Abstract: Provided is an offshore structure, especially offshore wind turbine, including a platform that is connected to the seabed, especially via a foundation that carries the platform, and an appliance, wherein it comprises guiding means for guiding at least one tube or cable along a guidance path from a respective entry point at which the tube or cable enters the platform to a respective connection point at which the tube or cable is connected or connectable to the appliance.

Abstract: An abandonment and recovery system for a subsea pipeline. The system according includes a pipeline attachment assembly configured to be attached to a pipeline end; and a cable attachment assembly configured to be attached to at least one abandonment and recovery cable. The bendable connection has, over the distance thereof, an essentially constant circumferential shape and an essentially constant size.

Abstract: The disclosure relates to a gripping apparatus, for use in connecting to a pipe wherein the pipe defines an inside radius, the apparatus having at least one discrete gripping device mounted on a body, wherein the body is a wedge cone; an outer surface on each of the at least one discrete gripping device, wherein the outer surface has a transition surface defined by a means for reducing any sharp transition point; a collective actuation-retraction mechanism connected to the wedge cone and to each of the at least one discrete gripping device; and a collective extension-retractable mechanism connected to each of at least one discrete gripping device. The disclosure further relates to an alternative exemplary embodiment wherein the gripping apparatus further includes a spring, wherein the spring pre-biases each of the at least one discrete gripping device beyond the inside radius of the pipe to instantly grip the inside radius.

Abstract: Disclosed are systems and methods for protecting subsea pipeline from damage caused by excessive stress or fatigue loading caused by geo-hazards, and environmental and operating loads. The systems and methods utilize lifting buoyancy modules capable of being attached to a section of subsea pipeline to lift the subsea pipeline off the seabed to a predetermined height over a predetermined length upon being activated by a planned or unplanned triggering event.

Abstract: Retriever systems for marine geophysical survey cables. At least some of the illustrative embodiments are methods including causing a submerged sensor streamer to surface. The causing may be by moving a piston within a cylinder of a housing coupled to the sensor streamer, the moving of the piston responsive to pressure exerted on a face of the piston as the sensor streamer reaches or exceeds a predetermined depth, wherein the pressure exerted on the face of the piston overcomes a latching force tending to hold the piston in place at depths above the predetermined depth; and responsive to the piston overcoming the force that latches the piston releasing a ballast weight, wherein prior to the releasing the ballast weight is at least partially held in place based on position of the piston, and the releasing responsive to movement of the piston.

Abstract: A method for installing a self-supporting tower at a sea bed. An anchoring mechanism (32) is installed on the bed. A float (18) and a tubular pipe (68) are submerged and then driven towards the bed (12) to attach to one of the ends (72) of the anchoring mechanism (32), while the float (18) is fastened to the other (70) of the ends keeping the pipe (68) vertical above the anchoring mechanism (32). The tubular pipe (68) and the float (18) are supplied separately. The float (18) is kept submerged at a distance away from the anchoring mechanism (32). The tubular pipe (68) is suspended from the float via the other (70) of the ends of the pipe.

Abstract: A substantially cylindrical buoyancy module for a marine riser includes a plurality of buoyancy elements separated along at least one helical separation plane.

Abstract: Depth triggers for marine geophysical survey cable retriever systems. At least some of the illustrative embodiments include causing a submerged geophysical survey cable to surface. In some cases, the causing the cable to surface may include: fracturing a frangible link wherein the frangible link, before the fracturing, affixes position of a piston within a cylinder bore of a housing coupled to the geophysical survey cable, and the fracturing of the frangible link responsive to pressure exerted on a face of the piston as the geophysical survey cable reaches or exceeds a predetermined depth; moving the piston within the cylinder bore; and deploying a mechanism that makes the geophysical survey cable more positively buoyant.

Abstract: A pipe float is configured for receiving a pipe therein and providing buoyancy for maintaining the pipe along the surface of a body of water. The pipe float has an inner surface presenting a central passage adapted for receiving the pipe, the inner surface including a plurality of preferably substantially planar, longitudinally extending panels which provide a continuous inner surface. Adjacent panels are angularly oriented relative to one another, and the pipe float is preferably provided as a plurality of pipe float sections assembled together whereby one panel of a pipe float section is preferably oriented at an obtuse angle to an adjacent panel of that pipe float section. The panels may be of different transverse dimensions whereby the passage has a greater transverse dimension G which is substantially greater than a smaller transverse dimension S, with the outer diameter D of the pipe received in the passage being of a value equal to or smaller than G and greater than or equal to S.

Abstract: Retriever systems for marine geophysical survey sensor streamers. At least some of the illustrative embodiments are methods including attaching a retriever system to a sensor streamer by: wrapping a lifting bag assembly at least partially around the sensor streamer, the lifting bag assembly comprising a deflated lifting bag, a gas cylinder, and a depth trigger mechanism; and covering the lifting bag assembly with an outer cover.

Abstract: Disclosed are systems and methods for protecting subsea pipeline from damage caused by excessive stress or fatigue loading caused by geo-hazards, and environmental and operating loads. The systems and methods utilize lifting buoyancy modules capable of being attached to a section of subsea pipeline to lift the subsea pipeline off the seabed to a predetermined height over a predetermined length upon being activated by a planned or unplanned triggering event.

Abstract: Retriever systems for marine geophysical survey cables. At least some of the illustrative embodiments are methods including causing a submerged sensor streamer to surface. The causing may be by moving a piston within a cylinder of a housing coupled to the sensor streamer, the moving of the piston responsive to pressure exerted on a face of the piston as the sensor streamer reaches or exceeds a predetermined depth, wherein the pressure exerted on the face of the piston overcomes a latching force tending to hold the piston in place at depths above the predetermined depth; and responsive to the piston overcoming the force that latches the piston releasing a ballast weight, wherein prior to the releasing the ballast weight is at least partially held in place based on position of the piston, and the releasing responsive to movement of the piston.

Abstract: Depth triggers for marine geophysical survey cable retriever systems. At least some of the illustrative embodiments include causing a submerged geophysical survey cable to surface. In some cases, the causing the cable to surface may include: fracturing a frangible link wherein the frangible link, before the fracturing, affixes position of a piston within a cylinder bore of a housing coupled to the geophysical survey cable, and the fracturing of the frangible link responsive to pressure exerted on a face of the piston as the geophysical survey cable reaches or exceeds a predetermined depth; moving the piston within the cylinder bore; and deploying a mechanism that makes the geophysical survey cable more positively buoyant.

Abstract: The invention relates to the implementation of a fluid transportation pipe. In order to achieve this, the pipe is equipped with a ballasting system, and, along a laying axis, the pipe, thus equipped, is immersed in a fluid having movement, such as the sea. A ballast mass of the ballasting system then substantially causes at least this ballasting system to sink.

Abstract: Depth triggers for marine geophysical survey cable retriever systems. At least some of the illustrative embodiments include causing a submerged geophysical survey cable to surface. In some cases, the causing the cable to surface may include: fracturing a frangible link wherein the frangible link, before the fracturing, affixes position of a piston within a cylinder bore of a housing coupled to the geophysical survey cable, and the fracturing of the frangible link responsive to pressure exerted on a face of the piston as the geophysical survey cable reaches or exceeds a predetermined depth; moving the piston within the cylinder bore; and deploying a mechanism that makes the geophysical survey cable more positively buoyant.

Abstract: Retriever systems for marine geophysical survey cables. At least some of the illustrative embodiments are methods including causing a submerged sensor streamer to surface by flooding an intermediate chamber with water, the intermediate chamber defined within a cylinder of a housing coupled to the sensor streamer, the flooding of the intermediate chamber responsive to the sensor streamer reaching or exceeding a predetermined depth; and responsive to flooding the intermediate chamber moving a first piston within the cylinder; and thereby puncturing a seal of a compressed gas cylinder responsive to movement of the first piston, the puncturing makes the sensor streamer more positively buoyant.

Abstract: This method comprises connecting a downstream point (40) of a pipe (24) to a buoy (26) and completely submerging the buoy (26). It comprises deploying in the body of water (12) an intermediate section (30) of the pipe (24) from the downstream point (40) to at least as far as an upstream point (38), anchoring the upstream point (38), and tensioning the intermediate section (30) to keep it vertical. The connecting step includes activating a traction unit (96) to raise the downstream point (40) on the buoy (26). During the connecting step, the buoy (26) is carried in the body of water (12) virtually exclusively by its own floatability.

Abstract: An apparatus for installing means to supply cold water from depth to a floating vessel comprises a template having a plurality of receptacles for receiving a plurality of vertically-oriented cold water pipes. A method for installing a plurality of cold water pipes at a floating, offshore ocean thermal energy conversion facility comprises: lowering such a template to the seafloor; inserting vertically-oriented pipes into the receptacles on the template; providing sufficient buoyancy near the top of the pipe to maintain the pipe in a generally vertical state; positioning a floating vessel having receptacles configured to engage the upper ends of the pipes over the template; raising the template with the inserted pipes from the seafloor until the upper ends of the pipes engage the receptacles; and, locking the pipes in the receptacles such that the pipes are in fluid communication with a cold water sump on the floating vessel.

Abstract: Disclosed are systems and methods for protecting subsea pipeline from damage caused by excessive stress or fatigue loading caused by geo-hazards, and environmental and operating loads. The systems and methods utilize lifting buoyancy modules capable of being attached to a section of subsea pipeline to lift the subsea pipeline off the seabed to a predetermined height over a predetermined length upon being activated by a planned or unplanned triggering event.

Abstract: Disclosed are systems and methods for protecting subsea pipeline from damage caused by excessive stress or fatigue loading caused by geo-hazards, and environmental and operating loads. The systems and methods utilize lifting buoyancy modules capable of being attached to a section of subsea pipeline to lift the subsea pipeline off the seabed to a predetermined height over a predetermined length upon being activated by a planned or unplanned triggering event.

Abstract: A device includes a digging device to cut the seafloor and with a device for hooking onto a pipeline and for sliding over the same. The device includes at least one float device constrainable to the pipeline for supporting it in span, connected to the back of said digging device with respect to the direction of the movement. The method includes excavating the seafloor by a digging device, collecting a float device from a storage base and transporting it to said pipeline, constraining the first float device to the pipeline behind the digging device and connecting the first float device to the digging device, when at least one portion of pipeline is in a suspended configuration, and when the portion of suspended pipeline increases, collecting a subsequent float device and constraining it to the pipeline and connecting the same to the float device previously constrained.

Abstract: A method for constructing a riser assembly (1) for transporting a fluid from a vessel and on a seabed includes providing an elongate frame (4) having a first frame end (5) and a second frame end (6), where the first frame end is connected to the seabed (3) and the second frame end is connected to a buoy (7), providing at least one riser (9) for transporting a fluid, and connecting the at least one riser to the second frame end and/or the buoy.

Abstract: A marine geophysical survey cable retriever system. At least some of the illustrative embodiments are methods including causing a submerged survey cable to surface. In some cases, causing the submerged survey cable to surface includes: shedding ballast weights when the survey cable reaches or exceeds a first predetermined depth; and inflating a lifting bag when the survey cable reaches or exceeds a second predetermined depth.

Abstract: This method comprises connecting a downstream point (40) of a pipe (24) to a buoy (26) and completely submerging the buoy (26). It comprises deploying in the body of water (12) an intermediate section (30) of the pipe (24) from the downstream point (40) to at least as far as an upstream point (38), anchoring the upstream point (38), and tensioning the intermediate section (30) to keep it vertical. The height of the buoy (26) is less than 1.5 times its greatest transverse dimension. The method comprises moving the buoy (26) between a remote position and an installed position in line with an anchoring region, keeping the buoy (26) partly submerged on the surface (16) of the body of water.

Abstract: Disclosed are systems and methods for controlling lateral deformation and reducing axial displacement, also referred to as walking, of a subsea conduit such as a pipeline for conveying produced hydrocarbon fluids. The systems and methods include the installation of rolling assemblies on the conduit at predetermined locations. The rolling assemblies include elements for forming rolling modules rotatable with respect to the conduit. Also disclosed is a system for monitoring displacement of the conduit over time.

Abstract: The invention facilitates provision of a point-to-point cable connection between first and second points separated by an extended span of water including a first region of shallow water and a second region of relatively deep water. A plurality of ducts are provided from the first point through the first region of the extended span to an offshore termination point between the first and second points. Preferably, the ducts are buried in the seabed to prevent damage. At least one first cable is placed in one of the plurality of ducts to provide a connection between the first point and the offshore termination point. A second cable from the second point is received at the offshore termination point. The first cable is connected to the second cable at the offshore termination point to create the point-to-point cable connection. In one embodiment, the offshore termination point is located on the continental shelf near the transition to deep water.

Abstract: Economical heavy concrete weight coating is used as a weight coating for submarine pipes. The developed economical heavy concrete weight includes steel slag and iron ore as aggregate. Steel slag can contain iron and thus have a higher density than some other types of slag. By supplementing the steel slag with iron ore as aggregate, the economical heavy concrete weight coating can have a higher density than a coating having just slag. Economical heavy concrete weight coating can have a density greater than 190 pcf.

Abstract: A submarine pipeline towing equipment including: a floater of prismatic shape with a horizontal or vertical axis, with a variable or partially variable buoyancy, whose lower base is at least partially open by an opening or hole to operate as an air chamber. The floater includes: at least one inlet including a valve through which air is supplied; at least one outlet including a valve through which air is discharged; an actuator to control the valve to supply air; an actuator to control the valve to discharge air; a mechanism connecting the equipment to the pipeline; a mechanism transferring air to the floater; a mechanism actuating the actuator to control the valve to supply air in function of a predefined level in the floater; and a mechanism actuating the actuator to control the valve to discharge air in function of the distance of the floater itself from the seabed.

Abstract: There is disclosed a system comprising a subsea structure; and a carrier comprising an opening adapted to receive the subsea structure.

Abstract: An offshore riser system comprising a tubular from a sea floor to a sea surface comprising a first horizontal portion at the sea floor; a second vertical portion near the sea surface; and a third curved portion located between the first and second portions; and a buoyancy module connected to the second portion, adapted to maintain a shape of the curved portion and enable a connection of a vessel to the second portion.

Abstract: Retriever systems for marine geophysical survey sensor streamers. At least some of the illustrative embodiments are methods including attaching a retriever system to a sensor streamer by: wrapping a lifting bag assembly at least partially around the sensor streamer, the lifting bag assembly comprising a deflated lifting bag, a gas cylinder, and a depth trigger mechanism; and covering the lifting bag assembly with an outer cover.

Abstract: An apparatus and method for mounting a buoyancy module onto a rigid pipe having a clamp. In one embodiment the clamp includes pads for clamping onto the outer surface or coating of the rigid pip, the pads having a teeth or serrations formed thereon for gripping the outer surface of the pipe. In a second embodiment, the clamp includes one or more coil springs formed from a resilient material adapted to be wound around the outer circumference of the pipe. The method for mounting a buoyancy module onto a rigid pipe includes the steps of reducing the outer diameter of the pipe at a location of the pipe to which a buoyancy module is to be attached and subsequently mounting a buoyancy module at such location.

Abstract: Systems for lifting drilling risers that serve as thrust collars to retain buoyancy modules on the risers and also enable the risers to be lifted using lifting lugs that are attached to the thrust collars. In one embodiment, a lifting device uses two annular ribs at the edges of a cylindrical collar, wherein the ribs have substantially constant height, but varying thickness. The thickness of each rib is greater at the position of the lifting lug, and may also be greater at its base than that its top or outermost edge. The collar may be segmented, where the segments are bolted together to assemble the device around the riser. The segments may be pre-stressed to reduce stresses during lifting. The device may include an elastomeric layer on its inner surface.

Abstract: A pipe float is configured for receiving a pipe therein and providing buoyancy for maintaining the pipe along the surface of a body of water. The pipe float has an inner surface presenting a central passage adapted for receiving the pipe, the inner surface including a plurality of preferably substantially planar, longitudinally extending panels which provide a continuous inner surface. Adjacent panels are angularly oriented relative to one another, and the pipe float is preferably provided as a plurality of pipe float sections assembled together whereby one panel of a pipe float section is preferably oriented at an obtuse angle to an adjacent panel of that pipe float section. The panels may be of different transverse dimensions whereby the passage has a greater transverse dimension G which is substantially greater than a smaller transverse dimension S, with the outer diameter D of the pipe received in the passage being of a value equal to or smaller than G and greater than or equal to S.

Abstract: Depth triggers for marine geophysical survey cable retriever systems. At least some of the illustrative embodiments are methods including causing a submerged geophysical survey cable to surface. The cause may include: moving a piston within a cylinder of a housing coupled to the geophysical survey cable, the moving of the piston responsive to pressure exerted on a face of the piston as the geophysical survey cable reaches or exceeds a predetermined depth, wherein the movement of the piston overcomes a force created by interaction between two materials, the force latches the piston in place at depths above the predetermined depth; and responsive to the piston overcoming the force that latches the piston deploying a mechanism that makes the geophysical survey cable more positively buoyant, the deploying responsive to movement of the piston.

Abstract: A floatation collar for a sensor package forming part of a detection array comprises two halves that when joined together act as a protective casing that secures and orients a sensor package in an optimal configuration within a water column. The collar comprises a shell tilled with syntactic foam. The cellar top portion includes a series of projections strategically placed to protecting the sensor package transducers against mechanical damage. The base bottom portion of the collar is conical with an integral thimble to allow the collar to ride down and then emerge under a passing trawl net or other fishing lines or cables by presenting a smooth aspect and a secure means of tethering said unit to a bottom anchor.

Abstract: Disclosed are systems and methods for controlling lateral deformation and reducing axial displacement, also referred to as walking, of a subsea conduit such as a pipeline for conveying produced hydrocarbon fluids. The systems and methods include the installation of rolling assemblies on the conduit at predetermined locations. The rolling assemblies include elements for forming rolling modules rotatable with respect to the conduit. Also disclosed is a system for monitoring displacement of the conduit over time.

Abstract: Depth triggers for marine geophysical survey cable retriever systems. At least some of the illustrative embodiments are methods including causing a submerged geophysical survey cable to surface. The cause may include: moving a piston within a cylinder of a housing coupled to the geophysical survey cable, the moving of the piston responsive to pressure exerted on a face of the piston as the geophysical survey cable reaches or exceeds a predetermined depth, wherein the movement of the piston overcomes a force created by interaction between two materials, the force latches the piston in place at depths above the predetermined depth; and responsive to the piston overcoming the force that latches the piston deploying a mechanism that makes the geophysical survey cable more positively buoyant, the deploying responsive to movement of the piston.

Abstract: A marine geophysical survey cable retriever system. At least some of the illustrative embodiments are methods including causing a submerged survey cable to surface. In some cases, causing the submerged survey cable to surface includes: shedding ballast weights when the survey cable reaches or exceeds a first predetermined depth; and inflating a lifting bag when the survey cable reaches or exceeds a second predetermined depth.

Abstract: Retriever systems for marine geophysical survey cables. At least some of the illustrative embodiments are methods including causing a submerged sensor streamer to surface by flooding an intermediate chamber with water, the intermediate chamber defined within a cylinder of a housing coupled to the sensor streamer, the flooding of the intermediate chamber responsive to the sensor streamer reaching or exceeding a predetermined depth; and responsive to flooding the intermediate chamber moving a first piston within the cylinder; and thereby puncturing a seal of a compressed gas cylinder responsive to movement of the first piston, the puncturing makes the sensor streamer more positively buoyant.

Abstract: An offshore drilling riser joint has a central riser pipe, a number of auxiliary lines mounted around it, and a buoyancy module assembly of a buoyant material. A pair of upper thrust sleeves slide over two of the auxiliary lines, each of the upper thrust sleeves having a flange in contact with an upper end of the buoyancy module assembly. Each of the upper thrust sleeves transfer upward thrust imposed by the buoyancy module assembly to an upper support flange mounted to the central riser pipe. A pair of lower thrust sleeves slide over two of the auxiliary lines. Each lower thrust sleeve has a lower thrust flange that is engaged by a lower end of the buoyancy module assembly. Each of the lower thrust sleeves transfer weight of the buoyancy module assembly while out of water to a lower support flange mounted to the central riser pipe.

Abstract: A method of installing an underwater riser includes anchoring an installation to the seabed; coupling a tubular pipe to the installation; equipping the installation with a submersible float; submerging the float and the pipe, while the float and the pipe are being held from a surface vessel; a cable and a return device are installed on the seabed installation so that the cable can be connected to the pipe; attaching a submerged hauling buoy to the hauling cable; then removing ballast from the float in order to compensate for the tensile forces corresponding to the weight of the float and the pipe and to some of the load applied to the cable; and finally, anchoring of the hauling buoy to the installation and gradually releasing the float.

Abstract: Systems, methods and apparatuses for the installation or removal of buoyancy modules onto or from a submerged conduit are described herein. A system may include a buoyancy module (30), a control panel (76), an actuating means (72), and a clamp tool (40). The buoyancy module may include at least two sections. The clamp tool may hold the sections of the buoyancy module. The clamp tool (40) may include at least two plates (50, 52, 54, 56) that are actuated opened or closed using the control panel (76) and/or the actuating means (72) during attachment or removal of the buoyancy module (30) to the submerged conduit (10).

Abstract: A pipeline segment 5, used for the manufacture of a thin-walled underwater pipeline 50. Terminal pipe sections 20 are at either end of main pipe section 10. Terminal pipe sections 20 are thick-walled or otherwise resistant to collapse due to external pressure. A pressure isolation device 30 maintains an internal pressure in main pipe section 10 above a shut off pressure. A pressure compensation system 35 can protect main pipe section 10 from collapse due to external pressure. Pipeline segments 5 can be manufactured by connecting and winding stalks 100 onto storage device 110 forming main pipe section 10. Terminal pipe section 20 can be connected to the lead end of main pipe section 10, and main pipe section 10 can be unwound from storage device 110 while towing.

Abstract: In one embodiment, the subsea deployment system may be used to install flying leads with integral buoyancy. In another embodiment, the subsea deployment system may be used to install flying leads with separate buoyancy modules. The installation sling assembly may be used with the subsea deployment system or with other systems to deploy flying leads subsea. The universal removable cartridge may be interchanged for use on a horizontal drive unit and a mud mat.

Abstract: The present invention relates to a group and a method for laying and burying pipelines at the seafloor, wherein the laying and burying group according to the present invention comprises a digging device (11) provided with at least means for cutting the seafloor (20) and with means for hooking onto a pipeline (15) and for sliding over the same, and is characterized in that it comprises at least one float device (14) constrainable to the pipeline (15) for supporting it (15) in span, connected to the back of said digging device (11) with respect to the direction of the movement thereof (11).

Abstract: An undersea installation for transporting hydrocarbons between a seabed and a surface and to a method for installing same. The installation includes a tubular undersea pipeline, a float and a coupling device. The undersea pipeline has a rising part, a connecting part and an intermediate portion. The coupling device includes a first longitudinal part and a second part connected in a coupling region of the first part. The coupling region of the first longitudinal part and the float being configured to be connected together. The first part is configured to pivot about the coupling region while bending the intermediate portion when the rising part is unwound and tilts towards the seabed.

Abstract: The invention relates to a pipeline assembly and a method of installing a pipeline assembly, wherein the pipeline extends at least in part on a seabed and curves upwardly from the seabed along a curved section thereof, the pipeline extending toward a delivery end provided at the water surface, wherein a connecting device connects the pipeline at a coupling point to an anchoring device at the seabed for preventing the coupling point from moving upward. The invention further relates to a pipeline device comprising at least two pipeline assemblies which are interconnected at a substantial distance from the seabed.

Abstract: Guide arrangement for marine risers, in particular for offshore oil and gas operations. The guide arrangement has at least one guide structure (21, 22) for a length of riser, a frame assembly (10, 10A-D) for supporting said guide structure, anchor means (11, 12) at the seabed, tether means (13, 14) connecting said frame assembly to said anchor means, and a buoyancy element (1) for keeping said guide structure (21, 22) at a desired level in the sea during operation. The guide structure (21, 22) is pivotably supported by said frame assembly (10, 10A-D) with a pivot axis (21P, 22P) being substantially horizontal.

Abstract: A riser installation method including the steps of providing a first vessel situated over a hydrocarbon well, supporting a hydrocarbon transfer duct from the first vessel by a first end that is attached to a lowering device on the first vessel, and attaching a second end of the hydrocarbon duct to a second vessel, at a position near the first vessel. The method also includes the steps of lowering the transfer duct, increasing the distance of the second vessel from the first vessel, pulling the transfer duct until the second vessel is near the third vessel, contacting a section of the transfer duct with the sea bed, displacing the second end of the transfer duct from the first vessel, returning the second end of the transfer duct to the mooring position, and bringing the second end of the hydrocarbon transfer duct in fluid communication with the third vessel.