Abstract:
A method and apparatus are described for exploiting the crushing power of the ocean, the principle of the lever, and the weight of a deep-sea oil drilling rig to provide a mechanism that is the simplest and most rapidly deployable way possible to plug a subsea leak. This mechanism for plugging subsea leaks has an inflatable plug and a folding reinforcement mechanism that are contained in a streamlining sheath so that they can be inserted into a leaking high-pressure subsea pipe, and a housing that, in a controlled manner, can be crushed by subsea water pressure to force fluid into the inflatable plug to cause it to inflate to plug the leak; and, depending on the pressure in the pipe, there is a weight basket available that can easily add weight to the mechanism, if necessary.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/465,382, filed Mar. 17, 2011, the contents of which are hereby incorporated by reference herein. 
         [0002]    This application is related to U.S. Provisional Application No. 61/396,092, filed May 22, 2010. 
     
    
     TECHNICAL FIELD 
       [0003]    This application generally relates to a method and apparatus for plugging a subsea leak. 
       BACKGROUND 
       [0004]    The present invention seeks to provide a mechanism for plugging subsea leaks that utilizes a lever to convert the crushing power of the sea into power to operate a mechanism that forces water or cement into an inflatable plug to plug a leak in a subsea well. 
         [0005]    U.S. Pat. Nos. 3,595,012 and 7,424,917 are examples of prior art that uses subsea water pressure in the operation a tool, and there are many inflatable plugs in the prior art, the most pertinent being U.S. Pat. No. 5,205,358, which, curiously, was invented to plug surface oil wells that were intentionally blown up during the war in Iraq in 1991, while the present invention was invented to plug the Macondo well, the subsea well owned by the BP oil company that accidentally exploded in the Gulf of Mexico in 2010. 
         [0006]    Because of the high pressure in the Macondo well, which is one mile deep in the Gulf of Mexico, it took BP several months to stop the leak, which made it very obvious that there is a need for tools—in fact, Tony Hayward, then the CEO of BP, was quoted in the financial press saying he lacked tools—that can be used to try to deal with the problems of subsea leaks, and the present invention is intended to provide such a tool. Because it harnesses the enormous water pressure at the site of the leak at the bottom of the ocean to counteract the high pressure of the leak, it actually works better the deeper it goes. For the most rapid deployment possible if there is a subsea leak, this simple and reliable self-contained tool could be installed on every ocean drilling rig: it would be similar to a fire extinguisher, something that is hopefully a waste of money, but something that is extremely valuable in the rare instances when it is needed. 
       SUMMARY 
       [0007]    The present invention is a mechanism for plugging subsea leaks having an airtight, lever-equipped, fluid-containing housing that is connected by a pipe to a normally deflated inflatable plug that, together with a collapsible reinforcement mechanism behind the inflatable plug, is contained in a sheath that streamlines the deflated inflatable plug and collapsed reinforcement mechanism so they can be inserted into a subsea pipe from which oil is leaking high great pressure into the sea, whereupon a winch can be operated to allow the housing to be crushed by the enormous subsea water pressure, which forces fluid from a bladder in the housing into the inflatable plug, which tears away the sheath as it inflates and opens out the reinforcement mechanism that reinforces it against the high pressure of the leak. And, if the pressure coming from the leak is so powerful that it can push the inflatable plug out of the pipe, there is a weight basket that, when filled with heavy objects from the oil rig, can connect to the mechanism to add enough weight to the mechanism to hold the inflatable plug in the pipe against the high pressure of the leak. 
         [0008]    Another object of the invention is to provide an inflatable plug that can convert into a solid plug by using cement in the inflatable plug. A high pressure subsea oil leak can throw sand and debris, and, although this mechanism can use an extremely strong inflatable plug made of kevlar-reinforced rubber, the inflatable plug could possibly be deflated by the sand and debris thrown against it; by therefore, since this mechanism is simply a fluid transfer system that forces fluid from a bladder into an inflatable plug, it would be possible to use cement in the fluid transfer system, which cement would harden inside the inflatable plug, creating a much more durable cement plug with a rubber seal between it and the pipe. 
         [0009]    Another object of the invention is to provide a fluid transfer pipe that is equipped with a flexible joint mechanism that enables the fluid transfer pipe to flex when the inflatable plug at the end of the fluid transfer pipe is inflated, with the flexing of the fluid transfer pipe allowing the inflatable plug to center itself inside an oil well pipe when it is inflated, in the event that the deflated inflatable plug is off-center when it is inserted into the oil well pipe. 
         [0010]    Other features and advantages of the invention will become apparent during the course of the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings herein: 
           [0012]      FIG. 1A  is a partially cutaway perspective view of the mechanism; 
           [0013]      FIG. 1B  is a view similar to  FIG. 1A  with the lever operated; 
           [0014]      FIG. 2A  is cross-sectional side elevation view of the mechanism; 
           [0015]      FIG. 2B  is a view similar to  FIG. 2A , with the lever operated; 
           [0016]      FIG. 3A  is an enlarged fragmentary cross-sectional view of  FIG. 1A  taken along line  3 A- 3 A; 
           [0017]      FIG. 3B  is an enlarged fragmentary cross-sectional view of  FIG. 1B  taken along line  3 B- 3 B; 
           [0018]      FIG. 4  is a plan view of the weight basket; 
           [0019]      FIG. 5  is a side elevation view showing the weight basket containing weighty objects and with the mechanism attached and the inflatable plug assembly in a vertical pipe; 
           [0020]      FIG. 6A  is a side elevation view showing the mechanism fitted onto a pair of skids and adjacent to a horizontal pipe; 
           [0021]      FIG. 6B  is a view similar to  FIG. 6A  showing the skid-equipped mechanism having been pulled so the skids straddle the end of the horizontal pipe; 
           [0022]      FIG. 6C  is a view similar to  FIG. 6B  showing the weight basket adjacent to the skid-equipped mechanism; 
           [0023]      FIG. 7A  is an enlarged fragmentary view of  FIG. 5  with the pipe cutaway showing the inflatable plug assembly in the pipe; 
           [0024]      FIG. 7B  is a view similar to  FIG. 7A  with the inflatable plug assembly sheath cutaway; 
           [0025]      FIG. 7C  is a view similar to  FIG. 7B  with the inflatable plug, inflatable plug clamp, and reinforcement assembly cutaway; 
           [0026]      FIG. 7D  is a cross-sectional view taken along line  7 D- 7 D of  FIG. 7C  showing the connection between the fluid transfer pipe and the inflatable plug support rod; 
           [0027]      FIG. 7E  is a view similar to  FIG. 7A  showing the inflatable plug inflated inside the pipe; 
           [0028]      FIG. 8A  is a view similar to  FIG. 2A  with the bladder cutaway to show cement in the bladder; 
           [0029]      FIG. 8B  is a view similar to  FIG. 2B  with the inflatable plug cutaway to show cement in the inflatable plug; 
           [0030]      FIG. 8C  is a view similar to  FIG. 7E  with the inflatable plug cutaway to show cement in the inflated inflatable plug; 
           [0031]      FIG. 9  is a view similar to  FIG. 2A  showing a second embodiment of the invention; 
           [0032]      FIG. 10A  is fragmentary plan view of a third embodiment of the invention showing the inflatable plug assembly and flexible joint assembly; 
           [0033]      FIG. 10B  is an elevated side view of  FIG. 10A ; 
           [0034]      FIG. 10C  is a view similar to  FIG. 10B  with the collar cut away and the inflatable plug assembly and flexible joint assembly inserted into and positioned off-center in a pipe; and, 
           [0035]      FIG. 10D  is a view similar to  FIG. 10C  with the inflatable plug inflated and the flexible joint having flexed to reposition the inflatable plug assembly centrally in the pipe. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    Referring to the drawings in detail wherein like numerals designate like parts, and referring intially to  FIGS. 1A through 8C , a mechanism for plugging subsea leaks according to the present invention is described herein. 
         [0037]    A mechanism for plugging subsea leaks  10  is shown in perspective in  FIGS. 1A and 1B , cutaway in  FIGS. 2A and 2B , and enlarged in fragmentary views in  FIGS. 3A ,  3 B, and  7 A through  7 E, the mechanism  10  having a fluid transfer system operating through a fluid transfer pipe  11  having a fluid intake pipe  12  and fluid intake pipe cap  13  that allow fluid to be introduced into and held in the fluid transfer system, at one end of the fluid transfer pipe  11  there being a fluid-containing bladder  14  (see FIGS.  2 A, 2 B) connected to the fluid transfer pipe  11  by a bladder clamp  15  (see FIGS.  2 A, 2 B) and at the opposite end of the fluid transfer pipe  11  there being an inflatable plug assembly  18 , the inflatable plug assembly  16  comprising an inflatable plug  17  connected to the fluid transfer pipe  11  by an inflatable plug clamp  18 , there being connected to the inside of and extending from the end of the fluid transfer pipe  11  an inflatable plug support rod  19  (see FIGS.  7 C, 7 D) that is inside the inflatable plug  17 , the inflatable plug support rod  19  connected to the inside of the fluid transfer pipe  11  by inflatable plug support rod connectors  20  (see FIGS.  7 C, 7 D) the inflatable plug  17  normally deflated and held against the inflatable plug support rod  19  by breakable inflatable plug bands  21  (see FIGS.  7 B, 7 C) and arrayed around and longitudinal with and normally collapsed against the normally deflated inflatable plug  17  there being inflatable plug reinforcement arms  22  that are in hinged connection to the inflatable plug clamp  18  and that are connected together by inflatable plug reinforcement cables  23 , and there being a tearable inflatable plug assembly sheath  24  (see  FIG. 7B ) that covers the normally deflated inflatable plug  17  and the normally collapsed inflatable plug reinforcement arms  22  and the normally collapsed inflatable plug reinforcement cables  23 . To prepare the mechanism  10  for plugging a subsea leak, fluid is introduced into the fluid intake pipe  12  until the entire fluid transfer system is full of fluid: fluid is allowed to trickle into and fill the deflated inflatable plug  17  that is held against the inflatable plug rod  19  by the breakable inflatable plug bands  21 , the breakable inflatable plug bands  21  being sufficiently strong to prevent the fluid from inflating the deflated inflatable plug  17 , and the fluid fills the bladder  14 , fluid transfer pipe  11 , and fluid intake pipe  12 , after which the fluid intake pipe cap  13  is tightly closed onto the fluid intake pipe  12 . 
         [0038]    If cement C (see  FIGS. 8A-8C ) is used in the fluid transfer system, it will be necessary to select a cement C that will maintain its fluidity until the cement C is forced from the bladder  14  into the inflatable plug  17 , and to make that selection it will be required to estimate the time it will take for the mechanism  10  to descend from the surface of the ocean to the leaking pipe P, as well as the time that will be required to maneuver the inflatable plug  17  into the pipe P. 
         [0039]    The fluid transfer pipe  11  is connected to and passes through a lever housing  25  such that the bladder  14  and the bladder clamp  15  are inside the lever housing  25 , the bladder  14  being positioned adjacent to the lever housing  25  and accessible through a bladder access cover  26  on the lever housing  25 . There is an opening  29  in the top of the lever housing  25 , and inside the lever housing  25  is a lever  27  that pivots on a fulcrum  28 —see FIGS.  2 A, 2 B—the lever  27  normally positioned in a readiness position in which the lever  27  is positioned adjacent to the bladder  14 , such that the bladder  14  is between the lever housing  25  and the lever  27 , and is positioned in the opening  29  in the top of the lever housing  25  such that the lever  27  is exposed to subsea water pressure when the mechanism  10  is submerged into the sea. Around the lever  27  when the lever  27  is in the readiness position in the opening  29  is a narrow gap  30  (see FIGS.  3 A, 3 B) between the lever  27  and the lever housing  25 , and straddling the narrow gap  30  is a flexible U-shaped sealing collar  31  (see FIGS.  3 A, 3 B) that is connected onto both the lever  27  and the lever housing  25 , the U-shaped sealing collar  31  fitting onto threaded clamping posts  32  (see FIGS.  3 A, 3 B) on both the lever  27  and the lever housing  25  and able to be clamped onto both the lever  27  and the lever housing  25  such that the U-shaped sealing collar  31  can make the lever housing  25  airtight, the clamping able to be effected by ribbed clamping strips  33  (see FIGS.  3 A, 3 B) that fit onto the threaded clamping posts  32  and over the U-shaped sealing collar  31  on both the lever  27  and the lever housing  25  and by tightening nuts  34  (see FIGS.  3 A, 3 B) that fit onto the threaded clamping posts  32  and are tightened down onto the ribbed clamping strips  33 . The lever  27  is normally held in the readiness position by a bar  35  (see FIGS.  2 A, 2 B) that is positioned between upper housing-mounted rollers  36  (see FIGS.  2 A, 2 B) and lower housing-mounted rollers  37  (see FIGS.  2 A, 2 B) in the lever housing  25 , the bar  35  normally extending from between the housing-mounted rollers  36  and  37  such that it is positioned under the lever  27  to prevent the lever  27  from falling within the lever housing  25 , there being lever-mounted rollers  38  (see FIGS.  2 A, 2 B) on the underside of the lever  27  that rest on the bar  35 , the housing-mounted rollers  36  and  37  and the lever-mounted rollers  38  able to facilitate the bar  35  being pulled out from under the lever  27  to allow the lever  27  to fall within the lever housing  25 , the bar  35  able to be pulled by a cable  39  that is connected to a winch  40  (see FIGS.  2 A, 2 B) inside the lever housing  25 , there being a winch access cover  41  on the lever housing  25  that permits access to the winch  40 , cable  39 , and bar  35 . On the top of the lever housing  25  at each corner are housing lifting rings  42  and on the top of the lever  27  is a lever lifting ring  43 . 
         [0040]    The mechanism  10  can be lowered into the sea to plug a leak in a well when the fluid transfer system is full of fluid and the lever  27  is in the readiness position and the U-shaped sealing collar  31  has created an airtight seal between the lever  27  and the lever housing  25 ; and, if weight needs to be added to the mechanism  10 , there is a weight basket  44  available for use, at each corner of the weight basket  44  there being weight basket lifting rings  45  that enable the weight basket  44  to be lowered into the sea, the weight basket  44  able to contain sufficient loose weighty objects W of different sizes and shapes to hold the mechanism  10  in place against pressure coming from the leak. If the well has a vertical pipe P (see  FIG. 5 ) the mechanism  10  can be attached onto the weight basket  44  such that the fluid transfer pipe  11  on the mechanism  10  extends down through a center opening  46  in the weight basket  44  such that the inflatable plug assembly  16  on the fluid transfer pipe  11  is centrally positioned below the weight basket  44 , the mechanism  10  and weight basket  44  when connected together having sufficient weight to enable the inflatable plug assembly  16  to be lowered into and held in the vertical pipe P against pressure coming from the leak. If the well has a horizontal pipe P (see  FIGS. 6A-6C ) skids  47  can be fitted under opposite elongate sides of the lever housing  25  and the fluid transfer pipe  11  can be bent such that the inflatable plug assembly  16  is beneath the lever housing  25  and between the skids  47 , the skid  47 -equipped mechanism  10  then able to be lowered into the sea and positioned such that the skids  47  and the lever housing  25  straddle the horizontal pipe P and the inflatable plug assembly  16  is positioned in the horizontal pipe P, whereupon the weight basket  44  containing loose weighty objects W can be lowered into the sea and positioned to abut against the skid  47 -equipped mechanism  10  to hold the inflatable plug assembly  16  in the horizontal pipe P against oil pressure coming from the leak. 
         [0041]    With the inflatable plug assembly  16  in the pipe P, plugging the leak can be accomplished by operating the winch  40  to pull the cable  39  which pulls the bar  35  out from under the lever  27  to allow the lever  27 , under both its own weight and the enormous weight of subsea water pressure pressing down on it, to crash down in the lever housing  25  and pivot on the fulcrum  28  to squeeze the bladder  14  between the lever  27  and the lever housing  25 , thus forcing the fluid in the bladder  14  to flow under extreme pressure through the fluid transfer pipe  11  and into the inflatable plug  17  and cause the inflatable plug  17  to break the inflatable plug bands  21  and tear the inflatable plug assembly sheath  24  as it inflates and forces the inflatable plug reinforcement arms  22  and the inflatable plug reinforcement cables  23  to open out. It is very important to note that the volumes of the bladder  14  and the inflatable plug  17  must be very carefully calculated so that the amount of fluid transferred from the bladder  14  into the inflatable plug  17  is precisely the amount of fluid required to fully inflate the inflatable plug  17 . 
         [0042]      FIG. 9  shows a second embodiment of the invention in which the winch  40  is eliminated, and is replaced by a connecting ring  48  outside the lever housing  25  that is connected to the cable  39 , the cable  39  extending outside the lever housing  25 , with there being a cable roller  49  inside the lever housing  25  that facilities the pulling of the cable  39  by the connecting ring  48 . To operate the mechanism  10 , the connecting ring  48  is pulled by an external pulling device, such as an underwater vehicle or a cable lowered into the sea from a winch on a ship on the ocean surface. 
         [0043]      FIGS. 10A through 10D  show a third embodiment of the invention in which, adjacent to the inflatable plug clamp  18 , the fluid transfer pipe  12  is cut and connected together by a flexible joint  50 , the flexible joint  50  being secured to both pieces of the cut fluid transfer pipe  12  by a pair of joint clamps  51 . The purpose of the flexible joint  50  is to enable the inflatable plug assembly  16  to reposition itself inside a pipe P if the inflatable plug assembly  16  is not positioned centrally in the pipe P when it is inserted into the pipe P. Insertion of the inflatable plug assembly  16  into the pipe P requires that the cut fluid transfer pipe  12  and the flexible joint  50  are held stationary during the insertion, and for that purpose there is a collar  52  on the fluid transfer pipe  12  and over the flexible joint  50  and joint clamps  51 , the collar  52  abutting against both the joint clamps  51  to minimize movement of the flexible joint  50 . The collar  52  has a collar hinge  53  that connects together two collar half-sections  54 , and opposite the hinge  53  on each collar half-section  54  there is a locking tab  55 , and when the collar  52  is fitted over the flexible joint  50  and the joint clamps  51  the pair of locking tabs  55  are parallel and symmetrically aligned and spaced apart such that each locking tab  55  can be engaged by one of a pair of locking hooks  56  that are on opposite sides of one end of a locking rod  57 , the engagement of the locking tabs  55  by the locking hooks  56  effectively locking the collar  52  onto the fluid transfer pipe  12 , flexible joint  50 , and joint clamps  51 . The locking rod  57  has at one end the locking hooks  56 , and at its opposite end the locking rod  57  is connected by a pivot  58  to one of the inflatable plug reinforcement arms  22  of the inflatable plug assembly  16 . 
         [0044]    When the inflatable plug assembly  16  is inserted into a pipe P and the inflatable plug  17  is inflated inside the pipe P the inflation of the inflatable plug  17  causes the outward and backward movement of the pivot  58  on the inflatable plug reinforcement arm  22 , with the backward movement of the pivot  58  causing the backward movement of the locking rod  57  that is connected to the pivot  58 , and the backward movement of the locking rod  57  disengages the locking hooks  56  from the locking tabs  55  on the collar  52 , thus unlocking the collar  52 , and thus allowing the hinged-together collar half-sections  54  to open out and fall away from the fluid transfer pipe  12 , flexible joint  50 , and joint clamps  51 , and thus freeing the flexible joint  50  to flex so as to allow the inflatable plug assembly  16  to reposition itself centrally inside the pipe P. 
         [0045]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.