A vessel for laying a pipeline includes a plurality of workstations disposed along a pipelaying path that includes an upstream portion away from a first end of the vessel and a plurality of ramps, includes a first ramp and a downstream second ramp disposed along the pipelaying path, in the region of the first end of the vessel. Each of the plurality of ramps has a first upstream end, a second downstream end, and an adjustable inclination. The downstream end of the first ramp is positioned inboard of the first end of the vessel and above the bottom of the vessel and the upstream end of the second ramp is positioned inboard of the first end of the vessel and above the bottom of the vessel. An external ramp assembly includes ramps that can be pivoted relative to one another and locked in a selected position.

A tensioner system holds back elongate products such as subsea pipelines being laid into water. The system comprises at least one endless circulatory track and an array of rollers supporting the track. Each of the rollers of the array is mounted for rotation around a respective shaft. At least one of the shafts comprises a load pin that is arranged to sense loads applied to the surrounding roller in directions normal to an axis of rotation of that roller.

A tensioner system holds back elongate products such as subsea pipelines being laid into water. The system comprises at least one endless circulatory track and an array of rollers supporting the track. Each of the rollers of the array is mounted for rotation around a respective shaft. At least one of the shafts comprises a load pin that is arranged to sense loads applied to the surrounding roller in directions normal to an axis of rotation of that roller.

A method of installing a wave-configuration subsea riser of unbonded flexible pipe comprises lowering the riser progressively into the sea from an installation vessel while suspending an elongate clump weight in a catenary shape that comprises first and 5 second limbs extending upwardly from a conjoining bottom portion. An upper end of the first limb, at a distal end of the clump weight, is attached to the riser and an upper end of the second limb, at a proximal end of the clump weight, is suspended from a winch or crane of the vessel. While lowering the riser from the vessel, the weight load applied to the riser by the clump weight is controlled by adjusting the relative lengths of the first 0 and second limbs of the clump weight.

A method of installing a wave-configuration subsea riser of unbonded flexible pipe comprises lowering the riser progressively into the sea from an installation vessel while suspending an elongate clump weight in a catenary shape that comprises first and 5 second limbs extending upwardly from a conjoining bottom portion. An upper end of the first limb, at a distal end of the clump weight, is attached to the riser and an upper end of the second limb, at a proximal end of the clump weight, is suspended from a winch or crane of the vessel. While lowering the riser from the vessel, the weight load applied to the riser by the clump weight is controlled by adjusting the relative lengths of the first 0 and second limbs of the clump weight.

This invention provides a system for laying a high bending radius and low weight pipeline on the seabed comprising a subsea pipe-laying vessel comprising a moonpool and at least one coil with at least one pipeline segment to be installed wrapped around it, in which the moonpool comprises an internal baffle element adapted to smooth out the pipeline bend due to the of the pipe-laying vessel movement regarding the seabed, current, and catenary angle, where the system comprises at least one supporting element to support at least one coil allowing it to rotate to unwind the pipeline and where at least one supporting element comprises a handling system allowing the movement of at least one supporting element and at least one coil in at least one axis. A method of laying a pipeline on the seabed is also provided, performed using the described system.

This invention provides a system for laying a high bending radius and low weight pipeline on the seabed comprising a subsea pipe-laying vessel comprising a moonpool and at least one coil with at least one pipeline segment to be installed wrapped around it, in which the moonpool comprises an internal baffle element adapted to smooth out the pipeline bend due to the of the pipe-laying vessel movement regarding the seabed, current, and catenary angle, where the system comprises at least one supporting element to support at least one coil allowing it to rotate to unwind the pipeline and where at least one supporting element comprises a handling system allowing the movement of at least one supporting element and at least one coil in at least one axis. A method of laying a pipeline on the seabed is also provided, performed using the described system.

A laying tower for laying pipelines on the bed of a body of water has a supporting structure extending along a longitudinal axis and provided with guides parallel to the longitudinal axis; a first clamp, which is mounted on the supporting structure and configured for selectively clamping and releasing the pipeline in a given point along the longitudinal axis; and a second clamp, which is selectively movable along a path, which extends along a first section above the first clamp; and a second section below the first clamp and, partly, below the supporting structure and configured for selectively clamping and releasing the pipeline along the path.

A laying tower for laying pipelines on the bed of a body of water has a supporting structure extending along a longitudinal axis and provided with guides parallel to the longitudinal axis; a first clamp, which is mounted on the supporting structure and configured for selectively clamping and releasing the pipeline in a given point along the longitudinal axis; and a second clamp, which is selectively movable along a path, which extends along a first section above the first clamp; and a second section below the first clamp and, partly, below the supporting structure and configured for selectively clamping and releasing the pipeline along the path.

Methods for real-time coiled tubing fatigue monitoring can establish a remaining operational life of a coiled tubing strand. Standard or low-cycle plastic fatigue in bending is measured each time the coiled tubing strand is deployed through a guide arch. Also, smaller, but higher frequency loads, e.g., high cycle loads imparted to the coiled tubing strand due to interaction with an oceanic environment, are also measured. A plurality of weight detectors may be coupled to a support frame below the guide for monitoring the high-cycle loads. The remaining operational life of the coiled tubing strand may be calculated based on both the plastic strains using a low-cycle fatigue analysis and the elastic strains using a high-cycle fatigue analysis. An operator may retire a coiled tubing strand prior to failure based on the calculated remaining operational life.