A supporting system for a floating unit in shallow water exerts controlled stresses on the floating unit hull and includes supporting structure for the hull. An extendable supporting device operatively connects to the supporting structure and is suitable to support a predetermined weight of the floating unit and load when entirely supported by the extendable supporting device and when the extendable supporting device rests on a bed of a water body. An actuator device connects to the supporting structure and operatively connects to the extendable supporting device for extension or contraction. A control device operatively connects to the actuator device to control the extraction or contraction movement of the extendable supporting device. The system includes at least one hull stress monitoring device operatively connected to the control device. A device to monitor the stress, or load, on the extendable supporting device operatively connects to the control device.

This disclosure provides an experiment device for spudcan penetration and pullout of a jack-up rig, comprising an experiment bench and a spudcan leg, and further comprising: a ballasting tank; supporting wheels provided on the experiment bench; a suspension rope wound around the supporting wheels with two ends being connected respectively to the spudcan leg and the ballasting tank, wherein the ballasting tank has a first state of being seated on the spudcan leg and a second state of being separated from the spudcan leg and suspended under the suspension rope, by configuring the ballasting tank to have two different states, the gravity of the ballasting tank can be used as both the penetration force and the pullout force, and eliminating the need to provide two loading devices to apply the penetration pressure and the pullout force respectively.

The present invention relates in some embodiments to a bottom supported drilling unit having two drilling stations for independently drilling (or otherwise working on) two wells simultaneously from a cantilever.

The offshore jack-up has a hull and a plurality of moveable legs engageable with the seafloor. The offshore jack-up is arranged to move the legs with respect to the hull to position the hull out of the water. The method comprises moving at least a portion of a vessel underneath the hull of the offshore jack-up or within a cut-out of the hull when the hull is positioned out of the water and the legs engage the seafloor. A stabilizing mechanism mounted on the jack-up is engaged against the vessel. The stabilizing mechanism is pushed down on the vessel to increase the buoyant force acting on the vessel.

For controlling movement of a cantilever of an offshore platform, displacements required for displacing an item to a target position including longitudinal skidding displacement and transverse skidding displacement of the cantilever of the cantilever are determined from current position data and target position data. From position dependent support load data support loads during the longitudinal skidding displacement are determined. If and until a sum of support loads or a highest support load decreases during the longitudinal skidding displacement towards the target position, the longitudinal skidding displacement precedes the transverse skidding displacement. If a sum of support loads or a highest support load increases during the longitudinal skidding displacement towards the target position, the transverse skidding displacement towards the target position precedes the longitudinal skidding displacement.

An offshore LNG processing plant includes a first module including a personnel accommodation facility on a first vessel, a second module including a gas treatment facility on a second vessel, and a third module including a gas liquefaction facility on a third vessel. Each of the first, second, and third modules are assembled on the corresponding vessels, and then transported to an offshore location in a body of water, such as a river, a lake, or a sea. At the offshore location, each vessel deploys legs to the bed of the body of water to raise a hull of each vessel out of the water. The first module is then coupled to the second module, and the second module is coupled to the third module. A fourth module on a fourth vessel is coupled to the third module to provide LNG storage.

An apparatus for use in marine platform jacking is disclosed herein. In one aspect, a jetting valve includes a valve body with a piston assembly disposed therein. The piston assembly is selectively operated to open and close the valve. A biasing member is coupled to the piston assembly. The piston assembly includes a first piston and a second piston. The dual pistons, in cooperation with the biasing member, allow the valve to self-seal thereby preventing entry of a fluid which is external to the valve.

A spud greasing system includes a spudwell and a spud configured to slidingly engage with the spudwell between a deployed position and an undeployed position. The spud includes an access window configured to align and correspond with a window of the spudwell when the spud is in the undeployed position. A sheave assembly is mounted in the spud and includes a first sheave and a second sheave rotationally mounted proximate a front end and a back end of the housing, respectively. When the spud is in the undeployed position, a grease supply is configured to be selectively connected to a supply pipe through the window and access window of the spudwell and spud thereby supplying grease to the first sheave of the sheave assembly without removing the spud from the spudwell.

Method for stabilizing a jack-up platform unit, the unit including a hull, a plurality of legs which are extendible from and/or through the hull and which are arranged to support the platform unit during off-shore operations, and a jacking system arranged to move the legs between a transport position and an operational position, wherein the jacking system is also arranged to move the hull along the plurality of legs between a floating position and an operational position, the method comprising the steps of lowering the plurality of legs until the legs stand on or in the seabed, raising the hull substantially above the sea surface, temporarily applying a preloading on the plurality of legs, further raising the hull to an operational height above the sea surface.

A deployed L-shaped rack structure interengaged with a self-elevating vessel is used for supporting a feeder transport vessel, such as an ocean or sea barge, to eliminate relative motion or movement between the vessels. Some of the proposed rack structures are movable between a stowed position and a deployed position. The method of use for the movable rack structures includes the self-elevating vessel arriving at a predetermined location, elevating the hull of the self-elevating to a suitable height above the sea surface at a desired still water line (SWL) to create an air gap, and then deploying the rack structure. A feeder transport vessel, with its cargo and/or components, can then be floated over the deployed rack structure. The self-elevating vessel then uses its jacking system including a plurality of legs supported on the seabed to raise the feeder transport vessel and its cargo and/or components to a desired height above the SWL. From this position relative motion between the self-elevating vessel and transport vessel is eliminated so that the self-elevating vessel lifting device, such as a crane, can be more safely used to install energy components, such as wind turbine components. A bottom supported tower/column section could also be assembled and installed in seabed using the self-elevating vessel and rack structure along with the lifting device. A fixed rack structure system and its method can also be advantageously used with a self-elevating vessel. The systems and methods could be used in reversing the method or steps for deinstallation of the energy components installed in the sea.