Abstract: A method of connecting a conduit to a subsea structure is provided. In the disclosed method, a tensioning member is provided on the conduit and attached to the conduit at two locations proximate a first end of the conduit. The tensioning member is used to maintain a curvature formed in the conduit between the two locations e.g. by deflecting a portion of the conduit. A first end of the conduit is engaged with a guide assembly provided adjacent to the subsea structure, and tension in the tensioning member is released to adjust the axial position of the first end of the conduit to enable direct connection between the conduit and the subsea structure. A method of disconnecting a conduit from a subsea structure, and a system for connecting a conduit to a subsea structure are also provided.

Abstract: A method for laying a pipeline on a seabed in order to provide controlled thermal expansion includes feeding the pipeline from a pipeline reel through a straightener system; and at the straightener system, imparting an alternating and continuously varying degree of residual curvature on at least a portion of the pipeline.

Abstract: A method of connecting a conduit to a subsea structure is provided. In the disclosed method, a tensioning member is provided on the conduit and attached to the conduit at two locations proximate a first end of the conduit. The tensioning member is used to maintain a curvature formed in the conduit between the two locations e.g. by deflecting a portion of the conduit. A first end of the conduit is engaged with a guide assembly provided adjacent to the subsea structure, and tension in the tensioning member is released to adjust the axial position of the first end of the conduit to enable direct connection between the conduit and the subsea structure. A method of disconnecting a conduit from a subsea structure, and a system for connecting a conduit to a subsea structure are also provided.

Abstract: A reelable pipeline includes a pipe-in-pipe section and a single pipe section coupled to the pipe-in-pipe section. The single pipe section has a bending stiffness that is different from the bending stiffness of the pipe-in-pipe section. The reelable pipeline includes a transition piece connected between the pipe-in-pipe section and the single pipe section and having a bending stiffness that varies along its length.

Abstract: A method of installing a subsea pipeline having a direct tie-in to a subsea structure includes landing an end of a pipeline onto a pipeline landing frame, the pipeline landing frame being on a surface of a subsea structure, the pipeline landing frame providing a location for landing the end of the pipeline before connection to a connection point of the subsea structure; subsequently lowering the pipeline end; and connecting the pipeline end to a connection point of the subsea structure. A pipeline landing frame for implementing the method is also described.

Abstract: A subsea structure includes a support in the form of a foundation or a supporting structure mounted to a foundation. A method for installing a pipeline includes: providing the support with a pull-in point at a proximal location at a first side of the support; providing the support with a strong point at a distal location, which is spaced apart from the proximal location, there being a straight clear path between the pull-in point and the strong point bridging some of or all of a width of the support; passing a pull down wire through a guide at the strong point and using the pull down wire to pull in the pipeline; laying down the pipeline and passing the pull down wire along the clear path; and continuing the laying down and/or pulling in until a tie-in head of the pipeline is at a required location at the pull-in point.

Abstract: A method and apparatus for direct tie-in of pipelines are disclosed. An apparatus is attached to a portion of a pipeline, the apparatus including a tensioning member and a buoyancy element attached to the tensioning member such that, when submerged, the pipeline is deflected as a result of a buoyancy force tensioning the tensioning member, and on releasing the buoyancy element, direct tie-in of the pipeline is performed.

Abstract: 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.

Abstract: A method and apparatus for direct tie-in of pipelines are disclosed. An apparatus is attached to a portion of a pipeline, the apparatus including a tensioning member and a buoyancy element attached to the tensioning member such that, when submerged, the pipeline is deflected as a result of a buoyancy force tensioning the tensioning member, and on releasing the buoyancy element, direct tie-in of the pipeline is performed.

Abstract: A reelable pipeline includes a pipe-in-pipe section and a single pipe section coupled to the pipe-in-pipe section. The single pipe section has a bending stiffness that is different from the bending stiffness of the pipe-in-pipe section. The reelable pipeline includes a transition piece connected between the pipe-in-pipe section and the single pipe section and having a bending stiffness that varies along its length.

Abstract: A method of installing a subsea pipeline having a direct tie-in to a subsea structure includes, during introduction of the pipeline into the sea from a pipe laying vessel, applying a plastic deformation to a region of the pipeline at or close to an end of the pipeline to be tied-in and, either during or following tie-in, elastically deforming the region to increase its radius of curvature.

Abstract: A subsea structure includes a support in the form of a foundation or a supporting structure mounted to a foundation. A method for installing a pipeline includes: providing the support with a pull-in point at a proximal location at a first side of the support; providing the support with a strong point at a distal location, which is spaced apart from the proximal location, there being a straight clear path between the pull-in point and the strong point bridging some of or all of a width of the support; passing a pull down wire through a guide at the strong point and using the pull down wire to pull in the pipeline; laying down the pipeline and passing the pull down wire along the clear path; and continuing the laying down and/or pulling in until a tie-in head of the pipeline is at a required location at the pull-in point.

Abstract: A method of installing a subsea pipeline having a direct tie-in to a subsea structure includes landing an end of a pipeline onto a pipeline landing frame, the pipeline landing frame being on a surface of a subsea structure, the pipeline landing frame providing a location for landing the end of the pipeline before connection to a connection point of the subsea structure; subsequently lowering the pipeline end; and connecting the pipeline end to a connection point of the subsea structure. A pipeline landing frame for implementing the method is also described.

Abstract: A method and apparatus for direct tie-in of pipelines are disclosed. An apparatus is attached to a portion of a pipeline, the apparatus including a tensioning member and a buoyancy element attached to the tensioning member such that, when submerged, the pipeline is deflected as a result of a buoyancy force tensioning the tensioning member, and on releasing the buoyancy element, direct tie-in of the pipeline is performed.

Abstract: 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.

Abstract: A method of installing a subsea pipeline having a direct tie-in to a subsea structure includes, during introduction of the pipeline into the sea from a pipe laying vessel, applying a plastic deformation to a region of the pipeline at or close to an end of the pipeline to be tied-in and, either during or following tie-in, elastically deforming the region to increase its radius of curvature.

Abstract: A cable for direct electrical heating of a subsea pipeline includes an axially soft inner core; and electrically conducting wires surrounding said core. A system includes such a cable, use of such a cable, and a method for direct electrical heating of a subsea oil/gas pipeline.

Abstract: Method for laying a pipeline onto a seabed from a lay barge, the pipeline having an inner corrosion proof metallic cladding that is closely fitted with metallic contact to an outer pipe material that is less corrosion proof. The method includes reeling a section of the pipeline onto a pipe laying drum, while an overpressure of 5-25 bar is maintained within the section by a pressurized fluid inside the section, b) joining a further pipeline section to the section already reeled onto the pipe laying drum, while the pipeline is motionless without mechanical movement, as the overpressure can he relieved as long as the sections are without mechanical movement, c) applying an overpressure of 5-25 bar within the sections and the further section is reeled onto the pipe laying drum, d) and joining several sections together and reeling the joined sections onto one or several pipe laying drums by repeating step b) and c) until the predetermined pipeline length is achieved.

Abstract: Method for laying a pipeline onto a seabed from a lay barge, the pipeline having an inner corrosion proof metallic cladding that is closely fitted with metallic contact to an outer pipe material that is less corrosion proof, distinguished in that a) a section of the pipeline is reeled onto a pipe laying drum, whilst an overpressure of 5-25 bar is maintained within the section by means of a pressurised fluid inside the section, b) a further pipeline section is joined to the section already reeled onto the pipe laying drum, whilst the pipeline is motionless without mechanical movement, as the overpressure can be relieved as long as the sections are without mechanical movement, c) an overpressure of 5-25 bar is applied within the sections and the further section is reeled onto the pipe laying drum, d) several sections are joined together and reeled onto one or several pipe laying drums by repeating step b) and c) until the predetermined pipeline length is achieved, e) the pipeline is laid from the lay barge onto

Abstract: A method for laying a pipeline on the sea bed from a lay barge in order to achieve controlled thermal expansion, comprises the following steps: Feeding out of the pipeline having a radius of initial residual curvature from a pipeline reel, preferably via a stinger to a curvature device where a radius of reversal curvature is applied to the opposite side of the pipeline with respect to the radius of initial residual curvature when the pipelines is passing through the curvature device. The curvature device straightens out the pipeline to longer, mainly straight portions with length having a radius of residual curvature which is larger than a desire minimum radius of residual curvature. The curvature device exposes shorter portions of the pipeline with a length for a radius of counter curvature forming the thermal expansion loops having a radius of residual curvature which is less than a desired maximum radius of residual curvature for the thermal expansion loops.