ao) United States
`a2) Patent Application Publication co) Pub. No.: US 2015/0361736 Al
` Berganetal. (43) Pub. Date: Dec. 17, 2015
`
`
`
`US 20150361736A1
`
`(54) HEAVE COMPENSATION WINCHES
`
`(72)
`
`(71) Applicant: Cameron Sense AS,Kristiansand (NO)
`5
`Inventors: Hakon F. Bergan, Kristiansand (NO);
`Bard H. Kaasin, Gvarv (NO); Joe R.
`Berry, Cypress, TX (US); Alv Repstad,
`Songe (NO)
`(21) Appl. No.: 14/304,748
`
`(22) Filed:
`
`Jun. 13, 2014
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`E21B 19/00
`B66D 1/60
`
`(2006.01)
`(2006.01)
`
`
`
`yf
`
`(2006.01)
`(2006.01)
`
`B66D 1/30
`B66D 1/22
`(52) US.CL
`CPC ceceeeeseeees E£21B 19/006 (2013.01); B66D 1/22
`(2013.01); Bo66D 1/60 (2013.01); BO6D 1/50
`(2013.01)
`‘
`
`ABSTRACT
`(57)
`Various hoisting systems with heave compensation are pro-
`vided. In one embodiment, an apparatus includes a winch
`having a rotatable drum and a heave compensation system
`with both active and passive drive input devices. The heave
`compensation system can be coupled to the rotatable drum so
`that the active and passive drive input devices can each be
`used to drive rotation of the rotatable drum in response to
`heaving, motion of the winch. Additional systems, devices,
`and methodsare also disclosed.
`
`
`
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`Patent Application Publication
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`Dec. 17,2015 Sheet 1 of 7
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`US 2015/0361736 Al
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`
`
`
`
`
`
`PASSIVE HEAVE
`
`COMPENSATION
`
`
`36
`
`MOTION
`REFERENCE
`UNIT
`
`
`
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`Patent Application Publication
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`Dec. 17,2015 Sheet 2 of 7
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`US 2015/0361736 Al
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`LIBERTY EXHIBIT 1006, Page 3
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`Patent Application Publication
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`Dec. 17,2015 Sheet 3 of 7
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`US 2015/0361736 Al
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`Patent Application Publication
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`Dec. 17,2015 Sheet 4 of 7
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`4/7
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` SA
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`it Giae
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`FIG. 5
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`
`
`ACTIVE DRIVE INPUT
`-ELECTRIC MOTOR
`-HYDRAULIC MOTOR
`-HYDRAULIC CYLINDER
`
`PASSIVE HEAVE COMPENSATION
`-HYDRAULIC MOTOR
`-HYDRAULIC CYLINDER
`
`GEAR SYSTEM
`-SUN GEAR
`-RING GEAR
`-PLANETARY GEARS
`AND CARRIER
`
`FIG. 7
`
` 160
`
`164
`
`166
`
`CRANKSHAFT
`
`SUN GEAR
`
`FIG. 9
`
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`RESERVOIR
`
`[]LOWPRESSURE
`
`
`VALVEBLOCK
`
`woLo—
`
`
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`HEAVE COMPENSATION WINCHES
`
`BACKGROUND
`
`[0001] This section is intended to introduce the reader to
`various aspects of art that mayberelatedto various aspects of
`the presently described embodiments. This discussion is
`believed to be helpful in providing the reader with back-
`ground information to facilitate a better understanding of the
`various aspects of the present embodiments. Accordingly,it
`should be understood that these statements are to be read in
`
`this light, and not as admissionsofpriorart.
`[0002]
`Inorderto meet consumerand industrial demandfor
`natural resources, companiesoften invest significant amounts
`of ime and moneyin finding and extracting 01], natural gas,
`and other subterranean resources fromthe earth. Particularly,
`once a desired subterranean resource suchasoil or natural gas
`is discovered, drilling and production systems are often
`employed to access and extract the resource. ‘hese systems
`maybelocated onshore or offshore dependingonthe location
`of a desired resource.
`
`Floating drilling platforms are sometimes used for
`[0003]
`offshore drilling operations and includea hoisting system for
`raising and lowering equipment, suchas a drill string, to a
`subsea wellsite. Because these platformsfloat at the surface
`ofthe water and are not anchoredto the seabed withlegs, the
`platformscan vertically rise and fall (i.e., heave) with waves
`in the water. Heave compensation can be used to counteract
`the vertical heaving motion and reduce movementofthe drill
`string or other hoisted load with respect to the seabed.
`[0004] Various types of heave compensators have been
`used in an effort to maintain a constant weight on bit for a
`hoisted drill string and reduce deviationofthe drill string with
`respect to the seabed as the drilling platform rises andfalls
`with the waves. Simple heave compensators acting as shack
`absorbers have been provided between traveling blocks and
`drill strings hoisted with a drawworks system. Active heave
`compensation hasalso been used, in which heaving motion of
`the drilling platform is measured andusedto actively control
`the position ofthe drill string.
`[0005] As operators have moved to deeper waters and
`deeper wells, the weight of the equipment to be hoisted by
`offshore rigs(e.g., drill strings, casing strings, and wellhead
`equipment) has
`increased. Multi-part block-and-tackle
`arrangements have been used with drawworksfor hoisting on
`drilling rigs,
`in which hoisting lines are reeved through
`sheaves of crown andtraveling blocks to provide a mechani-
`cal advantage. One approachto increasing the hoisting capa-
`bilities of such arrangementsis to add morelines and sheaves
`and increase the size of the hoisting lines. Drilling platforms
`have also been provided as hydraulically driven “cylinder
`rigs,” which use large hydraulic cylinders instead of draw-
`works. The hydraulic cylinders in such rigs can provide both
`the main hoisting function and a heave compensating func-
`tion.
`
`SUMMARY
`
`[0007] Embodiments of the present disclosure generally
`relate to hoisting systems having heave compensation func-
`tions. In certain embodiments, hoisting systems include both
`active heave compensation at drawworks (or winches)ofthe
`systems and passive heave compensation. And in at least
`some embodiments, active heave compensation and passive
`heave compensation are provided at a winchthat includes a
`planetary gear system, which allows both active and passive
`heave compensation to be applied to a rotating drum of the
`winch.
`
`[0008] Various refinements ofthe features noted above may
`exist in relation to various aspects of the present embadi-
`ments. urther features may also be incorporated in these
`various aspects as well. These refinements and additional
`features may exist individually or in any combination. For
`instance, various features discussed below in relation to one
`or moreoftheillustrated embodiments may be incorporated
`into any of the above-described aspects of the present disclo-
`sure alone or in any combination. Again, the brief summary
`presented above is intended only to familiarize the reader
`with certain aspects and contexts of some embodiments with-
`out limitation to the claimed subject matter.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`‘These and otherfeatures, aspects, and advantages of
`[0009]
`certain embodiments will becomebetter understood when the
`
`following detailed description is read with reference to the
`accompanying drawings in which like characters represent
`like parts throughout the drawings, wherein:
`[0010] VIG. 1 generally depicts a floating drilling rig with a
`hoisting system in accordance with one embodiment of the
`presentdisclosure;
`[0011] VIG. 2 is a block diagram representing a hoisting
`system having both active and passive heave compensation
`functions in accordance with one embodiment;
`[0012] FIG.3 isa front perspective view of a winch having
`both active and passive heave compensation in accordance
`with one embodiment;
`[0013]
`FIG. 4 is a sectioned viewof the winchof FIG. 3;
`[0014] FIG.5isa detail view ofthe sectioned winchof FIG.
`4 and showsa planetary gear system for driving rotation of a
`drum of the winch in accordance with one embodiment;
`[0015]
`FIG. 6 is a cross-section of the winch of FIG. 4
`showing planetary gears disposed between a sun gear and a
`ring gear in accordance with one embodiment;
`[0016]
`FIG. 7 is a block diagram ofvarious active drive
`inputs and passive heave compensation systems that can be
`connected to a gear system to drive rotation of a drum of a
`winch in accordance with various embodiments;
`[0017]
`FIG. 8is a schematic of a winch system with active
`heave compensation provided by electric motors and passive
`heave compensation provided by hydraulic motors in accor-
`dance with one embodiment; and
`[0018]
`FIG. 9 is a block diagramof a sun gear that can be
`operated by hydraulic cylinders via a crankshaft to drive
`rotation of a drum of a winch in accordance with one embodi-
`ment.
`
`[0006] Certain aspects of some embodiments disclosed
`hereinare set forth below.It should be understood that these
`DETAILED DESCRIPTION OF SPECIFIC
`aspects are presented merely to provide the reader withabrief
`EMBODIMENTS
`summaryof certain forms the invention might take and that
`these aspects are not intendedto limit the scope of the inven-
`tion. Indeed,
`the invention may encompass a variety of
`aspects that may not be set forth below.
`
`Specific embodimentsof the present disclosure are
`[0019]
`described below.In an effort to provide a concise description
`of these embodiments, all features of an actual implementa-
`
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`tion may not be described in the specification. It should be
`appreciated that in the developmentof any such actual imple-
`mentation,as in any engineering or design project, numerous
`unplementation-specific decisions must be made to achieve
`the developers’ specific goals, such as compliance with sys-
`tem-related and business-related constraints, which may vary
`from one implementation to another. Moreover, it should be
`appreciated that such a developmenteffort might be complex
`and time consuming, but would nevertheless be a routine
`undertaking of design, fabrication, and manufacturefor those
`of ordinaryskill having the benefit of this disclosure.
`[0020] When introducing elements of various embodi-
`ments,the articles “a,” “an,”“the,” and “said” are intended to
`meanthat there are one or more of the elements. The terms
`
`“comprising,” “including,” and “having” are intended to be
`inclusive and mean that there may be additional elements
`other than the listed elements. Moreover, any use of “top,”
`“bottom,” “above,” “below,” other directional
`terms, and
`variations of these terms is made for convenience, but does
`not require any particular orientation of the components.
`[0021] Turning now to the present figures, a system 10 is
`illustrated in FIG. 1 in accordance with one embodiment. In
`this example, the system 10 is an offshore drilling rig in the
`form of a floating vessel 12. More specifically, the floating
`vessel 12 is generally depicted as a drillship in FIG. 1, but the
`floating vessel could be provided in another form, such as a
`semi-submersible drilling rig, in other embodiments.
`[0022] The vessel 12 includes a hoisting system for raising
`and lowering equipment with respect to a drill floor of the
`vessel, which facilitates well drilling and completion opera-
`tions. The depicted hoisting system includes a derrick 14
`constructed onthe drill floor of the vessel 12. Various equip-
`ment and other loads can be supported by one or morehoist-
`ing lines 20 of the hoisting system. In FIG. 1, the supported
`load includes a top drive 16 and a drill string 18 suspended
`from the top drive 16. The drill string 18 extends through a
`hole in the drill floor ofthe vessel 12 and canbe rotated by the
`top drive 16 to facilitate drilling of a subsea well. It will be
`appreciated that the hoisting system could be used for hoist-
`ing other loads, such as casing strings, wellhead equipment,
`and other subsea well components.
`[0023] The hoisting system includes a drawworks 22,
`which can be provided onthe drill floor with the derrick 14, as
`shown in FIG.1, or at another location. The drawworks 22
`includesa rotatable drum 26 (FIG.2) that can reel in and reel
`out the hoisting line (or lines) 20 wound on the rotatable
`drum. Each hoisting line 20 can be reeved over a sheave in a
`crown block 24 coupled to the derrick 14 and connectedto the
`supported load so that the reeling in and reeling out of the
`hoisting line 20 via the drum 26 raises and lowers the sup-
`ported load.
`
`In at least some embodiments, the hoisting system
`[0024]
`includes both active heave compensation and passive heave
`compensation to compensate for heaving motionofthe float-
`ing vessel 12 from wave action at the surface of the water. One
`such embodimentis generally depicted in FIG. 2 by way of
`example. In this figure, a load 30 is supported bya hoisting
`system including the crownblock 24 and the drawworks 22
`with the rotatable drum 26. As described above, one or more
`hoisting lines 20 can be wound from the drum 26 and reeved
`over the crown block 24 to support a given load 30. Although
`not depicted here, it is noted that the hoisting lines 20 can be
`coupled to the load 30 by a traveling block suspended from
`
`the crown block 24 with the hoisting lines 20. Butthe travel-
`ing block is omitted in some embodiments.
`[0025] As theload 30 is suspended from the crown block 24
`with the hoisting lines 20, heave of the vessel 12 causes the
`load 30 to move up and downwith respect to the underlying
`seabed. During drilling operations, such movement can cause
`a drill bit at the end of the drill string 18 to be pulled off the
`bottom of the well (with upward heave) or to be pushed with
`greater force against the bottom if the well (with downward
`heave).
`To compensate for the heaving motion and reduce
`[0026]
`deviation ofthe hoisted load 30 with respect to the seabed, the
`hoisting system in FIG. 2 includes an active heave compen-
`sation system 34 and a passive heave compensation system
`36. A motion reference unit 32 can be used to detect the heave
`of the vessel 12. In at least some embodiments, the active
`heave compensation system 34 uses the measured heave to
`actively compensate for heaving motion through control of
`the drawworks 22. For instance, the active heave compensa-
`tion system 34 can include a controller(e.g., a programmable
`logic controller or a programmed general-purpose computer)
`that receives the measured heave as an input and controls
`operation of the drawworks 22 to raise and lower the load 30
`(with respect to the drill floor) to compensate for the heaving
`motion. The controller can control operation in any suitable
`manner, such as by sending commandsignals to motors ofthe
`drawworks 22 that control rotation of the drum 26. These
`motors can be considered part of the active heave compensa-
`tion system 34 as well.
`[0027] The passive heave compensation system 36 can also
`beused to counter heaving motionofthe vessel 12. In contrast
`to the active heave compensation system 34, the passive heave
`compensation system 36 can counter heave without requiring
`external power. For example, the passive heave compensation
`system 36 can include one or more hydraulic devices(e.g.,
`hydraulic cylinders or hydraulic motors) that passively store
`and release energy from the heaving motion of the vessel 12
`to move the load 30 with respectto the drill floor to reduce the
`deviation of the load 30 fromits position with respect to the
`seabed. In some instances, the passive heave compensation
`system 36 could also include an active component(e.g., a
`hydraulic cylinder that passively compensates for heave and
`that can also be actively driven for further heave compensa-
`tion).
`[0028] Various examplesof hoisting systems having both
`active and passive heave compensation are described in U.S.
`patent application Ser. No. 14/304,728, which wasfiled on
`June 13, 2014, andat the timeoffiling wasentitled “Hoisting
`Systems with Heave Compensation,” named Erling Tambs et
`al. as inventors, and was marked with an attorney docket
`number of DRL-032158 US; that application is hereby incor-
`porated by reference in its entirety. In someinstances of the
`present technique, such as those described below with respect
`to FIGS. 3-9, hoisting systems include drawworks or winches
`having both active and passive heave control. While the
`winches described below could be used as a drawworks ona
`
`drilling rig, itis noted that the winches could alsoor instead be
`used in other applications (e.g., in hoisting systems on other
`vessels not used fordrilling, or on floating docks).
`[0029]
`In FIG. 3, a depicted heave-compensated system 70
`includes a drawworks or winch 72 having a rotatable drum 74
`mounted ona frame. Hoisting lines 20 are wound onthe drum
`74. Although omitted here for the sake of clarity, it will be
`appreciated that portionsofthe hoisting lines 20 extend from
`
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`the drum 74 and can be usedto support a hoisted load. In some
`instances the winch 72 could be used with a crown block and
`a derrick, but in other embodiments the winch 72 could be
`used without one or both of those additional components.
`Further, the hoisting lines 20 can be provided as single-part
`lines (rather than multi-part lines) for supporting the hoisted
`load.
`
`[0030] Motors 78 can be operated to drive rotation of the
`drum 74to reelin orreel out the hoisting lines 20 to raise and
`lower an attached load 30. Any suitable motors 78 could be
`used. The motors 78 can include electric motors, for example.
`The motors 78 can also provide active heave control via the
`drum74, in which case the motors are actively controlled to
`compensate for heave as generally described above.
`[0031]
`Passive heave compensation can be applied to the
`winch 72 by hydraulic cylinders 82. These cylinders 82 are
`depicted with cylinder housings 84 with extendable rods 86
`connected to sheaves 92. In at least some instances, other
`sheaves are coupled below the cylinders 82. In one embodi-
`ment, the hydraulic cylinders 82 are provided in a jigger
`winch assembly with tension lines 96 to rotate a ring gear 98
`of a planetary gear system of the winch 72, although other
`arrangements could instead be used.
`[0032] As generally shownin FIG. 4 and morespecifically
`shownin FIGS. 5 and 6, the planetary gear system includes
`the ring gear 98, planetary gears 102, and a sun gear 104. A
`carrier 106 is coupled to rotate with the planetary gears 102 as
`they orbit the sun gear 104 in operation. In this embodiment,
`the active drive system (here the motors 78, which provide
`both a primary hoisting function and active heave compensa-
`tion) is connectedto drive the sun gear 104. Morespecifically,
`the motors 78 are connectedto drive rotation ofa gear 110 of
`a slew bearing 112. The gear 110 is coupled to a sun wheel
`114 having the sun gear 104 suchthat the motors 78 rotate the
`sun gear 104 via the wheel 114 and the gear 110. The plan-
`etary gears 102 are mounted on axles 118 coupled to the
`carrier 106, which is coupled to drive the drum 74. This
`allowsthe orbit of the planetary gears 102 to drive rotation of
`both the carrier 106 and the drum 74.
`
`
`
`In this embodiment, the passive heave compensa-
`[0033]
`ion system (here including the cylinders 82) is connected to
`he ring gear 98. This allows a combination of active and
`passive adjustmentof the rotational position of the drum 74
`hrougha differential regulation principle. In the embodiment
`depicted in FIG. 5, active heave compensation varies rotation
`of the sun gear 104 and passive heave compensation varies
`rotation of the ring gear 98. Rotation of the sun gear 104 and
`he ring gear 98 causes the planetary gears 102 to rotate and
`orbit about the sun gear 104. Thecarrier 106 is coupled to
`drive rotation of the drum74 in responseto the orbit of these
`planetary gears 104, as noted above.
`[0034] Various active and passive components can be used
`o drive rotation of different elements of the planetary gear
`system. As shownin FIG. 7 in accordance with some embodi-
`ments, differential heave compensation systems 120 include
`aclive drive input devices 122 (which can have active heave
`compensation) and passive heave compensation devices 124
`(which can also be considered passive drive input devices)
`coupled to elements of planetary gear systems 126 to drive
`rotation of a drum 128. ‘lhe system 70 depicted in FIGS. 3-6
`is one example of a differential heave compensation system
`120, with motors 78 coupled to the sun gear 104as the active
`drive input devices 122, hydraulic cylinders 82 coupled to the
`ring gear 98 as the passive heave compensation devices 124,
`
`and a drum 74 coupled to the planetary gears 102 and carrier
`106. But other active and passive drive devices could be used.
`For example, the active drive input devices 122 can include
`actively driven hydraulic motors or hydraulic cylinders, and
`the passive heave compensation devices 124 can include a
`passively operating hydraulic motor. Further, although cer-
`tain embodiments may havesingle-part lines reeled in and out
`from a drum, the differential heave compensation systems
`120 can be used in embodiments using single-part lines or
`other embodiments having multi-part lines.
`the passive
`[0035] Moreover,
`the active devices 122,
`devices 124, and the drum 128 could be connectedto the ring
`gear, sun gear, and the set of planetary gears in any combina-
`tion. It is noted that there are six permutations of coupling
`each ofthe active devices 122, the passive devices 124, and
`the drum 128 with one ofthe ring gear, the sun gear, and the
`planetary gears of the gear set 126. For instance, the connec-
`tions of the active drive devices 122 and the passive heave
`compensation devices 124 could be switched from the
`arrangement of system 70, with the active devices 122
`coupledto the ring gear and the passive devices 124 coupled
`to the sun gear. In other embodiments, the drum 128 could be
`connected to the sun gear or the ring gear instead of the
`planetary gears, which could be driven by the active devices
`122 orthe passive devices 124. Although these embodiments
`use a differential system on a planetary gear arrangement
`principle, a regular differential may also be used(e.g., in the
`case ofpassive andactive drive inputs each being provided by
`motors).
`system with a planetary gear
`[0036] The differential
`arrangementcan be usedto hoist a load by rotating the drum
`128. The system can be considered to have two types of
`mechanical input (active drive and passive drive) and one
`mechanical output (to rotate the drum). The differential can
`be controlled in such way that drum motion is from active
`input alone, from passive input alone, or from the simulta-
`neous combination of both inputs. Drum movementis then
`controlled by the sun ofany moving inputs. It is noted that the
`drum can have either one or more wire ropes or chains, and
`might have one or more layers. Drum output speed varies
`dependent ondirect acting hoisting or via block-and-tackle
`systems.
`[0037] A passive drive input can be characterized as one
`that does not require an external power source to be able to
`perform the desired motion compensation. If the compensa-
`tion is taken care of by the passive side, rig power consump-
`tion is al a minimum. A semi-aclive system is typically used
`when passive compensation is performed by hydraulic
`motors; in such cases power consumption can be used just to
`control displacement of motors. The passive side can also be
`used as a regenerative device for hoisting, in which motors are
`used for braking when lowering and charging accumulators
`and the stored energy is then used for hoisting the traveling
`load. The passive system can also have a parallel active sys-
`tem attached. This system can he usedeither as a performance
`booster while in a constant tension mode (maintaining a ten-
`sion level on the hoisting line) or as an energy saver when in
`active heave compensation mode.
`[0038] The passive drive inputs can include any suitable
`devices and arrangements. For example, in some embodi-
`ments, the passive drive inputs are provided as hydraulic
`cylinders with wire or chain connections. In at least some
`instances, these wire or chain connections are passed over
`eccentric sheaves before entering the system to compensate
`
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`for the differential in passive compensation componentprop-
`erties. The passive drive inputs can instead include hydraulic
`motors with or without a semi-active part. One example of a
`differential heave compensation system 120 using hydraulic
`motors with semi-active parts as the passive drive inputs is
`depicted in FIG. 8 and described in greater detail below. The
`passive drive inputs could also be provided by hydraulic
`cylinders connected to the planetary gear system with a
`crankshaft (as depicted in FIG. 9 and discussed. below),
`hydraulic cylinders with an active part, or hydraulic cylinders
`with rack-and-pinion connections for rotation.
`[0039]
`‘The active side (..e., the active drive inputs) can be
`characterizedasthe part of the system used for hoisting, and
`also for active heave compensation. The activepart is depen-
`dent on an external powersourceto drive rotation ofthe drum.
`The active drive inputs can be provided in any suitable form,
`such as an electric motor, a hydraulic motor, or a hydraulic
`cylinder. The electric and hydraulic motors provided asactive
`drive inputs could be used with or without gearboxes and with
`or without brakes in various embodiments.
`
`In some embodiments, multiple input drive devices
`[0040]
`(whether active or passive) may be used, which can provide
`redundancy andincreased performance. By way of example,
`when four passive cylinders are present in a hoisting system,
`only two can be used if compensating lowerloadsto increase
`performance (from an accumulator bank for the four cylin-
`ders being made available to only half of the cylinders).
`[0041] A further example of a differential heave compen-
`sation system 120 is depicted in FIG.8. In this example, the
`system 120 includesactive drive input devices 122 in the form
`of electric motors 132 coupled to planetary gear systems 126
`via gearboxes 134. The system 120 depicted here also
`includes passive heave compensation devices 124 in the form
`ofvariable displacement hydraulic motors 138 coupled to the
`planetary gear systems 126 via gearboxes 140. In other
`embodiments, the gearboxes 134 and 140 could be omitted.
`The ring gear of the gear system 126 can be provided with
`external teeth, and the hydraulic motors 138 can act on the
`ring gear via the external teeth to provide passive heave com-
`pensation. The hydraulic motors 138 act as hydraulic pumps
`to absorb the energy from the hoist whenthe vessel heaves
`upward and act as motors (turning the opposite direction)
`whenthe vessel heaves downward.
`
`
`
`[0042] A hydraulic accumulator 144 is connected to the
`hydraulic motors 138 and to gas storage bottles 146. In the
`system 70 described above, similar gas storage bottles
`allached to the hydraulic cylinders 82 provide the volume
`allowing the extension andretraction of the cylinder rods 86
`or passive heave compensation. The compensating load
`value is regulated by increasing or decreasing the charge
`pressure (e.g., of nitrogen) in these storage volumes. In the
`embodiment shown here in FIG. 8, however, the compensat-
`ing load value is regulated by changing the displacement of
`he hydraulic motors 138 while maintaining a constant charge
`pressure in the gas storage bottles 146.
`[0043] The compensation system 120 in FIG. 8 includes a
`hydraulic power system 150 for actively controlling displace-
`mentof the hydraulic motors 138. The hydraulic power sys-
`em150 can include one or more main power units 152 that
`draw hydraulic fluid from a reservoir 156 and route the
`hydraulic fluid through a valve block 154 to the hydraulic
`motors 138. In passive cylinder systems, the compensating
`oad value changes due to the compression and decompres-
`sion of the gas in the storage bottles as the cylinders extend
`
`and retract. This load variation can be negated through the use
`of an active set of cylinders acting on the passive cylinders.
`But the active cylinders could be quite large, requiring a
`hydraulic powerunit of substantial size. In the system of FIG.
`8, the displacement ofthe hydraulic motors can be actively
`increased and decreased on the fly to maintain a more con-
`stant compensating load value to negate the change in pres-
`sure in gas storage bottles 146 as the vessel heaves up and
`down.In this system, the main powerunit 152 can be used to
`compensate for leakage ofthe hydraulic motors 138, but there
`would be no additional power unit demand to provide the
`active override to obtain a more constant compensating load
`value. Consequently, a smaller main power unit 152 can be
`used in the system of FIG. 8 compared to that of passive
`cylinder embodiments.
`[0044] As generally noted above, in at least one embodi-
`ment passive heave compensation can be provided by one or
`more hydraulic cylinders via a crankshaft coupled to the
`planetary gear system. In FIG.9, a passive heave compensa-
`tion system 160 includes hydraulic cylinders 162 connected
`to drive a crankshaft 164 that is coupled to a sun gear 166
`(e.g., of the planetary gear system 126). Further, the active
`drive input can be connected to the ring gear and the drum128
`can be connectedto the set of planetary gears such that the
`drum 128 can be rotated by the active drive input and the
`passive drive input(e.g., the cylinders 162).
`[0045]
`Thoughall-hydraulic cylinder rigs can be used for
`hoisting functions, they can have certain drawbacks, such as
`the complexity of the hydraulics, the size and expense of a
`hydraulic powerunit sufficient for the rig, and the piping and
`cylinders required to provide both the main hoisting function
`(which mayrequire about 180 feet of vertical travel) and the
`heave compensating system. In contrast, certain embodi-
`ments disclosed herein includeanelectrically driven winch or
`drawworks for normal hoisting functions and active heave
`compensation combined with a hydraulic passive heave com-
`pensating system with much less complexity than the all-
`hydraulic designs. This reduction in complexity enables
`lighter hoisting systems to be used andfacilitates installation
`and servicing. The present systems may also have reduced
`power consumption compared to certain previous designs.
`Further, moving the passive heave compensation systemto
`the drill floor from highin the derrick provides a lower center
`of gravity. And in the use of single-part lines in some embodi-
`ments enables a faster hoisting speed while maintaining a
`reasonable rotation speed of the drum of the winch.
`[0046] While the aspects of the present disclosure may be
`susceptible to various modifications and alternative forms,
`specific embodiments have been shown by wayof example in
`the drawings and have been described in detail herein. Butit
`should be understood that the invention is not intended to be
`
`limited to the particular forms disclosed. Rather, the invention
`is to cover all modifications, equivalents, and alternatives
`falling within the spirit and scope of the invention as defined
`by the following appended claims.
`1. An apparatus comprising:
`a winch including a rotatable drum and a heave compen-
`sation system having both an active drive input device
`and a passive drive input device, wherein the heave
`compensation system is coupled to the rotatable drum
`such that the active drive input device and the passive
`drive input device can eachbe usedto drive rotation of
`the rotatable drum in response to heaving motion ofthe
`winch.
`
`LIBERTY EXHIBIT 1006, Page 12
`
`LIBERTY EXHIBIT 1006, Page 12
`
`

`

`US 2015/0361736 Al
`
`Dec. 17, 2015
`
`2. The apparatus of claim 1, wherein the active drive input
`device includesan electric motor with active heave compen-
`sation.
`
`3. The apparatus ofclaim 1, whereinthe passive drive input
`device includes a hydraulic cylinder or a hydraulic motor.
`4. The apparatus of claim 1, wherein the winch includes a
`planetary gear system and the heave compensation systemis
`coupled to the rotatable drum via the planetary gear system to
`enable the planetarygear system to convert mechanical inputs
`from the active and passive drive input devices into mechani-
`cal output to control reeling of a hoisting line from the rotat-
`able drum.
`5. The apparatus of claim 4, wherein the planetary gear
`system includes:
`a sun gear coupled to the active drive input device;
`a ring gear coupledto the passive drive input devi