AU2013204745A1

AU2013204745A1 - Hydrocarbon Conduit Connection

Info

Publication number: AU2013204745A1
Application number: AU2013204745A
Authority: AU
Inventors: Jim Lawson HUGHES; Dale Parker
Original assignee: HP WELLHEAD SOLUTIONS Pty Ltd
Current assignee: HP WELLHEAD SOLUTIONS Pty Ltd
Priority date: 2012-10-11
Filing date: 2013-04-12
Publication date: 2014-05-01
Also published as: WO2014056045A1

Abstract

An apparatus 520 for connecting to a hydrocarbon conduit 501 comprises a sealing device 502 including a body 532 through which a passage 533 for receiving the conduit 501 extends. A seal 546 is operable to seal a gap between the body 532 and the conduit 501. Figure 3. scyt ~*511 b~j BOTTOM FIGURE 1 512 ......................... \. - . . . .. . .. .. .

Description

1 HYDROCARBON CONDUIT CONNECTION FIELD OF THE INVENTION [0001] The present invention relates generally to connecting to a hydrocarbon conduit. [0002] Although the present invention will be described with particular reference to being used to connect to a riser pipe extending from a subsea hydrocarbon well, it will be appreciated that it is not necessarily limited to this particular use and that it may be used to connect to other hydrocarbon conduits. For example, it may be used to connect to a hydrocarbon conduit such as a hydrocarbon pipeline or flowline. BACKGROUND ART [0003] A blowout in the context of well drilling is the uncontrolled release of crude oil and/or natural gas from an oil well or gas well after pressure control systems have failed. [0004] There have recently been a number of significant oil well blowouts. On 21 August 2009 the West atlas oil rig was involved in a blowout that occurred in the Timor Sea off the coast of Western Australia. Another blowout which resulted in the destruction and sinking of the Deepwater Horizon oil rig occurred in the Gulf of Mexico on 20 April 2010. [0005] Both the Timor Sea blowout and the Gulf of Mexico blowout resulted in the uncontrolled release of large quantities of crude oil and natural gas into the surrounding environment. The release of this crude oil and natural gas has been quite harmful to the surrounding environments as well as to the wildlife inhabiting those environments. [0006] When drilling a well, a large specialised valve called a "blowout preventer" or "BOP" is normally used to cope with extreme erratic pressures and uncontrolled flow (formation kick) emanating from a well reservoir, and for preventing well blowouts. In addition to controlling the downhole pressure and the flow of oil and gas, blowout preventers are intended to prevent tubing (e.g. drill pipe and well casing), tools and drilling fluid from being blown out of the wellbore when a blowout threatens. Blowout preventers are critical to the safety 2 of crew, rig, and the environment, and to the monitoring and maintenance of well integrity. Consequently, blowout preventers are intended to be fail-safe devices. [0007] Blowout preventers are installed early on in the process of drilling a well before any blowouts can occur. In the event of a blowout of a well which has a blowout preventer installed, the blowout preventer can usually be successfully operated to bring the well back under control. However, if a problem occurs with the blowout preventer itself so that it cannot bring a blownout well back under control, it can be very difficult to regain control over the well. In such situations, it would be desirable to have an apparatus that can be readily installed on the well after the blowout has occurred, and that can be employed to bring the well back under control. [0008] It is against this background that the present invention has been developed. SUMMARY OF THE INVENTION [0009] It is an object of the present invention to overcome, or at least ameliorate, one or more of the deficiencies of the prior art mentioned above, or to provide the consumer with a useful or commercial choice. [0010] Other objects and advantages of the present invention will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, a preferred embodiment of the present invention is disclosed. [0011] According to a first broad aspect of the present invention, there is provided an apparatus for connecting to a hydrocarbon conduit, the apparatus comprising a sealing device including a body through which a passage for receiving the conduit extends, and a seal operable to seal a gap between the body and the conduit. [0012] Preferably, the apparatus is adapted for connecting to a riser that extends from the wellbore of a hydrocarbon well such as a subsea hydrocarbon well, for example. It is also preferred that the apparatus is for connecting to a hydrocarbon conduit such as a hydrocarbon pipeline or flowline. [0013] Preferably, the passage comprises a bore.

3 [0014] Preferably, the sealing device comprises an annular blowout preventer valve, and the seal comprises a packing unit of the annular blowout preventer valve. It is preferred that the annular blowout preventer valve comprises a spherical blowout preventer valve. [0015] Preferably, the apparatus also comprises a guide for guiding the conduit into the passage of the sealing device body. By guiding the conduit into the passage of the sealing device body, the guide allows for easy alignment and engagement of the sealing device body with the conduit. It is preferred that the guide comprises a funnel. [0016] To prevent or at least inhibit the momentum of a hydrocarbon stream that emanates from the conduit from impacting the guide and creating side loads which could make it difficult or impossible to insert the conduit into the passage of the sealing device body, one or more openings may be provided in a side wall of the guide so that at least some of the hydrocarbon stream can pass through the side wall of the guide without exerting high loads on the guide, sealing device, or any components that may be secured thereto (e.g. a riser assembly). Although the openings may be any suitable shape, it is preferred that the openings comprise slots. The size, shape, and arrangement of the slots are preferably such that the guide is configured substantially as a cage. [0017] Preferably, the apparatus also comprises a securing device for securing the apparatus to the conduit. Preferably, the securing device comprises one or more pins operable to be inserted into one or more latching/locking features of the conduit. Preferably, the one or more latching/locking features comprise one or more holes in a wall of the conduit. Preferably, the securing device comprises a compression fitting. [0018] Preferably, the apparatus also comprises a drill for drilling the one or more holes in the wall of the conduit. [0019] Preferably, the apparatus also comprises a diverter valve operable to divert a fluid flowing from the conduit. It is preferred that the diverter valve is also operable to actuate the sealing device so that the seal of the sealing device is able to seal the gap between the sealing device body and the conduit. Preferably, the diverter valve comprises a piston, a valve body comprising a 4 valve seat for the piston to seal against, and an inlet that extends through the valve body of the diverter valve to the valve seat so that a fluid injected through the inlet is able to clean the valve seat. [0020] Preferably, the apparatus also comprises an automatic fail-safe device/system that is able to operate the diverter valve in the event of the failure of other systems that are operable to control the diverter valve. [0021] Preferably, the apparatus also comprises a riser or other conduit such as a flowline through which a fluid flowing from the hydrocarbon conduit is able to flow. [0022] Preferably, the apparatus also comprises a cutting device for cutting off a portion of the conduit prior to the passage of the sealing device receiving the conduit. It is preferred that the cutting device comprises a saw. [0023] Preferably, the apparatus also comprises a jamming prevention device for preventing the cutting device from jamming as it cuts through the conduit. For example, the jamming prevention device is able to prevent a partially cut-off portion of the conduit from collapsing under its own weight or the weight of any devices secured to it back on to the remainder of the conduit and the cutting device as the conduit is being cut. [0024] Preferably, the apparatus also comprises a clamping device for clamping the apparatus to the conduit. [0025] Preferably, the apparatus also comprises a hydraulic cylinder operable to lower the sealing device on to the conduit. [0026] Preferably, the apparatus also comprises a support for supporting the apparatus on a substantially horizontal surface when the conduit has a substantially horizontal orientation. [0027] Preferably, the apparatus also comprises a choke and kill line that is able to communicate with the passage of the sealing device body. Preferably, the apparatus also comprises a control valve that is connected to the choke and kill line.

5 [0028] According to a second broad aspect of the present invention, there is provided a method of connecting the apparatus according to the first broad aspect of the present invention to a hydrocarbon conduit, the method comprising the steps of: inserting the conduit into the passage of the sealing device body of the apparatus; and actuating the sealing device so that the seal of the sealing device is able to seal a gap between the body of the device and the conduit. [0029] According to a third broad aspect of the present invention, there is provided a sealing device for the apparatus according to the first broad aspect of the present invention, the sealing device comprising a body through which a passage for receiving a hydrocarbon conduit extends, and a seal operable to seal a gap between the body and the conduit. [0030] According to a fourth broad aspect of the present invention, there is provided a method of operating the sealing device according to the third broad aspect of the present invention, the method comprising the steps of: inserting a hydrocarbon conduit into the passage of the sealing device body; and actuating the sealing device so that the seal of the sealing device is able to seal a gap between the body of the device and the conduit. BRIEF DESCRIPTION OF THE DRAWINGS [0031] In order that the invention may be more fully understood and put into practice, a preferred embodiment thereof will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a subsea well riser and a partial cross-sectional perspective view of a first preferred embodiment of an apparatus for connecting to the riser; Figure 2 is a perspective view of a subsea well riser and a partial cross-sectional perspective view of a second preferred embodiment of an apparatus for connecting to the riser; Figure 3 is a cross-sectional view of the sealing device and the diverter valve of the apparatus depicted in figure 2; 6 Figure 4 is a perspective view of a lower portion of the apparatus depicted in figure 2 which includes the clamping device, one of the drilling devices, and the hydraulic cylinders for lowering the sealing device over the well riser; Figure 5 is a cross-sectional plan view of the apparatus depicted in figure 2 which depicts the clamping device, and the hydraulic cylinders for lowering the sealing device over the well riser; Figure 6 is a perspective view of the cutting device of the apparatus depicted in figure 2 and the hydraulic cylinders for lowering the sealing device of the apparatus over the well riser; Figure 7 is a cross-sectional plan view of the apparatus depicted in figure 2 which depicts the cutting device, and the hydraulic cylinders for lowering the sealing device over the well riser; Figure 8 is a perspective view of the sealing device and funnel of the apparatus depicted in figure 2 when the sealing device comprises an annular blowout preventer valve rather than a spherical blowout preventer valve; Figure 9 depicts the sealing device of the apparatus depicted in figure 2 when the sealing device comprises an annular blowout preventer valve and as the sealing device is lowered on to the riser by the hydraulic cylinders of the apparatus; Figure 10 is a perspective view of the apparatus depicted in figure 9 when a riser pipe is connected to the annular blowout preventer; Figure 11 is a cross-sectional plan view of the apparatus which is similar to figure 7 except that it also shows a support which can be used to support the apparatus on the seabed when the riser has a horizontal orientation; Figure 12 is a diagrammatic cross-sectional view of the sealing device depicted in figure 3 and a first alternative diverter valve; Figure 13 is a diagrammatic cross-sectional view of the sealing device depicted in figure 3 and a second alternative diverter valve; Figure 14 is a diagrammatic cross-sectional view of the sealing device depicted in figure 3 and a third alternative diverter valve; and Figure 15 is a cross-sectional view of a third preferred embodiment of an apparatus for connecting to a subsea well riser.

7 DESCRIPTION OF EMBODIMENTS [0032] In the drawings, like features have been referenced with like reference numbers. [0033] Referring to figure 1 there is shown an apparatus/rescue riser clamp 500 for connecting to a hydrocarbon conduit in the form of a subsea hydrocarbon well riser pipe 501. [0034] Apparatus 500 comprises a sealing device 502 that comprises an annular blowout preventer valve 503. Annular blowout preventer valve 503 includes a body 504 through which a passage in the form of a bore 505 for receiving the pipe 501 extends. In addition, annular blowout preventer valve 503 includes a seal comprising a packing unit (not depicted) operable to seal a gap (not depicted) between the body 504 and the pipe 501 so that a fluid flowing from the pipe 501 is prevented by the seal from leaking out of the bore 505 through the gap. [0035] A guide comprising a funnel 506 for funneling the fluid flowing from the pipe 501 into the bore 505 of the sealing device 502 and for guiding the pipe 501 into the bore 505 is secured to a lower end 507 of the body 504 using appropriate flange adaptors, bolts, gaskets, etc. [0036] A securing device 508 for securing the apparatus 500 to the pipe 501 is secured to an upper end 509 of the body 504. Securing device 509 includes a body 510 through which the bore 505 extends. A plurality of screw-in locking pins 511 are housed within the body 510 and are able to be extended into and retracted out of the bore 505 by screwing them in an appropriate direction. [0037] Prior to inserting the pipe 501 into the bore 505 of the sealing device 502, one or more holes 512 are drilled in a wall 513 of the pipe 501. The purpose of these holes 512 is to receive the pins 511 of the securing device 508 so that the apparatus 500 is thereby secured to the pipe 501. [0038] Apparatus 500 can include other components such as a diverter valve, riser pipe, or another blow out preventer valve so that the fluid flowing from the pipe 501 is able to flow through them. For example, if hydrocarbons such as crude oil and/or natural gas are flowing uncontrolled from the pipe 501 8 and into the surrounding environment for some reason, the apparatus 500 could include a diverter valve and another blowout preventer valve. The diverter valve would enable the apparatus 500 to be initially used to divert the hydrocarbons to storage tanks so that the hydrocarbons do not continue to pollute the surrounding environment. Then, the additional blowout preventer valve and the diverter valve could be operated to completely shut down the flow of hydrocarbons from the pipe 501. [0039] In such a scenario, the apparatus 500 could be lowered on to the pipe 501, with or without the assistance of a Remotely Operated underwater Vehicle (ROV), by a crane of a Mobile Offshore Drilling Unit (MODU) which is positioned above the pipe 501. Once the apparatus 500 has been lowered on to the pipe 501 following the drilling of the holes 512 through the pipe wall 513, the ROV would operate the securing device 508 so that the pins 511 are inserted into the holes 512 to thereby secure the apparatus 500 to the pipe 501. [0040] An apparatus/rescue riser clamp 520 for connecting to a subsea hydrocarbon well riser pipe 501 is depicted in figures 2 to 7. [0041] Like the apparatus 500, the apparatus 520 comprises a sealing device 502 that comprises an annular blowout preventer 503. However, the annular blowout preventer 503 of the apparatus 520 is a spherical blowout preventer 521. [0042] Apparatus 520 also includes a diverter valve 522. Diverter valve 522 includes a valve body 523 that includes a passage in the form of a bore 524 through which fluid flowing from the pipe 501 is able to flow. Valve body 523 also includes a plurality of outlets 525 connected to the bore 524 by a plurality of upwardly inclined passages 526 so that the fluid flowing through the bore 524 is able to be diverted to flow from the bore 524 and out of the valve body 523 through each outlet 525 instead of all of the way through the bore 524. [0043] Diverter valve 522 also includes a hollow piston 527 that is received by the bore 524 of the valve body 523. Piston 527 is slidingly moveable along the bore 524 of the valve body 523 so as to control the flow of the fluid through each outlet 525 and to actuate the sealing device 502.

9 [0044] An upper end 528 of the valve body 523 is machined or otherwise configured so that it is able to be connected to a riser pipe 529 which is also part of the apparatus 520. [0045] The valve body 523 includes a valve seat 530, and an upper end 531 of the piston 527 is configured so that the upper end 531 is able to sealingly engage with the valve seat 530. [0046] The spherical blowout preventer valve 521 comprises an annular valve body 532 that includes a passage in the form of a bore 533 through which fluid flowing from the pipe 501 is able to flow. The valve body 532 is inserted into the bore 524 of the diverter valve body 523 such that the valve body 532 and the piston 527 overlap with each other as shown in figure 3. The diverter valve body 523 and the blowout preventer valve body 532 are secured together by a H4 connector or a latch locking system (not depicted). The valve bodies 523, 532 are secured together such that the joint between them is sealed. [0047] A piston chamber 534 is defined by the valve bodies 523, 532. The piston chamber 534 is sealed by a plurality of O-ring seals (not depicted) that are located in grooves 535 in the valve body 523, and by a plurality of O-ring seals (not depicted) that are located in a plurality of grooves 536 in the valve body 532. The piston chamber 534 is divided into separate sealed sections by a plurality of O-ring seals (not depicted) that are located in a plurality of grooves 537 in the piston 527. [0048] The maximum length of travel of the piston 527 in the piston chamber 534 is the same as the length of an upper section 538 of the piston 527. [0049] A hollow piston 539 is received by the bore 524 such that the piston 539 is slidingly moveable along the bore 524 and such that the piston 539 overlaps with the piston 527 as shown. A piston chamber 540 is defined by the valve body 532. The piston chamber 540 is sealed by a plurality of O-ring seals (not depicted) that are located in a plurality of grooves 541 and 542 in the piston 539, and by the plurality of O-ring seals (not depicted) in the plurality of grooves 536 in the piston 527. [0050] The maximum length of travel of the piston 527 in the piston chamber 540 is roughly 75% of the maximum length of travel of the piston 527 in the 10 piston chamber 534. Consequently, the diverter valve 522 can only be opened by roughly 75% before the piston 527 reaches the maximum extent of its travel within the piston chamber 540. [0051] A seal ring 543 is inserted into the bore 533 such that it extends around the piston 539. The seal ring 543 is secured to a removable head 544 that includes a curved, spherical inner surface 545. A packing unit 546 is disposed between the piston 539 and the head 544. The head 544 is secured to the valve body 532 by a plurality of bolts and/or a latch locking system. A wear plate (not depicted) is located between the head 544 and the packing unit 546, and another wear plate (not depicted) is located between the piston 539 and the packing unit 546. [0052] Like apparatus 500, the apparatus 520 includes a funnel 506 for funneling fluid flowing from the pipe 501 into the bore 533 of the valve body 532. A lower end 547 of the head 544 is machined or otherwise configured so that it is able to be connected to the funnel 506. [0053] The packing unit 546 includes a curved, rubber or elastomeric annular body 548, and a plurality of curved metal inserts (not depicted) corresponding to the curved, spherical inner surface 545 of the head 544. The metal inserts are disposed within the annular body 548 in a generally circular fashion and spaced apart in radial planes extending from a central axis of the bore 533. [0054] The piston 539 resides in a piston chamber 549 which is sealed by the plurality of O-ring seals located in the grooves 542 in the piston 539, and by a plurality of O-ring seals (not depicted) that are located in grooves 550 in the seal ring 543. The seal ring 543 and the O-rings located in the grooves 550 seal the chamber 549 off from the packing unit 546. The piston chamber 549 is divided into separate sealed section by a plurality of O-ring seals (not depicted) that are located in a plurality of grooves 551 in the piston 539. [0055] The piston 539 reaches its maximum extent of upward travel in the piston chamber 549 when the piston 527 reaches it maximum extent of upward travel in the piston chamber 534. [0056] The valve body 523 includes a port 552 that is connected to an upper section of the piston chamber 534, and a port 553 that is connected to a lower 11 section of the piston chamber 534. Hydraulic fluid can be pumped into or vented from the upper section of the piston chamber 534 via the port 552. Similarly, hydraulic fluid can be pumped into or vented from the lower section of the piston chamber 534 via the port 553. [0057] The valve body 532 includes a port 554 that is connected to the piston chamber 540 so that hydraulic fluid can be pumped into or vented from the piston chamber via the port 554. [0058] Sealing device 502 and the funnel 506 of the apparatus 520 are secured to a support frame 555 which is in turn secured to four pistons 556 belonging to four upstanding hydraulic cylinders 557. Cylinders 557 are operable to lower the sealing device 502 on to the pipe 501, and can also be used to raise the sealing device 502 above the pipe 501. [0059] Apparatus 520 also includes a clamping device 558 for clamping the apparatus 520 to the pipe 501. Clamping device 558 includes a pipe backrest 559 which is secured to a cross member 560 and a cross member 561 which are both secured to the same pair of cylinders 557 such that they extend between the cylinders 557 at different locations. Two jaws 562 are hinged to the backrest 559 and the jaws 562 are operable to be opened and closed by a respective hydraulic cylinder 563 that extends between and that is secured to each jaw 562 and the cross member 560. Jaws 562 are also operable to be opened and closed by a respective hydraulic cylinder 564 that extends between and that is secured to each jaw 562 and a respective cross member 565 secured to a respective pair of the hydraulic cylinders 557. Cylinders 563 and 564 are operable to open and close the jaws 562 such that the pipe 501 is able to be clamped by the jaws 562 between them and the backrest 559 as shown. The locations of the hinges that secure the jaws 562 to the backrest 559 are off centre to allow for easy insertion and removal of the pipe 501 against the backrest 559 and between the jaws 562. [0060] Inserts (not depicted) may be fitted to the back rest 559 and the jaws 562 so that smaller diameter pipes are able to be clamped by the jaws 562 between them and the backrest 559.

12 [0061] Although not shown in the drawings, the apparatus 520 may also include a securing device 508 for securing the apparatus 520 to the pipe 501. To enable the securing device 508 to secure the apparatus 520 to the pipe 501, the apparatus 520 may also include three drills 566 for drilling three holes 512 in the wall 513 of the pipe 501 for receiving the pins 511 of the securing device 508. The drills 566 may for example be hydraulic, electric, or ROV operated drills. Two of the drills 566 are each secured to a respective one of the jaws 562, with the third drill 566 being secured to the backrest 559. [0062] Apparatus 520 also includes a cutting device 567 for cutting off a portion of the pipe 501 prior to the bore 533 of the sealing device 502 receiving the pipe 501. Cutting device 567 comprises a saw 568 and includes a motor 569 that is secured to the cross member 561. Motor 569 may for example be a hydraulic, electric, or ROV operated motor. A rotatable drive shaft 570 is coupled to the motor 569 and to a respective gearbox 571 secured to each cross member 565 such that the motor 569 is able to rotate the shaft 570 about its longitudinal axis. A respective threaded drive shaft 572 is coupled to each gearbox 571 and extends along a respective one of the cross members 565 as shown. The threaded drive shafts 572 are secured to the cross members 565 and are coupled to the gearboxes 571such that they are able to be rotated about their longitudinal axes by the motor 569. A travelling block 573 is slideably engaged with a dovetail track way 574 of one of the cross members 565, and a motor 575 is slideably engaged with a dovetail track way 576 of the other one of the cross members 565. The block 573 and the motor 575 are coupled to the drive shafts 572 such that rotation of the drive shafts 572 by the motor 569 causes the block 573 and the motor 575 to respectively slideably move along the way 574 and the way 576. Reversing the direction of rotation of the motor 569 causes the block 573 and the motor 575 to slideably move along the ways 574, 576 in the opposite direction. Motors 569 and 575 may for example be hydraulic, electric, and/or ROV operated motors. An endless cutting chain 577 is trained around a drive wheel or sprocket 578 which is able to be rotated by the motor 575, and around an idler wheel or sprocket 579 which is mounted on the block 573 such that it is able to rotate relative thereto. Cutting chain 577 can be circulated around the wheels 578, 579 by operating the motor 575. The direction of circulation of the cutting chain 577 can be reversed simply by operating the 13 motor 575 to reverse the direction of rotation of the drive wheel 578. The tension on the cutting chain 577 can be adjusted by moving the wheel 579 so that it is displaced relative to the wheel 578. [0063] Saw 568 is able to cut through the pipe 501 by firstly operating the motor 569 to position the block 573 and the motor 575 along the threaded shafts 572 such that the cutting chain 577 is located off to one side of the pipe 501. Motor 575 rotates the cutting chain 577 at an appropriate speed and in an appropriate direction to cut the pipe 501. As the chain 577 cuts through the pipe 501, motor 569 is operated to progressively move the block 573 and the motor 575 further towards the pipe 501 in a synchronous manner. After the saw 568 has cut through the pipe 501 the motor 575 is operated so that circulation of the chain 577 ceases and the motor 569 is operated to return the block 573 and motor 575 to their starting positions on the opposite side of the pipe 501. [0064] Apparatus 520 may also include a jamming prevention device 580 for preventing the cutting device 567 from jamming as it cuts through the pipe 501. Jamming prevention device 580 may include a hydraulic cylinder 581 that is operable to drive a pointed member such as a chisel-ended member in to the cut in the pipe 501 behind the cutting chain 577 so that the pointed member is able to prevent the portion of the pipe 501 above the cut resting on the chain 577 and preventing it from circulating. [0065] Instead of the apparatus 520 having a spherical blowout preventer 521, it may have an annular blowout preventer valve 590 as shown in figure 8. [0066] Also, as shown in figure 9, the apparatus 520 need not include the diverter valve 522 or anything else connected to the sealing device 502. However, in some situations, the riser pipe 529 may be connected directly to the sealing device 502 as shown in figure 10. [0067] The riser pipe 529 may extend to an intervention vessel or an oil rig and may allow tooling to be passed through the diverter valve 522 (if present) and the sealing device 502 once they are securely locked on to the riser pipe 501. The diverter valve 522 is able to divert the flow of hydrocarbons from the riser pipe 501 through the outlets 525 so that it is then possible to restring the well.

14 [0068] The apparatus 520 can be employed in a similar manner to the apparatus 500 to bring a well that includes the riser 501 under control. The apparatus 520 can be lowered as a single unit over the riser 501 by a crane that is connected to the apparatus 520 by a plurality of cables that are connected to the tops of the hydraulic cylinders 557. Alternatively, the apparatus 520 can be lowered as a single unit over the riser 501 by a riser or string attached to the diverter valve 522 (if present), or the sealing device 502 if the apparatus 520 does not include the diverter valve 522. A ROV may be used to assist in positioning the apparatus 520 over the riser 501. [0069] The apparatus 520 is positioned relative to the riser 501 so that the riser 501 contacts the backrest 559 and is located between the jaws 562 of the clamping device 558. The flow rate of hydrocarbons from the riser 501 will generally be very high, consequently the clamping device 558 is brought into proximity of the riser 501 from the side of the riser 501 such that the sealing device 502 is not passed across the stream of hydrocarbons flowing out of the riser 501 which would tend to deflect the sealing device 502 off centre relative to the riser 501. If it is necessary to remove a portion of the riser 501 or a piece of equipment connected to the riser 501 which is damaged and/or which will prevent the riser 501 being received by the sealing device 502, the cutting device 567 is positioned so that it is located beneath that portion of the riser 501. The hydraulic cylinders 563, 564 of the clamping device 558 are operated so that the riser 501 is firmly clamped between the jaws 562 and the backrest 559 of the clamping device 558. The cutting device 567 and the jamming prevention device 580 are operated in the previously described manner to cut off and dress the portion of the riser 501 which is located above the cutting device 567. Also, the drills 566 are operated to drill the holes 512 in the pipe wall 513. [0070] Once the cutting and drilling procedures have been completed, and the cutting chain 577 has been returned to its starting position adjacent to the motor 569 of the cutting device 558, the jaws 562 of the clamping device 558 are loosened by suitably operating the hydraulic cylinders 563, 564. The crane or riser to which the apparatus 520 is still attached is then operated so as to lower the apparatus 520 further down the riser 501 to a position which will allow the sealing device 502 to be lowered on to the riser by operating the hydraulic 15 cylinders 557, and which will also allow the securing device 508 (if present) to be operated to insert the pins 511 into the holes 512 so that the apparatus 520 is securely locked to the riser 501. [0071] After operating the clamping device 558 to clamp the repositioned apparatus 520 to the riser 501, the hydraulic cylinders 557 are operated to retract the pistons 556 so that the sealing device 502 is drawn down over the riser 501 in such a manner that the riser 501 is received by the bore 533 of the sealing device 502. If the apparatus 520 includes a securing device 508, the sealing device 502 is drawn down over the riser 501 so that the securing device 508 can be operated to insert its pins 511 into the holes 512 in the pipe wall 513 so that the apparatus 520 is securely locked to the riser 501. The funnel 506 guides the riser pipe 501 into the sealing device 502 and also guides fluid flowing from the pipe 501 into the device 502. [0072] The sealing device 502 is operated so that that the gap between the valve body 523 and the riser 501 is sealed by the seal of the sealing device 502 so that any hydrocarbons flowing from the riser 501 cannot pass or leak through the gap at the bottom of the sealing device 502. [0073] In the case of the sealing device 502 being the spherical blowout preventer valve 521, the packing unit 546 which functions as the seal can be operated to seal the gap. This can be done in a number of ways. One way is to pump hydraulic fluid into the upper section of the piston chamber 549 through a port in the valve body 532 that leads to the chamber 549, and by allowing hydraulic fluid in the lower section of the piston chamber 549 to be vented through another port in the valve body 532 that leads to the chamber 549. This moves the piston 539 downwardly along the bore 533. As the piston 539 moves downwards it translates force to packing unit 546. The force translated to the packing unit 546 from the piston 539 is directed downward toward the head 544. Because the packing unit 546 is retained against the curved, spherical inner surface 545 of the head 544, the packing unit 546 displaces downward and inwardly, which compresses the packing unit 546 against the riser 501 so that the packing unit 546 forms a seal between the riser 501 and the valve body 532. [0074] Another way to operate the spherical blowout preventer valve 521 so that the packing unit 546 forms a seal between the riser 501 and the valve body 16 532 is by operating the diverter valve 522 so that the diverter valve 522 thereby actuates the spherical blowout preventer 521. This can be accomplished by pumping hydraulic fluid into the upper section of the piston chamber 534 through the port 552 and by venting hydraulic fluid in the lower section of the piston chamber 534 through the port 553 so that the piston 527 is moved downwards towards the piston 539. As the piston 527 moves further towards the piston 539, hydraulic fluid in the piston chamber 540 is vented therefrom through the port 554. After the piston 527 reaches the piston 539 it continues to move downwards and forces the piston 539 to move downwards so that the piston 539 moves the packing unit 546 to the closed position where it forms a seal between the riser 501 and the valve body 532. As the piston 539 is forced to move downwards, hydraulic fluid is vented from the lower section of the piston chamber 549 so that the downward movement of the piston 539 is not impeded. [0075] Once the packing unit 546 is in the closed position, the hydraulic ports leading to the piston chamber 549 can be locked to prevent the piston 539 from moving upwards and causing the packing unit 546 to open. [0076] The diverter valve 522 remains in the fully open position for as long as is required for the well to remain open so that fluid flowing from the well is diverted to flow from the bore 524 and out of the valve body 523 through the outlets 525. [0077] This second method of operation of the spherical blowout preventer valve 521 can be particularly useful in the event that the spherical blowout preventer 521 has a hydraulic failure which prevents the packing unit 546 from being moved to the closed position by pumping hydraulic fluid into the upper section of the piston chamber 549 and venting hydraulic fluid from the lower section of the piston chamber 549. [0078] Operating the diverter valve 522 in the manner just described fully opens the valve 522 so that fluid that flows from the riser 501 is diverted to flow through the passages 526 and out of the outlets 525 of the diverter valve 522 rather than all of the way through the diverter valve 522 through the bore 524. The outlets 525 may be connected to pipes or hoses that lead to a storage tank on a floating production storage and offloading (FPSO) vessel or elsewhere so that the fluid is captured and does not pollute the surrounding environment. A 17 vacuum may be applied to the pipes or hoses connected to the outlets 525 to make it easier to fit the apparatus 520 on to the riser pipe 501. [0079] If the upper end 531 of the piston 527 is in sealing engagement with the valve seat 530, the piston 527 blocks the passages 526 and therefore the outlets 525 so that no fluid is able to flow from the bore 524 into the passages 526 and out of the valve body 523 through the outlets 525. Instead, the fluid will simply pass through the bore 524 and flow into the riser pipe 529. [0080] The diverter valve 522 is able to be opened by a maximum of about 75% before the piston 527 contacts the piston 539 of the spherical blowout preventer valve 521. As mentioned above, if the piston 527 is operated so as to operate the spherical blowout preventer valve 521, the diverter valve 522 will then be fully open (i.e. 100% open) so that more hydrocarbons can flow out of the valve body 523 through the outlets 525. [0081] Once the apparatus 520 has been fitted to the riser pipe 501 and the flow of hydrocarbons from the pipe 501 has been brought under control so that the hydrocarbons are flowing through the outlets 525, tooling can be run through the bore of the apparatus 520 to work the well to which the pipe 501 is connected so that the well can be repaired or relieved. [0082] The apparatus 500, 520 may include another blowout preventer valve (not depicted) such as an annular or spherical blowout preventer valve, for example. This additional blowout preventer valve may be operable to completely shut down the flow of hydrocarbons from the riser pipe 501. In the case of the apparatus 520 also including the diverter valve 522, the diverter valve 522 would also need to be closed in order for the flow of hydrocarbons from the riser pipe 501 to be completely shut down, and this would usually be done after the additional blowout preventer valve is closed. [0083] The diverter valve 522 can be closed by pumping hydraulic fluid into the lower section of the piston chamber 534 through the port 553, pumping hydraulic fluid into the piston chamber 540 through the port 554, and by allowing hydraulic fluid in the upper section of the piston chamber 534 to be vented out through the port 552. The diverter valve 522 is closed once the upper end 531 of the piston 527 sealingly engages with the valve seat 530 so that fluid from the 18 well to which the riser pipe 501 is connected is no longer able to flow from the bore 524 and out of the valve body 523 through the outlets 525. [0084] Once the diverter valve 522 is closed along with the additional blowout preventer valve, the well is shutdown so that fluid can no longer flow out of it from the riser pipe 501. [0085] If positive hydraulic pressure is applied to the piston 539 so that the piston 539 is driven towards the packing unit 546 when the packing unit 546 is closed and when the diverter valve 522 is closed, this hydraulic pressure will also act to keep the piston 527 closed. This consequently forms a double hydraulic locking system which provides added safety. [0086] In the case of the sealing device 502 of the apparatus 520 being the spherical blowout preventer valve 521, the spherical blowout preventer valve 521 can be opened to unseal the gap between the valve body 532 and the riser 501 by opening the packing unit 546. This can be accomplished by pumping hydraulic fluid into the lower section of the piston chamber 549 through the port connected to that section of the piston chamber 549, and by allowing hydraulic fluid in the upper section of the chamber 549 to be vented out through the ports connected to that section of the chamber 549. [0087] The apparatus 500, 520 can be unlocked from the riser pipe 501 by operating the securing device 508 (if present, in the case of the apparatus 520) so that the pins 511 are withdrawn from the holes 512 in the pipe wall 513. The pipe 501 can then be withdrawn from the sealing device 502. This is done by moving the sealing device 502 along the pipe 501 until the pipe 501 is no longer received by the sealing device 502. In the case of the apparatus 520, the pipe 501 can be removed from the sealing device 502 by operating the hydraulic cylinders 557 to extend the pistons 556. Before withdrawing the pipe 501 from the sealing device 502, the sealing device 502 will usually be operated so that the gap between the sealing device body and the pipe 501 is no longer sealed. [0088] Referring to figure 11, the apparatus 520 may also include a support 600 comprising a support frame 601 for supporting the apparatus 520 on the seabed when the riser 501 has a horizontal orientation that necessitates the apparatus 520 to also have a horizontal orientation. The support frame 601 is 19 secured to mounting points 602 on the cross members 565. Support frame 601 includes a plurality of hydraulic cylinders 603 for adjusting the height of the apparatus 520 above the seabed and for lowering the clamping device 558 on to the pipe 501. [0089] Figure 12 depicts the sealing device 502 depicted in figure 3 and a first alternative diverter valve 650 which is identical to the diverter valve 522 except that it also includes an automatic fail-safe device/system 651 that is able to operate the diverter valve 650 in the event of the failure of other systems that are operable to control the diverter valve 650. The automatic fail-safe device/system 651 includes a coil spring 652 that extends around the piston 527 and that is located on a lowering side of the piston 527 between the piston 527 and the valve body 523. The coil spring 652 is compressed when the diverter valve 650 is closed. If a problem arises and power or a signal is lost to the stack, a solenoid-operated valve (not depicted) of the diverter valve 650 will open so that hydraulic pressure on the opposite side of the piston 527 to the spring 652 will be released so as to allow the spring 652 to lower the piston 527 and open the diverter valve 650. Once the diverter valve 650 is opened the diverter valve 650 is able to divert the flow of fluid in the usual manner. The piston 527 is shown moving to an open position in figure 12. [0090] Figure 13 depicts the sealing device 502 depicted in figure 3 and a second alternative diverter valve 660 which is identical to the diverter valve 650 except that it includes a coil spring 661 located on a lifting side of the piston 527 between the piston 527 and the valve body 523. The coil spring 661 is compressed when the diverter valve 660 is open. If a problem arises and power or a signal is lost to the stack, a solenoid-operated valve (not depicted) of the diverter valve 660 will open so that hydraulic pressure on the opposite side of the piston 527 to the spring 661 will be released so as to allow the spring 661 to lift the piston 527 and close the diverter valve 660. Once the diverter valve 660 is closed the diverter valve 660 is unable to divert the flow of fluid. The piston 527 is shown moving to a closed position in figure 13. [0091] Figure 14 depicts the sealing device 502 depicted in figure 3 and a third alternative diverter valve 670 which is identical to the diverter valve 650 except that, in addition to the coil spring 652, it includes a coil spring 661 located 20 on a lifting side of the piston 527 between the piston 527 and the valve body 523. If a problem arises and power or a signal is lost to the stack while the diverter valve 670 is closed, a first solenoid-operated valve (not depicted) of the diverter valve 670 will open so that hydraulic pressure on the opposite side of the piston 527 to the spring 652 will be released so as to allow the spring 652 to lower the piston 527 and open the diverter valve 670. Once the diverter valve 670 is opened the diverter valve 670 is able to divert the flow of fluid in the usual manner. Alternatively, if a problem arises and power or a signal is lost to the stack while the diverter valve 670 is open, a second solenoid-operated valve (not depicted) of the diverter valve 670 will open so that hydraulic pressure on the opposite side of the piston 527 to the spring 661 will be released so as to allow the spring 661 to lift the piston 527 and close the diverter valve 670. Once the diverter valve 670 is closed the diverter valve 670 is unable to divert the flow of fluid. The piston 527 is shown in a closed position in figure 14. Combining the springs 652, 661 with the necessary hydraulics allows the fail-safe device/system 651 of the diverter valve 670 to function as a double locking system. [0092] Referring to figure 15, an apparatus 700 for connecting to a subsea well riser. Apparatus 700 includes a sealing device 502 and a diverter valve 522 which are very similar to the sealing device 502 and diverter valve 522 of the apparatus 520 except that the passages 526 of the diverter valve 522 of the apparatus 700 are downwardly inclined rather than upwardly inclined. [0093] The valve body 523 of the diverter valve 522 includes a plurality of inlets 701 that extend to the valve seat 530. The inlets 701 are part of a flushing or cleaning system that is operable to clean the valve seat 530 to ensure that the piston 527 is able to properly seal against the valve seat 530 when the valve 522 is closed. The flushing system functions by injecting a suitable cleaning fluid through the inlets 701 so that the fluid cleans the valve seat 530. [0094] Apparatus 700 also includes a securing device 508 in the form of a compression fitting 702 for sealingly securing the sealing device 502 to a pipe such as a well riser pipe that the apparatus 700 is to be connected to. Compression fitting 702 comprises a compression ring/collet 703 which is preferably made from a malleable metal such as copper or brass, for example. The compression ring/collet 703 is configured so that the pipe is able to be 21 inserted through it. In addition, the compression fitting 702 includes a compression sleeve/collet housing 704 that receives the compression ring/collet 703. A plurality of bolts 705 secure the compression sleeve/collet housing 704 to the removable head 544 of the sealing device 502. Each bolt 705 includes a respective torque multiplier 706. To secure the sealing device 502 to a pipe using the compression fitting 702, the pipe is inserted through the compression ring/collet 703. The torque multipliers 706 are then operated to tighten the bolts 705. As the bolts 705 are tightened, the compression sleeve/collet housing 704 is drawn towards the head 544. As the compression sleeve/collet housing 704 is drawn towards the head 544, the compression ring/collet 703 is sealingly compressed against the pipe. [0095] Although not shown in figure 15, the apparatus 700 includes a plurality of choke and kill lines that are able to communicate with bores 524, 533. Each choke and kill line is able to be used to supply kill mud to a well that the apparatus 700 is connected to, measure the pressure in the well, periodically flush or clean the interior of the apparatus 700, and/or quench gas which may emanate from the well. A respective control valve (not depicted) connected in series with each choke and kill line is operable to open or close the line. [0096] Each apparatus 500, 520, and 700 is configurable as a work through apparatus so that drill strings, wirelines, or other equipment are able to be inserted through it and the bore of the conduit (e.g. well riser) to which the apparatus is connected so that work can be carried out through the conduit bore while the apparatus is connected to the conduit. [0097] It will be appreciated by those skilled in the art that variations and modifications to the invention described herein will be apparent without departing from the spirit and scope thereof. The variations and modifications as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth. [0098] Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

22 [0099] Throughout the specification and claims, unless the context requires otherwise, the term "substantially" or "about" will be understood to not be limited to the value for the range qualified by the terms. [00100] Also, future patent applications may be filed in Australia or overseas on the basis of, or claiming priority from, the present application. It is to be understood that the following provisional claims are provided by way of example only, and are not intended to limit the scope of what may be claimed in any such future application. Features may be added to or omitted from the provisional claims at a later date so as to further define or re-define the invention or inventions. Moreover, additional claims may be added at a later date so as to claim other aspects of the invention. [00101] It will be clearly understood that, if a prior art publication is referred to herein, that reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

Claims

1. An apparatus for connecting to a hydrocarbon conduit, the apparatus comprising a sealing device including a body through which a passage for receiving the conduit extends, and a seal operable to seal a gap between the body and the conduit.

2. The apparatus defined by claim 1, wherein the apparatus is adapted for connecting to a riser that extends from a wellbore of a hydrocarbon well.

3. The apparatus defined by claim 1, wherein the apparatus is adapted for connecting to a hydrocarbon pipeline or flowline.

4. The apparatus defined by any one of the preceding claims, wherein the passage comprises a bore.

5. The apparatus defined by any one of the preceding claims, wherein the sealing device comprises an annular blowout preventer valve, and the seal comprises a packing unit of the annular blowout preventer valve.

6. The apparatus defined by claim 5, wherein the annular blowout preventer valve comprises a spherical blowout preventer valve.

7. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a guide for guiding the conduit into the passage of the sealing device body.

8. The apparatus defined by claim 7, wherein the guide comprises a funnel.

9. The apparatus defined by claim 7 or 8, wherein the guide comprises a side wall that includes one or more openings.

10. The apparatus defined by claim 9, wherein the openings comprise slots.

11. The apparatus defined by claim 10, wherein the guide is configured substantially as a cage.

12. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a securing device for securing the apparatus to the conduit. 24

13. The apparatus defined by claim 12, wherein the securing device comprises one or more pins operable to be inserted into one or more latching/locking features of the conduit.

14. The apparatus defined by claim 13, wherein the one or more latching/locking features comprise one or more holes in a wall of the conduit.

15. The apparatus defined by claim 12, wherein the securing device comprises a compression fitting.

16. The apparatus defined by claim 14, wherein the apparatus also comprises a drill for drilling the one or more holes in the wall of the conduit.

17. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a diverter valve operable to divert a fluid flowing from the conduit.

18. The apparatus defined by claim 17, wherein the diverter valve is also operable to actuate the sealing device so that the seal of the sealing device is able to seal the gap between the sealing device body and the conduit.

19. The apparatus defined by any one of claims 17 to 18, wherein the diverter valve comprises a piston, a valve body comprising a valve seat for the piston to seal against, and an inlet that extends through the valve body of the diverter valve to the valve seat so that a fluid injected through the inlet is able to clean the valve seat.

20. The apparatus defined by any one of claims 17 to 19, wherein the apparatus also comprises an automatic fail-safe device/system that is able to operate the diverter valve in the event of the failure of other systems that are operable to control the diverter valve.

21. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a riser or other conduit such as a flowline through which a fluid flowing from the hydrocarbon conduit is able to flow.

22. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a cutting device for cutting off a portion of the conduit prior to the passage of the sealing device receiving the conduit. 25

23. The apparatus defined by claim 22, wherein the cutting device comprises a saw.

24. The apparatus defined by any one of claims 22 to 23, wherein the apparatus also comprises a jamming prevention device for preventing the cutting device from jamming as it cuts through the conduit.

25. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a clamping device for clamping the apparatus to the conduit.

26. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a hydraulic cylinder operable to lower the sealing device on to the conduit.

27. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a support for supporting the apparatus on a substantially horizontal surface when the conduit has a substantially horizontal orientation.

28. The apparatus defined by any one of the preceding claims, wherein the apparatus also comprises a choke and kill line that is able to communicate with the passage of the sealing device body.

29. The apparatus defined by claim 28, wherein the apparatus also comprises a control valve that is connected to the choke and kill line.

30. A method of connecting the apparatus defined by any one of the preceding claims to a hydrocarbon conduit, the method comprising the steps of: inserting the conduit into the passage of the sealing device body of the apparatus; and actuating the sealing device so that the seal of the sealing device is able to seal a gap between the body of the device and the conduit.

31. A sealing device for the apparatus defined by any one of claims 1 to 29, the sealing device comprising a body through which a passage for receiving a hydrocarbon conduit extends, and a seal operable to seal a gap between the body and the conduit. 26

32. A method of operating the sealing device defined by claim 31, the method comprising the steps of: inserting a hydrocarbon conduit into the passage of the sealing device body; and actuating the sealing device so that the seal of the sealing device is able to seal a gap between the body of the device and the conduit.

33. An apparatus for connecting to a hydrocarbon conduit, the apparatus being substantially as hereinbefore described with reference to the drawings.

34. A method of connecting an apparatus to a hydrocarbon conduit, the method being substantially as hereinbefore described with reference to the drawings.

35. A sealing device for an apparatus, the sealing device being substantially as hereinbefore described with reference to the drawings.

36. A method of operating a sealing device, the method being substantially as hereinbefore described with reference to the drawings.