Method for vibration damping of and vibration damper assembly for semi-submerged or submerged structure, based on separating hydrodynamic added mass from the semi-submerged or submerged structure by means of a vibration damper assembly exhibiting spring and/or damper properties and use the hydrodynamic added mass as a reaction mass in the vibration damper assembly.

The present invention relates to a structure and method of hoisting pipelines for subsea connection assisted by a remotely operated vehicle, ROV. Particularly, the present invention describes a pipeline hoisting structure comprising three beams joined together in a U-shape, and two hoisting systems, each being coupled to one of the vertical beams of the hoisting structure.

The present invention relates to a structure and method of hoisting pipelines for subsea connection assisted by a remotely operated vehicle, ROV. Particularly, the present invention describes a pipeline hoisting structure comprising three beams joined together in a U-shape, and two hoisting systems, each being coupled to one of the vertical beams of the hoisting structure.

The invention provides a method of emptying an undersea fluid transport pipe (2) that is submerged and full of water, the method comprising pumping out at least a portion of the water present inside the submerged pipe by means of a submersible pump unit (6) connected to a point of the pipe, the volume of water pumped out from the inside of the pipe being compensated by a gas injected under pressure into the submerged pipe from a point (18) thereof that is situated higher than the connection point (12; 14) to the submersible pump unit. The invention also provides an installation for performing such a method.

The invention provides a method of emptying an undersea fluid transport pipe (2) that is submerged and full of water, the method comprising pumping out at least a portion of the water present inside the submerged pipe by means of a submersible pump unit (6) connected to a point of the pipe, the volume of water pumped out from the inside of the pipe being compensated by a gas injected under pressure into the submerged pipe from a point (18) thereof that is situated higher than the connection point (12; 14) to the submersible pump unit. The invention also provides an installation for performing such a method.

A bend restriction element (1) is modular for forming a tube segment (12) all around a conduit through locked interlocking circumferential interconnection of multiple similar such elements (1). The tube segment (12) is modular for forming an articulated tube (100) around the conduit through locked interlocking longitudinal interconnection of multiple similar such tube segments (12). The locking of the circumferential interconnection of the elements (1) is ensured both by the manner of interlocking of a tube segment concerned (12) with a tube segment (16) situated on one side thereof, and by the manner of interlocking of the tube segment concerned (12) with a tube segment (14) situated on the other side thereof.

A pipe-in-pipe bulkhead assembly has inner and outer rings spaced in concentric relation to define a thermally-isolating gap in the annulus between them. Interlocking formations project into the annulus from each of the rings, presenting confronting faces where they overlap radially. The gap extends between the longitudinally-spaced faces. A thermally-insulating spacer is interposed between the faces in the gap to carry axial mechanical loads between the inner and outer rings. Heating elements outside the inner ring extend longitudinally beyond the gap between the faces and along a longitudinal passageway that passes through or beside an interlocking formation of the inner ring. The spacer may be positioned before or after the outer ring is placed, for example as a discrete element or as an injected mass. An additional sealing mass may also be positioned in the annulus, for example by injection, to promote a gas-tight seal.

A non-metallic clip connection system includes a non-metallic clip having a substantially rectangular base portion, a first longitudinal flared wing portion, and a second longitudinal flared wing portion, wherein a plurality of edges of the clip along a path of insertion are beveled or radiused. The non-metallic clip connection system also includes a first non-metallic member having a first portion of a non-metallic clip receiver and a second non-metallic member having a second portion of the non-metallic clip receiver. The first non-metallic member is secured to the second non-metallic member by inserting the non-metallic clip in the non-metallic clip receiver. A non-metallic vertebrae bend restrictor and a non-metallic vertebrae end piece may use a non-metallic clip connection system.

A termination arrangement for use in a horizontal connection system for subsea connection of a first tubular member to a second tubular member, the termination arrangement including a base structure with a horizontal tubular body. The first tubular member is rotatably mounted to the tubular body through an annular bearing. An internal fluid chamber accommodating a liquid having heat-storing capacity is formed inside the tubular body and delimited at one end by the annular bearing and at another end by a rear end wall. A section of the first tubular member extends through the fluid chamber and is in contact with the liquid in the fluid chamber so as to allow the liquid to delay cooling of this section of the first tubular member by means of heat stored in the liquid.

A termination arrangement for use in a horizontal connection system for subsea connection of a first tubular member to a second tubular member, the termination arrangement including a base structure with a horizontal tubular body. The first tubular member is rotatably mounted to the tubular body through an annular bearing. An internal fluid chamber accommodating a liquid having heat-storing capacity is formed inside the tubular body and delimited at one end by the annular bearing and at another end by a rear end wall. A section of the first tubular member extends through the fluid chamber and is in contact with the liquid in the fluid chamber so as to allow the liquid to delay cooling of this section of the first tubular member by means of heat stored in the liquid.