Techniques and systems to reduce deflection of a riser extending from offshore platform. A riser may include an outer enclosure. This outer enclosure may be coupled to a current deflector. The current deflector is configured to generate a lift on the riser in response to a fluid flowing across the current deflector. This lift that is generated by the current deflector may counteract currents or other factors to mitigate deflection in the riser.

A polymer geo-injection apparatus for protecting an underground structure is provided. The apparatus includes: a mechanized vehicle for moving on the ground in order to transport the apparatus while the apparatus forms a subsurface polymer layer that protects the underground structure; a polymer supply tank coupled to the mechanized vehicle and configured to supply solid polymer during the forming of the polymer layer; a polymer melting unit coupled to the mechanized vehicle and configured to receive and melt the supplied solid polymer and to supply the molten polymer during the forming of the polymer layer; and a subsurface ripper coupled to the mechanized vehicle and configured to move through the ground in response to the movement of the mechanized vehicle while receiving and injecting the supplied molten polymer into the ground above the underground structure in order to form the polymer layer and protect the underground structure.

A protection assembly for mounting in an underwater support structure includes at least one bend protection device coupled to a retaining device so that together they provide a through-going passage for receiving an elongate member which is to be protected. The elongate member passes through a support structure opening, and the retaining device is configured to be received in the support structure opening and to engage with the support structure to resist subsequent withdrawal from it. Installation of the protection assembly includes grasping the protection assembly with a releasable clamp, arranging a pulling line to pass through the support structure opening to the mechanical clamp and securing the pulling line to the mechanical clamp, drawing the retaining device of the protection assembly into the support structure opening using the pulling line and engaging the retaining device with the support structure, and releasing the clamp from the protection assembly.

A flow modification device connectable to a generally cylindrical element adapted for immersion in a fluid medium is provided. The device comprises an elongate body having a length and a generally circular cross-section; a plurality of raised body portions disposed about and extending along the length of the elongate body, the raised body portions having a height between 2% and 10% of a diameter of the body; and an aperture extending through the length of the elongate body, the aperture being adapted to receive the generally cylindrical element such that the flow modification device is arranged about the cylindrical element. The plurality of raised body portions are helically arranged or twisted about a longitudinal axis of the elongate body and are adapted to reduce vortex-induced vibration and/or drag on the cylindrical element when the device is connected to the cylindrical element and the connected device and cylindrical element are immersed in the fluid medium and there is relative movement between the connected device and cylindrical element and the fluid medium.

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.

Embodiments of the disclosure include methods and apparatus for a shroud that permits efficient installation and removal thereof from a flange of a pipeline. In one embodiment, a shroud is disclosed that includes a cover structure, and a plurality of retaining members coupled to an interior surface of the cover structure. Each of the plurality of retaining members comprises a rectangular arm coupled to a hinge structure, the hinge structure comprising a spring that fixes the rectangular arm in a position that is substantially orthogonal to a plane of the interior surface, wherein the hinge structure allows movement of the rectangular arm in a first direction and temporarily prevents movement of the rectangular arm in a second direction opposite to the first direction.

A vortex-shedding mitigation assembly includes a jacket sufficiently flexible to lay substantially flat under its own weight and that is comprised of a woven, non-metallic material. The assembly further includes a fin row comprising a plurality of discrete fins protruding from the jacket and arrayed in series diagonally across the jacket such that, when the jacket is wrapped around a cylindrical structure, the fin row forms a helical strake having an axis substantially parallel to an axis of the cylindrical structure. The helical strake is operable to induce turbulence in a fluid flowing past the cylindrical structure, thereby reducing vibration of the cylindrical structure induced by vortex shedding from the fluid flow.

Protection apparatus for a flexible elongate member. The apparatus comprises a plurality of protection members 10. Each protection member 10 defines an opening 22 through which a flexible elongate member can extend. Each protection member 10 is interconnectable end to end with other such protection members 10 to provide protection along the length of an elongate member. Each protection member 10 comprises two parts 12 which are mountable together to define the opening 22 through which an elongate member can extend. The two parts 12 together form a female formation 18 at one end, and a male formation 20 at the other end, such that the female formation 18 can receive a male formation 20 on an adjacent protection member 10 to interconnect the adjacent projection members 10. The female and male formations 18, 20 are configured to permit a predetermined amount of relative pivotal movement between adjacent protection members 10.

This invention relates to oil and gas exploration and comprises a direct connection system referred to as a Lower Riser Termination Assembly (LRTA), between risers made of composite material and horizontal lines installed on the seabed (flowlines). The system is applicable to a hybrid riser and its construction method allows cost reduction and system assembly/installation time optimization. The LRTA connection system is applicable to both rigid and flexible flowlines without need for any intermediate connection section/equipment between these and the risers. The construction of the system allows free vertical expansion of the risers along the entire structure. In addition, in the construction method developed for this system, the required area is significantly reduced.

A concrete mat apparatus, including a plurality of elongated concrete members, each member being aligned with and next to another concrete member. Each of the concrete members has an upper generally flat surface, a lower generally flat surface, and a plurality of inclined surfaces that each extend away from an upper or lower surface. Reinforcement extends from a first end portion of each concrete member to a second end portion thereof, the reinforcement including a plurality of longitudinally extending reinforcement bars and a plurality of encircling tie bars at spaced apart intervals. Cabling connects each of the elongated concrete members to another of the elongated concrete members. The combination of elongated concrete members has a width and a length that is at least twice as long as the width. The upper inclined surfaces of one of the elongated concrete members forms a plane with the lower inclined surface of an adjacent elongated concrete member. A plurality of loops are provided along opposed edges of the mat, each loop formed by a portion of the cabling. The loops can be spaced between about one and three feet (30.5 and 91.4 cm) apart.