Pipelines with a control system and forced circulation of fluids through the annulus between an inner barrier and an outer cover of a pipe use a system configured to force circulation of fluids through the annulus. The pipe includes segments (T1, T2, T3, TN) joined together by means of connectors, wherein each segment of the pipe has an injector pipe (I1, I2, I3, IN) for injecting fluid into the annulus at a first end of the segment, and a return pipe (R1, R2, R3, RN) for removing fluid from the annulus at a second end of the segment.

The present invention relates to a marine drilling riser joint, adapted for the securement of one or more umbilicals (36) thereto. The marine drilling riser joint comprises one or more umbilical gutter assemblies (8), connected to or formed integral in an outer surface of a buoyancy module on the exterior of the marine drilling riser joint and provided parallel to the riser pipe, the umbilical gutter assembly comprising: an umbilical gutter (8) adapted to accommodate one or more umbilicals; and a resilient gutter cover (82a, 82b), which is elastically deformable by a loom tool, which resilient gutter cover in a closed position covers the umbilical gutter and in an elastically deformed position provides a working clearance to allow the one or more umbilicals to be introduced into the umbilical gutter.

A flotation system includes one or more floatation modules, each having a first section and a second section, each having an internal core made of a buoyant material. The first section includes two end faces and a projection extending from one of the end faces. The projection has a contoured profile. The second section includes two end faces and a reciprocal recess in one of the end faces. The end faces of the first section engage the end faces of the second section such that the projection engages the reciprocal recess in a mating engagement. A stop collar may be disposed adjacent each end of the floatation module. The floatation system may be attached to a tubular string that is lowered into a marine riser to reduce a load applied to a rig disposed over the marine riser.

A system for transporting hydrocarbons from reserves located under the sea floor to a turret connected to a hydrocarbon production vessel floating at the sea surface, the hydrocarbons being transferred through at least one rigid catenary riser extending from the sea floor to a buoy, the system for transporting hydrocarbons includes an upper section of the at least one substantially rigid riser directly attached to the buoy and provided with fairings, a middle section of the rigid riser is provided with buoyancy modules so to give it a lazy wave shape and a lower section of the substantially rigid riser is in contact with the seafloor at a distance X from the buoy vertical axis that is smaller than a distance Y between the buoy vertical axis and the mooring lines anchoring elements.

A riser system (202) comprises a riser (204) to be secured between a floating body (206) and a subsea location (209). The riser comprises a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix. In use, the riser (204) comprises an upper portion (214) extending from the floating body (206) and having a region arranged to be in tension, a lower portion (216) extending from the subsea location (209) and having a region arranged to be in tension, and an intermediate portion (218) located between the upper and lower portions (214, 216) and having a region arranged to be in compression. A flow-line jumper (302, 402) configured to be secured between two subsea locations, a flow-line jumper arrangement comprising a flow-line jumper (302, 402) and a method of forming a flow-line jumper 302, 402 are also disclosed.

A drilling marine riser section comprises a main riser pipe with radially extending flanges and multiple auxiliary pipes at least comprising a choke line and a kill line. One or more clamps retain the auxiliary pipes. Further the riser section has buoyancy members. The choke line and the kill line are connected to each of the flanges in a tensile load sharing arrangement, so that—in vertical use orientation of the riser section in a riser string—weight stress is distributed in the main riser pipe and the choke line and the kill line. The buoyancy members form an exterior of the riser section including diametrically opposed and parallel flat bottom and top stacking faces relative to the axis of the main riser pipe, allowing stacking of riser sections in horizontal orientation. The choke line and the kill line are arranged diametrically opposite from one another and between the flat bottom and top stacking faces.

An offloading system for conveying hydrocarbons from a buoyancy-supported subsea riser to a surface tanker vessel comprises a flexible hose that hangs from the riser structure in a U-shape having first and second limbs. An upper end of the first limb communicates with the riser and an upper end of the second limb terminates in a pulling head for connecting the hose to the tanker. A clump weight acts on a lowermost bend of the hose between the limbs to maintain tension in the limbs. A subsurface holder fixed to the riser structure is arranged to hold the pulling head against the tension in the second limb of the hose when the system is in a standby state. The holder is offset laterally from a central longitudinal axis of the riser structure and a counterweight is positioned to a side of that axis opposed to the holder.

Systems and methods are described for monitoring displacement on structural elements of subsea systems such as on components of a subsea pipeline network used to transport production fluid from a subsurface wellhead to surface facilities. The described techniques sense changes in displacement using a sensing blade, for example made of crystalline material such as sapphire, that is anchored to the structural element such that it is approximately perpendicular to the direction of sensed displacement. Displacement is sensed as bending of the sensing blade using one or more instruments fabricated on the blade. Robustness of design is in part provided by additional flexible non-sensing blades mounted in parallel to the sensing blade.

A method of installing a wave-configuration subsea riser of unbonded flexible pipe comprises lowering the riser progressively into the sea from an installation vessel while suspending an elongate clump weight in a catenary shape that comprises first and 5 second limbs extending upwardly from a conjoining bottom portion. An upper end of the first limb, at a distal end of the clump weight, is attached to the riser and an upper end of the second limb, at a proximal end of the clump weight, is suspended from a winch or crane of the vessel. While lowering the riser from the vessel, the weight load applied to the riser by the clump weight is controlled by adjusting the relative lengths of the first 0 and second limbs of the clump weight.

A slurry transporting riser assembly includes a buoyant device that has an outer surface with a first end portion, a second end portion and an elongated portion. The elongated portion extends from the first end portion to the second end portion. The buoyant device is shaped and configured to attach to a slurry pipe. The elongated portion of the outer surface has a concaved section that extends from the first end portion to the second end portion. The concaved section has a shape that complements an outer radius of the slurry pipe with the buoyant device attached to the slurry pipe.