Floating Unit with Under Keel Tank
AssigneeChevron U.S.A. Inc.
InventorsWei Ma, Fei Yang, Jack Darryl Payne, Peter Leitch, Renjian Roger Lu, Tao Wang, Jon Husby, Erling Storaune
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Abstract
A tank is secured under the keel of a floating structure for offshore energy development. The tank is filled with ballast material that supplements or replaces the ballast already present on the floating structure, thereby gaining larger topsides payload capacity for the floating structure or increasing stability and motion performance of the floating structure.
Claims20
A semi-submersible floating structure for offshore energy development, the semi-submersible floating structure comprising:
- a pontoon;
- a column or a plurality of columns extending from the pontoon to a deck;
- an under keel tank or a plurality of under keel tanks secured under the pontoon, and filled with air, water, or solid material, or any combination thereof, as ballast;
- a system of tendons, rods, or wires vertically supporting the under keel tank relative to the pontoon and connected to one or more support structures on top of the pontoon, wherein the system of tendons, rods, or wires is under tension via a torque mechanism located on the one or more support structures;
- and
- one or more lateral restraints resisting lateral movement of the under keel tank relative to the pontoon.
A method of increasing payload capacity and/or stability of a floating structure for offshore energy development comprising:
- securing an under keel tank under a keel of the floating structure, wherein securing the under keel tank under the keel comprises:
- vertically supporting the under keel tank relative to a pontoon of the floating structure using a system of tendons, rods, or wires connected to one or more support structures on top of the pontoon, wherein the system of tendons, rods, or wires is under tension;
- and
- restraining lateral movement of the under keel tank relative to the pontoon using one or more lateral restraints positioned against the pontoon and under keel tank;
- wherein the under keel tank is filled with air, water, or solid material, or any combination thereof, as ballast;
- wherein the ballast of the under keel tank supplements or replaces a ballast of the floating structure, thereby lowering the vertical center of gravity of the floating structure and increasing the payload capacity and/or stability of the floating structure.
An under keel tank configured to be installed under the keel of a floating structure for offshore energy development, comprising:
- one or more compartments capable of being ballasted so as to allow the under keel tank to have sufficient ballast to expand a payload capacity of the floating structure, or to provide additional stability for the floating structure;
- and
- one or more structures attached to the one or more compartments configured to allow the tank to be secured under the keel of the floating structure,
- wherein the one or more structures comprise a system of tendons, rods, or wires configured to connect the one or more compartments to one or more support structures on top of the pontoon, through the system of tendons, rods, or wires being under tension via a torque mechanism located on the one or more support structures.
Dependencies are inferred from the claim text.