Abstract:
An assembly for clamping a flanged tubular components, the assembly including a segmented clamp having a recess configured to accept the flanges of the tubular components, and a hole oriented substantially perpendicular to the longitudinal axes of the tubular components. The assembly also includes a housing surrounding an outer portion of the segmented clamp and configured for attachment to at least one of the tubular components, and a drive screw that passes through the housing and is threadedly engaged with the hole of the segmented clamp. As the drive screw rotates, it drives the segmented clamp perpendicularly relative to the tubular components between a locked position, in which the circumferential recess engages the flanges of the tubular components, and an unlocked position, in which the circumferential recess is positioned laterally out of engagement with the flanges of the tubular components.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This technology relates to oil and gas wells, and in particular to adaptors for clamping connectors in oilfield equipment. 
     2. Brief Description of Related Art 
     Conventional adapters for joining tubular wellhead components, such as API hub connectors, have two-piece clamps that are positioned to engage the flanges of the components, and are joined with bolts. The wellhead components may be, for example, a casing or wellhead, and a tubing head. Such adapters are often slow and cumbersome to stall. In addition, such adapters may be unreliable, thereby allowing leakage between the flanges, and raising environmental and safety concerns. Alternative adapters have been developed to overcome the shortcomings of conventional two-piece clamps. For example, some adapters may drive dogs around the flanges to clamp the flanges together. However, many of these adapters require vendor-specific non-standard threads or other features on the components or equipment to which they are applied. This prohibits the use of such adapters with any equipment that is not specifically designed for use with that adapter. This also prevents use of the adapter to retrofit equipment originally supplied by a vendor other than the vendor of the adapter. What is needed, therefore, is an adapter that is more reliable than the conventional two-piece clamp adapter, but that can be used universally with any oil field equipment manufactured by any vendor. 
     SUMMARY OF THE INVENTION 
     Disclosed herein is an adapter for clamping flanged, or hub, ends of first and second tubular components. The adapter includes a clamp that may have two split halves, or a plurality of dog segments, with each half or dog segment having a hole extending therethrough. Each half or dog segment also includes upper and lower protrusions that define a recess therebetween, and that are spaced to accept the flanges at the ends of the first and second tubular components. 
     The adapter also includes a housing that surrounds at least an outer portion of the clamp. The housing is configured for removable attachment to either the first or second tubular component, or both. Such attachment may be accomplished by means of fasteners attaching the housing to the tubular component(s), or threads on the surface of the housing configured to engage threads on the surface of the tubular component(s). 
     A plurality of drive screws pass through the housing and engage threads in the holes of the clamp. As each drive screw rotates, it drives a half or dog segment of the clamp perpendicularly relative to the first and second tubular components. When the screw drives the clamp into engagement with the flanges, the clamp is in a locked position. Alternatively, when the screw drives the clamp away from, and out of engagement with, the flanges, the clamp is in an unlocked position. 
     This adapter is stronger and more robust than conventional split-type, two-piece clamps that consist only of the clamp to hold the faces of the connectors together. The adapter disclosed herein includes both an inner clamping device, and an outer housing that adds strength to the adapter assembly. This increases the ability of the adapter to withstand increased pressure and bending forces compared to conventional clamp designs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present technology will be better understood on reading the following detailed description of nonlimiting embodiments thereof and on examining the accompanying drawings, in which: 
         FIG. 1A  is a side cross-sectional view of a connection assembly according to an embodiment of the present technology, with the clamp in an unlocked position; 
         FIG. 1B  is a side cross-sectional view of the connection assembly according to the embodiment of  FIG. 1A , with the clamp in a locked position; 
         FIG. 2A  is a side cross-sectional view of a connection assembly according to an alternate embodiment of the present technology, with the clamp in an unlocked position; and 
         FIG. 2B  is a side cross-sectional view of the connection assembly according to the embodiment of  FIG. 2A , with the clamp in a locked position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     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. However, the technology 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. 
     Many oilfield operations require the connection of adjacent tubular components, such as API hub connectors. Such tubular components may typically include wellhead components, like casing heads or tubing heads. For example, as shown in  FIG. 1A , such equipment may include a first tubular component  10  having a first flange  12  at a lower end. The first tubular component  10  may be attached to a corresponding second tubular component  14 , which has a second flange  16 . Typically, when the first and second tubular components  10 ,  14  are joined, a seal  18  is positioned therebetween to prevent fluids from leaking through the joint at the interface between the flanges  12 ,  16 . As shown, for example, in  FIG. 1A , an adapter assembly  20  according to the present technology may be used to lock the first and second flanges  12 ,  16  together. Such an adapter assembly  20  connects the first and second tubular components  10 ,  14 , and keeps them from separating. The adapter assembly described herein is compact, and fits within the minimum clearance outlined by the API  16 A standard, as promulgated by the American Petroleum Institute. Accordingly, the adapter assembly  20  may be used with any API  6 A hub connection, including those supplied by any vendor. 
     The adapter assembly includes a clamp  22  having a recess  24 . The clamp  22  may be divided into separate halves, or multiple dog segments, around the circumference of the first and second tubular components  10 ,  14 . The clamp  22  is configured to move between an unlocked position, shown in  FIG. 1A , and a locked position, shown in  FIG. 1B , and as described in detail below. When the clamp  22  is in the locked position, as shown in  FIG. 1B , the recess  24  accepts the first and second flanges  12 ,  16 . The recess  24  is bounded on the top and the bottom by an upper protrusion  26  and a lower protrusion  28  respectively, and is configured to accept the first and second flanges  12 ,  16  when the flanges  12 ,  16  are joined together. In addition, each section, or dog segment, of the clamp  22  includes a hole  38  that may be threaded. 
     The upper and lower protrusions  26 ,  28  of the clamp  22  may optionally have tapered surfaces  30 ,  32  configured to substantially correspond to matching tapered surfaces  34 ,  36  of the first and second flanges  12 ,  16 . This allows a more even distribution of forces on the clamp  22  by the flanges  12 ,  16  when the clamp is in the locked position. In addition, the tapered surfaces may allow easier entry of the flanges  12 ,  16  into the recess  24  as the clamp  22  moves into a locked position, even when the flanges  12 ,  16  are not perfectly aligned with the clamp  22 . Furthermore, as the tapered surfaces  30 ,  32  of the upper and lower protrusions  26 ,  28  engage the tapered surfaces  34 ,  36  of the first and second flanges  12 ,  16 , the protrusions  26 ,  28  will tend to squeeze the flanges  12 ,  16  together, thereby strengthening the seal between the flanges. 
     In  FIGS. 1A and 1B , a housing  40  is shown attached to the first tubular component  10 , and substantially surrounding at least the outside, upper, and lower portions of the clamp  22 . Although not shown, the housing  40  may alternatively be attached to the second tubular component  14 , or to both the first and second tubular components  10 ,  14  simultaneously. The housing  40  may be a single annular piece that surrounds the clamp  22 . Internal corners  60  of the housing  40  may be radiused, as shown, thereby decreasing stress concentrations in the housing  40 . The housing  40  provides additional structural support to the adapter assembly  20  compared with a conventional clamp assembly that does not include such a housing  40 . 
     In the embodiment shown in  FIGS. 1A and 1B , the housing  40  is attached to the first tubular component  10  by fasteners  44  and a bracket  62 . The bracket  62  is an L-shaped member having an upright portion bolted to the first tubular member  10  by a bolt. Fastener  44  extends axially downward through a hole in the horizontal part of the bracket  62  into a threaded hole in the housing  40 . The bracket  62  may be an annular member that surrounds the first tubular component  10 . Alternatively, there may be multiple brackets  62  attached to the housing  40  and the first tubular component  10  at discrete intervals around the first tubular component  10 . The inner diameter of the housing  40  may be less than the inner diameter of the bracket  62 . Such an arrangement allows the housing  40  to be easily retrofit onto any existing tubular component, regardless of vendor, by hole forming a threaded hole in the tubular component to accept the fastener  44 . Accordingly, the adapter assembly  20  may be used with existing equipment at an oil drilling site. 
     The housing  40  provides a channel  42  in which the clamp  22  runs. The channel is defined by downward and upward facing flat surfaces that are perpendicular to the longitudinal axis of the first and second tubular components. When in its unlocked position, as shown in  FIG. 1A , the clamp  22  is retracted into the channel  42 , with an outside surface  46  of the clamp  22  proximate to the housing  40 . Conversely, when in its locked position, as shown in  FIG. 1B , the clamp  22  is extended at least partially out of the channel  42 . Optional wear pads  48  may be positioned on the upper and lower fiat surfaces of the channel  42  between the housing  40  and the clamp  22  to protect the surfaces of the housing  40  and the clamp  22  as the clamp  22  moves relative to the housing  40 . The wear pads  48  protect surfaces from wear by being constructed of a high strength material that is less susceptible to deterioration over time. The wear pads  48  act to reduce the friction between moving parts, and prolong the life and usage of the parts. in addition, the wear pads  48  are replaceable, adding further flexibility to the design. The channel  42  may be dimensioned so that the clamp  22  fits therein with limited tolerance, thereby helping to ensure that the clamp sections or dog segments remain square to the ends of the first and second flanges  12 ,  16 . 
     Movement of the clamp  22  between its unlocked and locked positions is effected by drive screws  50 . There may be a drive screw  50  corresponding to each clamp section or dog segment. Each drive screw  50  is configured to pass through a hole in the outer sidewall of the housing  40  and into a hole  38  in the clamp  22 . Threads  52  on each drive screw  50  interact with corresponding threads on each hole  38  of the clamp  22 , so that when the drive screw  50  rotates, the threads  52  drive the clamp  22  toward or away from the first and second flanges  12 ,  16  of the first and second tubular components  10 ,  14 . As the threads  52  on the drive screw  50  drive the clamp  22 , the drive screw  50  maintains substantially the same position relative to the housing  40 , and does not travel inwardly or outwardly toward or away from the flanges  12 ,  16 . In other words, the drive screw  50  may be fixed relative to the housing  40  in an axial direction. The drive screws  50  have a tool engagement slot  54  at an outer end thereof that can be used to turn the drive screw  50 . For example, in the embodiments of  FIGS. 1A and 1B , the drive screw  50  has a hexagon head that can be turned with a high impact gun using a hexagon attachment. The drive screws  50  may be made of a high strength material. 
     A guide bushing  56  may be provided in hole in the sidewall of the housing  40  to provide a path for, and help align, each drive screw  50  relative to the housing  40 . The guide bushings  56  may be made of a high strength material, and may be bored to have a diameter with a close tolerance to the diameter of the drive screw  50  to guide the drive screw  50  through the housing  40 . The guide bushing  56  may be removable to allow greater access to the drive screws  50  and the clamp  22 . 
     Referring now to  FIGS. 2A and 2B , there is shown an embodiment of the present technology that is similar to that shown in  FIGS. 1A and 1B , and discussed above. For example, the embodiment of  FIGS. 2A and 2B  includes a first tubular component  110  having a first flange  112 , a second tubular component  114  having a second flange  116 , and a seal  118  therebetween. Furthermore, the adapter assembly  120  includes a clamp  122 , a housing  140 , and drive screws  150  configured to drive the clamp  122  relative to the housing  140 . The clamp  122  includes a recess  124 , protrusions  126 ,  128  having angled surfaces  130 ,  132 , and a threaded hole  138 . The housing  140  includes a channel  142  in which the clamp  122  slides. Wear pads  148  may be inserted to maintain a separation between surfaces of the housing  140  and surfaces of the clamp  122 , and to prevent wear to the surfaces of the housing  140  and the clamp  122 , thereby prolonging the life thereof The drive screws  150  include threads  152  and are turned by inserting a tool into a tool engagement slot  154  and turning the drive screw  150 . Bushings  156  are provided in the housing  140  to align the drive screws  150  with the housing  140 . Each of the elements herein identified functions in a similar way to similar elements shown in  FIGS. 1A and 1B  and described above. 
     One feature of the embodiment shown in  FIGS. 2A and 2B  that is not described above, however, is the threads  158 , which allow the housing  140  to be threadedly attached to the first tubular component  110 , rather than being attached using fasteners, as shown in the embodiment of  FIGS. 1A and 1B . The threads  158  extend circumferentially around the first tubular component  110 , and an inner diameter of the housing  140 . The ability to threadedly engage the housing  140  and the first tubular component  110  may be advantageous because it may provide a more secure connection and additional stability to the adapter assembly  120  relative to the first tubular component  110 . Of course, although the housing  140  is shown in  FIGS. 2A and 2B  to be attached to the first tubular component  110 , it may alternatively be attached to the second tubular component  114 , or to both the first and second tubular components  110 ,  114  simultaneously. 
     Also shown in  FIGS. 2A and 2B  is a retainer plate  164  and bolt  166 . The retainer plate  164  is positioned on top of the housing  140 , and the bolt  166  attaches the retainer plate  164  to the housing  140 . The inner surface  168  of the retainer plate  164  has a diameter that is less than the diameter of the threads  158 , so that the retainer plate  164  cannot slide past the threads  158 . Accordingly, the retainer plate  164 , when mounted to the top of the housing  140 , prevents the housing  140  from moving axially downward relative to the first tubular component  110  past the threads  158 . Thus, the adapter assembly  120  cannot unthread and become detached from the first tubular member  110 . 
     The method for locking first and second tubular components  10 ,  14  together using the adapter assembly  20  of the present technology includes first aligning the flanges  12 ,  16  of the first and second tubular components  10 ,  14 . In addition, the adapter assembly  20  is installed on the upper tubular member  10 . The adapter assembly  20  may be pre-assembled prior to installation on the first or second tubular components  10 ,  14 . For example, the clamp  22  may be pre-attached to the housing  40  by passing the drive screws through the housing  40  and into threaded engagement with the holes  38  in the clamp sections, or dog segments. It may be desirable to turn the drive screws  50  so that the clamp  22  is fully retracted into the channel  42  of the housing  40  during installation. With the adapter assembly  20  assembled, the housing  40  may be attached to either the first or second tubular components  10 ,  14 , or both, using the fasteners  44 . Alternatively, the housing  40  may be threadedly engaged with at least one of the tubular components, as shown in  FIGS. 2A and 2B . 
     Once the adapter assembly  20  is in place relative to the first and second tubular components  10 ,  14 , with the housing attached thereto, the drive screws  50  can be turned, by engaging a tool with the tool engagement slots  54  at the end of each drive screw  50 . As the drive screws  50  turn, the threads  52  of the drive screws engage with the threaded holes  38  of the clamp sections, and the clamp  22  is driven inward toward the flanges  12 ,  16  of the first and second tubular components  10 ,  14 . The clamp  22  may be driven inward until the recess  24  accepts the flanges  12 ,  16 . In some embodiments, the tapered surfaces  30 ,  32  of the upper and lower protrusions  26 ,  28  may engage the tapered surfaces  34 ,  36  of the first and second flanges  12 ,  16 . As the tapered surfaces  30 ,  32  of the upper and lower protrusions  26 ,  28  engage the tapered surfaces  34 ,  36  of the first and second flanges  12 ,  16 , the first and second flanges  12 ,  16  are squeezed together and the seal between the flanges is strengthened. With the clamp thus positioned, the first and second flanges  12 ,  16  are locked, and unable to separate. 
     While the technology has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention. Furthermore, it is to be understood that the above disclosed embodiments are merely illustrative of the principles and applications of the present invention. Accordingly, numerous modifications may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.