A hot-rolled steel sheet for a heavy-wall, high-strength line pipe, the steel sheet having a chemical composition including, in mass %, C: 0.02 to 0.20%, Mn: 0.80 to 2.10%, Si: 0.01 to 0.50%, P: 0.034% or less, S: 0.0050% or less, Nb: 0.01 to 0.15%, Ti: 0.001 to 0.030%, and Al: 0.001 to 0.080%, the balance being Fe and incidental impurities, the steel sheet having a microstructure in which a main phase is a continuous cooling transformation structure and in which {001}.sub.α grains in a plane whose normal direction is the sheet width direction constitute an area fraction of 10% or less and have a combined size of 10 μm or less, wherein the steel sheet has a tensile strength of 520 MPa or greater, and, in a drop weight tear test, a temperature at which a percent ductile fracture reaches 85% is −25° C. or lower.

A method for controlling buckling in subsea pipelines involves identifying spaced-apart sections of a subsea pipeline suitable for controlled lateral buckling. Sets of inclined sleepers are installed at each spaced-apart section and are selected to support the spaced-apart sections of the subsea pipeline in an orientation that is perpendicular to the initial as-laid position. Any buckling caused by thermal expansion of the subsea pipeline is distributed to two or more of the spaced-apart sections, causing the two or more spaced-apart sections to deflect laterally along the inclined sleepers outwardly from an initial as-laid position.

External heating assembly 1 is usable to heat subsea flowline 100 and remediate a blockage in subsea flowline 100 and comprises a predetermined set of heaters 10; one or more conductive layers 20 configured to uniformly distribute heat over an exterior of subsea flowline 100; one or more insulating layers 30 adapted to shield subsea flowline 100, the predetermined set of heaters 10, and conductive layers 20 from ambient seawater temperature; an anchor; and a strength member. The predetermined set of heaters 10 may comprise one or more mineral insulated cables capable of reaching very high temperatures with very little power and minimal controls.

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 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 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.

An element for a bend restrictor including a first part and a second part which together provide a cavity for receipt of a flexible pipe, in use, the two parts are pivotably connected together at a first portion thereof and are releasably coupled or couplable together at a second portion thereof. Successive elements may be secured together to form a bend restrictor.

A mechanically lined pipe including a host pipe having an inner surface which is lined with a metallic liner, the metallic liner having an inner surface which is lined with a polymer liner which presses the metallic liner against the inner surface of the host pipe, as well as to methods of reeling and unreeling the mechanically lined pipe. A method of making a mechanically lined pipe having an internal polymer liner, the mechanically lined pipe including a host pipe having an inner surface which is lined with a metallic liner, the method including the steps of: (a) providing a mechanically lined pipe having an internal diameter, (b) providing a polymer liner having an outer diameter which is greater than the internal diameter of the mechanically liner pipe, (c) reducing the outer diameter of the polymer liner such that it is less than the internal diameter of the mechanically liner pipe, (d) inserting the polymer liner into the mechanically lined pipe, and (e) allowing the polymer liner to expand such that it presses the metallic liner against the inner surface of the host pipe.

An apparatus (1) for restricting the bending of a tubular member underwater comprises a plurality of interlocking modules each formed from a first half shell component (2) circumferentially displaced from a second half-shell component (3), wherein the first half shell component comprises one or more projections (19) extending from a side edge (18) thereof and the second half shell component comprises one or more grooves (21) in a side edge (18) thereof, the projections and grooves being angled to the side edges of the first and second half shell components, the arrangement being such that when assembled together each of the one of more projections of the first half shell component are inter-engaged with a corresponding groove of the second half shell component to secure the two half shells together.

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.