WO2014153494A2

WO2014153494A2 - Vertical subsea roller mining tool system and method

Info

Publication number: WO2014153494A2
Application number: PCT/US2014/031408
Authority: WO
Inventors: Brian Joseph RIORDAN
Original assignee: Technip France
Priority date: 2013-03-22
Filing date: 2014-03-21
Publication date: 2014-09-25
Also published as: WO2014153494A3

Abstract

A system and method is provided for subsea mining from a vessel having a miner configured to be suspended from the vessel, with the miner having a plurality of mining drums each rotatable about a drum axis oriented at a non-zero angle to a vertical line from the miner to the vessel and having an outer peripheral surface; a rotatable pilot extending below the mining drums; and a mechanical auger rotationally coupled to the pilot and extending above the mining drums. The miner can be lowered to a seafloor, and the pilot engaged with the seafloor to restrict lateral movement of the miner. The pilot can be actuated to rotate with the auger and the mining drums can be actuated to mine materials in the seafloor. The mining drums push the mined materials toward the auger to lift the mined materials toward the vessel above the mining drums.

Description

VERTICAL SUBSEA ROLLER MINING TOOL SYSTEM AND METHOD

[0001] Vertical Subsea Roller Mining Tool System And Method CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This international patent application claims the benefit to U.S. Provisional Application No. 61/804,401 , filed March 22, 2013.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0003] Not applicable.

REFERENCE TO APPENDIX

[0004] Not applicable.

BACKGROUND OF THE INVENTION

[0005] Field of the Invention.

[0006] The inventions disclosed and taught herein relate generally to deep sea mining; and more specifically related to a suspended deep sea mining riser and lift system.

[0007] Description of the Related Art.

[0008] Currently, for subsea mining extraction, a vertical riser is deployed from a sea surface by a floating structure, such as a vessel. The top of this riser is maintained to a deck of the vessel and is vertically deployed under the vessel by a moonpool or from the side of the vessel. A transfer assembly, such as a subsea pump, air lift, or water lift, can be connected to the bottom of the vertical riser. A flexible pipe (or jumper) is connected between the subsea pump and a subsea miner placed on the seafloor. The miner can move around on the seafloor with continuous tracks/treads, wheels, or other traction devices, while mining solids on the seafloor and thus beneficially use the flexibility of the flexible pipe. Usually, the bottom of the riser is connected to the subsea pump and a first portion of the jumper is connected to the pump. The mined solids are suctioned into the miner, flow through the flexible pipe to the pump and then pumped vertically through the riser to the vessel.

[0009] For example, WO2010036278 discloses a method and system of deep sea mining comprising mining seafloor massive sulfide deposits from the seafloor with a subsea miner grounded on the seafloor, pumping the solids from the subsea miner through a jumper and pumping the solids from the jumper up a riser to a surface vessel.

[0010] Some of the complexities and flow paths in such an arrangement of a miner grounded on the seafloor and connected through a flexible pipe to an intermediate pump and then to the vessel are due to the challenges of directly mining from a vertical riser when the miner is suspended to the vertical riser. The miner has little rotational stiffness through the riser to mine solids. Further, the suspended miner may have little, if any, lateral ability or rotational ability to remain in position when suspended during the mining operation.

[0011] Nevertheless, if an advantageous solution were found to mining with a miner directly suspended from a riser, the system could be simplified, costs reduced, and more opportunity provided for additional mining.

[0012] There remains a need for a simplified and improved mining system and method that includes a suspended miner on a riser.

BRIEF SUMMARY OF THE INVENTION

[0013] A system and method is provided for subsea mining from a vessel having a miner configured to be suspended from the vessel, with the miner having a plurality of mining drums each rotatable about a drum axis oriented at a non-zero angle to a vertical line from the miner to the vessel and having an outer peripheral surface; a rotatable pilot extending below the mining drums; and a mechanical auger rotationally coupled to the pilot and extending above the mining drums. The miner can be lowered to a seafloor, and the pilot engaged with the seafloor to restrict lateral movement of the miner. The pilot can be actuated to rotate with the auger and the mining drums can be actuated to mine materials in the seafloor. The mining drums push the mined materials toward the auger to lift the mined materials toward the vessel above the mining drums.

[0014] The disclosure provides a system for subsea mining from a vessel, comprising: a miner configured to be suspended from the vessel, comprising: a plurality of mining drums each rotatable about a drum axis oriented at a non-zero angle to a vertical line from the miner to the vessel and having an outer peripheral surface; a rotatable pilot extending below the mining drums; and a mechanical auger rotationally coupled to the pilot and extending above the mining drums.

[0015] The disclosure also provides a method of subsea mining from a vessel, comprising: suspending a miner from the vessel, the miner comprising a plurality of mining drums each rotatable about a drum axis oriented at a non-zero angle to a vertical line from the miner to the vessel and having an outer peripheral surface; a rotatable pilot extending below the mining drums; and a mechanical auger rotationally coupled to the pilot and extending above the mining drums; lowering the miner to a seafloor; engaging the pilot with the seafloor to restrict lateral movement of the miner; rotating the pilot with the auger; rotating the plurality of mining drums; pushing mined materials toward the auger; and lifting the mined materials in the auger toward the vessel above the minder drums.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0016] Figure 1 is a side view of a schematic diagram illustrating an exemplary embodiment of a vertical subsea roller mining tool system.

[0017] Figure 2 is a side view of a schematic diagram illustrating another exemplary embodiment of a vertical subsea roller mining tool system.

[0018] Figure 3 is a side view of a schematic diagram illustrating an exemplary embodiment of a vertical subsea roller mining tool.

[0019] Figure 4 is a top view of a schematic diagram of the mining tool of Figure 3.

[0020] Figure 5 is a top, perspective, cut-away view of a schematic diagram of the mining tool of Figure 3. [0021] Figure 6 is an end view of a schematic diagram of another embodiment of the mining tool, having multiple pairs of mining drums.

[0022] Figure 7 is a side view of a schematic diagram of the mining tool of Figure 6.

DETAILED DESCRIPTION OF THE INVENTION

[0023] The Figures described above and the written description of specific structures and functions below are not presented to limit the scope of what Applicant has invented or the scope of the appended claims. Rather, the Figures and written description are provided to teach any person skilled in the art how to make and use the inventions for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business- related, government-related and other constraints, which may vary by specific implementation, location, and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of ordinary skill in this art having benefit of this disclosure. It must be understood that the inventions disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. The use of a singular term, such as, but not limited to, "a," is not intended as limiting of the number of items. Also, the use of relational terms, such as, but not limited to, "top," "bottom," "left," "right," "upper," "lower," "down," "up," "side," and the like are used in the written description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims. Where appropriate, elements have been labeled with an "A" or "B" to designate one portion of the system or another. When referring generally to such elements, the number without the letter is used. Further, such designations do not limit the number of elements that can be used for that function. [0024] A system and method is provided for subsea mining from a vessel having a miner configured to be suspended from the vessel, with the miner having a plurality of mining drums each rotatable about a drum axis oriented at a non-zero angle to a vertical line from the miner to the vessel and having an outer peripheral surface; a rotatable pilot extending below the mining drums; and a mechanical auger rotationally coupled to the pilot and extending above the mining drums. The miner can be lowered to a seafloor, and the pilot engaged with the seafloor to restrict lateral movement of the miner. The pilot can be actuated to rotate with the auger and the mining drums can be actuated to mine materials in the seafloor. The mining drums push the mined materials toward the auger to lift the mined materials toward the vessel above the miner drums.

[0025] Figure 1 is a side view of a schematic diagram illustrating an exemplary embodiment of a vertical subsea roller mining tool system. A mining system 2 can include a floating vessel 4 having one or more cranes 8. The vessel 4 supports a suspended subsea miner 12 under the vessel 4. The miner 12 includes a plurality of mining drums having mining picks coupled to a peripheral surface, as described below. The mining drums rotate to abrade away material from the strata of the seafloor, and an auger transfers the materials to a transfer assembly to move the materials into the vessel, thereby mining the materials.

[0026] In at least one embodiment, the miner 12 is suspended from the vessel 4 by a riser 16. The riser 16 can include one or more portions, such as first portion 16A and a second portion 16B. One of the portions, such as portion 16A, can be a rigid pipe, while the second portion 16B can be a flexible portion that includes a plurality of flexible joints coupled together. The addition of flexible joints can provide assistance in controlling heave of the floating vessel 4 on the water surface 10 while the miner is in operation. Further, the system 2 can include a heave compensation system 18 coupled to the vessel 4 and the riser 16. A heave compensation system is known in the art and is not believed necessary to describe in detail other than to reference that the heave compensation system can allow for movement of the vessel 4 due to wave action on the water surface 10 and maintain a relatively constant height of the subsea miner 12 relative to the seafloor 14. In at least one embodiment, the system 2 can include a pump 20 coupled between the miner 12 and the riser 16. The pump 20 is capable of receiving the mined materials from the miner 12 and configured to pump materials up through the riser 16 to the floating vessel 4. The pump may be assisted by an air lift assembly or water lift assembly (not shown). The miner 12 can further include an auger 22 to elevate the materials mined upward toward the pump 20. The tip of the auger 22 can include a pilot drill for laterally stabilizing at least an initial penetration of the miner 12 into the seafloor 14. Ultimately, the miner 12 will mine a vertical opening 24 into the seafloor 14.

[0027] Figure 2 is a side view of a schematic diagram illustrating another exemplary embodiment of a vertical subsea roller mining tool system. The vessel 4 supports the miner 12 in a similar capacity as shown in Figure 1 . However in this embodiment, the miner 12 is suspended under the vessel by the crane 8 with a cable or synthetic rope 26. A pump 28 with the riser 16 can be suspended from the vessel, and a heave compensation system 18 can compensate for heave of the vessel relative to the riser. The miner 12 and pump 20 can be coupled though a flexible jumper 17 to the pump 28 on the riser 16. The pump 20 can receive materials from the miner 12, and pump the materials through the jumper 17 into the pump 28. The pump 28 can then lift the materials up the riser 16 to the vessel 4.

[0028] Figure 3 is a side view of a schematic diagram illustrating an exemplary embodiment of a vertical subsea roller mining tool. Figure 4 is a top view of a schematic diagram of the mining tool of Figure 3. Figure 5 is a top, perspective, cut-away view of a schematic diagram of the mining tool of Figure 3. The figures will be described in conjunction with each other. The miner 12 can include in at least one embodiment the following main components: a plurality of minor drums 21 , an auger 22 to receive materials from the drums, and an optional hopper 46. A frame 48 can be formed in the miner 12 to provide structural integrity, and can support, for example, the drums 21 , the auger 22, and the optional hopper 46.

[0029] The miner 12 can include generally at least two mining drums 21 . The mining drums 21 rotate about their respective drum axis 38. The drum axis 38 is generally at a non-zero angle β to the vertical line 52 that extends from the miner 12 to the vessel 4. A plurality of mining picks 30 are coupled to an outer peripheral surface of the drum and can be used to dislodge material from the seafloor when the drum rotates to mine the materials. The mining drums can rotate by mechanical, hydraulic, or other actuation. Rotating a drum by mechanical action is known in the industry and is not believed to require detailed description such as by using chain or gear drives or other actuators. Rotating a drum by hydraulic actuation is known in the industry and is not believed to require detailed description other than the hydraulic actuation generally requires a hydraulic pump, and a hydraulic motor, and controls to receive the fluid from the hydraulic pump and rotate the mining drum.

[0030] More specifically, the mining drum 21 generally includes a variable diameter peripheral surface 32. For illustrative purposes, the mining drum is shown as having three sections in the mining drum peripheral surface 32 in Figure 4, with the understanding that different numbers of sections, more or less, and different shapes could be formed in keeping with the general principles described in this application. For example, the peripheral surface 32 of the mining drum 21 can include a first portion 32A having a peripheral surface at a radius R1 from the center line of the drum axis 38. A corresponding portion 32B of the peripheral surface 32 can also extend outwardly to a radius and can have the same or different radius as the first portion 32A. A reduced portion 32C of the peripheral surface 32 can extend outwardly from the center line of the drum axis by a radius R2 which is less in length than the radius R1 . In at least one embodiment, the shape of reduced portion 32C forms an arc as shown in the top view of Figure 4 and the radius R2 is measured to the smallest radius of the arc from the drum axis 38. As described below, the reduced peripheral portion 32C advantageously surrounds at least a portion of an auger periphery 44, where the auger periphery is defined by the rotation of the auger vane of the auger 22. In the exemplary embodiment with a plurality of mining drums 21 , a majority of the auger periphery 44 is surrounded by the plurality of reduced peripheral portions 32C. The result is that the auger periphery 44 is at distance A1 from the drum axis 38, shown in Figure 4, which is smaller than the radius R1 from the drum axis 38 of the portion 32A, 32B, and in general greater than the radius R2 from the drum axis 38 of the reduced portion 32C. In one aspect, the shape of the mining drum 21 allows the drum axis 38 of each mining drum to be positioned closer to each other and is believed to increase efficiency in providing the materials to the auger 22. [0031] In general, the mining drum will include a plurality of drum picks 30 that are coupled around one or more portions of the peripheral surface 32 of the mining drum 21 . The picks assist in dislocating the strata surfaces of the seafloor to mine the materials. To facilitate moving the mined material from the mining drum toward the auger 22, the plurality of the drum pick 30 can be arranged in an inclined line L at an angle "a" around the mining drum. For example, the picks can be arranged in a spiral pattern illustrated by the line L at an angle a from the center line of the mining drum 21 B as shown in Figure 4. In some embodiments, it may be advantageous to include clean out picks 36 to help break up material and otherwise assist in moving the mined material toward the auger 22.

[0032] The auger 22 extends below an elevation of the mining drum 21 . The mining drums can form a plane that passes at a non-zero angle to a vertical line 52 and the auger 22 can extend below that plane. An end of the auger 22 can include a drill bit or other penetrating extension as a pilot 50. The pilot 50 functions to initially set the lateral location of the miner 12 into the seafloor from which the materials will be extracted and provide stability for the initial penetration of the miner. This aspect functionally differs from some prior art miners in which miners are physically placed onto the seafloor and travel around on the seafloor mining material. Because the miners are laterally secure due to their placement on the seafloor, the lateral stability is not an issue. Because miner 12 of the present invention is suspended from the vessel and does not have the stability of being located on the seafloor, the miner needs at least initial lateral stability to maintain its position as it penetrates into the seafloor 14. Thus, the auger 22 can extend below mining drum 21 to a depth that accommodates lateral stability during initial penetration with the pilot 50 of seafloor slopes of customary inclinations, and exposes a length of auger appropriate to efficiently convey material cuttings at a predetermined volumetric flow rate.

[0033] The auger 22 further includes a central shaft 42 around which at least one auger vane 40 spirals upwardly around the shaft 42. An auger tube 45 surrounds the vane 40 and extends at least partially along the length of the auger 22 to help retain the mined materials within the auger perimeter 44, so that the auger vane can lift the mining materials to the hopper 46. The auger tube 45 can extend from below an elevation of the mining drum 21 and pass with the auger vane 40 through the opening between the reduced peripheral portions 32C of the mining drums 21 A, 21 B. Because the reduced peripheral portions of the mining drums allow closer location of the mining drums relative to each other when the auger is interposed between the mining drums, the mining drums surround a majority of the envelope of the auger periphery 44 formed by the rotation of the auger vane 40.

[0034] The hopper 46 can be coupled to the pump 20 described and shown in Figures 1 and 2, so that the pump can receive the mining materials and lift the materials toward the vessel 4 in Figures 1 and 2 through the riser 16, also shown in Figure 1 , or through the jumper 17, also shown in Figure 2.

[0035] Figure 6 is an end view of a schematic diagram of another embodiment of the mining tool, having multiple pairs of mining drums. Figure 7 is a side view of a schematic diagram of the mining tool of Figure 6. The figures will be described in conjunction with each other. This embodiment of the miner drums has similar features as described above but further includes a second pair of mining drums. The second pair of mining drums 23A, 23B can be disposed at a different elevation than the pair of mining drums 21A, 22B. In the embodiment shown, the mining drums 23 are disposed above the mining drums 21 . Other variations are possible including below, or to the side for a larger footprint. The mining drums 23 can be offset laterally relative to a vertical axis from the mining drums 21 . Thus, the pair of mining drums 23 can engage other surfaces of the seafloor 14 shown in Figure 1 or Figure 2 to help facilitate the mining of the materials. In some instances, the mining of the materials that increase in production and efficiency, and in other instances may be necessary for particular types of mined materials and the particular composition of the seafloor to pre-grind away materials from the seafloor for further grinding, mining and process by the other pair of mining drums.

[0036] Other and further embodiments utilizing one or more aspects of the inventions described above can be devised without departing from the spirit of Applicant's invention. For example, the transfer assembly can include a pump, air lift assembly, water lift assembly, or a combination of any or all. As a further example, multiple layers of mining drums, various angles of mining drums, a plurality of augers, various angles of augers, various pilot shapes and relative sizes, various shapes and relative sizes of auger vanes, and other variations are possible in keeping with the claims.

[0037] The various methods and embodiments described herein can be included in combination with each other to produce variations of the disclosed methods and embodiments. Discussion of singular elements can include plural elements and vice-versa. References to at least one item followed by a reference to the item may include one or more items. Also, various aspects of the embodiments could be used in conjunction with each other to accomplish the understood goals of the disclosure. Unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising," should be understood to imply the inclusion of at least the stated element or step or group of elements or steps or equivalents thereof, and not the exclusion of a greater numerical quantity or any other element or step or group of elements or steps or equivalents thereof. The device or system may be used in a number of directions and orientations. The term "coupled," "coupling," "coupler," and like terms are used broadly herein and may include any method or device for securing, binding, bonding, fastening, attaching, joining, inserting therein, forming thereon or therein, communicating, or otherwise associating, for example, mechanically, magnetically, electrically, chemically, operably, directly or indirectly with intermediate elements, one or more pieces of members together and may further include without limitation integrally forming one functional member with another in a unitary fashion. The coupling may occur in any direction, including rotationally.

[0038] The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and/or split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions.

[0039] The inventions have been described in the context of preferred and other embodiments and not every embodiment of the invention has been described. Apparent modifications and alterations to the described embodiments are available to those of ordinary skill in the art given the disclosure contained herein. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by the Applicant, but rather, in conformity with the patent laws, Applicant intends to protect fully all such modifications and improvements that come within the scope or range of equivalent of the following claims.

Claims

WHAT IS CLAIMED IS:

1 . A system for subsea mining from a vessel, comprising: a miner configured to be suspended from the vessel, comprising: a plurality of mining drums each rotatable about a drum axis oriented at a non-zero angle to a vertical line from the miner to the vessel and having an outer peripheral surface; a rotatable pilot extending below the mining drums; and a mechanical auger rotationally coupled to the pilot and extending above the mining drums.

2. The system of claim 1 , wherein at least one of the mining drums comprises a reduced peripheral portion having a diameter smaller than the outer peripheral surface, the reduced peripheral portion being sized to fit around at least a portion of an auger periphery and wherein the auger periphery is closer to the drum axis of the mining drum than the outer peripheral surface of the mining drum.

3. The system of claim 1 , further comprising two mining drums adjacent each other with each mining drum having a ring portion with a diameter smaller than the outer peripheral surface of each mining drum, the ring portions being sized to fit around an auger periphery and wherein the auger periphery is closer to the riser axis of each mining drum than the outer peripheral surface of the mining drums.

4. The system of claim 1 , further comprising transfer assembly suspended from the vessel and coupled to the auger to accept mined materials from the auger.

5. The system of claim 1 , further comprising a pump suspended from the vessel and coupled to the auger to accept mined materials from the auger, the pump configured to pump mined materials to the vessel.

6. The system of claim 1 , further comprising a hopper suspended from the vessel and coupled to the auger to accept mined materials from the auger.

7. The system of claim 1 , further comprising a plurality of miner picks coupled to the outer peripheral surface of the mining drums.

8. The system of claim 1 , further comprising a plurality of miner picks coupled to the outer peripheral surface of the mining drums, the miner picks being arranged in at least one partial spiral row around at least a portion of the peripheral surface and configured to push mined materials toward the auger.

9. The system of claim 1 , wherein a subsea vertical riser system defines a longitudinal riser axis and is suspended from the vessel and the miner is suspended from the riser system.

10. The system of claim 1 , wherein a subsea vertical riser system defines a longitudinal riser axis and is suspended from the vessel and wherein a transfer assembly is suspended from the riser system, wherein the miner is suspended from the vessel separate from the transfer assembly, and wherein the miner is configured to flow mined materials to the transfer assembly to transfer the mined materials to the vessel.

1 1 . The system of claim 1 , further comprising the subsea vertical riser system suspended from the vessel.

12. The system of claim 1 , wherein the riser system comprises a rigid pipe, a flexible pipe, or a combination thereof.

13. A method of subsea mining from a vessel, comprising: suspending a miner from the vessel, the miner comprising a plurality of mining drums each rotatable about a drum axis oriented at a non-zero angle to a vertical line from the miner to the vessel and having an outer peripheral surface; a rotatable pilot extending below the mining drums; and a mechanical auger rotationally coupled to the pilot and extending above the mining drums; lowering the miner to a seafloor; engaging the pilot with the seafloor to restrict lateral movement of the miner; rotating the pilot with the auger; rotating the plurality of mining drums; pushing mined materials toward the auger; and lifting the mined materials in the auger toward the vessel above the miner drums.

14. The method of claim 13, further comprising rotating at least two mining drums adjacent each other with the mining drums having a ring portion with a diameter smaller than the outer peripheral surface of each mining drum, and rotating the auger to receive mined materials from the ring portions around the mining drums.

15. The method of claim 13, further comprising flowing the mined materials from the auger to a hopper suspended from the vessel.

16. The method of claim 13, further comprising flowing the mined materials from the auger to a transfer assembly and transferring the mined materials to the vessel.