A subsea drilling rig carried by ROV

Abstract

The present invention discloses a subsea drilling rig carried by an ROV, comprising a power device, a housing (5), and a main shaft (11), characterized in that the power device is connected to the main shaft (11) through a gear, the power device is connected to the housing (5), a buffer column (4) is arranged above the housing (5), a buffer spring (3) is placed on the mandrel at the top of the buffer column (4), an upper crossbeam (1) that can move up and down along the mandrel is arranged on the top of the buffer column (4), the upper end of the buffer spring (3) abuts against the bottom of the upper crossbeam (1), and the middle of the upper crossbeam (1) is connected to the ROV feed cylinder. The present invention has the advantages of small size, light weight, low cost, effective prevention of drill jamming, ability to withstand greater pressure, and suitability for ROV carrying.

Description

Technical Field

[0001] The present invention relates to the field of seabed drilling equipment, and in particular to a seabed drilling rig carried by an ROV. Background Art

[0002] The vast ocean floor is rich in mineral resources, which have great economic value and strategic significance. The deep sea is one of the few unknown areas on Earth. Scientists have a strong interest in the composition, age, formation mechanism, physical and chemical properties of deep-sea minerals, and the biological and environmental conditions around minerals. These studies covering multiple disciplines such as marine geology, marine biology, marine chemistry, marine physics, marine prospecting, and marine mining all require a large number of deep-sea mineral samples. Therefore, the acquisition of deep-sea mineral core samples plays a vital role in the research of marine science and the exploration and development of seabed minerals.

[0003] The operating environment on the seabed is harsh, and the drilling rig needs to withstand high pressure. The mass loading requirements of ROV (underwater robot) underwater are very strict, which requires the drilling rig to be light in weight while ensuring good high pressure resistance and sealing performance. This brings considerable difficulty to the design of the drilling rig. In addition, the complex and changeable rock formations on the seabed make it easy for drill jams to occur during drilling, which poses a great safety hazard to remote-controlled underwater robots. Therefore, the drilling rig must be designed with corresponding countermeasures to ensure the safety of remote-controlled underwater robots in the deep sea. However, the existing deep-sea drilling rigs are complicated in structure, large in size, and too heavy in weight, and are not suitable for being carried on remote-controlled underwater robots. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a subsea drilling rig suitable for ROV mounting which is small in size, light in weight, low in cost, can effectively avoid drill sticking, and can withstand greater pressure.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A subsea drilling rig carried by an ROV, comprising a power unit, a housing 5, and a main shaft 11, characterized in that: the power unit is connected to the main shaft 11 through gears, and the main shaft 11 is driven by the power unit to drive the drill bit for drilling, the power unit is connected to the housing 5, and serves to provide a rotational torque for the main shaft of the drilling rig, a buffer column 4 is arranged above the housing 5, a buffer spring 3 is placed on the core shaft on the upper part of the buffer column 4, an upper crossbeam 1 that can move up and down along the core shaft is arranged on the upper part of the buffer column 4, the upper end of the buffer spring 3 is against the bottom of the upper crossbeam 1, so that the drilling rig can achieve buffering during the feeding process, and the middle part of the upper crossbeam 1 is connected to the ROV feeding cylinder to carry the drilling rig on the ROV and obtain feeding power at the same time.

[0007] As a further improvement of the above technical solution:

[0008] The power device includes a hydraulic motor a2 and a hydraulic motor b7, which provide rotational power for the main shaft of the drilling rig.

[0009] The hydraulic motor a2 is connected to the spline shaft a8 through a spline, the spline shaft a8 is connected to the gear a9 through a flat key, the hydraulic motor b7 is connected to the spline shaft b13 through a spline, the spline shaft b13 is connected to the gear b12 through a flat key, the spline shaft a8 and the spline shaft b13 are both connected to the housing 5 through bearings, the gear a9 and the gear b12 are both meshed with the gear c10, and the gear c10 is connected to the main shaft 11 through a flat key, so that the drilling rig can achieve normal drilling and have the ability to reversely operate to remove the threads connecting the drilling tool and the main shaft 11 and then complete the buckle.

[0010] The housing 5 is connected to the pressure compensator 6 , and the interior of the pressure compensator 6 is communicated with the interior of the housing 5 , so that the pressure compensator 6 can perform pressure regulation.

[0011] The housing 5 is connected to the pressure compensator 6 by bolts. The connecting surface between the housing 5 and the pressure compensator 6 is sealed by a sealing ring to ensure sealing performance. A piston is provided inside the pressure compensator 6. The piston moves with the change of water pressure to compensate for the volume of the lubricating oil compressed by the high water pressure to achieve internal and external pressure balance.

[0012] The housing 5 is connected to the buffer columns 4 by bolts, and at least two buffer columns 4 are symmetrically arranged.

[0013] The lower part of the upper cross beam 1 is provided with a sleeve which matches with the core shaft at the upper part of the buffer column 4 .

[0014] The upper cross beam 1 is connected to the connecting flange on the ROV feed cylinder by bolts.

[0015] Compared with the prior art, the advantages of the present invention are:

[0016] Small size, light weight, low cost, can effectively handle drill stuck accidents, and can withstand greater water pressure. Compared with the prior art, this technology uses a buffer column 4 and a buffer spring 3 to form a buffer mechanism, which can enable the drilling rig to achieve buffering during the feeding process, avoiding drill bit stuck accidents caused by the mismatch between the feeding speed and the speed of the drill bit cutting the rock; the design of the power device can be unhooked in the event of the drill bit being stuck, so as to ensure that the ROV will not be fixed to the seabed due to a drill stuck accident, which plays an extremely important role in ensuring the safety of the ROV and greatly reduces equipment losses; in addition, the pressure compensator 6 is used to enable the drilling rig to withstand greater water pressure and work in deeper waters; and its small size and light weight are more conducive to reducing the load of the ROV or being carried on a smaller ROV, and the manufacturing cost is also lower than the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a cross-sectional view of the present invention.

[0019] Figure 3 This is a schematic diagram of an ROV equipped with a seabed drilling rig according to the present invention.

[0020] In the figure: 1-upper crossbeam, 2-hydraulic motor a, 3-buffer spring, 4-buffer column, 5-housing, 6-pressure compensator, 7-hydraulic motor b, 8-spline shaft a, 9-gear a, 10-gear c, 11-main shaft, 12-gear b, 13-spline shaft b. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to specific drawings and embodiments.

[0022] Embodiment 1, the present invention includes a power device, a housing 5, and a main shaft 11, characterized in that: the power device is connected to the main shaft 11 through a gear, and the main shaft 11 is driven by the power device to drive the drill bit to drill, the power device is connected to the housing 5, and provides a rotational torque for the main shaft of the drilling rig, a buffer column 4 is arranged above the housing 5, a buffer spring 3 is placed on the mandrel on the upper part of the buffer column 4, an upper crossbeam 1 that can move up and down along the mandrel is arranged on the upper part of the buffer column 4, the upper end of the buffer spring 3 is against the bottom of the upper crossbeam 1, so that the drilling rig can achieve buffering during the feeding process, and the middle part of the upper crossbeam 1 is connected to the ROV feeding cylinder to obtain the feeding thrust. During operation, the piston of the feeding cylinder moves downward to push the drilling rig to feed downward. The upper crossbeam 1, the buffer spring 3 and the buffer column 4 together constitute a feed buffer mechanism, through which the drilling rig can achieve buffering during the feeding process, avoiding the drill bit getting stuck due to the mismatch between the oil cylinder feeding speed and the drilling speed, thereby avoiding accidents such as drill bit sticking in the hole. Figure 1-3 .

[0023] Embodiment 2, the present invention also includes the following optimization scheme: the power device includes a hydraulic motor a2 and a hydraulic motor b7, which provide rotational power for the main shaft of the drilling rig. The hydraulic motor a2 is connected to the spline shaft a8 through a spline, and the spline shaft a8 is connected to the gear a9 through a flat key. The hydraulic motor b7 is connected to the spline shaft b13 through a spline, and the spline shaft b13 is connected to the gear b12 through a flat key. The spline shaft a8 and the spline shaft b13 are both connected to the housing 5 through a bearing, and the gear a9 and the gear b12 are both meshed with the gear c10, and the gear c10 is connected to the main shaft 11 through a flat key, so that the drilling rig can achieve normal drilling and have the ability to reverse operation, that is, to remove the thread connecting the drilling tool and the main shaft 11 and complete the ability to detach the buckle. During normal drilling, hydraulic motor a2 drives gear a9 through spline shaft a8, gear a9 drives gear c10, gear c10 drives main shaft 11, and at the same time, gear c10 drives gear b12, gear b12 drives spline shaft b13, spline shaft b13 drives hydraulic motor b7, and hydraulic motor b7 idles and does not output torque. In this working state, the drilling rig can achieve normal drilling; when a drill bit stuck accident occurs, the drill bit is stuck by the stone inside the borehole. At this time, it is necessary to enter the unbuckling state to unbolt the thread connecting the drill bit and the main shaft 11. The torque output by the hydraulic motor a2 alone cannot guarantee the completion of the task of unbolting the thread. At this time, the hydraulic motor a2 and the hydraulic motor b7 work at the same time, and their output rotation directions are opposite. At this time, the torque output by the hydraulic motor a2 and the hydraulic motor b7 is transmitted to the gear a9 and the gear b12 through the spline shaft a8 and the spline shaft b13. The gear a9 and the gear b12 simultaneously transmit the torque output by the hydraulic motor a2 and the hydraulic motor b7 to the gear c10, and the gear c10 then transmits the torque to the main shaft 11. At this time, the main shaft 11 obtains 2 times the torque of the first working state, thereby unbolting the thread connecting the drill bit and the main shaft 11. Therefore, the unbuckling state can ensure that the ROV will not be fixed to the seabed due to a drill bit stuck accident, which plays an extremely important role in ensuring the safety of the ROV and can avoid greater equipment losses. See more Figure 1-3 , and the rest is referred to Example 1.

[0024] Embodiment 3, the present invention also includes the following optimization scheme: the outer shell 5 is connected to the pressure compensator 6, the interior of the pressure compensator 6 is connected to the outer shell 5, so that the pressure compensator 6 can perform pressure regulation, the outer shell 5 and the pressure compensator 6 are connected by bolts, the connecting surface between the outer shell 5 and the pressure compensator 6 is sealed by a sealing ring to ensure the sealing performance, and a piston is provided inside the pressure compensator 6, and the piston moves with the change of water pressure, thereby compensating for the volume of the lubricating oil compressed by the high water pressure, so as to realize the pressure regulation function. When the drilling rig is working, the inside of the shell 5 is filled with lubricating oil, and the piston inside the pressure compensator 6 separates the seawater from the lubricating oil inside the shell 5. When the drilling rig is on the sea surface, the inside of the pressure compensator 6 is filled with lubricating oil, and the piston is at the end away from the upper cross beam 1. When the drilling rig enters the seawater, with the increase of water pressure, the volume of the lubricating oil inside the shell 5 is compressed, and the piston inside the pressure compensator 6 moves toward the direction close to the upper cross beam 1, thereby compensating for the volume of the lubricating oil compressed by the high water pressure, ensuring the balance of the pressure inside and outside the shell 5, so that the shell 5 will not deform under strong water pressure. This structure can ensure that the drilling rig can work normally at a water depth of no more than 5000m. Figure 1-3 , and the rest refer to the above embodiment.

[0025] Embodiment 4, the present invention also includes the following optimization scheme: the housing 5 is connected to the buffer column 4 by bolts, the buffer column 4 is symmetrically provided with at least two, the lower part of the upper crossbeam 1 is provided with a sleeve that matches the core shaft of the upper part of the buffer column 4, and the upper crossbeam 1 is connected to the connecting flange on the ROV feed cylinder by bolts. While the overall structure is more solid, it can also realize convenient replacement of damaged parts and reduce maintenance costs. Figure 1-3 , and the rest refer to the above embodiment.

[0026] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above, or modify it into an equivalent embodiment of equivalent changes without departing from the scope of the technical solution of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A subsea drilling rig carried by an ROV, comprising a power device, a housing (5), and a main shaft (11), characterized in that: The power device is connected to the main shaft (11) via a gear, and the power device is connected to the housing (5). A buffer column (4) is arranged above the housing (5). A buffer spring (3) is placed on the core shaft at the top of the buffer column (4). An upper crossbeam (1) that can move up and down along the core shaft is arranged at the top of the buffer column (4). The upper end of the buffer spring (3) abuts against the bottom of the upper crossbeam (1), and the middle of the upper crossbeam (1) is connected to the ROV feed cylinder. The power device comprises a hydraulic motor a (2) and a hydraulic motor b (7); The hydraulic motor a (2) is connected to the spline shaft a (8) via a spline, the spline shaft a (8) is connected to the gear a (9) via a flat key, the hydraulic motor b (7) is connected to the spline shaft b (13) via a spline, the spline shaft b (13) is connected to the gear b (12) via a flat key, the spline shaft a (8) and the spline shaft b (13) are both connected to the housing (5) via a bearing, the gear a (9) and the gear b (12) are both meshed with the gear c (10), and the gear c (10) is connected to the main shaft (11) via a flat key; The housing (5) is connected to the pressure compensator (6), and the interior of the pressure compensator (6) is in communication with the interior of the housing (5); The housing (5) and the pressure compensator (6) are connected by bolts, the connection surface between the housing (5) and the pressure compensator (6) is sealed by a sealing ring, and a piston is provided inside the pressure compensator (6); The housing (5) is connected to the buffer column (4) by means of bolts, and at least two buffer columns (4) are symmetrically arranged; The lower part of the upper cross beam (1) is provided with a sleeve which matches the core shaft of the upper part of the buffer column (4); The upper cross beam (1) is connected to the connecting flange on the ROV feed cylinder via bolts.

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