A method for laying a pipeline on the bed of a body of water comprises assembling a pipeline on a laying vessel; launching the pipeline from the laying vessel; identifying a zone of the bed of the body of water that causes stresses greater than a threshold value determined for the pipeline; progressively laying the pipeline on the bed of the body of water by advancing the laying vessel; and making, through controlled plastic deformation, at least one curved section along the pipeline with a curvature concordant with the curvature assumed by the pipeline in proximity to said zone, when the pipeline is at least partly laid on the bed of the body of water and partly suspended with respect to the bed of the body of water in proximity to said zone.

A method for laying a pipeline on the bed of a body of water comprises assembling a pipeline on a laying vessel; launching the pipeline from the laying vessel; identifying a zone of the bed of the body of water that causes stresses greater than a threshold value determined for the pipeline; progressively laying the pipeline on the bed of the body of water by advancing the laying vessel; and making, through controlled plastic deformation, at least one curved section along the pipeline with a curvature concordant with the curvature assumed by the pipeline in proximity to said zone, when the pipeline is at least partly laid on the bed of the body of water and partly suspended with respect to the bed of the body of water in proximity to said zone.

Disclosed is conduit anchor, an offshore system comprising a conduit anchor and a method of deployment. The conduit anchor includes a base section adapted for attachment to a conduit, and a conduit guide extending from the base section. In use a dynamic conduit extends along a dynamic conduit pathway range defined by the anchor, via the conduit guide. The conduit guide comprises a convex bend protecting surface region oriented towards the dynamic conduit pathway range which in use protects against over bending of the dynamic conduit.

The present invention relates to a system and method for uncovering and removing pipeline from the seafloor using a subsea trenching system using pressurized water to uncover pipe, a subsea shear carried by a barge to cut lengths of the pipeline, and a grapple carried by a barge to lift cut lengths of pipeline for placement on a pipe haul and recovery barge.

A subsea pipeline (10) of pipe-in-pipe configuration comprises an inner pipe (14), an outer pipe (16) spaced radially from the inner pipe and an annulus (20) defined by the radial spacing between the inner and outer pipes. A series of longitudinally-spaced outward projections (22) extend radially outwardly into the annulus from the inner pipe and are movable longitudinally relative to the outer pipe. A corresponding series of longitudinally-spaced inward projections (24) extend radially inwardly into the annulus from the outer pipe and are movable longitudinally relative to the inner pipe. When the inner pipe is subject to thermal elongation or contraction in use of the pipeline, the inner pipe is movable longitudinally relative to the outer pipe, hence moving the outward projections between and relative to the inward projections. The pipeline may be buried to restrain the outer pipe. The annulus may be flooded, in which case the inner pipe is covered with wet insulation.

A method and apparatus are provided for laying pipelines. The apparatus is attached to a portion of a pipeline and includes a tensioning member and a buoyancy element attached to a mid-portion of the tensioning member. When the buoyancy element is submerged, the buoyancy force tensions the tensioning member, and the pipeline will take the intended deflected shape to follow seabed depressions.

A bending restrictor assembly has a pipeline section, a first overlying pipe section having a wall overlying a portion of the pipeline section at one end thereof, a second overlying pipe section having a wall overlying another portion of the pipeline section at an opposite end thereof, and a plurality of cylindrical members overlying the pipeline section between the first and second overlying pipe sections. The first and second overlying pipe sections extend outwardly beyond the respective ends of the pipeline section. The bending restrictor assembly achieves a permanent bend and restricts ovality of a subsea pipe.

A method of laying an off-shore pipeline (1) comprises: —installing on the seabed (3) a fixed receiving structure (4) having a redirecting device (5), —paying-out from a laying vessel (7) a pipeline (1) with the pipeline end termination device (9) vertically towards the seabed (3), —extending a damping cable (6) from the pipeline end termination device (9) through the redirecting device (5) to an underwater damping buoy (14), —connecting an underwater suspension buoy (15) to the pipeline end termination device (9), —inclining the pipeline (1) from a vertical orientation towards the horizontal orientation, using: —the suspension buoy (14) to counterbalance at least part of the weight of the pipeline end termination device (9), —the damping buoy (14) for damping the pipeline (1).

De-trenching apparatus (100) for extracting a buried line, such as a cable or pipeline, is disclosed. The de-trenching apparatus comprises a channel (112) configured to receive a buried line to be extracted, the channel comprising a first flared opening (114) at a front end of the de-trenching apparatus and a second flared opening (115) at the rear end of the de-trenching apparatus, the first and second flared openings each having a curved surface (111) configured to support the line during extraction, and material removal means for removing material from around the buried line ahead of the de-trenching apparatus.

A method of dewatering a subsea pipeline bundle assembly before lifting the assembly from the seabed comprises adding discrete buoyancy to an elongate carrier pipe of the assembly. The buoyancy elevates one or more portions of the carrier pipe disposed between drainage outlets of the assembly. Each elevated portion defines inclined falls that slope downwardly in opposed longitudinal directions toward the respective outlets. Water within the carrier pipe drains down the falls toward the outlets. Injecting a dewatering fluid into the carrier pipe promotes expulsion of water from the pipe through the outlets by downward displacement of the water. Drainage can be assisted by a venturi effect driven by accelerating the flow of the dewatering fluid at a location in line with an outlet.