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.

The present invention relates to a device for pushing four piles into the ground or into a seabed in a square configuration or in a diamond configuration, the device comprising: —a bridge assembly which defines a first, second, third and fourth connecting location arranged in a square or diamond configuration, —four connection assemblies via which in use each of the four piles is connected to the bridge assembly, wherein each pile connection assembly comprises: —an actuator comprising an upper actuator part and a lower actuator part, wherein the actuator is configured to extend, —a pile connector connected to the lower actuator part, —a control device configured for alternately letting each of the actuators extend, and configured for letting the pile which is pushed into the ground or seabed receive a greater force than the opposite pile of the square or diamond configuration, wherein the exerted push force is transferred into the bridge assembly and transferred at least partially from the bridge assembly as a tension force and a bending moment into the two adjoining piles via the two adjoining pile connection assemblies.

The present invention relates to a device for pushing four piles into the ground or into a seabed in a square configuration or in a diamond configuration, the device comprising: —a bridge assembly which defines a first, second, third and fourth connecting location arranged in a square or diamond configuration, —four connection assemblies via which in use each of the four piles is connected to the bridge assembly, wherein each pile connection assembly comprises: —an actuator comprising an upper actuator part and a lower actuator part, wherein the actuator is configured to extend, —a pile connector connected to the lower actuator part, —a control device configured for alternately letting each of the actuators extend, and configured for letting the pile which is pushed into the ground or seabed receive a greater force than the opposite pile of the square or diamond configuration, wherein the exerted push force is transferred into the bridge assembly and transferred at least partially from the bridge assembly as a tension force and a bending moment into the two adjoining piles via the two adjoining pile connection assemblies.

A method of lowering a discrete load (32) from a pipelay yessel comprises: holding a rigid rod (30) on an upright launch axis where the rod extends through a hold-back system (26); coupling a lower end of the rod to the load; connecting a wire (24) to the load either directly or indirectly via the rod; operating the hold-back system to advance the rod downwardly, hence submerging the load, while the weight of the load is suspended from the holdback system via the rod; when the load is underwater and beneath the splash zone, transferring the weight of the load directly or indirectly from the holdback system to the wire; and continuing to lower the load in the water, suspended directly or indirectly from the wire. The method may be reversed to recover a load from a subsea location, such as when lifting a wellhead or blowout preventer from the seabed.

A method of lowering a discrete load (32) from a pipelay yessel comprises: holding a rigid rod (30) on an upright launch axis where the rod extends through a hold-back system (26); coupling a lower end of the rod to the load; connecting a wire (24) to the load either directly or indirectly via the rod; operating the hold-back system to advance the rod downwardly, hence submerging the load, while the weight of the load is suspended from the holdback system via the rod; when the load is underwater and beneath the splash zone, transferring the weight of the load directly or indirectly from the holdback system to the wire; and continuing to lower the load in the water, suspended directly or indirectly from the wire. The method may be reversed to recover a load from a subsea location, such as when lifting a wellhead or blowout preventer from the seabed.

A method of installing a subsea pipeline supports at least one elongate pipe stalk at the surface of the sea at a first, relatively shallow-water location by virtue of buoyancy added to the pipe stalk. The pipe stalk is then towed at the surface to a second location that is in deeper water. There, with the pipe stalk supported between leading and trailing towing vessels, at least some of the added buoyancy is removed. This causes the pipe stalk to hang with catenary curvature beneath the surface between the vessels. The catenary-curved pipe stalk hanging between the vessels is then towed to a third location for subsea installation, which may involve upending the pipe stalk before landing a lower end portion of it on the seabed.

Deployment of coiled tubing may be assisted using an apparatus comprising a source of coiled tubing, a coiled tubing distributor that comprises a passageway adapted to allow engaging the coiled tubing from the source of coiled tubing where the passageway comprises a coiled tubing receiver comprising a predetermined radius and a support frame, connected to the passageway, that is adapted to accept a portion of the coiled tubing therethrough, and a slip disposed intermediate the passageway and the support frame where the slip is adapted to accept a portion of the coiled tubing therethrough. The apparatus may be mounted to a structure and a portion of the coiled tubing deployed from the source of coiled tubing about the coiled tubing receiver through the slip. The apparatus is allowed to compensate for motion of the structure while the portion of the coiled tubing is deployed about the coiled tubing receiver through the slip.

Deployment of coiled tubing may be assisted using an apparatus comprising a source of coiled tubing, a coiled tubing distributor that comprises a passageway adapted to allow engaging the coiled tubing from the source of coiled tubing where the passageway comprises a coiled tubing receiver comprising a predetermined radius and a support frame, connected to the passageway, that is adapted to accept a portion of the coiled tubing therethrough, and a slip disposed intermediate the passageway and the support frame where the slip is adapted to accept a portion of the coiled tubing therethrough. The apparatus may be mounted to a structure and a portion of the coiled tubing deployed from the source of coiled tubing about the coiled tubing receiver through the slip. The apparatus is allowed to compensate for motion of the structure while the portion of the coiled tubing is deployed about the coiled tubing receiver through the slip.

A drag-reducing separator plate for a moonpool, wherein the upper part thereof is a straight wall perpendicular to the sea level, the lower part thereof is connected to a baffle, and a connecting portion is connected between the straight wall and the baffle. The connecting portion may be in the shape of an arc. The shape of the drag-reducing separator plate matches that of the rear wall of the moonpool. During navigation, the drag-reducing separator plate is located in the middle or front of the moonpool, and can cooperate with a drag-reducing notch on the rear wall of the moonpool to greatly reduce the drag induced by intense sloshing of water in the moonpool during navigation of an offshore vessel. When offshore operations are performed under a station keeping condition, the drag-reducing separator plate is moved to the rear wall of the moonpool to avoid hindering the offshore operations.

A method of installing a subsea pipeline supports at least one elongate pipe stalk at the surface of the sea at a first, relatively shallow-water location by virtue of buoyancy added to the pipe stalk. The pipe stalk is then towed at the surface to a second location that is in deeper water. There, with the pipe stalk supported between leading and trailing towing vessels, at least some of the added buoyancy is removed. This causes the pipe stalk to hang with catenary curvature beneath the surface between the vessels. The catenary-curved pipe stalk hanging between the vessels is then towed to a third location for subsea installation, which may involve upending the pipe stalk before landing a lower end portion of it on the seabed.