Abstract:
In embodiments, a large diameter, low pressure plug can be used to seal a pipe subsea. The large diameter, low pressure plug comprises a nose, two or more counter-rotating rings, and one or more seals. Other embodiments disclosed have varying additional structure. The large diameter, low pressure plug is inserted into the inner annulus of a tubular and a sealing action created by rotating the counter-rotating rings to create axial compression, in turn causing radial expansion in the seal against the inner annulus of the tubular, sealing the tubular.

Description:
RELATION TO PRIOR APPLICATIONS 
       [0001]    This application claims priority through U.S. Provisional Application 61/979,430 entitled “Large Diameter Pipe Plug” and filed on Apr. 14, 2014. 
     
    
     BACKGROUND 
       [0002]    There is a need to seal open pipes subsea, especially a way to seal open pipes subsea using only a remotely operated vehicle (“ROV”) for the installation of the seal. 
     
    
     
       DRAWINGS 
         [0003]    Various figures are included herein which illustrate aspects of embodiments of the disclosed inventions. 
           [0004]      FIG. 1  is an exploded view in partial perspective of a first exemplary embodiment of the invention; 
           [0005]      FIG. 2  is a cutaway view in partial perspective of the first exemplary embodiment of the invention; 
           [0006]      FIG. 3  is an cutaway view in partial perspective of a second exemplary embodiment of the invention; 
           [0007]      FIG. 4  is an end view in partial perspective of the second exemplary embodiment of the invention; 
           [0008]      FIG. 5  is a view in partial perspective of an embodiment of the invention comprising a plurality of ports; and 
           [0009]      FIG. 6  is a cutaway view in partial perspective illustrating an exemplary embodiment of the invention inserted into a tubular. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0010]    Referring now to  FIGS. 1-2 , in a first embodiment large diameter, low pressure plug  100  comprises nose  113  configured to selectively be inserted into and fit within inner annulus  301  ( FIG. 6 ) of tubular  300  ( FIG. 6 ). In certain embodiments nose  113  comprises a convex leading face for which the convex portion will protrude in inner annulus  301  ( FIG. 6 ) of tubular  300  ( FIG. 6 ) when nose  113  is inserted into inner annulus  301 . In certain embodiments, nose  113  comprises a substantially round outer boundary and collar  114  comprises a substantially round outer boundary which is complementary to the substantially round outer boundary of nose  113 . 
         [0011]    Collar  114  is connected to the nose  113  about an outer boundary of nose  113 , where collar  114  is configured to slidingly fit within tubular  300 . 
         [0012]    Plate top  103  is connected to collar  114  opposite nose  113 . 
         [0013]    Slip bowl  101  is disposed proximate nose  113  about an outer surface of collar  114 . Large diameter, low pressure plug  100  may further comprise first spring  122  disposed about an outer surface of slip bowl  101 . 
         [0014]    One or more O-rings  123  is disposed proximate the outer surface of collar  114  intermediate nose  113  and slip bowl  101 . O-ring  123 , which may comprise a large cross section and/or a large diameter, typically comprises a soft elastomeric material. 
         [0015]    Slip  104  is disposed about an outer surface of slip bowl  101  in sliding communication with slip bowl  101 . Slip  104  may comprise teeth and/or a serrated outer surface. In contemplated embodiments, slip  104  comprises a tapered edge and slip bowl  101  comprises a complementarily tapered edge in sliding communication with the slip tapered edge. 
         [0016]    Nose  113 , slip  104 , and slip bowl  101  are configured to selectively position one or more O-rings  123  to a first position which does not form a seal between large diameter, low pressure plug  100  and inner annulus  301  of tubular  300  into which large diameter, low pressure plug  100  is positioned and to a second position which does form a seal between large diameter, low pressure plug  100  and inner annulus  301  of tubular  300  into which large diameter, low pressure plug  100  is positioned. 
         [0017]    A set of counter-rotating rings  106 ,  109  comprises bottom ramp  106 , disposed about the outer surface of collar  114  proximate plate top  103 , and top ramp  109 , disposed about the outer surface of collar  114  intermediate plate top  103  and bottom ramp  106 . Top ramp  109  is in communication with bottom ramp  106 . In certain embodiments, bottom ramp  106  and top ramp  109  are arranged in a counter-rotating relationship relative to each other and are further configured to produce an axial force to compress O-ring  123 . An assembly comprising one or more screw cap socket heads  107 , square nuts  115  (or the like), screw tubes  116  (or the like), and springs  117  may be present and disposed proximate collar  114 . 
         [0018]    Slip pusher  102  is disposed at least partially intermediate bottom ramp  106  and slip  104  about the outer surface of collar  114  and is in communication with slip  104 . Slip pusher  102  may be configured to engage an end portion of tubular  300  ( FIG. 6 ) and at least partially impede insertion of large diameter, low pressure plug  100  into annulus  301  ( FIG. 6 ) of tubular  300  ( FIG. 6 ). 
         [0019]    Bolt setter  111  is in communication with the outer surface of slip bowl  101  and is configured to provide axial movement to at least one of bottom ramp  106  and top ramp  109 . Bolt setter  111  can be hydraulically actuated, actuated mechanically via a wrench or remotely operated vehicle (ROV), or the like, or a combination thereof. Bolt setter  111  can comprise a hydraulic pump and/or cylinder and typically turns and moves top ramp  109  against bottom ramp  106 . In certain embodiments, bolt setter  111  comprises a plurality of bolt setters  111  disposed at least partially opposite each other. 
         [0020]    Large diameter, low pressure plug  100  may further comprise ROV handle  118  connected to plate top  103 . 
         [0021]    Referring now to  FIGS. 3-4 , in a further embodiment, large diameter, low pressure plug  200  comprises leading nose  201  configured to be insertable into inner annulus  301  ( FIG. 6 ) of tubular  300  ( FIG. 6 ), where leading nose  201  comprises substantially circular descending collar  201   b  and substantially solid convex leading face  201   a , which can be convex. 
         [0022]    Back plate  215  is connected to descending collar  201   b  and disposed opposite solid leading face  201   a.    
         [0023]    A set of set of counter-rotating rings comprises one or more conical ramp rings  206 , connected to back plate  215  and disposed about an outer surface of descending collar  201   b , and counter-rotating ramp ring  207 , disposed about an outer surface of descending collar  201   b  intermediate at least one conical ramp ring  206  and slip pusher  203 . Counter-rotating ramp ring  207  is in communication with slip pusher  203 . Conical ramp ring  206  may be configured to be stationary with respect to counter-rotating ramp ring  207 . 
         [0024]    Slip pusher  203  is disposed about an outer surface of descending collar  201   b  intermediate at least one conical ramp ring  206  and descending collar  201   b . Slip pusher  203  is in communication with back plate  215 . 
         [0025]    First slip  204  comprises a tapered edge and is disposed about the outer surface of descending collar  201   b  intermediate slip pusher  203  and leading nose  201 . First slip  204  is in communication with slip pusher  203 . In embodiments, first slip  204  comprises a serrated outer surface. 
         [0026]    Sliding slip bowl  202  comprises a tapered edge which is complimentarily tapered with respect to and engaged with the tapered edge of first slip  204  and is disposed about the outer surface of descending collar  201   b  intermediate first slip  204  and leading nose  201 . 
         [0027]    One or more large cross section, large diameter O-rings  213  are disposed intermediate sliding slip bowl  202  and substantially solid leading face  201   a . Counter-rotating ramp ring  207  is configured to produce an axial force to compress O-ring  213 . O-ring  213  typically comprises a soft elastomeric material. 
         [0028]    Setting screw  212 , which is operatively in communication with conical ramp ring  206  and counter-rotating ramp ring  207 , is configured to selectively rotate or counter-rotate at least one of conical ramp ring  206  and counter-rotating ramp ring  207 . 
         [0029]    Referring now to  FIG. 5 , in either embodiment described above one or more ports  150  may be present and adapted to removably receive a hose (not shown in the figures) which may be attachable via a complimentary hot stab. Ports  150 , e.g. 3 inch connections, may be configured to be opened or closed as needed and may be placed where and as needed, e.g. proximate nose  113  ( FIG. 1 ) or nose  201  ( FIG. 3 ). Ports  150  may comprise a connector such as a hydraulic connector, a check valve, or the like, or a combination thereof. 
         [0030]    In the operation of exemplary embodiments, a pipe, e.g. tubular  300 , may be sealed subsea by maneuvering large diameter, low pressure plug  100  proximate an open end of tubular  300 . The operation described herein applies equally to large diameter, low pressure plug  200 . One or more ROV handles  118  may be used to aid in positioning large diameter, low pressure plug  100 . 
         [0031]    Referring to  FIG. 6  and additionally to  FIGS. 1 and 2 , when positioned to its desired proximity of tubular  300 , large diameter, low pressure plug  100  is inserted into inner annulus  301  of tubular  300 , with nose  113  leading into inner annulus  301 . When inserted sufficiently, e.g. when a ledge such as slip pusher  102  or back plate  215  engages an open end portion of tubular  300 , axial compression is applied by rotating top ramp  109  against bottom ramp  106 . The rotational movement is translated to axial movement due to meshing angles in both top ramp  109  and bottom ramp  106 . A sealing action is created by rotating a set of counter-rotating rings, e.g. top ramp  109  against bottom ramp  106  or conical ramp ring  206  with respect to counter-rotating ramp ring  207 . This causes radial expansion in a seal, such as O-ring  123  or O-ring  213 , against inner annulus  301  of tubular  300  by the rotation of one ring of the set of counter-rotating rings with respect to the other ring or rings of the set of counter-rotating rings. 
         [0032]    In configurations, the leading portion of large diameter, low pressure plug  100 , i.e. nose  113 , is shaped to withstand internal pressure within inner annulus  301 , e.g. convexly, such that the internal pressure, e.g. from fluid present in inner annulus  301 , does not push large diameter, low pressure plug  100  out from inner annulus  301  once large diameter, low pressure plug  100  is secured within inner annulus  301 . 
         [0033]    Conical ramp ring  206  may be configured with one or more protruding arms  112  and a corresponding set of springs  110 , each of which is connected to a corresponding protruding arm  112 . In such embodiments, each such protruding arm  112  is allowed to compress its spring  110  which operates to maintain tension of a preload and insure that protruding arm  112  does not come off. When started, this action keeps spring  110  and applied torque, e.g. with a wrench or the like, will overcome the force exerted by spring  110 . 
         [0034]    Large diameter, low pressure plug  100  may be locked into place using hydraulic pressure and toothed slips  104 . In an embodiment, first slip  104  comprises a serrated edge which is used to bite axially into inner annulus  301  to prevent large diameter, low pressure plug  100  from being pushed out of inner annulus  301 . First slip  104  may be expanded by pushing slip bowl  101  underneath first slip  104  with the same axial force that compresses O-ring  113 . In other configurations, slip pusher  203  is pushed underneath first slip  204  to compress O-ring  113 . 
         [0035]    In embodiments, protruding arm  112  comprises a plurality of opposing protruding arms  112  which may be pulled toward each other. In other embodiments, setting screw  212  comprises a plurality of opposing setting screws  212  which may be pulled toward each other. 
         [0036]    A slight axial movement may be caused with pressure the large diameter, low pressure plug  100  is designed to hold and the slight axial movement used to relax the axial setting force of conical ramp rings  206 . Moreover, an original setting force of conical ramp rings  206  may be restored by having conical ramp rings  206  brought even closer together using stored energy in one or more compressed springs  210 . 
         [0037]    If ports  150  are present, they may be used to help stabilize pressure within tubular  300  such as when retrieving or otherwise repositioning tubular  300 . 
         [0038]    The foregoing disclosure and description of the inventions are illustrative and explanatory. Various changes in the size, shape, and materials, as well as in the details of the illustrative construction and/or an illustrative method may be made without departing from the spirit of the invention.