Air-freightable containment cap for containing a subsea well

Abstract

A modular containment cap for containing a subsea wellbore discharging hydrocarbons comprises a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end. In addition the containment cap comprises an upper assembly including a spool piece having an upper end, a lower end opposite the upper end, a throughbore extending from the upper end to the lower end, and a first spool piece valve disposed in the throughbore. The first spool piece valve is configured to control the flow of fluids through the throughbore of the spool piece. The upper end of the spool body is releasably connected to the lower end of the spool piece, and the first throughbore of the spool body is coaxially aligned with and in fluid communication with the throughbore of the spool piece.

1 . A modular containment cap for containing a subsea wellbore discharging hydrocarbons into the surrounding sea, comprising:
 a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end;   an upper assembly including a spool piece having an upper end, a lower end opposite the upper end, a throughbore extending from the upper end to the lower end, and a first spool piece valve disposed in the throughbore, wherein the first spool piece valve is configured to control the flow of fluids through the throughbore of the spool piece;   wherein the upper end of the spool body is releasably connected to the lower end of the spool piece, and wherein the first throughbore of the spool body is coaxially aligned with and in fluid communication with the throughbore of the spool piece.   
     
     
         2 . The containment cap of  claim 1 , wherein the spool body of the lower assembly further comprises:
 a second throughbore extending from the first throughbore;   a first spool body valve disposed in the second throughbore; and   wherein the first spool body valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.   
     
     
         3 . The containment cap of  claim 1 , wherein the upper assembly further comprising a second spool piece valve disposed in the throughbore of the spool piece of the upper assembly, wherein the second spool piece valve is configured to control the flow of fluids through the throughbore of the spool piece of the upper assembly;
 wherein the spool body of the lower assembly further comprises a second spool body valve disposed in the second throughbore, wherein the second spool body valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.   
     
     
         4 . The containment cap of  claim 2 , wherein the second throughbore has a first end intersecting the first throughbore and a second end distal the first throughbore, wherein the second end of the second throughbore is coupled to a choke valve. 
     
     
         5 . The containment cap of  claim 4 , wherein the lower assembly further comprises a fluid conduit extending from the choke valve, wherein the fluid conduit has a first end coupled to the choke valve and a second end distal the choke valve, and wherein the second end of the fluid conduit comprises an upward-facing hub configured to releasably engage a mating downward-facing receptacle. 
     
     
         6 . The containment cap of  claim 2 , wherein the first throughbore of the spool body is configured to provide full bore access to the wellbore. 
     
     
         7 . The containment cap of  claim 2 , further comprising:
 a kill-flowback assembly including a spool piece having an upper end, a lower end opposite the upper end, and a throughbore extending from the upper end to the lower end;   wherein the upper end of the spool piece of the upper assembly is releasably connected to the lower end of the spool piece of the kill-flowback assembly, and wherein the throughbore of the spool piece of the upper assembly is coaxially aligned with and in fluid communication with the throughbore of the spool piece of the kill-flowback assembly.   
     
     
         8 . The containment cap of  claim 7 , wherein the kill-flowback assembly includes a fluid conduit coupled to the upper end of the spool piece of the kill-flowback assembly, wherein the fluid conduit is configured to produce the wellbore or supply kill fluids to the wellbore. 
     
     
         9 . The containment cap of  claim 7 , wherein the lower assembly, the upper assembly, and the kill-flowback assembly are each configured to be air freightable. 
     
     
         10 . The containment cap of  claim 9 , wherein the lower assembly has a first weight, the upper assembly has a second weight, and the kill-flowback assembly has a third weight;
 wherein the first weight, the second weight, and the third weight are each less than 120 tons.   
     
     
         11 . The containment cap of  claim 10 , wherein the sum of any two of the first weight, the second weight, and the third weight is less than 120 tons. 
     
     
         12 . The containment cap of  claim 10 , wherein the lower assembly, the upper assembly, and the kill-flowback assembly each has a maximum height, a maximum width, and a maximum length; and
 wherein at least one of the maximum height, the maximum width, and the maximum length of each of the lower assembly, the upper assembly, and the kill-flowback assembly is less than 21 ft. and at least a different one of the maximum height, the maximum width, and the maximum length of each of the lower assembly, the upper assembly, and the kill-flowback assembly is less than 14 ft.   
     
     
         13 . The containment cap of  claim 7 , wherein the lower assembly comprises a frame coupled to the spool body, the upper assembly comprises a frame coupled to the spool piece of the upper assembly, and the kill-flowback assembly comprises a frame coupled to the spool piece of the kill-flowback assembly; and
 wherein the frame of the lower assembly is configured to support the spool body, the frame of the upper assembly is configured to support the spool piece of the upper assembly, and the frame of the kill-flowback assembly is configured to support the spool piece of the kill-flowback assembly.   
     
     
         14 . The containment cap of  claim 2 , wherein the lower end of the spool body comprises a downward-facing receptacle configured to engage an upward-facing hub to form a wellhead-type connection;
 wherein the upper end of the spool body comprises an upward-facing hub that releasably engages a mating downward-facing receptacle at the lower end of the spool piece to form a wellhead-type connection between the spool body and the spool piece; and   wherein the upper end of the spool piece comprises an upward-facing hub configured to engage a downward-facing receptacle to form a wellhead-type connection.   
     
     
         15 . A method for containing and/or producing a subsea wellbore discharging hydrocarbons into the surrounding sea, wherein a wellhead is disposed at the sea floor at the upper end of the wellbore, a subsea BOP is mounted to the wellhead, an LMRP is mounted to the BOP, and a riser extends from the LMRP, the method comprising:
 (a) selecting a subsea landing site from one of the BOP, the LMRP, or the wellhead;   (b) preparing the landing site for connection to a modular containment cap, wherein the containment cap comprises a lower assembly including a spool body and an upper assembly including a spool piece;   (c) transporting the lower assembly and the upper assembly to an offshore location;   (d) lowering the lower assembly subsea and releasably connecting the lower assembly to the landing site;   (e) lowering the upper assembly subsea and releasably connecting the upper assembly to the lower assembly;   (f) shutting in the wellbore with the containment cap after (d) and (e).   
     
     
         16 . The method of  claim 15 , wherein the spool body of the lower assembly has an upper end, a lower end opposite the upper end, a first throughbore extending from the upper end to the lower end, a second throughbore extending from the first throughbore, a first spool body valve disposed in the second throughbore, and a second spool body valve disposed in the second throughbore;
 wherein the spool piece of the upper assembly has an upper end, a lower end opposite the upper end, a throughbore extending from the upper end to the lower end, a first spool piece valve disposed in the throughbore, and a second spool piece valve disposed in the throughbore;   wherein the upper end of the spool body is releasably connected to the lower end of the spool piece, and wherein the first throughbore of the spool body is in fluid communication with the throughbore of the spool piece.   
     
     
         17 . The method of  claim 16 , further comprising:
 opening the first spool body valve and the second spool body valve before (d); and   opening the first spool piece valve and the second spool piece valve before (e).   
     
     
         18 . The method of  claim 17 , wherein (f) comprises:
 (f1) closing the first spool piece valve;   (f2) closing the first spool body valve after (f1).   
     
     
         19 . The method of  claim 18 , wherein (f) further comprises:
 closing the second spool piece valve after (f1); and closing the second spool body valve after (f2).   
     
     
         20 . The method of  claim 18 , further comprising:
 flowing at least a portion of the hydrocarbon fluids through the first throughbore and the second throughbore before (f);   flowing at least a portion of the hydrocarbon fluids through the throughbore of the spool piece before (f);   restricting the flow of the hydrocarbon fluids through the throughbore of the spool piece after (f1);   flowing at least a portion of the hydrocarbon fluids through the second throughbore after (f1); and   restricting the flow of the hydrocarbon fluids through the first throughbore and the second throughbore after (f2).   
     
     
         21 . The method of  claim 15 , wherein the LMRP has an upper end including a riser flex joint connected to the riser, and wherein the subsea landing site is a riser adapter of the flex joint; and
 wherein (b) comprises removing the riser from the riser flex joint before (d).   
     
     
         22 . The method of  claim 21 , further comprising:
 lowering a transition spool subsea and connecting it to the riser flex joint; and   wherein (d) comprises lowering the lower assembly subsea and releasably connecting the lower assembly to the transition spool.   
     
     
         23 . The method of  claim 22 , wherein the transition spool has a longitudinal axis, an upper end, a lower end comprising a mule shoe, and an annular flange axially disposed between the upper end and the mule shoe. 
     
     
         24 . The method of  claim 15 , wherein the subsea landing site is an upward-facing hub at an upper end of the BOP or an upper end of the wellhead;
 wherein (d) comprises releasably connecting a downward-facing receptacle at a lower end of the lower assembly with the upward-facing hub.   
     
     
         25 . The method of  claim 16 , further comprising:
 lowering a kill-flowback assembly subsea and releasably connecting the kill-flowback assembly to the upper assembly after (e).   
     
     
         26 . The method of  claim 25 , wherein (f) further comprises:
 Pumping kill weight fluids through the kill-flowback assembly, the upper assembly, and the lower assembly into the wellbore.   
     
     
         27 . The method of  claim 25 , further comprising:
 (g) producing the hydrocarbons through the kill-flowback assembly.   
     
     
         28 . The method of  claim 15 , wherein (c) comprises:
 (c1) transporting the lower assembly and the upper assembly by air from a first land location to a second land location.   
     
     
         29 . The method of  claim 27 , wherein (c) further comprises:
 (c2) transporting the lower assembly and the upper assembly from the second location to an onshore location; and   (c3) transporting the lower assembly and the upper assembly from the onshore location to the offshore location by surface vessel.   
     
     
         30 . A containment cap for containing a subsea wellbore discharging hydrocarbons into the surrounding sea, comprising:
 a lower assembly including a spool body having an upper end, a lower end opposite the upper end, and a first throughbore extending from the upper end to the lower end;   a valve assembly slidingly disposed in the first throughbore, wherein the valve assembly comprises a tubular body and a first spool body valve, wherein the tubular body has an upper end extending from the first throughbore, a lower end disposed within the first throughbore, and a throughbore extending between the upper end and the lower end of the tubular body;   wherein the first spool body valve is disposed along the throughbore of the tubular body and is configured to control the flow of fluids through the throughbore of the tubular body;   a plurality of annular seal assemblies radially positioned between the spool body and the tubular body, wherein each seal assembly is configured to restrict the flow of fluids between the tubular body and the spool body.   
     
     
         31 . The containment cap of  claim 30 , wherein the spool body of the lower assembly further comprises:
 a second throughbore extending from the first throughbore;   a first valve disposed in the second throughbore; and   wherein the first valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.   
     
     
         32 . The containment cap of  claim 31 , wherein the valve assembly further comprises a second spool body valve disposed along the throughbore of the tubular body and configured to control the flow of fluids through the throughbore of the tubular body;
 wherein the spool body of the lower assembly further comprises a second valve disposed in the second throughbore;   wherein the second valve in the second throughbore is configured to control the flow of fluids through the second throughbore of the spool body.   
     
     
         33 . The containment cap of  claim 31 , further comprising an annular insert disposed in the first throughbore and axially positioned between the tubular body and an annular shoulder in the first throughbore, wherein the lower end of the tubular body is seated in a cylindrical recess in the insert. 
     
     
         34 . The containment cap of  claim 30 , further comprising a cap disposed about the upper end of the tubular body, wherein the cap has an upper end comprising an upward-facing hub, a lower end comprising a downward-facing hub, and a flow passage extending from the lower end to the upper end;
 wherein the flow passage is in fluid communication with the throughbore of the tubular body.   
     
     
         35 . The containment cap of  claim 34 , further comprising an annular coupling member disposed about the lower end of the cap and the upper end of the spool body, wherein the coupling member has an upper end comprising an upward-facing receptacle and a lower end comprising a downward-facing receptacle;
 wherein the downward-facing hub at the lower end of the cap releasably engages the receptacle at the upper end of the coupling member, and an upward-facing hub at the upper end of the spool body releasably engages the receptacle at the lower end of the coupling member.   
     
     
         36 . The containment cap of  claim 31 , wherein the second throughbore has a first end intersection the first throughbore and a second end distal the first throughbore, wherein the second end of the second throughbore is coupled to a choke valve. 
     
     
         37 . The containment cap of  claim 36 , wherein the lower assembly further comprises a fluid conduit extending from the choke valve, wherein the fluid conduit has a first end coupled to the choke valve and a second end distal the choke valve, and wherein the second end of the fluid conduit comprises an upward-facing hub configured to releasably engage a mating downward-facing receptacle. 
     
     
         38 . The containment cap of  31 , wherein the first throughbore of the spool body is configured to provide full bore access to the wellbore. 
     
     
         39 . The containment cap of  claim 35 , wherein the lower assembly, the valve assembly, the cap, and the coupling member are each configured to be air freightable. 
     
     
         40 . The containment cap of  claim 39 , wherein the lower assembly has a first weight and the valve assembly has a second weight;
 wherein the sum of the first weight and the second weight is less than 120 tons.