A system for deploying a coil of spoolable pipe from a vessel includes a first tower configured to move longitudinally and transversely along a first track coupled to the vessel, a second tower configured to move longitudinally along a second track coupled to the vessel, and a coil drum assembly coupled to the first tower. The first tower is configured to insert the coil drum assembly transversely into an interior channel of the coil when the coil drum assembly is in a retracted position, the coil drum assembly is configured to support the coil when the coil drum assembly is in an extended position and rotate during deployment of the spoolable pipe, and the first tower and the second tower are configured to move the coil drum assembly vertically.

A system for deploying a coil of spoolable pipe from a vessel includes a first tower configured to move longitudinally and transversely along a first track coupled to the vessel, a second tower configured to move longitudinally along a second track coupled to the vessel, and a coil drum assembly coupled to the first tower. The first tower is configured to insert the coil drum assembly transversely into an interior channel of the coil when the coil drum assembly is in a retracted position, the coil drum assembly is configured to support the coil when the coil drum assembly is in an extended position and rotate during deployment of the spoolable pipe, and the first tower and the second tower are configured to move the coil drum assembly vertically.

A system for deploying a coil of spoolable pipe from a vessel includes a first tower configured to move longitudinally and transversely along a first track coupled to the vessel, a second tower configured to move longitudinally along a second track coupled to the vessel, and a coil drum assembly coupled to the first tower. The first tower is configured to insert the coil drum assembly transversely into an interior channel of the coil when the coil drum assembly is in a retracted position, the coil drum assembly is configured to support the coil when the coil drum assembly is in an extended position and rotate during deployment of the spoolable pipe, and the first tower and the second tower are configured to move the coil drum assembly vertically.

A system for deploying a coil of spoolable pipe from a vessel includes a first tower configured to move longitudinally and transversely along a first track coupled to the vessel, a second tower configured to move longitudinally along a second track coupled to the vessel, and a coil drum assembly coupled to the first tower. The first tower is configured to insert the coil drum assembly transversely into an interior channel of the coil when the coil drum assembly is in a retracted position, the coil drum assembly is configured to support the coil when the coil drum assembly is in an extended position and rotate during deployment of the spoolable pipe, and the first tower and the second tower are configured to move the coil drum assembly vertically.

A subsea riser is installed by lowering at least one riser conduit to the seabed when piggybacked to an elongate support that comprises at least one flowline. The elongate support may be a pipeline bundle, which may be attached to one or more towheads in a towable bundle unit. The riser conduit may be in fluid communication with the flowline. At the seabed, a free end portion of the riser conduit is detached from the elongate support by releasing subsea-releasable fastenings. Then, with the elongate support and a root end of the riser remaining at the seabed, the detached free end portion of the riser conduit is lifted away from the elongate support to a riser support, such as a platform, an FPSO (floating production, storage and offloading vessel), or a buoy.

A subsea riser is installed by lowering at least one riser conduit to the seabed when piggybacked to an elongate support that comprises at least one flowline. The elongate support may be a pipeline bundle, which may be attached to one or more towheads in a towable bundle unit. The riser conduit may be in fluid communication with the flowline. At the seabed, a free end portion of the riser conduit is detached from the elongate support by releasing subsea-releasable fastenings. Then, with the elongate support and a root end of the riser remaining at the seabed, the detached free end portion of the riser conduit is lifted away from the elongate support to a riser support, such as a platform, an FPSO (floating production, storage and offloading vessel), or a buoy.

A method of installing a subsea riser comprises placing an elongate negatively-buoyant support on the seabed and, when laying the riser on the seabed, guiding a riser portion onto the support to extend along and be cradled by the support. A hogbend region of 5 the riser is then formed by conferring positive buoyancy on the support to lift the support and the riser portion away from the seabed. An element of the support comprises a riser support disposed in a longitudinally-extending open-ended gap between buoyancy volumes disposed on opposite sides of 0 the gap. Coupling formations such as hinge portions can couple the element to a like element. When so coupled, the gaps of those elements align to define an upwardly-opening, longitudinally-extending groove to receive the riser.

A method of installing a subsea riser comprises placing an elongate negatively-buoyant support on the seabed and, when laying the riser on the seabed, guiding a riser portion onto the support to extend along and be cradled by the support. A hogbend region of 5 the riser is then formed by conferring positive buoyancy on the support to lift the support and the riser portion away from the seabed. An element of the support comprises a riser support disposed in a longitudinally-extending open-ended gap between buoyancy volumes disposed on opposite sides of 0 the gap. Coupling formations such as hinge portions can couple the element to a like element. When so coupled, the gaps of those elements align to define an upwardly-opening, longitudinally-extending groove to receive the riser.

A subsea riser is installed by lowering at least one riser conduit to the seabed when piggybacked to an elongate support that comprises at least one flowline. The elongate support may be a pipeline bundle, which may be attached to one or more towheads in a towable bundle unit. The riser conduit may be in fluid communication with the flowline. At the seabed, a free end portion of the riser conduit is detached from the elongate support by releasing subsea-releasable fastenings. Then, with the elongate support and a root end of the riser remaining at the seabed, the detached free end portion of the riser conduit is lifted away from the elongate support to a riser support, such as a platform, an FPSO (floating production, storage and offloading vessel), or a buoy.

A subsea riser is installed by lowering at least one riser conduit to the seabed when piggybacked to an elongate support that comprises at least one flowline. The elongate support may be a pipeline bundle, which may be attached to one or more towheads in a towable bundle unit. The riser conduit may be in fluid communication with the flowline. At the seabed, a free end portion of the riser conduit is detached from the elongate support by releasing subsea-releasable fastenings. Then, with the elongate support and a root end of the riser remaining at the seabed, the detached free end portion of the riser conduit is lifted away from the elongate support to a riser support, such as a platform, an FPSO (floating production, storage and offloading vessel), or a buoy.