An offshore drilling system includes a drilling tower, a tubular string hoisting device with a crown block and a travelling block suspended from the crown block in a multiple fall arrangement. A heave compensation system is adapted to provide heave compensation of the travelling block. The heave compensation system includes a hydraulic sheave compensator. The system further includes a mobile working deck which is movable with respect to the drilling tower within a motion range including a heave compensation motion range. The heave compensation system is further adapted to provide heave compensation of the mobile working deck by a hydraulic deck compensator, which is hydraulically connected via a hydraulic conduit to the hydraulic sheave compensator, such that in operation the deck compensator moves synchronously with the sheave compensator of the heave compensation system.

The invention relates to a vessel comprising a moonpool, a firing line hoist system, a stationary main deck for storing equipment and/or tubulars, and a mobile working deck having a front deck section and a rear deck section. The working deck can be moved between a working position and a transporting position. A rear deck lift system is provided for lifting and lowering a rear deck section between the working position and the transporting position. A front deck guide system is provided for guiding a front deck section in a substantially horizontal direction between the working position and the transporting position.

An oil storage apparatus (111) comprising a buoyant hull (102) comprising a single column of circular or polygonal cross-section. The interior of said hull (102) comprises at least one oil-over-water tank (103), and said oil storage apparatus (111) further comprises means for maintaining said tank in pressed full condition.

The present invention relates to a method for operating a drilling vessel adapted to run large diameters surface casing joints having a diameter of over 20 inch (51 cm) and a length of 30-50 feet (9-15 meters), and build a surface casing string. According to the invention three or more surface casing joints are interconnected into pre-assembled surface casing stands having a length of over 100 feet (30 meters). These surface casing stands are substantially horizontally stored and transferred by a casing stand handling system to a surface casing string handling capacity hoisting device, which subsequently lowers the surface casing string.

A flotation system includes one or more floatation modules, each having a first section and a second section, each having an internal core made of a buoyant material. The first section includes two end faces and a projection extending from one of the end faces. The projection has a contoured profile. The second section includes two end faces and a reciprocal recess in one of the end faces. The end faces of the first section engage the end faces of the second section such that the projection engages the reciprocal recess in a mating engagement. A stop collar may be disposed adjacent each end of the floatation module. The floatation system may be attached to a tubular string that is lowered into a marine riser to reduce a load applied to a rig disposed over the marine riser.

According to the invention a semi-submersible vessel including a semi-submersible platform body is provided. The semi-submersible platform body is adapted to float in a body of water wherein the platform body comprising a plurality of pontoons arranged together to form a triangular structure, a plurality of columns having a lower portion and an upper portion, the columns extending outwardly from each corner of the triangular structure, wherein each column is triangular. Further, the semi-submersible vessel includes a deck supported by the upper portion of the columns.

A sandglass type ocean engineering floating structure is provided with an upper structural body shaped as a circular truncated cone or frustum and a lower structural body shaped as a regular circular truncated cone or regular frustum; under a combined state, the smaller bottom surface of the upper structural body is fixedly connected with the smaller bottom surface of the lower structural body to form a junction surface; the axis of the upper structural body and the axis of the lower structural body are positioned on the same straight line; the larger bottom of the upper structural body acts as an upper deck of the floating structure and the larger bottom of the lower structural body acts as a lower plate underwater of the floating structure; the junction surface is a full-load waterplane of the floating structure.

A butt joint octagonal frustum type floating production storage and offloading (FPSO) system, wherein a floating body is provided with an upper structural body in an octagonal frustum shape and a lower structural body in a regular octagonal frustum shape; in a combined state, a smaller bottom surface of the upper structural body is fixedly connected with a smaller bottom surface of the lower structural body, to form a junction surface; the axis of the upper structural body and the axis of the lower structural body are positioned on the same straight line; the larger bottom of the upper structural body acts as an upper deck of the floating structure and the larger bottom of the lower structural body acts as a lower plate underwater of the floating structure; the junction surface is a full-load waterplane of the floating structure.

A vessel is adapted to perform subsea wellbore related operations involving a riser string between the subsea wellbore and the vessel, e.g. drilling and/or wellbore intervention. The vessel includes a hull having a deck, and a riser storage hold present within the hull below the deck. The riser storage hold includes storage racks adapted to store therein parallel stacks of multiple riser sections and/or pre-assembled riser stands in horizontal orientation. The vessel has an elongated riser transfer opening between the deck and the roof, the riser transfer opening extending in a direction parallel to the storage racks, the riser transfer opening having a length and a width so as to allow for transfer of a single riser section or a single riser stand in horizontal orientation via the riser transfer opening out of and into the riser storage hold, wherein the risers' handling system is suitable to work at the same time with two different lengths.

The present invention relates to an apparatus and method for controlling an auxiliary apparatus of drilling equipment in a drill ship. According to an embodiment of the present disclosure, the apparatus for controlling an auxiliary apparatus of drilling equipment in a drill ship comprises: drilling equipment controller for transmitting a main apparatus execution command to a DC/AC converter in order to operate a main apparatus; and the DC/AC converter for transmitting an auxiliary apparatus execution command to an MCC in order to operate an auxiliary apparatus related to the main apparatus when receiving the main apparatus execution command from the drilling equipment controller, and operating the main apparatus when the auxiliary apparatus is normally operated, wherein the auxiliary apparatus is an apparatus to be operated in advance in order to operate the main apparatus.