A system for lifting loads from a mobile offshore platform includes a boom pivotally at one longitudinal end mounted to the platform. A boom extension line is coupled at one end to the boom to cause rotational movement thereof about the pivotally mounted end of the boom. Another end of the boom extension line is either (i) coupled to a movable subplatform on the platform or (ii) supported by a device coupled to the movable subplatform. Movement of the subplatform causes change in effective length of the boom extension line so as to move the boom between an extended position and a retracted position.

A method for predicting heaving motion parameters of a semi-submersible offshore platform based on heaving acceleration includes: in heaving motion of a semi-submersible offshore platform, representing heaving acceleration of the semi-submersible offshore platform based on a linear potential flow theory; considering a noise influence of a heaving motion measurement marine environment, a low-frequency influence caused by a slow change of the environment and an influence caused by a baseline drift error of an acceleration sensor, introducing a noise term, a low-frequency change term and a baseline drift error term, and uniformly representing the noise term, the low-frequency change term and the baseline drift error term by a unified Prony sequence; and removing a drift term from uniformly represented heaving acceleration, establishing a relationship between the heaving acceleration and heaving motion parameters in terms of the remaining Prony sequence with the drift term being removed, and estimating the heaving motion parameters.

An offshore structure includes an adjustably buoyant hull including a plurality of vertical columns and a plurality of horizontal pontoons. Each pontoon extends between a pair of the columns. The adjustably buoyant hull is configured to receive a topside. Each column has a central axis, an upper end, and a lower end. Each pontoon has a longitudinal axis, a first end coupled to one of the columns, and a second end coupled to another one of the columns. The offshore structure also includes a foundation assembly attached to a lower end of the hull. The foundation assembly includes a column skirt extending downward from the lower end of each column and a pontoon skirt extending downward from a bottom surface of each pontoon.

A method for evaluating a securing system for a floating structure, where the method includes collecting a plurality of metocean data from a plurality of metocean sensor devices during a current time period coinciding with a field operation, where the field operation is conducted from the floating structure that is stabilized by the securing system. The method can also include evaluating the metocean data using a plurality of algorithms. The method can further include determining, based on evaluating the metocean data, a condition of the securing system at the current time period.

This invention relates generally to geotechnical rig systems and methods. In one embodiment, a cone penetration testing system includes, but is not limited to, a frame; at least one rotatable reel; at least one movable roller; and at least one sensor, wherein the at least one movable roller is configured to adjust a bend radius of at least one tube coiled about the at least one rotatable reel based at least partly on data received from the at least one sensor.

Systems, devices and methods enable generation and monitoring of support platform structural conditions in a manner that overcomes drawbacks associated with conventional approaches (e.g., load cells) for generating and monitoring similar operating condition information. In preferred embodiments, such systems, devices and methods utilize fiber optic strain gauges (i.e., fiber optic sensors) in place of (e.g., retrofit/data replacement) or in combination with conventional load cells. The fiber optic sensors are strategically placed at a plurality of locations on one or more support bodies of a support platform. In preferred embodiments, the fiber optic strain gauges are placed in positions within a hull and/or one or more pontoons of an offshore platform. Such positions are selected whereby resulting operating condition data generated by the fiber optic strain gauges suitably replaces data received by conventionally constructed and located load cells of an offshore platform (e.g., a TLP).

The present disclosure provides a system and a method for efficiently converting the structure of a drilling floating platform into a structure for a production floating platform. A riser support module can be coupled to a topsides of the drilling floating platform and suspended below a moonpool or other opening through the topsides to support risers and their respective riser pull tubes, if any. The riser support module can be prebuilt and installed as a unit for example at a quayside.

A ring-wing floating platform is disclosed. The ring-wing floating platform includes a floating hull, a top of the floating hull being above a sea surface and its geometry at a water plane is centrally symmetric, a ring-wing surrounding a perimeter of a bottom of the floating hull with a horizontal projection of concentric annular geometries, a positioning system located at the bottom of the floating hull, and a topsides located above the floating hull and connected to the floating hull by deck legs or installed directly on the top of the floating hull. The axes of the ring-wing and the floating hull are collinear, and their bottoms are in a same horizontal plane. The ring-wing and the floating hull are connected together as a unitary structure by multiple connecting components with an annular gap in-between.

A bearing system including a wheel assembly transmitting load to a damping assembly, wherein the wheel assembly is configured to rotate angularly relative to the damping assembly.

The present invention discloses a floating platform, wherein multiple layers of compartments are configured along the height direction of the floating platform, and the center of gravity of each layer of compartments in a full-load process and a loading and unloading process is always located on a vertical line where the whole center of gravity of the floating platform is located; the multiple annular compartments are of equal-ratio subdivision in volume: the volume ratio of every two adjacent upper and lower annular compartments is inversely proportional to the density of liquid stored in the compartments; in the practical loading process, the floating platform is always kept at a constant displacement to maintain the waterplane unchanged by adjusting crude oil or seawater loaded in different layers of compartments, and thus the floating plate always has optimal hydrodynamic performance.