An underwater facility (18) for the gas/liquid separation of a multiphase hydrocarbon mixture includes an underwater supply conduit (16) and a longitudinal separation chamber (26) intended to be installed substantially vertically, the separation chamber (26) having a lower end (30) and an opposing upper end (28), and an intermediate separation area (32), the separation chamber (26) further comprising an injection conduit (34) connected to the supply conduit (16), the injection conduit extending longitudinally into the intermediate area (32), the injection conduit having a tubular wall and a free opening that opens towards the upper end (28). The tubular wall is continuous to be impervious to the multiphase hydrocarbon mixture.

A coupling system (12) between a riser (2) and an underwater supporting structure (10), includes a coupling seat (13) and a coupling head (14) which can be inserted in the seat. A pull connector (16) constrains the head (14) to the seat (13) to prevent the extraction of the head (14) but to allow rotation of the head (14). A clamping connector (18) constrains the head (14) to the seat (13) to prevent transversal translation and rotation to the head (14) and the seat (13). The pull connector (16) can be actuated alone and independently from the clamping connector (18) to make a provisional, pull-only connection between the head (14) and the coupling seat (13). The clamping connector (18) can be actuated independently from the pull connector (16) to allow postponing the complete clamping with respect to the provisional connection.

An attachment device for securing a buoyancy module to a riser, the attachment device comprising an annular collar which is split into at least two parts, and at least one flange part, which is separable from the collar and has a generally planar flange and a connecting formation by means of which the flange part may be releasably connected to the collar so that the flange extends radially outwardly relative to the collar.

A retention strap assembly for a buoyancy module in a riser system, the retention strap assembly comprising: an elongate strap member comprising connection points at opposite ends, the strap member configured to wrap around the buoyancy module; a buckle member comprising connection formations configured to receive the connection points of the strap member, wherein the buckle member further comprises a tensioner configured to tension the strap member, the buckle member being configured to tension and hold the strap member around the buoyancy module; and a plurality of attachment formations spaced along a length of the strap member, each attachment formation comprising an attachment point configured for attachment to auxiliary riser equipment. The connection points of the strap member may be provided by ends of the strap member being looped or folded over. The strap member may comprise at least two overlapping layers.

Fastening devices are described. In one example, the fastening devices can be used for a landing string buoyancy solution. The landing string hardware includes a stop collar to be fitted and secured around a drill pipe and stop collar hardware to secure the stop collar together around the drill pipe. The stop collar can be secured at one end of a number of buoyancy modules placed along a longitudinal length of the drill pipe to hold them into place along the drill pipe. The stop collar can be formed from long fiber thermoplastic using extrusion-compression molding. The stop collar hardware includes a bolt having an external thread formed from long fiber thermoplastic and a nut having an internal thread formed from long fiber thermoplastic. Both the stop collar and the stop collar hardware are tested for suitability for the application of holding the buoyancy modules in place under operating conditions.

A generally cylindrical element 10 that is adapted for immersion in water is described. The generally cylindrical element 10 has an outer surface 11 that is in contact with the water in use. The outer surface 11 has at least two rows of repeating shapes 20, for example hexagons 20, provided on the surface 11, where each row of repeating shapes 20 is separated from the other or the adjacent row(s) by a groove arrangement 30. Each shape 20 within a row is separated from the, or each, adjacent shape 20 by at least one groove 30. This configuration of the surface 11 reduces Vortex Induced Vibration (VIV) and/or drag that may act upon the generally cylindrical element 10 when it is immersed in a body of water.

A wellbore self-retrievable tool for conveying and releasing a load in a well, such as for wellbore abandonment, wherein the load is a resin for producing a set resin plug. The tool comprises: a floatation device; a load carrier, such as a payload tube; and a load release mechanism, the floatation device being configured to render the tool buoyant in a wellbore liquid.

A method of monitoring variation in the thrust exerted by at least one buoy exerting traction on an undersea pipe, wherein: 1) the deformation of at least one optical fiber is measured by measuring variation of an optical signal in said fiber extending on the surface or embedded securely in the bulk of at least one of the following support elements: a) the buoy; b) at least a portion of: b1) the length of the tubular wall of the pipe or b2) an anticorrosion coating or a thermally insulating material fastened on the surface of said pipe, on which said buoy exerts traction, and c) an abutment part secured to said pipe or buoy, and on which said buoy exerts said thrust; 2) a variation of said thrust exerted by said buoy is determined as a function of said variation of the optical signal.

A creep resistant material comprises a core layer (12) of rigid polyurethane with a first tensile reinforcement layer (17) applied on one surface and a second tensile reinforcement layer (17) applied on the other opposed surface of the core layer, the entire respective first and second tensile reinforcement layers being in contact with the first and second surface of the core layer of the material.

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.