Patent Grant
9759021
The invention generally relates to offshore drilling rigs, often also referred to as offshore drilling platforms. More particularly, the invention relates to an apparatus and a method for the handling of marine riser joints on a floatable drilling vessel such as a semi-submersible drilling rig or drill ship.
Floatable offshore drilling rigs are widely used in the exploration and exploitation of hydrocarbon reservoirs under the sea floor, in particular at relatively high water depths.
One type of floatable drilling rig is the semi-submersible drilling rig that typically obtains its buoyancy from ballasted, watertight pontoons located below the ocean surface and wave action. The operating deck can be located high above the sea level due to the high stability of the design, and therefore the operating deck is kept well away from the waves. Structural columns connect the pontoons and operating deck. Another type of floatable drilling vessels is a drill ship.
Offshore drilling rigs and, in particular, floatable offshore drilling rigs utilise a variety of tubular equipment, such as drill pipes. Marine risers are a particular type of tubular equipment used in subsea drilling operations. The marine riser (in the present disclosure also simply referred to as the riser) is made up of marine riser joints. Most marine riser joints are large elongated structures, typically defining a main tube and a number of secondary tubes as well as a number of Buoyancy elements. During the drilling operation the marine riser joints are typically assembled to a string of marine riser joints forming the riser and lowered towards the sea floor so as to create a string of marine riser joints extending from the drilling rig to the sea floor. The drill string is then advanced through the central tube of the marine riser. Marine risers joints are very large and heavy tubular elements; typical risers joints are 50-75 ft and even 90 ft long and weigh many tons. Consequently they are difficult to handle, for example when loading or offloading them to/from the drilling rig, e.g. from/to a supply ship.
U.S. Pat. No. 4,129,221 discusses riser handling on a drill ship where the riser joints are stored in horizontal orientation and hoisted to the well centre by a crane.
However, on many drilling rigs it is preferred to store the riser joints in vertical orientation, as a vertical storage requires less deck space on the operational deck. U.S. Pat. No. 8,052,369, discloses an offshore drilling rig where tubulars are stored in a shaft in vertical position. The tubulars are lifted out of the shaft and across the main deck of the drilling rig towards a catwalk machine, where they are brought into horizontal position and axially fed through a V-door in the derrick to the well centre.
It is generally desirable to provide a drilling rig and corresponding riser handling apparatus allowing efficient, loading and offloading of riser joints onto/from the drill rig (e.g. for maintenance of the riser joints) and/or for efficient maintenance of riser joints.
Disclosed herein are embodiments of an offshore drilling rig.
According to one aspect, disclosed herein is an offshore drilling rig comprising:
Embodiments of the drilling rig disclosed herein allow riser joints that are stored in an upright position to be placed in a prostrate position, e.g. on the main deck of the drilling rig, without interfering with ongoing drilling operations at any of the well centers.
Once placed at the maintenance/transfer position, maintenance operations may be performed on the riser joint in a safe and efficient manner. Alternatively or additionally, the riser joint may by be picked up from the maintenance/transfer position by a crane and lifted, in prostrate orientation, off the drilling rig, e.g. onto a supply vessel. Similarly, riser joints may be loaded from a supply vessel onto the maintenance/transfer position and then moved to the upright storage position.
The term “well centre” refers to a hole in the drill floor deck through which the drilling rig is configured to lower tubular equipment towards the seabed, into the body of water on which the drilling rig floats and, in particular, through which tubular equipment may be lowered all the way to the seabed. A well centre is sometimes also referred to as a drilling centre. It will be appreciated that the drill floor deck may comprise additional holes such as foxholes and mouseholes that may e.g. be used for building stands of tubulars but through which the drilling rig cannot lower tubular equipment to the seabed and/or through which the drilling rig cannot perform drilling into the seabed e.g. by lacking a system arranged to rotate a drill string with sufficient force such as a top-drive or a turntable. In some embodiments, such an additional hole is a hole in the drill floor deck through which the drilling rig cannot progress a drill string through a riser system. In some embodiments, a well centre is differentiated from an additional hole by having a diverter and/or a diverter housing arranged below so that drill string passed through the well centre extends through said diverter or diverter housing. As the movement path does not intersect with any of the well centre or well centres, the or each well centre is displaced from the movement path. In particular the well centre may be displaced by at least 1 m, such as at least 2 m, such as at least 3 m from the movement path, i.e. such that the well centre is displaced from a riser joint positioned at any position along the movement path. Similarly, the well centre may be displaced from the axis defined by the prostrate maintenance/transfer position of the riser joint.
The offshore drilling rig may be a semi-submersible drilling rig, i.e. it may comprise one or more buoyancy pontoons located below the ocean surface and wave action, and an operation platform elevated above the ocean surface and supported by one or more column structures extending from the buoyancy pontoon to the operation platform. Alternatively, the offshore rig may be of a different type, such as a jack-up drilling rig or a drill ship.
For the purpose of the present description, the term “mast” refers to a support structure upwardly extending relative to the drill floor deck and supporting a hoisting system for hoisting and lowering tubular equipment (such as drill strings, casings and/or risers) towards the seabed so that drilling into the seabed can be performed. The mast may extend from the drill floor deck or from a deck different from the drill floor deck. The hoisting system may be a hydraulic hoisting system comprising upwardly extending cylinders for carrying the load to be hoisted or lowered typically via large sheaves mounted on top of the cylinders. In some embodiments, the hoisting system may be a draw works system. The mast of a drilling rig is sometimes formed as a derrick, a tower or other suitable support structure.
The term tubular equipment is intended to refer to tubular equipment that is advanced through the well centre towards the sea floor during one or more stages of the drilling operation. In particular, the term tubular equipment refers to straight tubular elements that can be joined to form a string of tubular equipment. The tubular equipment may be selected from drill pipes and/or other tubular elements of the drill string, risers, liners and casings. Examples of tubular elements of the drill string include drill pipes, drill collars, etc. For the purpose of the present descriptions these will also generally be referred to as tubulars. Tubulars such as riser joints define a longitudinal direction along their longitudinal axis and a lateral direction normal to the longitudinal axis.
For the purpose of this description, the term drill floor deck is intended to refer to the deck of an operating platform of an offshore drilling rig immediately above which joints of tubulars are assembled to form the drill string which is advanced through the well centre towards the seabed. The part of the drill floor deck in immediate proximity of the well centre is normally referred to as the drill floor, which is the primary work location for the rig crew and/or machines performing similar functions, such as iron roughnecks. The drill floor normally comprises a rotary table for rotating the drill string. The drill floor deck may be arranged on the same level as or on a different level than, e.g. elevated from, a main deck of the drilling rig. The main deck may comprise storage space e.g. for storing heavy equipment such as BOPs and Christmas trees.
The storage area for riser joints may be located in a riser bay having a floor that is recessed relative to the main deck. The riser bay me be sized such that less than 80%, e.g. less than 60%, e.g. less than 50%, e.g. less than 30% of the length of a riser joint stored upright in the riser bay extends above the main deck level or the level on which the maintenance/transfer position is located. Hence, the riser bay may be between 3 m and 30 m deep, e.g. more than 5 m, e.g. more than 10 m, e.g. more than 15 m, e.g. more than 20 m deep. A recessed storage position results in the centre of mass of the drill rig to be lowered.
Embodiments of the drilling rig disclosed herein allow loading/offloading of the riser joints without using the main hoisting system. Moreover, maintenance and/or other manipulations of the riser joints (including those that require removal of the Buoyancy elements that surround the riser joint) may be performed on board of the drilling rig, and without interfering with the drilling operation. The riser handling apparatus may be embodied as a single machine/device or as multiple machines/devices, e.g. a first riser handling machine and a second riser handling machine. The first riser handling machine may be operable to move a riser joint in upright orientation e.g. between a tilt position and a storage position of the riser; in particular, the first riser handling machine may be operable to move an upright riser joint laterally, i.e. substantially horizontally, across the floor of the storage area. It will be appreciated that the first riser handling machine may be operable to lift an upright riser joint relative to the floor of the storage area, e.g. sufficiently high so as to lift the riser joint out of or into an attachment mechanism or guiding mechanism, e.g. less than 5 m, e.g. less than 3 m e.g. less than 2 m. However, the first riser handling machine does not need to lift the riser entirely out of the recessed riser bay. The second riser handling machine may be operable, alone or in cooperation with the first riser handling machine, to tilt the riser joint between an upright and a prostrate orientation and, optionally, to elevate the riser joint from the tilt position to the maintenance/transfer position. In particular, the tilt position may be on the same level as the storage area or slightly elevated or recessed relative to the storage area, e.g. by less than 3 m, e.g. less than 2 m, e.g. less than 1 m. The first riser handling machine may be a crane, e.g. a gantry crane. The second riser handling machine may be an elevator device or a tilt mechanism comprising a pivotable support member.
For the purpose of the present description the term “upright” is intended to refer to a vertical or close to vertical orientation where a riser joint stands on one of its ends while the other end is pointing upward, e.g. an orientation defining a small angle compared to the vertical direction e.g. less than 45°, such as less than 30°, e.g. less than 20°, e.g. less than 10°, e.g. less than 5°. Similarly, the term “prostrate” is intended to refer to a horizontal or close to horizontal orientation where a riser joint lies flat on the deck or a similar support, e.g. defining a small angle compared to the horizontal direction e.g. less than 45°, such as less than 30°, e.g. less than 20°, e.g. less than 10°, e.g. less than 5°.
In some embodiments, the drilling rig is a dual (or even multiple) activity rig where more than one main drilling operations and/or parallel operations may be performed through two or even more separate well centres. To this end, in some embodiments, the offshore drilling rig comprises two (or even more) well centres displaced from each other, and corresponding masts (or a common mast structure) and hoisting systems configured for hoisting and lowering tubular equipment through the respective well centres.
The present disclosure relates to different aspects including the drilling rig described above and in the following, corresponding methods, apparatus, and/or products. Each aspect may yield one or more of the benefits and advantages described in connection with the other aspects, and each may have one or more embodiments corresponding to the embodiments described in connection with one of the other aspects and/or disclosed in the appended claims.
In particular, according to one aspect, disclosed herein is an offshore drilling rig comprising:
The tubular feeding apparatus may comprise horizontal and/or vertical pipe handling equipment. The horizontal pipe handling equipment may be any suitable apparatus or device for moving tubulars in a horizontal orientation, e.g. in the axial direction of the tubular. Examples of horizontal pipe handling equipment include catwalk machines, such as catwalk shuttles. The vertical pipe handling equipment may be any suitable apparatus or device for moving tubulars in a vertical orientation. Examples of vertical pipe handling equipment include column rackers, hydrarackers, and other types of rackers, hydraulic arms, gantry cranes, etc. or combinations thereof. In some embodiments, the drilling rig comprises pipe feeding equipment configured to advance drill pipes from a pipe storage location towards the well centre. The pipe storage may be located on one side of the well centre. The riser storage area may be located on a different side, e.g. opposite the pipe storage location. Accordingly a riser feeding equipment may be arranged to feed riser joints from the riser storage area to the well centre, e.g. using an inclined chute when the riser storage area is recessed relative to the drill floor and/or main deck and laterally positioned in close proximity e.g. immediately next to the mast.
When the riser handling apparatus comprises more than one machine or component, one or some of these components may also be operable to feed riser joints from the riser storage area to the hoisting system. For example, the riser handling machine may comprise a gantry crane or similar device for laterally moving riser joints in upright orientation between a storage position and different transport positions; one transport position may be a tilt position as described herein while another, different, transport position may be a chute for feeding riser joints upward to the well centre.
When all elements of the riser handling apparatus are different from any tubular feeding mechanism that is operable to feed tubular equipment other than riser joints to the well centre, a loading/offloading and/or maintenance of riser joints is facilitated even during ongoing drilling operations involving tubular equipment other than risers. Even when a part of the riser handling equipment is also used for feeding riser joints to the well centre, interference with drilling operations may be kept at a minimum.
In some embodiments, the riser storage area is arranged in immediate vicinity of the mast and recessed relative to the drill floor, thus allowing feeding of risers via a chute, e.g. an inclined chute towards the well centre where the hoisting system can pick up the riser joint. Consequently, moving a riser joint from the storage position to the well centre does not involve tilting the riser joint into a prostrate position. Consequently, the second riser handling equipment operable to tilt the riser joint is not needed for feeding the riser joints to the well centre, and tilting of riser joints to the maintenance/transfer position may be performed without significantly interfering with the running of risers or other drilling operations.
According to one aspect, disclosed herein is an offshore drilling rig comprising:
Hence, the movement of riser joints between their storage position and a maintenance/transfer position does not require large deck cranes such as knuckleboom cranes. Hence, these may be used for other operations parallel to the riser movement between storage and maintenance/transfer positions, e.g. for lifting riser joints between the maintenance/transfer position and a supply vessel. Moreover movement of riser joints may be performed in a safe and efficient manner.
According to one aspect, disclosed herein is an offshore drilling rig comprising:
Hence, the movement of riser joints between the storage and the maintenance/transfer position does not require cranes that have a lift capacity and height sufficient for lifting a riser joint in vertical orientation above and across the main deck. Moreover, the movement of riser joints is performed efficiently and safely. In some embodiments, the riser handling apparatus is operable to laterally move a marine riser joint in upright orientation from its storage position to a tilting position, i.e. the movement is along the lateral direction of the riser joint, normal to its longitudinal direction.
In some embodiments, when the marine riser joint is positioned at the tilting position, at least one end of the marine riser joint is located at a level below said maintenance/transfer position. Moreover, in some embodiments, during movement from the storage to the tilt position, at least one end of the marine riser joint is located at a level below an upper end of the riser joint when the riser joint is in its storage position and/or below said maintenance/transfer position.
From time to time, marine riser joints have to undergo maintenance operations, such as scheduled maintenance operations or maintenance occasioned by detected damages, malfunction, and wear and tear of the riser joint. Such maintenance operations may take several days and involve disassembly of parts of the riser joint such as removal of Buoyancy elements, and or operations such as sandblasting, paint removal, painting. To this end, marine riser joints are typically brought onshore to an onshore maintenance facility for maintenance. However, with an increasing desire to increase the length of riser joints, transporting riser joints becomes more and more difficult. In particular, the transport of the riser joints between a harbour and a maintenance facility by truck becomes increasingly difficult. It would thus be desirable to increase the efficiency of the maintenance of riser joints.
According to one aspect, disclosed herein is an offshore drilling rig comprising:
Hence, by providing a maintenance station for riser joints on an offshore drilling rig, the need for transporting riser joints from the drilling rig to an onshore maintenance facility is reduced or even eliminated.
In some embodiments, the riser maintenance station comprises one or more riser manipulation devices, each operable to perform at least one or more of the following operations on a respective marine riser joint while the marine riser joint is located at a prostrate maintenance position at the riser maintenance station:
In some embodiments, the riser maintenance station comprises a device operable to remove one or more Buoyancy elements from the marine riser joint while the marine riser joint is located at the maintenance station. Moreover, the maintenance station may comprise one or more riser maintenance machines operable to perform one or more maintenance operations on a riser joint, such as sandblasting equipment, riser inspection equipment insertable into the riser joint, and/or the like.
Consequently, efficient handling of the riser during maintenance is facilitated so as to allow personnel and/or equipment to access the riser from all sides. In some embodiments, the maintenance station comprises a protective enclosure shaped and sized to accommodate one or more riser joints in prostrate position separated from each other so as to allow service personnel to access each of the one or more riser joints from both lateral sides of the riser joint. Hence, the riser joint and maintenance crew is protected against humidity and bad weather during maintenance, and the surroundings of the maintenance station are protected from being negatively affected from e.g. sandblasting or other operations. The enclosure may be a housing completely enclosing the riser or it may be a structure that encloses the circumference of the riser joint but that has one or two open ends, or ends covered by doors or the like. The enclosure may have one or more closable access openings to allow riser joints to be moved into and out of the enclosure. For example the access openings may be in the form of doors or hatches and/or a portion of the roof or wall that may be slidable or that can otherwise be opened. In some embodiments the enclosure may be collapsed, folded, or otherwise reduced in shape when not in use. For example, the enclosure may comprise a number of separately slidable sections that may be slid into one another when not in use so as to free up deck space for other uses.
The riser maintenance station may be located on the main deck or another suitable operational deck or even under deck inside the hull of the drilling rig. In some embodiments, the storage area comprises a riser bay recessed relatively to an operational deck, e.g. the main deck, of the drilling rig, the riser bay having a floor and side walls connecting the floor and the operational deck; wherein the maintenance station is located on a level below said operational deck, and wherein the drilling rig comprises a passage from the floor of the riser bay and the maintenance station, e.g. a passage allowing an axial movement of a riser joint from the storage area to the maintenance station. The maintenance station may be located on the same level as the floor of the riser bay or on a different level, e.g. on a level between the floor level of the storage area and the operational deck or even below the floor level of the storage area. In some embodiments, the riser maintenance station may be part of a larger structure, e.g. a building providing accommodation and/or work areas for the crew and/or a building accommodating equipment.
The riser maintenance station may be shaped and sized so as to allow a single riser joint or several riser joints, e.g. no more than 2, e.g. no more than 3, e.g. no more than 4 or even more riser joints to be placed inside the enclosure spaced apart sufficiently far from each other that maintenance personnel and machines may access each riser joint from all sides. In particular, there may be a distance of at least 1 m, e.g. at least 1.5 m between adjacent riser joints and/or between a riser joint and a side wall of the enclosure. In some embodiments the riser joints may be located in separate enclosures or separated parts of a single enclosure. When the enclosure is adapted to accommodate several riser joints, the maintenance station may comprise multiple riser manipulation devices so as to allow concurrent work on multiple riser joints.
It will be appreciated that a riser maintenance station as described herein may be used on drilling rigs where riser joints are stored in upright orientation as well as on rigs with prostrate riser joint storage.
Further disclosed herein are embodiments of riser tilt equipment for tilting the riser joints from their upright storage position in the riser bay into a prostrate position for maintenance, either on the floor of the riser bay or on the main deck or other deck elevated from a riser bay floor.
In particular, according to one aspect, disclosed herein is a riser handling apparatus for moving a marine riser joint between an upright orientation and a prostrate orientation, the apparatus comprising an elongated support member for receiving and supporting at least a part of the length of the marine riser joint, the support member being arranged pivotally around a pivot axis, and a drive mechanism configured to pivot the support member and a marine riser joint supported by the support member between an upright orientation where the riser positioned on a first surface and a prostrate orientation where the riser is positioned on a second surface elevated relative to the first surface.
The pivot axis may be fixed relative to the elongated support; alternatively the elongated support may be operable to move axially during the pivoting. The support member may support the entire length of the riser joint or a major part of it such as at least 50%, e.g. at least 75%, e.g. at least 85%.
The first surface may be at or near a floor of a riser bay such as slightly elevated or recessed from the floor of the riser bay as described above. Similarly, the second surface may be at or near the main deck level, e.g. as described above. In some embodiments, the second level may be elevated above the main deck or it may be at a level between the first level and the main deck. For example, the maintenance/transfer bay may generally be provided at a level above the level of the lower ends of the riser joints stored in upright position in the storage area, e.g. a level between the lower and the upper ends of the riser joints stored in upright position in the storage area. The maintenance/transfer bay may even be provided at a level above, e.g. directly above, the level of the upper ends of the riser joints stored in upright position in the storage area so as to facilitate lifting the riser joint off the maintenance/transfer position by a crane. The support member may comprise one or more attachment devices, such as a clamp, a grapper, and/or a protrusion extending into a central tube of the riser joint, for securing the riser joint during the pivot operation.
According to yet another aspect, disclosed herein is a riser handling apparatus for moving a marine riser joint between an upright storage position on a storage surface and a prostrate maintenance/transfer surface elevated from the storage surface, the apparatus comprising:
The attachment device for attachment to a first end of a marine riser joint may be a gripper or clamp of a crane, e.g. a gantry crane. The attachment device for receiving a second end of a marine riser joint may be a gripper or clamp similar to the attachment device for attachment to a first end of a marine riser joint, just oriented in the opposite direction, or another suitable device for securing the second end to the hoisting device. The hoisting device may comprise a hydraulic device, a drawworks or other suitable device for lifting the second end of the marine riser joint.
In this example the drilling rig 100 is a semisubmersible drilling rig but other rig types using vertical storage of riser joints are also feasible. The rig 100 comprises pontoons (not shown) from which support columns 123 extend upwardly, and a topside platform 124 supported by the columns 123. During operation, the drilling rig floats at the ocean surface with the pontoons under the water and the support columns extending out of the water such that the topside platform is elevated above the water. To this end, the pontoons may be filled with ballast water so as to cause the rig to be submersed to the desired level.
The topside platform comprises a main deck 125 and a drill floor deck 126 arranged elevated from the main deck. In other embodiments, the drill floor deck may be on the same level as the main deck.
In some embodiments, having the riser joint fixed at both ends provides for a controlled flipping motion. It is typical for drilling vessels having vertical riser storage that a gantry crane is used to pick up riser joints from the storage position and to transport them in upright orientation towards the drill floor/well centre. In some embodiments the same gantry crane is used to perform the function of the gantry crane 309. However, compared to a conventional gantry crane for handling risers, the gantry crane 309 has an extended reach to allow the riser grapping tool 313 to be extended further towards the bottom of the riser bay. In some embodiments the grapping tool can be operated in a vertical range of more than 1 meter, such as more than 5 meters, such as more than 10 meters, such as more than 15 meters, such as more than 20 meters, such as more than 25 meters. In some embodiment the gantry crane 309 is arrange so that the riser grapping tool allows tilting of a grapped riser joint by about 90 degrees. In some embodiments a separate grapping tool is mounted for moving risers towards the drill floor with little or no allowance for tilting of the riser and the flipping operation with a larger allowance for tilting such as at least up to 90 degrees. In some embodiments an overhead crane, such as a knuckle-boom crane, performs the function of the gantry crane 309.
The access ways as shown in
a, b, c show examples of handling a riser joint in a horizontal position. When the riser joint is placed in a horizontal position, there are several ways of manipulating it in order to perform the desired tasks. In some embodiments the riser joint is placed in a handling apparatus 803 able to lift and/or rotate the riser joint. In some embodiments the functionality of the handling apparatus is integrated into the maintenance/transfer bay. In some embodiments the functionality of the handling apparatus is integrated into the elevator of
Generally, the force needed to raise the riser and the support can be supplied by the apparatus e.g. via a lifting cylinders or a pulley system arranged to extend or contract the support member 215. In some embodiments all or a part of the external force may be applied by an overhead crane e.g. coupled to the top mounting element 1201. In this way a mechanically simple device is achieved.
The riser tilting apparatus may be of the type shown in
Although some embodiments have been described and shown in detail, the invention is not restricted to them, but may also be embodied in other ways within the scope of the subject matter defined in the following claims. In particular, it is to be understood that other embodiments may be utilised and structural and functional modifications may be made without departing from the scope of the present invention.
In device claims enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims or described in different embodiments does not indicate that a combination of these measures cannot be used to advantage.
It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013 00302 | May 2013 | DK | national |
| 2013 70602 | Oct 2013 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/060323 | 5/20/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2014/187816 | 11/27/2014 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3716149 | Scaggs | Feb 1973 | A |
| 4033465 | Stine | Jul 1977 | A |
| 4129221 | Moller | Dec 1978 | A |
| 4176722 | Wetmore | Dec 1979 | A |
| 4692081 | Bennett et al. | Sep 1987 | A |
| 5046896 | Cole | Sep 1991 | A |
| 6250395 | Torres | Jun 2001 | B1 |
| 6321675 | Dybdahl | Nov 2001 | B1 |
| 6524049 | Minnes | Feb 2003 | B1 |
| 7918636 | Orgeron | Apr 2011 | B1 |
| 8052369 | Often et al. | Nov 2011 | B2 |
| 8291845 | Wijning | Oct 2012 | B2 |
| 8371790 | Sigmar et al. | Feb 2013 | B2 |
| 20030159853 | Archibald et al. | Aug 2003 | A1 |
| 20030170095 | Slettedal | Sep 2003 | A1 |
| 20040266290 | Gibson | Dec 2004 | A1 |
| 20050019100 | Simpson | Jan 2005 | A1 |
| 20050103526 | Ayling | May 2005 | A1 |
| 20060104747 | Zahn et al. | May 2006 | A1 |
| 20080136203 | Krijnen et al. | Jun 2008 | A1 |
| 20090220306 | Roodenburg | Sep 2009 | A1 |
| 20100307401 | Bereznitski | Dec 2010 | A1 |
| 20110048310 | Roodenburg | Mar 2011 | A1 |
| 20120067642 | Magnuson | Mar 2012 | A1 |
| 20120103623 | Wijning et al. | May 2012 | A1 |
| 20140190386 | Wijning et al. | Jul 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| 0 174 055 | Mar 1986 | EP |
| 0 178 870 | Apr 1986 | EP |
| 0 273 474 | Jul 1988 | EP |
| 1 038 088 | Sep 2000 | EP |
| 1255662 | Dec 1971 | GB |
| 1255663 | Dec 1971 | GB |
| 2150962 | Jul 1985 | GB |
| 8503050 | Jul 1985 | WO |
| WO 9856652 | Dec 1998 | WO |
| WO 9929999 | Jun 1999 | WO |
| WO 9931346 | Jun 1999 | WO |
| 0049266 | Aug 2000 | WO |
| WO 2009102196 | Aug 2009 | WO |
| WO 2010126357 | Nov 2010 | WO |
| Entry |
|---|
| International Search Report (PCT/ISA/210) mailed on Sep. 17, 2014, by the European Patent Office as the International Searching Authority for International Application No. PCT/EP2014/060323. |
| Friede and Goldman Ltd. “Riser Handling” http://www.fng.com/riser-handling Search. (4 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20160090797 A1 | Mar 2016 | US |
