A method for constructing a tubular connection assembly includes forming a first tubular having a first inner diameter, a first wall thickness, and a first connection end, forming a second tubular having a second inner diameter, a second wall thickness, and a second connection end, and increasing the first wall thickness of the first connection end, increasing the first inner diameter of the first connection end, increasing the second wall thickness of the second connection end, and increasing the second inner diameter of the second connection end. The first tubular and the second tubular are attached at a weld point between the first connection end and the second connection end so as to form a tubular connection assembly with a target amount of fatigue performance. A metallic riser, such as a steel catenary riser or a steel lazy wave riser, can be formed of a plurality of tubular connection assemblies.

A flexible dynamic riser comprising: a riser; a coil tubing disposed within the riser, wherein the riser and the coil tubing define an annulus; and a packing material disposed within the annulus.

A method of installing a subsea cable bundle including an umbilical and at least one direct current and fibre optic (DCFO) cable attached to an outside of the umbilical includes connecting a first end of the cable bundle to a pulling head, lowering the first end of the cable bundle into the se, connecting the pulling head to a winch cable of a winch (the winch may be connected before or after lowering the first end), the winch being located on a platform and the winch cable extending from the platform into the sea through a J-tube, and using the winch to pull the first end of the cable bundle up to the platform through the J-tube. The method further includes laying the cable bundle on the seafloor, and at a target location, at or close to a subsea structure, detaching the DFCO cable from the umbilical and connecting the DCFO cable and the umbilical at their second ends to the subsea structure.

Flexible riser hang-off for rigid risers deployed offshore is provided and called a spoolflex hang-off. The spoolflex hang-off utilizes combined torsional and bending flexibilities of a rigid tubular jumper deployed between a top of the riser and a floater piping. The rigid jumper transports fluids, contains the fluid pressure and accommodates angular deflections of the riser. The riser top is suspended from a pivoting arrangement that transfers the riser tension to the floater structure. The rigid jumper can be made of titanium or of other metallic or nonmetallic materials. The flexible riser hang-off provided has rotational stiffness independent on riser tension. Low static and fatigue bending loads on the riser and on the floater structure result. The hang-off allows large riser deflection angles.

Flexible riser hang-off for rigid risers deployed offshore is provided. The hang-off utilizes combined torsional and bending flexibilities of a rigid tubular jumper deployed between a top of the riser and a floater piping. The rigid jumper transports fluids, contains the fluid pressure and accommodates angular deflections of the riser. The riser top is suspended from a pivoting arrangement that transfers the riser tension to the floater structure. The rigid jumper can be made of titanium or of other metallic or nonmetallic materials. The flexible riser hang-off provided has rotational stiffness independent on riser tension. Low static and fatigue bending loads on the riser and on the floater structure result. The hang-off allows large riser deflection angles.

A subsea riser system with a gas-lift facility has a production riser having a riser conduit and at least one lift gas injection port communicating with the riser conduit. An umbilical is arranged to supply lift gas to the lift gas injection port. A heating unit is positioned to act on a downstream end region of the umbilical adjacent to the lift gas injection port. A method of providing lift gas to a subsea riser system includes the steps of conveying lift gas toward a production riser and, before injecting the lift gas into the production riser, heating the lift gas locally adjacent to the production riser.

A method of installing a flexible line between an offshore platform and a subsea structure and a method of removing a flexible line deployed between an offshore platform and a subsea structure. The method of installing includes at least partially deploying the line in the water using an installation vessel located outside of an exclusion zone in the vicinity of the platform, including lowering a topside end of the line either to the seabed or to an intermediate location between the seabed and the platform. The method further includes pulling the topside end to a position within the exclusion zone and winching the topside end up to the platform, and coupling the topside end to the platform. The method of removing includes decoupling a topside end of the riser from the platform, lowering the topside end from the platform and pulling the topside end to a position outside of an exclusion zone in the vicinity of the platform, and at least partially removing the line from the water using an installation vessel located outside of the exclusion zone, including raising the topside end of the line onto the installation vessel either from the seabed or from an intermediate location between the seabed and the platform.

Methods that may be employed to help to equalize the length of the teeth on a pin-and-box SCR connector during make-up include locating the make-up groove on the box at the far box end away from the pipe end. This causes the make-up force to tension and stretch the box to make it longer. Additionally or alternatively placing grease or other fluid in the nib groove creates a resistance force to nib entry. The grease or fluid exits through a nib vent port in the box while creating a resistance that compresses the pin and stretches the box causing the tooth spacing of the pin and the box to be similar. Providing a ring groove at both ends of the box allows a tensioning device to be used to tension the box causing box elongation, which equalizes the tooth length of pin and box members during connector make up.

A riser (171) to be arranged for injecting fluid from a vessel on a water surface (111) into a subterranean void (150) beneath a seabed (130) is attached to a buoy (170) as follows. An ROV (350) is controlled to attach a winch wire (320) to a head end (300) of the riser (171). Then, the ROV (350) is controlled to lead the winch wire (320) via the buoy (170) to a winch unit (330) on a seabed (130) below the buoy (170). Thereafter, the winch unit (330) is controlled to pull up the head end (300) of the riser (171) to a bottom side of the buoy (170). Finally, the ROV (350) is 10 controlled to connect the head end (300) of the riser (171) to a connector arrangement (210) in the bottom of the buoy (170).

A riser or jumper assembly for transporting production, exportation or injection fluids is disclosed as is a method for providing buoyancy to such an assembly. The riser or jumper assembly includes a first segment of flexible pipe comprising a portion of flexible pipe body and a first and second end fitting, a further segment of flexible pipe comprising a portion of flexible pipe body and a first and second end fitting and an intermediate segment of flexible pipe comprising a portion of flexible pipe body and a first and second end fitting and at least one buoyancy element.