A connection assembly for engaging a tubular member underwater to restrain the tubular member from radial movement relative to the connection assembly includes a plurality of pads for engaging the tubular member at circumferentially spaced positions; and a plurality of biasing arrangements, each for biasing a respective pad radially inwardly into engagement with the tubular member; wherein each biasing arrangement includes a pre-loadable, mechanical, compressed spring arrangement for resiliently pressing its respective pad against the tubular member. The assembly need not employ any hydraulic components.

A system and method for laying an underwater pipeline is provided. The present invention includes a plurality of pipe support rings connected together by tension cables. The tension cables are secured to a S or J laying ship by a winch. The plurality of pipe support rings form a pipe channel sized to guide the underwater pipeline. The present invention further includes a sea water pipe having a distal portion and a proximal end. The proximal end is fluidly connected with a pump on board the ship. The distal end includes a plurality of nozzles. The sea water pipe is disposed underneath the plurality of pipe support rings. The underwater pipeline is fed through the plurality of pipe support rings while the nozzles form a trench on a sea bed.

A spoolable swivel, methods, and systems for coupling a first and second length of coiled tubing. The spoolable swivel can include an inner tubular element and an outer tubular element. The inner tubular element and the outer tubular element can both have dimpled distal ends and races on their proximal ends, defining one or more annular voids for swivel bearings.

A helical strake for suppressing a vortex induced vibration (VIV) of a tubular. The helical strake having a shell dimensioned to at least partially encircle an underlying tubular, the shell having at least one fin opening; and at least one fin dimensioned to be positioned within the at least one fin opening formed by the shell, the at least one fin having a base portion dimensioned to be positioned along an underlying tubular and a tail portion dimensioned to extend through the at least one fin opening and radially outward from an underlying tubular.

A vortex-induced vibration (VIV) suppression apparatus comprising: a strake having a cylindrical body portion dimensioned to encircle an underlying tubular, a fin portion extending radially outward from the body portion and helically positioned around the body portion, and a gap formed through the body portion and the fin; and a connecting assembly configured to facilitate attachment of the strake to an underlying tubular.

The invention provides a flow system, a subsea valve (100), and a method of use in a subsea pipeline filling, flooding or pigging operation. The flow system comprises a subsea valve (100) comprising a valve inlet and a valve outlet configured to be coupled to a subsea pipeline (13). A pump (112) comprises a pump inlet connected to a fluid source and a pump outlet connected to the valve inlet. The pump is operable to pump fluid from the fluid source and into the subsea pipeline via the subsea valve. The subsea valve comprises a movable valve member and a biasing mechanism, by which the valve member is urged by a biasing force towards a closed position that prevents flow of fluid through the valve and into the subsea pipeline. The valve member is operable to be moved to an open position on activation of the pump to provide a pressure increase at the valve inlet sufficient to overcome the biasing force. In use, opposing sides of the valve member are exposed to ambient subsea pressure such that the subsea valve is pressure balanced.

The invention provides a flow system, a subsea valve (100), and a method of use in a subsea pipeline filling, flooding or pigging operation. The flow system comprises a subsea valve (100) comprising a valve inlet and a valve outlet configured to be coupled to a subsea pipeline (13). A pump (112) comprises a pump inlet connected to a fluid source and a pump outlet connected to the valve inlet. The pump is operable to pump fluid from the fluid source and into the subsea pipeline via the subsea valve. The subsea valve comprises a movable valve member and a biasing mechanism, by which the valve member is urged by a biasing force towards a closed position that prevents flow of fluid through the valve and into the subsea pipeline. The valve member is operable to be moved to an open position on activation of the pump to provide a pressure increase at the valve inlet sufficient to overcome the biasing force. In use, opposing sides of the valve member are exposed to ambient subsea pressure such that the subsea valve is pressure balanced.

A method for governing the elevation, attitude and structural integrity of a pressure-containing vessel in a body of liquid counterbalances flotation and incompressible ballast mediums against each other in separate serial compartments. Varying the quantity of incompressible ballast medium allows control of the elevation and attitude of the vessel. If the flotation medium is compressible, varying the quantity of flotation medium allows control of the ambient pressure of the vessel. The method facilitates floating and towing and laying of an undersea pipeline on, to and at a deep water site.

A method is provided for installing a pipeline on the seabed from a marine pipelaying vessel, including initiation, pipelaying, and abandonment of the pipeline. An embodiment of the abandonment of the pipeline includes halting pipelaying and engaging a hang-off clamp with the pipeline at a position below one or more tensioners, transferring the weight onto the hang-off clamp and holding the seagoing pipeline in the firing line, severing the pipeline, connecting the initiation cable to the lower end of the pipeline held by the one or more tensioners, transferring pipeline tension onto the initiation cable, releasing the one or more tensioners, so that a section of the pipeline is held in the firing line between the pipeline diverter and the initiation cable, vacating the firing line by at least displacing both the pipeline diverter and the initiation cable sheave and thereby displacing said section of the pipeline from the firing line, arranging the A&R cable in the firing line, connecting the A&R cable to the upper end of the seagoing pipeline held in the firing line, releasing the hang-off clamp, and operating the A&R winch and thereby lowering the pipeline onto the seabed.

The invention concerns a process and a device for laying a subsea pipeline according to the J-lay or S-lay method wherein straight sections are mounted onshore, dried and degassed then closed by plugs. The sections are loaded on a pipe-laying ship, are separated from their plugs before the welding. At the welding of each bulkhead a short pumping is operated to reduce the pressure in the part of the annulus located between the two last bulkheads and then the opening leading to the annulus are sealed.