Patent Publication Number: US-8979150-B1

Title: Tubing elevator latch

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit of U.S. Provisional Application Ser. No. 61/695,783, filed Aug. 31, 2012, the full disclosure of which is hereby incorporated by reference herein for all purposes. 
    
    
     BACKGROUND 
     1. Field of Invention 
     The present disclosure relates in general to an elevator for an oilfield tubular. More specifically, the present disclosure relates to an elevator having a locking system for maintaining engagement of the elevator with a tubular when the elevator encounters a collar on the tubular. 
     2. Description of Prior Art 
     Tubing elevators typically include left and right bodies that couple together on one end with a barrel type hinge. A semi-circular recess is generally provided axially along an inner surface of each of the bodies. Closing the elevator brings the bodies together so their respective recesses face one another and engage opposing sides of a tubing string. Generally, a retainer and lug are provided for latching together the left and right bodies when in the closed position. Typically, the lug projects outward from a front surface of the right body and the retainer pivotingly attaches to a front surface of the left body; the retainer is positioned so that it can selectively swing into latching engagement with the lug. When the retainer swings into the latching position, the lug inserts into an opening formed through the retainer. 
     Tubing elevators usually are equipped with tie bars that mount on lateral sides of the left and right bodies. The tie bars are engaged by elevator links provided on a traveling block for raising and lowering the tubing elevator; where drilling rig drawworks are typically included for controlling movement of the traveling block. The left and right bodies are kept in the closed position as long as the retainer is adjacent the front surface of the right body and the lug is inserted into the retainer opening. 
     SUMMARY OF THE INVENTION 
     Disclosed herein is an example of an elevator for use with a tubular string. In an example the elevator includes a main body that selectively moves between an open configuration and a closed configuration. The main body has an axial opening that selectively circumscribes the tubular string when the main body is in the closed configuration. A lug projects outward from the main body. Also included is a retainer with an end pivotingly coupled on a lateral surface of the main body. The retainer is moveable into a latching configuration with the lug so that the main body is held in the closed configuration. Also included with the main body is a retainer stop that can be moved into selective locking engagement with the retainer, so that the retainer remains in the latching configuration with the lug when in locking engagement with the retainer stop. In an alternative, the main body is made up of a left body hinged to a right body, and wherein a semi-circular channel on an inner surface of the left body faces a semi-circular channel on an inner surface of the right body when the main body is in the closed configuration to define the axial opening. The elevator can optionally further include a boss that projects radially inward from an inner surface of the retainer towards the tubular string, so that when the retainer stop is in locking engagement with the retainer, the retainer stop is in a path the boss follows when the retainer is pivoted away from the main body. In an example, the retainer stop has a planar upper section and a cylindrical shaped lower section, wherein the lower section inserts into an axial bore in the main body, and wherein when the upper section contacts a collar on the tubing string, the retainer stop is urged axially into the main body so that the lower section is moved into locking engagement with the retainer. In this example, the elevator has a spring for biasing the retainer stop upward, so that when the elevator is moved away from the collar, the retainer stop is urged out of locking engagement with the retainer. In an alternate embodiment, the elevator also has a profile on a lateral side of the retainer stop and a key coupled to the main body for maintaining an azimuthal orientation of the retainer stop. In an example embodiment, the elevator is a tubing elevator and the tubular string is a tubing string. 
     Another example of an elevator for use with a tubular string in a wellbore is made up of a left body, a right body hingedly coupled with the left body, semi-circular channels formed on respective surfaces of the left and right bodies, so that when the left and right bodies are put into a closed configuration, the channels face one another to define an axial opening. This example further includes a lug engageable by a retainer for retaining the left and right bodies in the closed configuration, and a retainer stop for selectively locking the retainer in engagement with the lug when the tubing elevator is proximate a collar on the tubing string. In an optional embodiment, the elevator includes a boss that projects outward from the retainer, and wherein the retainer stop moves axially to a locking position into interference with the boss for keeping the retainer in engagement with the lug. Optionally, an upper end of the retainer stop contacts a lower surface of the collar to move the retainer stop downward to lock the retainer in engagement with the lug. The elevator can also have a spring for biasing the retainer stop upward and out of locking engagement with the retainer when the elevator is moved away from the collar, a profile on a lateral side of the retainer stop, and a key coupled to the main body for maintaining an azimuthal orientation of the retainer stop. In an alternative example, an upper surface of at least one of the left body and right body slopes axially downward adjacent the axial opening. In an example embodiment, the retainer is made of a generally planar member having upper and lower lateral members joined at one end by a vertical member to define an open space bounded by the lateral and vertical members, and hinge couplings on ends of the lateral members distal from the vertical member that couple with the left body. In this example of the elevator, the retainer is engaged by the lug by pivoting the retainer about the hinge couplings so the vertical member is on a side of the lug opposite the hinge couplings and wherein the lug inserts into the open space. The elevator can further include a spring for biasing the retainer so the vertical member is adjacent the right body. A planar lock member may optionally be included that is hingedly mounted to the retainer adjacent where the retainer engages the lug, and a spring for biasing the lock. In an example, the elevator is a tubing elevator, and the tubular string is a tubing string. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Some of the features and benefits of the present invention 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 side perspective view of an example embodiment of a tubing elevator on a tubing string in accordance with the present invention. 
         FIG. 2  is an exploded view of an embodiment of the tubing elevator of  FIG. 1  in accordance with the present invention. 
         FIG. 3A  is a side sectional view of an embodiment of the tubing elevator and tubing string of  FIG. 1  taken along lines  3 A- 3 A and in accordance with the present invention. 
         FIG. 3B  is a side sectional view of an embodiment of the tubing elevator and tubing string of  FIG. 3A , where the tubing elevator is in contact with a collar on the tubing string and in accordance with the present invention. 
         FIG. 4  is a plan sectional view of an embodiment of the tubing elevator of  FIG. 1  taken along lines  4 - 4  and in accordance with the present invention. 
     
    
    
     While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention 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 invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF AN EMBODIMENT 
     The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. 
     It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. 
       FIG. 1  illustrates a side perspective view of one example of a elevator  10  shown having a main body  11  made up of a right body  12  and left body  14 . The right and left bodies  12 ,  14  are shown in a closed configuration and hingedly coupled to one another by a hinge pin  16  inserted into an end of each of the bodies  12 ,  14 . Each of the bodies  12 ,  14  have a semicircular channel formed through an inner surface so that when the bodies  12 ,  14  are put into the closed configuration, the channels face one another to define a generally circular opening  18  that extends axially through the main body  11 . A string of tubing  20  is shown inserted through the opening  18 , where individual segments of the string  20  are connected by a collar  21  shown set spaced above an upper surface of the main body  11 . The collar  21  has an outer diameter that extends radially past an outer diameter of the segments of tubing  20  to define a raised shoulder that faces an upper surface of the main body  11 . Although in the example of  FIG. 1  the elevator  10  handles tubing  20 , included in the present disclosure are embodiments of the elevator  10  that handle any tubular string, such as casing, a drill string, conductor pipe, and the like. 
     Below the elevator  10 , the tubing  20  projects downward into a borehole  22  that is formed in a subterranean formation  23 . Handles  24 ,  26  are shown on forward-facing surfaces of the right and left bodies  12 ,  14  and are elongated members that project radially outward from the main body  11 . The handles  24 ,  26  may be used for opening and closing the main body  11  so the elevator  10  may selectively engage and disengage the tubing string  20 . Each of the right and left bodies  12 ,  14  include a tie bar  28 ,  30  that provides a point on the main body  11  for attaching a link to a travelling block (not shown) for raising and lowering the elevator  10  on a drilling rig (not shown). 
     A retainer  32  is shown provided on a forward-facing surface of the main body  11  and, as will be described in more detail below, is for keeping the right and left bodies  12 ,  14  in the closed configuration shown in  FIG. 1 . Adjacent the retainer  32  on the forward-facing surface of the main body  11  is a lock  34  used for disengaging the retainer  32  so the bodies  12 ,  14  may be pivoted with respect to one another to put the main body  11  into an open configuration. Further provided in the example of  FIG. 1  is a retainer stop  36  shown projecting axially upward from an upper surface of the main body  11  and adjacent the opening  18 . The retainer stop  36  is axially moveable within a recess  37  that projects into the left body  14  downward from the upper surface of the main body  11  and along an outer radius of the opening  18 . Also on the left body  14  is a hinge pin  38  that axially depends into a bore and is for hingedly mounting the retainer  32  to the left body  14 . 
     An example embodiment of the elevator  10  is shown in an exploded view in  FIG. 2 . In this example a hinge pin  40  is shown set above the lock  34 , and when the elevator  10  is assembled, the hinge pin  40  inserts into tabs  42  that project radially inward from upper and lower ends of the lock  34 . Bores  44  are formed axially through the tabs  42  and are sized to receive and retain the hinge pin  40  therein. Further detail of the retainer  32  is provided in  FIG. 2  illustrating the retainer  32  includes a pair of lateral members  46  that define upper and lower portions of the retainer  32 . A cover plate  47  optionally mounts onto the retainer  32  and on a side opposite where the retainer  32  couples to the main body  11 . The lateral members  46  of  FIG. 2  are generally elongate and shown spaced vertically apart and connected to one another by an end member  48  that vertically extends between terminal ends of the lateral members  46 . Ends of the lateral members  46  distal from the end member  48  are provided with axial bores  50  and sized to receive hinge pin  38  therein so that the retainer  32  can rotate with respect to the left body  12  and about hinge pin  38 . 
     At least one of the lateral members  46  is provided with a boss  52 , which in the example of  FIG. 2  is an elongate planar shaped element that projects radially inward from the surface of the retainer  32  that faces the left member  14 . Axially spaced apart cylinders  54  are further illustrated disposed on a side of the retainer  32  opposite the boss  52  and on the end member  48 . The cylinders  54  are provided with axial bores  56  that receive hinge pin  40 , so that the lock  34  can rotate with respect to the retainer  32  and about hinge pin  40 . An optional pin  58  is shown insertable into an aperture shown formed through a sidewall of the lower of the cylinders  54  for engagement with a lower end of the hinge pin  40  so the hinge pin  40  is retained within cylinder  54 . A spring  60  is illustrated for circumscribing hinge pin  40  when assembled, which provides a biasing force onto the lock  34  to retain the lock  34  in a designated orientation. An additional spring  62  is shown for insertion between bores  50  and for receiving hinge pin  38  therein. The spring  62  biases the retainer  32  so that the end member  48  is set adjacent a forward-facing surface of the right body  12 . Additional cylinders  64  are shown mounted on the forward face of the left body  14  that are fitted with corresponding bores  66 ; registering the bores  50  with bores  66 , and inserting hinge pin  38  through the registered bores  50 ,  66  the retainer  32  may be hingedly mounted onto the left body  14 . 
     Still referring to  FIG. 2 , the retainer stop  36  is shown having an upper portion  68  which is a generally planer member with elongate sides that extend generally parallel to the axis A x  ( FIG. 1 ) of the elevator  10  and along the line radial to the axis A x . A profile  70  is shown formed along an elongate edge of an outer side of the upper portion  68 . A substantially cylindrical pin  72  depends axially downward from an end of the upper portion  68  and adjacent the profile  70 . A spring  74  shown adjacent a lower end of the pin  72  circumscribes the pin  72  when the elevator  10  is assembled. As will be described in more detail below, the spring  74  provides an upwardly biasing force onto the retainer stop  36 . To maintain the retainer stop  36  in the azimuthal orientation of  FIG. 2 , an optional stop key  76  is shown set within a recess on an upper portion of the left body  14 . In the example of  FIG. 2 , the stop key  76  is a washer-like member and having a portion of the outer periphery removed to define a lateral straight edge. 
     Cylinders  78  are shown set on an inner surface of the left body  14  at upper and lower ends of the body  14 . Axial bores  80  extend through the cylinders  78 . A corresponding barrel cylinder  82  is shown provided on a rearward end of the right body  12  and includes an axial bore  84  therethrough. When assembled, the barrel cylinder  82  sets between the cylinders  78  with the respective bores  80 ,  84  registered, so that hinge pin  86  may be inserted through the bores  80 ,  84  to thereby hingedly couple together the right and left bodies  12 ,  14 . An optional groove  86  is shown circumscribing an outer surface of hinge pin  16  engageable by a pin  88  that projects through a lateral aperture through cylinder  78  for retaining pin  16  within the left body  14 . Similarly, groove  90  circumscribes hinge pin  38  for engagement by a retaining pin (not shown) to keep the hinge pin  38  in place within the left body  14 . 
     A lug  92  is illustrated projecting radially outward from a forward surface  94  on the right body  12 . The retainer  32  is configured so that when pivoted over the forward surface  94 , the end member  48  extends past the lug  92  and on a side distal from the bores  50  on the lateral members  46 . When the retainer  32  is pivoted so the lateral members  46  run along the front faces of the right and left bodies  12 ,  14 , the end member  48  interferes with movement of the lug  92  in a direction away from the left body  14 . Thus, the retainer  32  prevents the right and left bodies  12 ,  14  from pivoting outward from one another thereby retaining the main body  11  in a closed position and in close cooperation with outer surface of the tubing  20 . 
       FIGS. 3A and 3B  respectively illustrate side sectional views of the elevator  10  spaced downward from a lower surface of collar  21 , and moved upward and into engagement with the lower surface of collar  21 . As illustrated in the example of  FIG. 3A , which is taken along lines  3 A- 3 A, the spring  74  is set in a slot  98  formed axially through the left body  14  for upwardly biasing the retainer stop  36  from within the slot  98 . Further illustrated in this example is that a lower surface  96  of the recess  37  slopes downward with distance towards the opening  18 , thereby providing for ease of removal of dirt, grease, and other debris from within the opening  18 . A port  100  is shown provided on a forward-facing surface of the left body  14  for providing lubricant into the slot  98 . Referring now to  FIG. 3B , the elevator  10  has been moved upward, such as by activating the drawworks and travelling block, so that an upper surface of the elevator contacts a lower surface of the collar  21 . With continued upward movement of the elevator  10 , the collar  21  contacts the upper portion  68  of the retainer stop  36  thereby downwardly urging the pin  72  to a position adjacent the boss  52  while depressing the spring  78 . In this example, the pin  72  is moved to adjacent the boss  52  to a position that interferes with a path the boss  52  would travel when disengaging the retainer  32  from lug  92 . As such, when the retainer stop  36  is depressed downward, the retainer  32  is locked into engagement with the lug  92 ; which as explained above prevents rotating the left and right bodies  12 ,  14  so that the main body  11  is kept in a closed position around tubing  20 . By locking the retainer  32  as described, the elevator  10  will continue to grapple and hold the tubing  20  for retaining the tubing  20  at a desired elevation. 
       FIG. 4  is a plan sectional view of the example elevator  10  of  FIG. 1  and taken along lines  4 - 4 . In the example of  FIG. 4 , the retainer stop  36  is shown in the locking position so that the pin  72  is urged downward and adjacent the boss  52 . Thus, in this example, the presence of the pin  72  interferes with prospective motion of the boss  52  thereby maintaining the retainer  32  in engagement with the lug  92  (shown in dashed outline). Further shown in the example of  FIG. 4  is the tubing held within the elevator  10  and inside the opening  18 . 
     The present invention 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 invention 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 invention disclosed herein and the scope of the appended claims.