Post on 27-May-2017
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JACK UPS IN OPERATION –th OCTOBER 2013
PRESENTED BY NANDAKUMAR KUNNANCHATH
– TYPES AND DIFFERENCES
PRESENTED BY NANDAKUMAR KUNNANCHATH
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Jack Ups in Operation
A jackup is a floating barge fitted with longlegs that can be raised or lowered. The jackupmaneuvered (self-propelled or by towing) intowith its legs up and the hull floating on theUpon arrival at the work location, the legs aredown onto the seafloor. Then "preloading"place, where the weight of the barge and additionalballast water are used to drive the legs securelythe sea bottom so they will not penetrate furtheroperations are carried out. After preloading,jacking system is used to raise the entire bargethe water to a predetermined height or "airthat wave, tidal and current loading acts onlyrelatively slender legs and not on the bargeModern jacking systems use a rack and pinionarrangement where the pinion gears are drivenhydraulic or electric motors and the rack is affixedthe legs.
Jackup rigs can only be placed in relativelywaters, generally less than 400 feet (120 m)However, a specialized class of jackup rigs knownpremium or ultra-premium jackups are knownhave operational capability in water depthsfrom 500 to 625 feet.
Jack Ups in Operation
long supportjackup is
into locationthe water.are jacked
"preloading" takesadditional
securely intofurther while
preloading, thebarge above
gap", soonly on thebarge hull.pinion gear
driven byaffixed to
relatively shallowof water.
known asknown to
depths ranging
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Jack Ups in Operation
Mobile Offshore Drilling Units (MODUs)
capable of drillingEarth's crust.mud (slurry) throughannulus, for coolinga well is drilledtons of pipe. Otherinto reservoirsnatural gas; andpermanent livingcrews (which mayrigs may operatekilometres distantinfrequent crew
Jack Ups in Operation - Types
Mobile Offshore Drilling Units (MODUs)
drilling through thousands of metres of theLarge "mud pumps" circulate drilling
through the drill bit and up the casingcooling and removing the "cuttings" while
drilled. Hoists in the rig can lift hundreds ofOther equipment can force acid or sand
reservoirs to facilitate extraction of the oil orand in remote locations there can be
living accommodation and catering formay be more than a hundred). Marine
operate many hundreds of miles ordistant from the supply base with
crew rotation or cycle.
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Jack Ups in Operation
Liftboats
Jack Ups in Operation - Types
A liftboat is a self-propelled, selfelevating vessel with a relatively largeopen deck capable of carryingequipment and supplies in supportvarious offshore mineral explorationproduction or offshore constructionactivities. A liftboat also hascapability of rapidly raising its hull clearof the water on its own legs so asprovide a stable platform from whichmaintenance and construction workmay be conducted. Liftboats are usuallyoutfitted with at least one crane; marinecranes are usually designed tospecification 2C or the equivalentclassification society guidelines.
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Jack Ups in Operation
Jack Up WTIVs
Jack Ups in Operation - Types
Wind Turbine Installation Vesselsare deployed to install turbinesoffshore wind farms. On arrivalthe site of the wind turbine,vessel lowers its legs to standthe seabed, and then jacksabove the surface of the seaThis provides a stable platformhammer down a mono-pilethe sea bed and install the windturbine. When the turbinebeen installed, vessel lowersherself and sails to the nextposition to repeat the process
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Jack Ups in Operation
MOPUs
Mobility enables reduced installation,decommissioning costs, compared withups have the added advantage of relocationplatforms provide large flat deck areasfunctional topside arrangement.
Jack Ups in Operation - Types
Mobile offshore production units(MOPUs) are production units thatcan be relocated from site to siteThe jackup has proven itself anexcellent candidate for shallowwater early production applicationJackups offer a cost efficientsolution for short life fields,compared with jacket or subseaapplications.
installation, hook up, and commissioningwith a jacket structure. Production jack
relocation and re-use at less cost. Jackupareas offering flexibility for a safe and
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Jack Ups in Operation
Jack Up Construction & Accommodation Barges
Jack Ups in Operation - Types
Jack Up Construction & Accommodation Barges
Specialized jack ups usedas a base for servicingother structures such as oiland gas platforms duringtheir construction, operationand maintenance and alsofor accommodation ofoffshore crew during hookup and commissioning.
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Jack Ups in OperationMajor Design ParametersThe overall jack up design optimizes thewould not desire a big deck area without a comparableelements to focus on:
1) Legs and PadsThe vast majority of jack ups are three-leggedthe cost of simply adding the cost of anotherlegs loaded diagonally is greater andoperationally, the setup time savings of aweigh the costs and benefits of three vs. fourProven to be a cost effective design, the vast(pipe legs). Columnar legs and pads provideare lowered to the sea floor. This buoyancyreduce the bottom bearing pressure on theliftboat pads are designed to reduce bottompenetration.Working water depth also affects the typemeters) of water, lattice legs are the norm.
Jack Ups in Operation - Differences
interrelationship of the key features, i.e.,comparable deck load. So there are certain
legged. The four-legged liftboat will cost moreanother leg, i.e., the jacking system to support
the hull structure is different/heavier.four-legged equates to money, so, one has
four legs.vast number of liftboats have three columnar
provide added buoyancy for the liftboat as thebuoyancy in both the legs and pads (spud cans) helps
pads. In combination with the buoyancy, largerbottom bearing pressure. This has the effect of
type of leg; for example, after about 220 feet
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Jack Ups in Operation
(2) Jacking System
The jacking system for a liftboat is veryup drilling rig. The two major differences
Speed of the liftboat jacking system is essentialelevates at two feet per minute, a liftboatand lower the legs at 14-18 feet per minuteon and off location significantly faster.
The jacking system for a liftboat encounterswould not be uncommon for a liftboat tonumber of times that a jack-up drilling rigthe wear factors, redundancy, materialbetween jack-ups and liftboats.
Jack Ups in Operation - Differences
different than the jacking system for a jackdifferences center on speed and cycles.
essential. While a typical jack-up drilling rigliftboat could elevate at four to six feet per minute
minute. This gives the liftboat the ability to get
encounters a very different operational cycle.to jack up and down in one year the samerig would encounter in its entire lifetime. So,
material grades and shock loads are different
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Jack Ups in Operation
(3) Working Water Depth
The expected wind, wave and current (environmentalworking water depth need to be determinedthe liftboat design, such as, net deck load,depth. An area with moderate environmentalconditions will be a significantly differentjacking system and hull.
(4) Open Deck Area
The deck area is the unobstructed, openequipment and materials around and on toThere is a relationship among these variablescrane capacity. Furthermore, you need athe expected deck loads and deck area.
Jack Ups in Operation - Differences
(environmental conditions) in the maximumdetermined. Although, other variables will go into
load, the starting point is still working waterenvironmental conditions vs. harsh environmental
different jackup design in all aspects, i.e., legs,
open area. The liftboat crane is used to moveto and off of the platform/offshore location.
variables – open deck area, net deck load andcrane capacity that is commensurate with
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Jack Ups in Operation
(5) Net Deck Load
The net deck load for a liftboat is whatthen jack up with on the deck. Consumablesetc.) are in addition to the net deck load.There is a definite relationship amongLiftboats are designed as multi-purposeAlso, one needs to consider the type ofthe deck, so that, various areas can beloadings, i.e., an area near the bow mayareas.
Jack Ups in Operation - Differences
you have on your deck in transit and canConsumables (such as water, fuel, hydraulic fluid,
.deck area, deck load and crane capacityvessels.equipment and components that will be on
be designed to accommodate the variousmay have higher point loading than other
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Jack Ups in Operation
(6) Crane Capacity
There are a variety of cranes for liftboatscrane manufacturers specifically for liftboatsliftboat design, so, every considerationincluding the crane. Therefore, cranes forthan a comparable offshore crane.
Regarding types of liftboat cranes, thereboom, pedestal mounted, and leg encircling
Jack Ups in Operation - Differences
liftboats. Cranes for liftboats are designed byliftboats. Weight is a key consideration in
consideration needs to be made in the overall designfor liftboats are typically structurally lighter
there are lattice boom, box boom, telescopicencircling cranes.
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Jack Ups in Operation
(7) Personnel Accommodations
The accommodations are anotheraccommodations are generally dividedcustomer/operational personnel. As liftboatscapacities, so have the requirements foraccommodation block would typicallyremaining 80 for customer/operational personnel
The type of job that the liftboat is performingrequirement, i.e., an offshore constructionpersonnel than a well intervention jobadditional modular living quarters on the
Jack Ups in Operation - Differences
feature of liftboats. The personneldivided into two areas – navigation crew and
liftboats have gotten bigger with increasedfor more personnel. For example, a 100-man
have about 20 navigation crew and thepersonnel.
performing will dictate the accommodationconstruction job would generally require more
job. The construction job may even requirethe deck.
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Jack Ups in Operation
(8) Propulsion
Majority of liftboats are self-propelled. Thisliftboat or to set up on location. The liftboatmove. The larger liftboats have integratedwith DP2 capability are becoming more common
(9) Classification Society Rules
Classification Society rules are also differentexample, whilst most of the MODU rulesare different rules and guidelines avaialbleLloyds Register), etc.
Jack Ups in Operation - Differences
This alleviates the need for tugs to move theliftboat can wait for a weather window and
integrated propulsion and bow thrusters. Liftboatscommon these days.
different for different types of jack ups. Forrules are applicable for Liftboats as well, there
avaialble for liftboats (MOUs for ABS, Liftboats for
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Jack Ups in OperationIn today’s market place, there are more thanunits, each having certain design techniquesunits more economical to build, better to operate,of these features.
Pinion versus pin and hold jacking systemSingle sided versus opposed rackFixed versus floating jacking unitsElectric versus hydraulic jacking powerTransparent versus robust leg designJack support systems (a) Stiffness ofbalancing devicesGuide tolerances and lengthsLeg bracing patternsSlo-Rol systemsHeave absorption systems
With such a complex group of variables andto produce so many different possibleunderstand the purpose and functions of somequantitative manner, before owners andjackups for a specific operation.
Jack Ups in Operation - Differencesthan a dozen major active designers for jack
techniques and features that they feel make theiroperate, or both. The following is a brief listing
system
Units (b) Leg Locking Devices (c) Torsion
and their implications which may be combinedbenefits or problems, it is important
some of these features in both qualitative andoperators can decide the specification
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Thank You for your attentionThank You for your attention
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