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.

A transportation device for an offshore platform, including a vessel and a floating structure which are fixedly connected. The floating structure is placed on a sea surface and is configured to assist the vessel to sail. The floating structure is provided with an adjustment mechanism which is configured to adjust the floating structure to rise and fall relative to the sea surface. A rail is arranged on the vessel and is in sliding connection with the topside module, so that the topside module slides onto the vessel from land. During the transportation of the topside module, the buoyancy of the floating structure is adjusted through the adjustment mechanism, so that the floating structure provides sufficient anti-rolling moments beside the vessel, thereby reducing the vibration of the topside module caused by the winds and waves during the sailing and reducing the potential damage to the topside module.

A control system retracts lifting devices to a stored reset height during a reset operation to raise support feet off of a base surface. The control device raises a load to a stored moving height above the base surface during a moving operation. The control system automatically repeats the reset and moving operations using the stored reset and stored moving heights. The control device may receive an adjustment signal identifying anew height of the support feet or load bearing frame above the base surface and uses the new height during subsequent reset or moving operations. The control device may default to a minimum reset height or a minimum moving height when the new height would cause the support feet or load bearing frame to drag on the base surface.

A truss-like hydraulic lifting apparatus with plugs including a pile reinforcing frame, a truss structure extending through and mounted within the pile reinforcing frame and a first number of uniformly disposed support legs, each having a support leg inserting hole. A first number of power source devices each has a plug corresponding to the support leg inserting hole. A detachable mechanism is provided for detachably fixing each of the power source devices to the pile reinforcing frame. The detachable mechanism includes a base plate laterally fixed relative to the pile reinforcing frame and having an opening through which the support leg vertically passes and forms a protective cap above the power source device. The lateral dimension of the protective cap is larger than the lateral dimension of the power source device.

A method of elevating the deck area of a marine platform (e.g., oil and gas well drilling or production platform) utilizes a specially configured sleeve support to support the platform legs so that they can be cut. Once cut, rams or jacks elevate the platform above the cuts. The sleeve support is then connected (e.g., welded) to the platform leg and becomes part of the structural support for the platform. In one embodiment, two sleeves are employed. In another embodiment, the jacks or rams elevate in two stages including a first stage wherein one sleeve elevates and the other sleeve does not elevate and a second stage wherein both sleeves elevate together.

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.

A truss-like hydraulic lifting apparatus with plugs including a pile reinforcing frame, a truss structure extending through and mounted within the pile reinforcing frame and a first number of uniformly disposed support legs, each having a support leg inserting hole. A first number of power source devices each has a plug corresponding to the support leg inserting hole. A detachable mechanism is provided for detachably fixing each of the power source devices to the pile reinforcing frame. The detachable mechanism includes a base plate laterally fixed relative to the pile reinforcing frame and having an opening through which the support leg vertically passes and forms a protective cap above the power source device. The lateral dimension of the protective cap is larger than the lateral dimension of the power source device.

A method of elevating the deck area of a marine platform (e.g., oil and gas well drilling or production platform) utilizes a specially configured sleeve support to support the platform legs so that they can be cut. Once cut, rams or jacks elevate the platform above the cuts. The sleeve support is then connected (e.g., welded) to the platform leg and becomes part of the structural support for the platform. In one embodiment, two sleeves are employed. In another embodiment, the jacks or rams elevate in two stages including a first stage wherein one sleeve elevates and the other sleeve does not elevate and a second stage wherein both sleeves elevate together.

Systems and method for compensation of motions of a floating structure, which includes a lifting system with a working platform supported by its actuators driven along vertical axis, where the foremost and the aft-most units are paired with each other providing a self-leveling movement; and a balance system, which can freely deviate from its position relative to the deck, with its own actuators and which is arranged to at least one side of the working platform, providing an even distribution of weight enabling the working platform to remain upright and steady, regardless of the floating structure. The lifting system is associated with the balance system by the plurality of arrangements of motion units, which assure the substantially constant angle between the working platform and the working frame, providing free linear movement relative to the working frame regardless of the base structure and the floating structure.

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.