Abstract:
A jumper for transferring fluids from an umbilical to a subsea tree assembly has a plurality of steel tubes. The steel tubes are bent so that the jumper is in a serpentine or w-shape while in a natural state. The steel allows resists damage to the jumper from the fluids and chemicals being transferred to the tree assembly. The w-shape of the jumper allows the jumper to be stretched or contracted so that the distance between the connectors on each end of the jumper can vary. The contracted width jumper is attached to a terminal plate located on the tree assembly as it is landed on a subsea wellhead. An ROV disconnects the jumper and connects the jumper to receptors on the tree assembly and the umbilical, while stretching the jumper to the necessary length to reach the receptors. The jumper can be disconnected from the tree assembly when maintenance is necessary without moving the umbilical.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates generally to subsea well installations, more specifically, to a jumper apparatus for connecting an umbilical to a subsea tree assembly.  
           [0003]    2. Background of the Related Art  
           [0004]    After a subsea tree assembly is landed on a subsea well assembly, hydraulic fluid control, electrical control, and in some cases chemicals are supplied from a surface platform. An umbilical is lowered from the platform to the tree assembly to supply the hydraulic fluid control, electrical control, and chemicals. Typically, the umbilical is connected to an umbilical terminal head, which in turn is connected to the tree assembly with a flying lead or a jumper. The jumper has multiple tubes that are bundled together so that different chemicals, fluids, and signals can be delivered to the tree assembly separately. The tree assembly normally has a single connection point for the jumper to connect. From the connection point, the different fluids and signals received are routed separately to different parts of the tree assembly.  
           [0005]    Prior art jumpers are made of flexible thermoplastic hoses. The thermoplastic hoses are easily maneuverable to extend from the umbilical terminal head to the connector on the tree assembly. The flexibility allows the jumper to be disconnected from the tree assembly for workover operations. The hoses are also made with extra length so that jumper can easily span the distance between the umbilical terminal head and the connector on the tree assembly.  
           [0006]    While the thermoplastic hoses allow the hoses to be maneuvered in many directions between the connections on the umbilical and the tree assembly, thermoplastic hoses are not as resistant to chemical attack from the fluids that they transport, as desired. Thermoplastic hoses also degrade when submerged in sea water for long periods of time.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    In a subsea well installation a tree assembly is landed onto the subsea well head. The hydraulic fluid control, electrical control, and chemicals for the well assembly are supplied to the tree assembly from the surface through an umbilical that extends downward so that its end or terminal head rests at a location near the tree assembly. A jumper connects the umbilical terminal head to the tree assembly. The umbilical and the tree assembly both have connector receptacles for the ends of the jumper to stab into in order fluidly connect the umbilical to the tree assembly.  
           [0008]    The jumper is lowered down with the tree assembly when the tree assembly is landed. A terminal parking plate is located on an exterior surface of the tree assembly adjacent to the tree receptacle. The jumper has an umbilical connector and a tree connector at opposite ends of the jumper which are attached to two terminal parking receptacles on a terminal parking plate while the tree assembly is being landed. The jumper is made up of a set or bundle of metal tubes. The tubes are bent in multiple places which makes the bundle capable of expanding or contracting in effective length from the umbilical connector to the tree connector.  
           [0009]    When the jumper is parked on the terminal parking plate, the jumper is in its contracted state. In this state, the umbilical and tree connectors are closer together than the actual distance between the umbilical terminal head and the tree receptacle. The jumper is flexed or expanded for the tree connector and umbilical connectors to connect to the umbilical terminal head and tree receptacle.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is an elevational view of a subsea well assembly comprising a jumper, an umbilical, and a subsea tree assembly constructed in accordance with this invention.  
         [0011]    [0011]FIG. 2 is an enlarged elevational view of the jumper of FIG. 1.  
         [0012]    [0012]FIG. 3 is an elevational view of the jumper of FIG. 1, shown mounted to a terminal parking plate located on the subsea tree assembly of FIG. 1.  
         [0013]    [0013]FIG. 4 is an elevational view similar to FIG. 3, but showing the terminal head of the umbilical of FIG. 1 lowered to an area adjacent to the tree assembly.  
         [0014]    [0014]FIG. 5 is an elevational view similar to FIG. 4, but showing the jumper of FIG. 1 being connected to the tree assembly of FIG. 1.  
         [0015]    [0015]FIG. 6 is an elevational view similar to FIG. 5, but showing the jumper of FIG. 1 being connected to the umbilical of FIG. 1.  
         [0016]    [0016]FIG. 7 is an elevational view similar to FIG. 6, but showing the jumper of FIG. 1 being removed from the tree assembly of FIG. 1 to perform maintenance the tree assembly.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    Referring to FIG. 1, a flying lead or jumper  11  connects an umbilical  13  to a subsea tree assembly  15  landed on a subsea well. Jumper  11  communicates hydraulic fluid control, electric signals, and/or chemicals from umbilical  13  to tree  15 . Umbilical  13  leads to a production platform (not shown) at the surface. Jumper  11  connects to umbilical  13  at an umbilical stab plate or receiver  17  located at an umbilical terminal head  18 . In the preferred embodiment, an umbilical connector  19  located at the end of jumper  11  closest to umbilical  13  stabs into receiver  17 . Jumper  11  connects to tree assembly  15  at a tree stab plate or receiver  21 . In the preferred embodiment, a tree connector  23  located at the end of jumper  11  oppositely situated from umbilical connector  19 , stabs into tree receiver  21 .  
         [0018]    Referring to FIG. 2, jumper  11  is comprised of a set or bundle  25  of tubes  27 . Typically tubes  27  are steel, but can be another metal resistant to corrosion and chemical attack. Both umbilical connector  19  and tree connector  23  have a plurality of tubular connectors  28  for attaching the ends of the tubes  27  to connectors  19  and  23 . Receptors (not shown) are located on both umbilical and tree receivers  17  (FIG. 1) and  21  (FIG. 1) for receiving connectors  28 . Tubular connectors  28  on tree connector  23  matingly fit with the receptors (not shown) in tree receiver  21  (FIG. 1) when connector  23  stabs into receiver  21 . Likewise, tubular connectors  28  on umbilical connector  19  matingly fit with the receptors (not shown) in umbilical receiver  17  (FIG. 1) when connector  19  stabs into receiver  21 . Individual connectors  28  for each tube  27  allow different fluids to be transferred from umbilical  13  (FIG. 1) to tree  15  (FIG. 1) within a single bundle  25 .  
         [0019]    A natural state distance is defined herein by the distance between umbilical connector  19  and tree connector  23  when bundle  25  is in its natural condition, without being flexed to either expand or contract. The total length of bundle  25  of jumper  11  is greater than the natural distance between the umbilical and tree connectors  19  and  23 . Bundle  25  of jumper  11  is flexible and resilient so that connectors  19  and  23  can be pushed closer together or pulled farther apart from each other than in their natural position. During normal use expanding and contracting the distance between connectors  19  and  23  will not exceed the yield strength of metal tubes  27 . The flexibility and resilience of jumper  11  is due to the serpentine configuration of bundle  25 . Tubes  27  extend downward in bundle  25  from the lower portion of umbilical connector  19 . After a desired distance, tubes  27  form an umbilical bend  29  in a substantially u-like manner towards tree connector  23  and extend upward until tubes are substantially level with connector  19 . Tubes  27  change direction at another bend or bight  31  which is substantially level with umbilical connector  19 . Bight  31  is substantially a u-shaped bend which redirects tubes  27  of bundle  25  downward. Tubes  27  form a tree bend  33  in a u-like manner that directs tubes  27  towards tree connector  23  at substantially the same level as bend  29 . Tubes  27  in bundle  25  extend from bend  33  to the lower portion of tree connector  23 . This arrangement results in four separate legs and three bends. The combination of bend  29 , bight  31 , and bend  33  forms a substantially serpentine or w-shaped bundle  25  of jumper  11 . Of course more than four legs is feasible.  
         [0020]    Typically, the w-shape of bundle  25  is formed with the natural, unflexed distance between connectors  19  and  23  being smaller than the distance between umbilical plate  17  and tree plate  21  (FIG. 1). Jumper  11  flexes from its natural state to enable connectors  19  and  23  to connect to umbilical and tree receivers  17  (FIG. 1) and  21  (FIG. 1).  
         [0021]    A clamp plate  41  is located at the base of each of connectors  19  and  23 . Passages  43  are located in clamp plate  41  that separately enclose each individual tube  27  of bundle  25  extending toward connector  19  or  23 . Typically, a liner (not shown) will be located on the inner surface of passages  43  or the portion of each tube  27  enclosed by passage  43 . In the preferred embodiment, the liner (not shown) is either a nylon or a plastic material, which is used to protect the tubes as connectors  19  and  23  are moved to contract or expand the natural unflexed length of bundle  25 . The portion of tubes  27  below clamp plate  41  is in the bundle arrangement comprising bundle  25 . The portion of tubes  27  above clamp plate  41  extends separately to each of their respective tubular connectors  28 . Clamp plate  41  prevents the portions of tubes  27  extending above clamp  41  from bending as bundle  25  is flexed and compressed, which may relieve stress on tubular connectors  28 .  
         [0022]    In the preferred embodiment, a cover sleeve  47  is located around the portion of bundle  25  in bight  31 . Cover sleeve is preferably a plastic or nylon material that protects tubes  27  and tree assembly  25  during any contact while bundle is flexed.  
         [0023]    Referring to FIG. 3, a jumper parking terminal plate  35  is mounted on tree assembly  15  adjacent to tree plate  21 . Parking plate  35  is a removable plate that is preferably landed with tree assembly  15 . Parking plate  35  has two parking terminals  37  and  39  adjacent to each other which face away from tree assembly  15 . Parking terminals  37  and  39  are blank receptacles  40  (as shown in FIG. 8) that are not connected to any components of the tree. Connectors  19  and  23  stab into parking terminals  37  and  39  to retain jumper  11  with tree assembly  15  as it is lowered with tree assembly  15  from the surface while tree assembly  15  is landed. Typically, the w-shape of bundle  25  is formed with a natural unflexed distance between connectors  19  and  23  that is greater than the distance between parking terminals  37  and  39 . Jumper  11  is contracted so that connectors  19  and  23  can stab into parking terminals  37  and  39 .  
         [0024]    Typically, a restraining mechanism (not shown) is used to maintain the contracted state of jumper  11  even after one of connectors  19  or  23  is removed from their terminal  37  or  39 . The restraining mechanism (not shown) can slowly release jumper  11  from its contracted state so that jumper  11  and other equipment does not get damaged when either connector  19  or  23  is removed from terminal  37  or  39 .  
         [0025]    In operation, jumper  11  is contracted and connectors  19  and  23  are stabbed into terminals  37  and  39  on parking plate  35  which is already secured to tree assembly  15  as shown in FIG. 3. Tree assembly  15  is then lowered from a vessel and landed on a subsea well (not shown) on the ocean floor. As shown in FIG. 4, umbilical  13  is lowered from a vessel on the surface after landing tree assembly  15  so that umbilical terminal head  18  having umbilical plate  17  is closer to umbilical connector  19  than to tree connector  23 . Umbilical terminal head  18  will be fairly closely spaced to tree assembly  15 , but the distance is variable. Umbilical terminal head  18  lands on the sea floor adjacent to treee assembly  15 .  
         [0026]    An ROV is used to remove tree connector  23  from parking terminal plate  39 . The restraining mechanism (not shown) maintains pressure on bundle  25 , preventing bundle  25  from expanding too quickly and damaging jumper  11  or tree assembly  15 . The ROV gradually releases the restraining mechanism (not shown) which allows jumper  11  to expand. The ROV then pulls tree connector  23  until it is aligned with tree receiver plate  21 . Pulling tree connector  23  causes bundle  25  to expand. A pair of buoyancy modules  45  (as shown in FIG. 2), which attach to the upper portions of connectors  19  and  23 , help to support the weight of jumper  11  as the ROV moves different portions of jumper  11 . Bend  33  and bight  31  both expand as connector  23  is pulled away from umbilical connector  19 , which remains stabbed into terminal parking plate  37 .  
         [0027]    As shown in FIG. 5, the distance between the straight portions of bundle  25  extending away from bight  31  towards bends  29  and  33  increases as bight  31  expands. The distance between portions of bundle  25  extending from bend  33  towards bight  31  and tree connector  23  also increases as bend  33  expands. The increase in distances between the straight portions accounts for most of the increase in the actual distance between connectors  19  and  23 . The straight portion of bundle  25  between connector  23  and tree bend  33  may bend slightly away from umbilical connector  19 . The straight portion of bundle  25  between bight  31  and bend  33  may also bend slightly. Then the ROV stabs tree connector  23  into tree plate  21 , as shown in FIG. 5, which connects tubular connectors  28  (FIG. 2) on tree connector  23  to the receivers (not shown) located on tree plate  21 .  
         [0028]    The ROV then removes umbilical connector  19  from parking terminal  37 . The ROV pulls umbilical connector  19  away from tree connector  23  towards umbilical plate  17 . As shown in FIG. 6, the distance between straight portions of bundle  25  extending from bight  31  towards bends  29  and  33  continues to increase when connector  19  is pulled towards umbilical plate  17 . The distance between portions of bundle  25  extending from bend  29  towards umbilical connector  19  and bight  31  also increases when connector  19  is pulled towards umbilical plate  17 . The increase in the distance between the straight portions from bend  29  and bight  31  accounts for most of the increase in the actual distance between connectors  19  and  23  for connector  23  to connect to umbilical plate  17 . As before, the straight portions of bundle  25  extending from bend  29  and bight  31  may also bend slightly as umbilical connector  19  is pulled by the ROV towards plate  17 . The ROV then stabs umbilical connector  19  into plate  17  which connects tubular connectors  28  on connector  19  to the receivers (not shown) located on plate  17 .  
         [0029]    With jumper  11  in the configuration shown in FIG. 6, the operator can pump hydraulic fluids, chemicals, and communicate signals from umbilical  13  through tubes  27  (FIG. 2) in jumper  11  to tree assembly  15 . The hydraulic fluids, chemicals, and electrical signals communicate from each tube  27  to the receivers (not shown) on tree assembly  15 , which then communicates the fluids, chemicals, and signals to different portions of tree assembly  15  and the well. In the portion of FIG. 3, jumper  11  is elastically contracted from its natural position, but to a point to exceed the yield strength of jumper  11 .  
         [0030]    When the operator needs to workover the well, the ROV is used to place jumper  11  in the configuration shown in FIG. 7. The ROV disengages tree connector  23  from tree plate  21  by pulling connector  23  perpendicularly away from plate  21 . The ROV then moves connector  23  towards terminal parking plate  39 . In doing so, the width of bundle  25  of jumper  11  reduces. The distance between the portions of bundle  25  extending from bight  31  towards bends  29  and  33  decreases as the ROV moves connector  23  towards terminal  39 . The distance between the portions of bundle  25  extending from bend  33  also decreases with the movement of connector  23  by the ROV.  
         [0031]    The ROV contracts the width bundle  25  until connector  23  aligns with parking terminal  39 . Then the ROV stabs connector  23  into terminal  39  by pushing connector  23  towards plate  39  from a direction that is substantially perpendicular to parking terminal  35 . In this configuration, a line (not shown) from a workover vessel can stab into tree plate  21  to perform the necessary workover. Upon completion of the workover, the ROV removes connector  23  from terminal  39  in terminal plate  35 , allows bundle  25  to expand in width to its natural position, and then flexes bundle  25  until connector  23  aligns with tree plate  21 , and then stabs connector  23  back into plate  21  so that jumper  11  is once again in the configuration shown in FIG. 5.  
         [0032]    If the operator needs to use jumper  11  on another well assembly, the ROV disengages umbilical connector  19  from plate  17 . Then the ROV moves connector  19  and aligns it with terminal  37  by contracting bundle  25 . The ROV then stabs connector  19  into terminal  37 . The ROV would then remove connector  23  from tree plate  21 , contracting bundle  25  while moving and aligning connector with terminal  39 , and stabing connector  23  into terminal  39 . After these operations, jumper  11  is in the configuration shown in FIG. 3. The operator can then remove terminal plate  35  along with jumper  11  from tree assembly  15  to use jumper  11  with another tree assembly.  
         [0033]    The flexibility of bundle  25  allows jumper  11  to be connected and disconnected like the conventional thermoplastic hoses while the steel material of tubes  27  in bundle  25  provide resistance to chemical attack and sea water. A jumper made of steel as described above saves money because jumper  11  does not need to be replaced, avoiding delays in oil or gas production. Jumper  11  allows umbilical  13  to be lowered to the general proximity of the tree assembly  15  instead of being lowered to a precise location, which is more expensive and time consuming. Further, jumper  11  may be readily disconnected in order for a workover on the tree assembly  15  to occur.  
         [0034]    Normally, the metal needed to travel from umbilical connector  19  to tree connector  23  would not compress enough to maneuver connectors  19  and  23  between umbilical  13  (FIG. 1) and tree  15  (FIG. 1) that are closer together than the length of the jumper. Similarly, the metal would not stretch if the distance between connectors  19  and  23  was greater than the length of the jumper. The w-shape of bundle  25  increases the length of tubes  27  in bundle  25 . The increase in length in addition to the w-shape of bundle  25  allows jumper  11  to increase and decrease the actual distance between connectors  19  and  23 , when bundle  25  is flexed or compressed.  
         [0035]    While the invention has been shown in only a few 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.