An underwater utility line, and associated systems and methods are disclosed. The underwater utility line can include an adjustably buoyant tube. The underwater utility line can also include a transmission line to transfer energy disposed in an interior of the adjustably buoyant tube. The underwater utility line can further include a gas source and a controller to control the gas provided by the gas source to alter the buoyancy of the adjustably buoyant tube.

A rigid riser system including a rigid riser and one or more fatigue performance enhancers. The rigid riser includes a plurality of rigid metal sections welded together to form a plurality of girth weld joints. The one or more fatigue performance enhancers are positioned over one or more of the plurality of girth weld joints of the rigid riser to enhance the fatigue resistance and/or fatigue life. The body of the fatigue performance enhancer may include a central region and two end regions with the central region having a greater average radial cross-sectional thickness than each of the end regions. Methods of enhancing fatigue performance of the rigid riser and fatigue performance enhancers are also disclosed.

A joining device of a continuous conduit is for changes in slope of seabeds. The continuous conduit defines a longitudinal direction substantially coinciding with the longitudinal direction of structural development of the continuous conduit. The continuous conduit has a longitudinal structural continuity and a fluidic continuity. The joining device includes a joint that includes at least one first joining branch, at least one second joining branch and at least one third joining branch. The first joining branch extends along the longitudinal direction and provides longitudinal structural and fluidic continuity of the continuous conduit and connects with a piece of the continuous conduit. The second joining branch provides longitudinal structural continuity of the continuous conduit. The third joining branch provides fluidic continuity of the continuous conduit. The second joining branch is exclusively suitable for providing the longitudinal structural continuity of the continuous conduit, and is unsuitable for providing the fluidic continuity.

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 cover including an elongate body, capable of being applied to be facing an outer surface of the pipe, and at least one longitudinal interaction element for interacting with the pipe, supported by the elongate body. The elongate body is reversibly deformable under the effect of its own weight, the elongate body having a length of more than 10 m. The cover treats solid build-ups within a fluid-transport pipe in a simple, straightforward and inexpensive manner.

A method of installing a subsea tie-in conduit comprises unspooling or manufacturing a steel rigid lined pipeline aboard an installation vessel and launching the pipeline progressively into water. A distal end of the tie-in conduit is coupled to a proximal end of the pipeline above the surface and is then launched into the water coupled to the pipeline. The suspended weight load of the pipeline is supported by an A&R wire connected to the proximal end of the pipeline, defining a load path that bypasses the tie-in conduit. A proximal end of the tie-in conduit may be suspended from that wire. The tie-in conduit is of composite or flexible pipe, hence being pliant relative to the lined rigid pipeline and maintaining its internal corrosion resistance. After landing on the seabed, the tie-in conduit may be deflected relative to the pipeline for connection to a subsea connection point.

An artificial cable trench (ACT) includes a body and a trench formed into the body. The trench is configured to hold a cable, umbilical, or similar feature. The ACT may be positioned along a seabed or shoreline to stabilize the cable and thereby prevent movement and eventual damage to the cable. The body of the ACT is shaped to overcome the flow induced loads caused by the relative motion between the cable and the surrounding waves and sea currents as well as providing effective friction/engagement with a contact surface (e.g., a shoreline surface). The ACT may have features that result in self-burying in sand and/or preventing lateral movement.

A system configured to handle reels for laying elongated members on the bed of a body of water, and in particular for transferring reels between an auxiliary structure and a laying vessel, has a bridge configured to connect the auxiliary structure and the laying vessel; and actuators configured to move a reel along and resting on the bridge.

A system configured to handle reels for laying elongated members on the bed of a body of water, and in particular for transferring reels between an auxiliary structure and a laying vessel, has a bridge configured to connect the auxiliary structure and the laying vessel; and actuators configured to move a reel along and resting on the bridge.

A pipeline including an accessory such as a flowline end termination or an in-line tee is lowered to the seabed and a mudmat foundation is subsequently lowered toward the seabed for subsea docking with the accessory to provide a permanent foundation support for the accessory. Once docked and with a mudmat of the foundation landed on the seabed, weight loads of the accessory structure and the attached pipe are transferred to the mudmat to provide a permanent foundation for the accessory structure. Before and during installation of the mudmat foundation, the pipe may be allowed to become embedded in the seabed. Temporary interim support such as buoyancy may be provided to the accessory to limit embedment into the seabed.