Techniques and systems to reduce deflection of a riser extending from an offshore vessel. A device may include a fairing assembly having a body segment configured to at least partially circumferentially surround a main tube of a riser joint of the riser, and a tail segment. The tail segment is configured to retract into a collapsed position and extend into an expanded position along an expansion direction. An expanded width of the fairing assembly in the expanded position is between 20 to 200 percent greater than a collapsed width of the fairing assembly. In some embodiments, the collapsed width of the fairing assembly is less than 1.5 times a length across the main tube, and an expanded width of the fairing assembly is greater than 1.5 times the length of the main tube.

Bend restrictor comprising at least one pipe section and at least one clamp section wherein the pipe section comprises an outward facing flange at each end, the pipe section is split in the longitudinal direction into at least two parts, wherein the clamp section comprises an inward facing flange at each end and a pipe shaped middle section therebetween, wherein the clamp section is split in the longitudinal direction into at least two parts, wherein said parts are connectable through bolt connections, and wherein each inward facing flange is adapted to receive the outward facing flange of a pipe section.

A subsea flexible riser installation has a seabed foundation and a steep-configuration flexible riser anchored to the seabed by the foundation. An attachment formation is fixed relative to the riser and a locating formation is fixed relative to the foundation, both at positions elevated above the seabed. The locating formation is engaged with the attachment formation on the riser. This holds the attachment formation and the riser against movement when engaged, protecting the base of the riser from over-bending and fatigue.

Stress reducing system and associated method for reducing stresses at a desired position in an offshore production or drilling system, the offshore production or drilling system comprising: a seabed structure, a floating structure and a riser (24) extending there between, the riser being tensioned, the riser (24) comprising at least a first part (45) and a second part (46), which second part (46) is connected to the first part (45) via a flexible connection (20) allowing an axial, angular and/or rotational movement between the first and second parts (45, 46), said stress reducing system comprises:a first sensor (41) for real-time monitoring of stresses at the desired position, positioned at or close to the desired position (20),an actuating system (42) arranged at the flexible connection (20, the actuating system (42) being connected to said first and second parts (45, 46), and wherein the actuating system (45, 46) is configured to apply a force to the first or second part (45, 46) when the first and second parts (45, 46) are moved out of a neutral position,a control system (40) adapted to receive monitoring data from the first sensor (41), wherein the control system (40) is connected to the actuating system (42) and is able of providing instruction signals to the actuating system (42), wherein the control system (40), based on said monitoring data from the first sensor (41), is able to calculate a real-time set of data for control of the applied force of the actuating system (42) and instructing the actuating system (42) to act accordingly, such as to reduce the stress at said desired position.

A method and apparatus are disclosed for determining a bending radius of a flexible pipe. The apparatus includes at least one bend sensor element comprising an elongate flexible substrate and at least one bend sensitive element on the substrate that has at least one electrical characteristic that is responsive to angular displacement of the substrate. The apparatus also comprises a flexible crush resistant elongate housing that supports and surrounds the bend sensor element.

A bend stiffener (50) includes an elongate stiffener body (52) having polymer material and two ends. A passage (58) extends through the stiffener body from end to end for receiving and embracing a flexible member (60). The stiffener body includes a coupling (66) for mounting the stiffener body in cantilever fashion. The stiffener body is sufficiently flexible to curve somewhat along with the flexible member under a bending load but is sufficiently stiff to resist excessive curvature which could damage the flexible member, and sufficiently resilient to recover its original shape afterwards. The stiffener body includes at least two stiffener body parts (64a, 64b) defining the passage. Each stiffener body part includes a respective interface member (68, 70) having material stiffer than the polymer material of the stiffener body. A securing arrangement (80, 83) secures the interface members of different stiffener body parts together around the elongate flexible member.

A riser top connector assembly (20) is shown. The assembly (20) includes a first connector part (21) arranged on a flexible jumper prepared for connection with a second connector part (40) arranged on top of a marine riser tower assembly projecting from the seabed. The first connector part (21) is provided with suspension means adapted to engage with supporting means in order to be supported and be able to tilt in the marine riser tower assembly. The first connector part (21) includes a housing (22) that receives an extendable termination hub (23) having a clamp connector (24) attached thereto. The jumper termination hub (23) is alignable with a riser hub (44) on the second connector part (40) when the first connector part (21) is being tilted relative to the marine riser tower assembly.

A fatigue life extender (10) has a cylindrical body (13) having a throughgoing passage (20), arranged to be incorporated at an end of a connection device such as a clamp (11). The cylindrical body has a mouth portion (18), the interior circumference of which is lined with a ring or band (22) of resilient material such as rubber or an elastomeric compound. The ring or band (22) is crosshatched into a grid creating a plurality of rectangular segments (24) of resilient material by a plurality of perpendicular cuts extending less than completely through the thickness of the material.

The invention relates to a method of manufacturing a pipe segment for a link tube between the sea floor and a petroleum drilling rig disposed on the sea surface, wherein it consists in: providing a transport pipe segment that is resistant to open-sea conditions; disposing a female bayonet-piece around one reinforced end of the transport pipe segment; welding or otherwise bonding a narrower portion of the bayonet-piece to said reinforced end; disposing an insulator around the transport pipe segment and around the bayonet-piece; inserting the transport pipe segment into an outer wall segment; welding or otherwise bonding a narrower portion of the outer wall segment to the other reinforced end of the transport pipe segment; disposing a cover-piece around the bayonet-piece; welding or otherwise bonding the cover-piece to the outer wall segment and to the bayonet-piece; it being possible to apply tightening torque to the outer wall segment and to transmit it to the transport pipe segment.

A bend stiffener for resisting excessive-bending of an elongate underwater member in a region where it meets a rigid structure, comprises: a sleeve (1) for receiving said elongate underwater member, said sleeve being capable of some degree of flexure; and a rigid interface mount (3) secured to said sleeve, said rigid interface mount being suitable for attachment to said rigid structure; wherein said rigid interface mount comprises one or more slots (4) or holes which are alignable with corresponding slots, holes or recesses on said rigid structure such that the rigid interface mount may be locked to the rigid structure by locking means (2), said locking means comprising projection(s) through the slots or holes of the rigid interface mount into the slots, holes or recesses of the rigid structure. The bend stiffener is particular suited to mid-line applications, amongst other applications.