A helical strake pole system that includes a tubular pole having a longitudinal axis and threaded attachment points. The system further includes a helical strake fin disposed circumferentially around a portion of the tubular pole along the longitudinal axis. The system further includes couplers disposed on the tubular pole. The couplers are configured such that each coupler has a first portion with a slot configured to receive an upper portion of the helical strake fin and a second portion configured to removably coupled to a threaded attachment point of the tubular pole. In addition, each coupler is configured to position a portion of the helical strake fin substantially perpendicular to a surface of the tubular pole.

Method is for operating fluid-processing plant configured to generate and store pressurized fluid, and spaced apart from body of water. Method includes: (A) positioning variable-buoyancy assembly in body of water in such way that buoyancy force urges variable-buoyancy assembly to move toward surface of body of water; (B) positionally anchoring, at least in part, non-collapsible fluid-line assembly underground in such way that non-collapsible fluid-line assembly extends, at least in part, into body of water; (C) fluidly connecting, via non-collapsible fluid-line assembly, fluid-processing plant and variable-buoyancy assembly together in such way that non-collapsible fluid-line assembly conveys pressurized fluid between fluid-processing plant and variable-buoyancy assembly; and (D) transmitting an anchoring force, via non-collapsible fluid-line assembly, from ground to variable-buoyancy assembly in such way that anchoring force substantially counteracts buoyancy force acting on non-collapsible fluid-line assembly, and anchoring force substantially urges variable-buoyancy assembly to remain below surface of body of water.

A system includes a foundation with a post mounted on the foundation top surface and a pipe module configured to couple to the foundation. The pipe module has a yoke to cooperate with the post to engage the pipe module with the foundation. The pipe module is connected to the end of a pipeline and is configured to slide along the foundation responsive to longitudinal and angular movements of the end of the pipeline. A method includes deploying a foundation subsea and securing the foundation to a seafloor. The foundation has a post. The method includes deploying the pipe module via the pipeline suspended by a pipe module installation machine. The pipe module has a yoke. The method includes engaging the yoke with the post, paying out the pipeline to lower the yoke, and lowering and engaging the pipe module with the foundation.

A dadding tube (1) for enveloping an underwater conduit (2), such as a pipeline or a cable line, has at least one clamping portion (6), which comprises at least one deformation portion (6A, 6B, 6C) being integrally manufactured with the cladding tube (1), which deformation portion (6A, 6B, 6C) is a first wall portion of the cladding tube (1), which has a larger thickness in the radial direction than at least one second wall portion (8) of the clamping portion concerned, in such manner that by said larger thickness the first wall portion is, and the at least one second wall portion (8) is not, pressed against the underwater conduit (2) by a tensioning strap (7) being tensioned all round. The deformation portion concerned is easy to produce, durable and reliable. Thanks to the at least one clamping portion the dadding tube can be designed in harder and lower-cost materials than the soft, flexible poly urethane, which is usually applied nowadays.

Pipeline segments can contain cables, such as communication cables (e.g., fiber optic cables) within insulation material surrounding the pipeline segments. Cables can be embedded within the insulation material, run through conduits embedded within the insulation material, placed in channels formed in the insulation material, or otherwise. Channels containing one or more cables can be filled with supplemental insulation material, thus securing the cables within the channels. Pipelines created as disclosed herein can enable data transfer between distant points without the need to lay fiber optic cable in addition to the pipeline. Further, fiber optic cable embedded thusly can be used to sense conditions in the pipeline, such as leaks, seismic activity, strain, and temperature information.

Pipeline segments can contain cables, such as communication cables (e.g., fiber optic cables) within insulation material surrounding the pipeline segments. Cables can be embedded within the insulation material, run through conduits embedded within the insulation material, placed in channels formed in the insulation material, or otherwise. Channels containing one or more cables can be filled with supplemental insulation material, thus securing the cables within the channels. Pipelines created as disclosed herein can enable data transfer between distant points without the need to lay fiber optic cable in addition to the pipeline. Further, fiber optic cable embedded thusly can be used to sense conditions in the pipeline, such as leaks, seismic activity, strain, and temperature information.

A bullhead-shaped grooved diversion jet and empennage swing vibration suppression device and method. The device consists of an impeller diversion module and a drainage rotary cover module. The impeller diversion module consists of a center impeller, sleeve bearings, small impellers, and small impeller rotating shafts. The drainage rotary cover module consists of a drainage front cover, a perforated jet rear cover, and empennages. The device is mounted on an outer wall of a riser in a sleeving manner. Under a combined action of drainage and space allocation of horizontal rectangular grooves, flow rate distribution of the center impeller, flow direction adjustment of the small impellers, diversion of lateral diversion holes, jet flows of side rear reducing holes, flowing space division and wake vortex turbulence of rotary swinging empennages, around-flow boundary layers at two sides and a tail of the riser are deeply damaged, which suppresses the formation of large vortexes.

A method of clamping elongate elements in a parallel piggybacked arrangement during subsea laying of the elements is disclosed. The method includes opposed reciprocating jaws which force together clamp segments around the elongate elements to assemble a piggybacking clamp. The piggybacking clamp applies clamping forces to the elongate elements.

A method of clamping elongate elements in a parallel piggybacked arrangement during subsea laying of the elements is disclosed. The method includes opposed reciprocating jaws which force together clamp segments around the elongate elements to assemble a piggybacking clamp. The piggybacking clamp applies clamping forces to the elongate elements.

Systems and methods are provided for operating streamer recovery devices to retrieve seismic streamers, for example streamers that become severed from their towing vessels. The streamer recovery can be remotely activated to cause the streamer to surface where the streamer is more easily retrieved.