WO2018152106A1

WO2018152106A1 - Submersible autonomous barge

Info

Publication number: WO2018152106A1
Application number: PCT/US2018/017996
Authority: WO
Inventors: Matthew Blieske; Jeremy MAUNUS; Garret FITZPATRICK
Original assignee: Shell Oil Company; Shell Internationale Research Maatschappij B.V.
Priority date: 2017-02-16
Filing date: 2018-02-13
Publication date: 2018-08-23

Abstract

A submersible barge (100) comprising a variable buoyancy system (110), one or more thrusters (121), and a subsea navigation system and associated methods and systems.

Description

SUBMERSIBLE AUTONOMOUS BARGE

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/459,819, filed February 16, 2017, which is incorporated herein by reference.

BACKGROUND

[0002] The present disclosure relates generally to submersible barges. More specifically, in certain embodiments, the present disclosure relates to submersible barges useful in low cost subsea installations or recoveries and associated methods and systems.

[0003] Currently, subsea equipment may be deployed and/or retrieved using a semi- submersible drilling rig. Typically, drilling rigs are configured to lower the subsea equipment to the ocean floor or to hoist the subsea equipment from the ocean floor to the surface through the use of cables and lines. The subsea equipment may pass through an opening in the center of the rig as it is lowered or lifted from the seafloor. The piece of subsea equipment being retrieved or deployed may be susceptible to being damaged during the installation process or while transporting the subsea equipment. Further, drilling rigs are extremely expensive to operate, costing around $600,000-$800,000/day to lease. Furthermore, drilling rigs are transported at a slow rate when compared to other floating vessels (e.g., ships, tug boats), which may increase the amount of time it takes to retrieve and/or deploy sub-sea equipment.

[0004] U.S. Patent No. 8,992,127, the entirety of which is hereby incorporated by reference, describes a method of subsea installation which uses a fully submersible deployment vehicle transported to the installation site by submerged tow. The deployment vehicle uses solid buoyancy modules in the form of syntactic foam to remain neutrally buoyant during the towing phase and achieves its final positioning and set down by means of chains lowered into the deployment vehicle that behave as soft springs to control buoyancy and minimize dynamic loading. While this deployment vehicle may not necessarily require the use of large vessels, this concept still requires the chartering of a vessel with a small crane to control positioning and set down.

[0005] Other methods of utilizing submersible deployment vehicles to install subsea structures is described in U.S. Patent Nos. 9,156,609, the entirety of which is hereby incorporated by reference

[0006] It is desirable to develop a subsea installation system that uses a submersible deployment vehicle that does not require the use of a crane. SUMMARY

[0007] The present disclosure relates generally to submersible barges. More specifically, in certain embodiments, the present disclosure relates to submersible barges useful in low cost subsea installations or recoveries and associated methods and systems.

[0008] In one embodiment, the present disclosure provides a submersible barge comprising: one or more buoyancy modules; one or more thrusters, and a subsea navigation system.

[0009] In another embodiment, the present disclosure provides a subsea installation system comprising: a submersible barge; subsea equipment; and a vessel.

[0010] In another embodiment, the present disclosure provides a method of installing subsea equipment comprising: providing a submersible barge, transporting the submersible barge to a location above a subsea well site, and maneuvering the barge to the seafloor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more complete and thorough understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings.

[0012] Figure 1 is an illustration of a submersible barge in accordance with certain embodiments of the present disclosure.

[0013] Figure 2 is an illustration of a submersible barge in accordance with certain embodiments of the present disclosure.

[0014] The features and advantages of the present disclosure will be readily apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the disclosure.

DETAILED DESCRIPTION

[0015] The description that follows includes exemplary apparatuses, methods, techniques, and/or instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details.

[0016] The present disclosure relates generally to submersible barges. More specifically, in certain embodiments, the present disclosure relates to submersible barges useful in low cost subsea installations or recoveries and associated methods and systems. [0017] In certain embodiments, the present disclosure describes methods and systems that enable a piece of subsea equipment to be installed on the seafloor without the use of a crane or a heavy lifting vessel. In certain embodiments, the present disclosure provides an alternative to methods that require expensive, multi-purpose, installation vessels to install subsea equipment by instead using a semi-autonomous, submersible barge that can be towed to an installation site by a small vessel.

[0018] In certain embodiments, the present disclosure describes a submersible barge. Referring now to Figure 1, Figure 1 illustrates submersible barge 100. In certain embodiments, submersible barge 100 may comprise a variable buoyancy system 110, thruster assembly 120, and subsea navigation system (not illustrated in Figure 1).

[0019] In certain embodiments, the variable buoyancy system 110 may comprise one or more pressure vessels 111. In certain embodiments, variable buoyancy system 110 may comprise from 10 to 200 pressure vessels 111. In certain embodiments, variable buoyancy system 110 may comprise from 50 to 100 pressure vessels 111.

[0020] In certain embodiments, the one or more pressure vessels 111 may be pressure vessels converted from Compressed Natural Gas (CNG) cylinders. In other embodiments, the one or more pressure vessels 111 may comprise rigid pressure vessels, flexible pressure bladders, and/or other buoyancy devices known in the art.

[0021] In certain embodiments, the one or more pressure vessels 111 may be pressurized with air. In certain embodiments, the one or more pressure vessels 111 may be pressure controlled from the surface to alter the buoyancy as the barge descends through the water column. In certain embodiments, a surface vessel may be used to control the pressure level in each of the one or more pressure vessels. In certain embodiments, the surface vessel may control the pressure level in each of the one or more pressure vessels 111. In certain embodiments, not illustrated in Figure 1, the surface vessel may be attached to submersible barge 100 through tether. In certain embodiments, the tether may be used to provide power and communications to submersible barge 100.

[0022] In certain embodiments, thruster assembly 120 may comprise one or more thrusters 121. In certain embodiments, thrusters 121 may comprise electric or hydraulic thrusters. In certain embodiments, thruster assembly 120 may comprise from 4 to 20 thrusters 121. In certain embodiments, thruster assembly 120 may comprise 4 to 10 thrusters 121.

[0023] In certain embodiments, thrusters 121 may be arranged on submersible barge 100 such that each of the thrusters are oriented along a horizontal plane. In other embodiments, one or more of the thrusters 121 may be orientated not along the horizontal plane. In certain embodiments, one or two thrusters 121 may be oriented at each corner of submersible barge 100. In certain embodiments, thruster assembly 120 may be capable of providing horizontal positioning while submersible barge 100 ascends or descends through a water column. In certain embodiments, the integrated control system may communicate with a surface vessel via the winch.

[0024] In certain embodiments, subsea navigation system may comprise an integrated control system (not illustrated in Figure 1) and an acoustic communication system (not illustrated in Figure 1). In certain embodiments, each thruster 121 may be connected through the integrated control system. In certain embodiments, the integrated control system may be capable of distributing power and commands to thrusters 121.

[0025] In certain embodiments, the subsea navigation system may be powered from the surface through a tether. In other embodiments, the subsea navigation system may be powered from a battery located on the submersible barge 100.

[0026] In certain embodiments, the acoustic communication system may be capable of communicating with one or more transponders located on a seafloor. In certain embodiments, the subsea navigation system may be capable of orienting submersible barge 100 relative to one or more transponders on the seafloor to achieve accurate positioning and set down of a subsea equipment module (not illustrated in Figure 1).

[0027] Referring now to Figure 2, Figure 2 illustrates submersible barge 100 connected to a subsea equipment module 150. For clarity sake in Figure 2, the variable buoyancy system is not illustrated. In certain embodiments, subsea equipment module 150 may comprise a subsea manifold, towhead, or other conventional subsea structure, component, or module. In certain embodiments, subsea equipment module 150 may be connected to an equipment attachment assembly (not illustrated in Figure 2) on submersible barge 100.

[0028] In certain embodiments, the present disclosure provides a method comprising: providing a submersible barge, transporting the submersible barge to a subsea well site, and maneuvering the barge to the seafloor.

[0029] In certain embodiments, the submersible barge may comprise any combination of features discussed above with respect to submersible barge 100 or 200. In certain embodiments, the submersible barge may be connected to a subsea equipment module. In certain embodiments, the subsea equipment module may comprise any combination of features discussed above with respect to subsea equipment modules 150 or 250. In certain embodiments, the subsea module may be connected to the submersible barge in a dry dock before it is transported to a subsea well site. In certain embodiments, the subsea module may be connected to the submersible barge after it is transported to a location above a subsea well site or while it is transported to a location above a subsea well site.

[0030] In certain embodiments, the submersible barge may be transported to the subsea well site by towing it with a vessel. In certain embodiments, the submersible barge may be towed by a tug boat. In certain embodiments, the submersible barge may be floating on a sea surface as it is towed. In other embodiments, the submersible barge may be submerged or partially submerged as it is towed. In certain embodiments, the submersible barge may be neutrally buoyant or near neutrally buoyant state and towed at a specified depth.

[0031] In certain embodiments, the submersible barge may be transported to a location above the subsea well site. In certain embodiments, three or more transponders may be located on the seafloor at or near the subsea well site. In certain embodiments, the three or more transponders may comprise acoustic transponding systems and arrangements similar to those typically used for subsea structure installations. In certain embodiments, the three or more transponders may be placed on the seafloor before the submersible barge is transported to a location above the subsea well site. In other embodiments, the one or more transponders may be placed on the seafloor after the submersible barge is transported to a location above the subsea well site or while the submersible barge is transported to a location above the subsea well site.

[0032] In certain embodiments, the submersible barge may be disconnected from the vessel after it is transported to the location above the subsea well site. In such embodiments, a tug line may be disconnected from submersible barge and a tether may remain connected. In certain embodiments, a variable buoyancy system located on the submersible barge may be depressurized allowing for the submersible barge to sink below and/or further below the sea surface. In such embodiments, thrusters may be capable of guiding the submersible barge towards a location on the seafloor. In such embodiments, a subsea navigation system may be capable of controlling the thrusters such that the submersible barge is transported to the seafloor location where one or more transponders are located.

[0033] In certain embodiments, the submersible barge may be maneuvered to the seafloor after it has been transported to a location above the subsea well site. In certain embodiments, a subsea navigation system on the submersible barge will orient the barge through acoustic signaling with transponders located on the seafloor.

[0034] In certain embodiments, the submersible barge may remain on the seafloor while the subsea equipment is put into operation. In certain embodiments, the submersible barge may be disconnected form the subsea equipment and return to the surface by re- pressurizing the variable buoyancy system from the surface after the subsea equipment is placed on the seafloor.

[0035] In certain embodiments, the submersible barge may return to the seafloor and retrieve the subsea equipment. In such embodiments, the submersible barge may then be capable of transporting the subsea equipment back to the sea surface.

[0036] While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible.

[0037] Plural instances may be provided for components, operations and/or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.

Claims

1. A submersible barge comprising: a variable buoyancy system, a thruster assembly, and a subsea navigation system.

2. The submersible barge of claim 1, wherein the variable buoyancy system comprises one or more pressure vessels.

3. The submersible barge of claim 1, wherein the thruster assembly comprise one or more thrusters.

4. The submersible barge of claim 3, wherein the one or more thrusters are arranged on the submersible barge such that each of the thrusters is oriented along a horizontal plane.

5. The submersible barge of claim 1, wherein the subsea navigation system comprises an integrated control system and an acoustic communication system.

6. The submersible barge of claim 5, wherein the integrated control system may be capable of distributing power and commands to the one or more thrusters.

7. The submersible barge of claim 5, wherein the acoustic communication system may be capable of communicating to one or more transponders.

8. The submersible barge of claim 1, wherein the submersible barge is connected to a subsea equipment module.

9. The submersible barge of claim 8, wherein the subsea equipment module comprises a subsea manifold, a tow head, or a conventional subsea structure, component, or module.

10. A method of installing subsea equipment comprising: providing a submersible barge, transporting the submersible barge to a location above a subsea well site, and maneuvering the barge to the seafloor.