan view of a first canted spring  110 A of the disclosed rotational lock  100 , and  FIG. 3B  illustrates a plan view of a second canted spring  110 B of the disclosed rotational lock  100 . The canted springs  110 A-B can be composed of a suitable material for wellhead applications, including metallic material, plastic, glass, composite, etc. 
     These two canted springs  110 A-B each have coils  112  angled at opposite pitches P relative to one another. The amount of pitch P for both may be the same or different from one another. In fact, the two springs  110 A-B may be identical to one another, but flipped relative to one another when installed in the component. 
     In general, the springs  110 A-B have inner diameters ID and outer diameters OD configured for the implementation at hand, such as the outer diameter of the tubing component ( 210 ) and the inner dimension of the circumferential groove ( 206 ) between which the spring  110  engages. Additionally, the coils  112  have a general coil width (CW) as shown in  FIG. 3C . Each of these various dimensions ID, OD, CW, P, and the like are configured for the implementation at hand. 
     Each of the canted springs  110 A-B may have the same OD and ID, but assemblies may use other combinations. For example, the canted springs  110 A-B may have different IDs, different ODs, or both different IDs and ODs. Additionally, each of the canted springs  110 A-B do not have to be disposed in similar grooves  206  in the mating component  200  and do not need to engage the same surface of the tubing component  210  to function as lock. Accordingly, one spring  110 A may have one or more different dimensions compared to the other spring  110 B, one of the grooves  206 A may have one or more different dimensions compared to the other grooves  206 B, and the surface against which the springs  110 A-B engage do not need to be the same surface (i.e., they can have different surfaces with different diameters). 
     For example,  FIG. 4  illustrates a schematic view of the elements of the disclosed rotational lock  100  during engagement. The circumferential groove  206  in the mating component  200  includes a divided backwall defining an angle θ. The divided backwall allows for two points of engagement against the coils  112  of the spring  110 . The groove  206  is defined at a groove depth SD and has a groove width SW. The tubing component  210  fits at a clearance C relative to the component  200  having the exposed canted spring  110 . 
     Each of these dimensions SW, SD, θ, and C combined with the dimensions ID, OD, CW, P of the canted spring  110  operate together for the canted spring  110  to engage between the tubing component  210  and the groove  206  and prevent relative rotation between the tubing component  210  and the mating component  200 . For example, the groove width SW combined with the coil width CW and the groove depth SD combined with the difference between the inner and outer dimensions ID, OD of the canted spring  110  as well as the clearance C define the amount of engagement. 
     As noted in the background of the present disclosure, historical solutions require predefined axial positions to engage features such as pins, pawls, splines, etc. to prevent rotation. Traditional solutions also require predefined rotational alignment to engage these types of features. This rotational lock  100  of the present disclosure is not dependent on rotational alignment and can engage at any rotational angle. This allows for axial movement for positioning the tubular elements and can remove the need to rotate the tubular elements at any axial position even during up and down tubing movement. 
     As disclosed herein, the rotation lock  100  includes one or more canted springs  110  in corresponding grooves  206 . Each canted spring  110  prevent rotation in one direction so rotation can be prevented in opposing directions by the opposing canted springs  110 A-B. Utilizing two opposing springs  110 A-B with grooves  206 A-B allows the tubing component  210  to be engaged and disengaged repeatedly without wear or damage during installation. 
     As will be appreciated during assembly of a wellhead during stages of drilling, completion, and eventual preparation for production, various wellhead components are installed one on top of the other on and inside the wellhead, can be installed by passing through other components, such as a blow-out preventer, or can be installed while other components are lifted out of the way. The challenges involved in completing these various assembly steps can be simplified by the disclosed rotational locks  100 . 
     The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. It will be appreciated with the benefit of the present disclosure that features described above in accordance with any embodiment or aspect of the disclosed subject matter can be utilized, either alone or in combination, with any other described feature, in any other embodiment or aspect of the disclosed subject matter. 
     In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.