JP2023084167A - Sea bottom resource excavation vessel - Google Patents

Abstract

To provide an excavation vessel capable of effectively recovering sea bottom resources by excavating the sea bottom by rotating an excavation vessel body to which an excavation unit is connected.SOLUTION: Means recovers methane gas G after excavating to a resource recovery unit 26 by causing an excavating body 23 to abut on a sea bottom S2 in a state of holding a cylindrical pipe 21 between a right vessel 11 and a left vessel 12, and carrying out excavating of the sea bottom S2 by rotating the excavation body 23 by rotating a hull with an excavation unit 20 in the center by a rotation screw 15 of an excavation vessel body 10 after fixing the excavation vessel body 10 and the cylindrical pipe 21 at a cylindrical pipe retaining unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a submarine resource drilling ship, and more specifically, a submarine resource for mining a methane hydrate layer buried in the seabed by a mining vessel body and a mining unit equipped on the mining vessel body for mining. It concerns a drillship.

In recent years, the territorial waters and exclusive economic zone (EEZ) claimed by the Japanese government have reached approximately 4.65 million square kilometers, making it the sixth largest in the world. In its territorial waters and exclusive economic zones (EEZ), mineral resources such as gold, silver, copper, zinc, lead, petroleum, cobalt-rich crust, etc., which are also called seabed resources, and abundant minerals such as gas hydrate layers The existence of natural resources and energy resources has been confirmed, and various researches and trial drillings related to the mining of these resources have been carried out.

Regarding the method of excavating and recovering seabed resources, especially methane hydrate, as in Japanese Patent No. 6140238 (Patent Document 1), after excavating the methane hydrate layer by lowering the excavator to the seabed, methane hydrate A technical proposal for taking excavated material containing rate into a gas recovery device installed at a predetermined location in the sea, warming the recovery device to gasify and recover methane hydrate, and Japanese Patent Application Laid-Open No. 2017-128950 (Patent Document 2). A technical proposal has been made to prepare such a gas collecting device and to collect methane gas generated from methane hydrate with pinpoint accuracy.

However, in the technical proposal according to Patent Document 1, it is difficult to recover the excavator used for drilling, and it is also possible to conduct heat from the heat exchange section in the marine vessel to the heating section in the gas recovery device 300 to 400 m away. It was difficult.
In addition, in the technical proposal of Patent Document 2, the amount of methane gas recovered varies depending on how often and how much the naturally occurring methane gas is ejected, so it is not feasible as a recovery method. It could be said that there were difficulties.

Therefore, the present applicant focused on a method of drilling a methane hydrate layer, and in a manner in which the drilling unit is connected to the drilling vessel body, the methane hydrate layer cannot be effectively drilled by rotating the drilling vessel body. Based on the idea of the drilling vessel, a rotating screw is installed at a predetermined location, and the weight of the hull is increased by the ballast unit, so that the drilling unit extended from the bottom of the vessel is brought into contact with the seabed where the methane hydrate layer is located. We have developed a drilling vessel capable of drilling the seabed by circularly rotating the drilling vessel body by means of a rotating screw, leading to the proposal of the "submarine resource drilling vessel" according to the present invention.

Japanese Patent No. 6140238 Japanese Patent Application Laid-Open No. 2017-128950

In view of the above problems, it is an object of the present invention to provide a drilling vessel capable of effectively recovering seabed resources by drilling the seabed by rotating the drilling vessel body to which the drilling unit is connected.

In order to solve the above problems, the present invention provides a submarine resource drilling vessel capable of mining the methane hydrate layer buried in the seabed, comprising a ballast unit and a rotating screw provided at a predetermined position of the hull and capable of rotating the hull. and a drilling unit equipped on the drillship body, and the drillship body has a hull structure that can be divided into a right ship and a left ship at approximately the center in the transverse direction, The drilling unit includes a tubular tube that can extend to the seabed, a tubular tube holding portion that connects the tubular tube and the drilling vessel body, a drilling body that is provided at the tip of the tubular tube and is capable of drilling the seabed, and a drilling unit. A combustion chamber provided near the body, an exhaust heat pipe for conducting heat exhaust heat discharged from the combustion chamber to the tip region of the cylindrical tube, and an upper end portion extending downward around the outer peripheral surface of the cylindrical tube. It is equipped with a resource recovery unit that is in the shape of an expanded funnel and is capable of recovering methane gas that has surfaced from the seabed, and a resource recovery tank that stores the recovered methane gas, and the cylindrical pipe is provided with the recovered methane gas to the resource recovery tank. A resource recovery pipe, a combustion pipe for sending fuel to the combustion chamber, and an exhaust pipe for sending out exhaust gas from the exhaust heat pipe are inserted, and the cylindrical pipe is sandwiched between the right and left ships. The drilling body is brought into contact with the seabed in this state, and after the drilling vessel body and the tubular tube are fixed by the tubular tube holding part, the drilling body is rotated around the drilling unit by the rotating screw of the drilling vessel body. is rotated to excavate the seabed, and methane gas after excavation is recovered by a resource recovery unit.

In addition, the present invention adopts means in which the combustion pipe is connected to a resource recovery tank, and part of the recovered methane gas can be flowed into the combustion chamber as fuel.

According to the submarine resource drilling ship according to the present invention, it is possible to make fine adjustments until the drilling body provided on the bottom of the ship comes into contact with the seabed by entering and discharging seawater by the ballast unit provided on the main body of the drilling ship. By allowing seawater to flow in in accordance with the excavation speed, there is an excellent effect that the excavated body is always kept in contact with the excavated surface. In addition, since the drilling ship is equipped with a rotating screw, a propulsion force for rotating the hull is generated, and circular rotation around the drilling unit becomes possible, which contributes to the drilling work. Furthermore, since the drilling vessel body has a hull structure that can be divided into the right and left ships at approximately the center in the transverse direction, a connecting rail is interposed between the right and left ships. It is possible to transport to the site in a state in which a number of divided cylindrical pipes are placed on top, and by adopting a fixing method that clamps the cylindrical pipes between the right and left ships during excavation, This contributes to reliable clamping and stable rotation of the cylindrical tube.

Further, according to the submarine resource drilling ship according to the present invention, a combustion chamber is provided in the vicinity of the drilling body, and exhaust heat from the combustion chamber is conducted to the tip region of the cylindrical tube through the heat exhaust pipe. , raises the temperature of the surrounding seawater, promotes the melting of the methane hydrate layer buried nearby, and the methane-methane gas that rises toward the sea surface due to melting can be easily recovered with a funnel-shaped resource recovery unit. It has excellent effects such as Furthermore, by letting a part of the methane gas recovered by the resource recovery unit flow into the combustion chamber, it becomes possible to use the recovered methane gas as fuel for combustion in the combustion chamber and supply of heat to the drilling body. It will contribute to the reduction of energy costs in

1 is an overall view showing an embodiment of a submarine resource drilling ship according to the present invention; FIG. 1 is an enlarged view of a main part showing an embodiment of a submarine resource drilling ship according to the present invention; FIG. 1 is an explanatory view showing an embodiment of a submarine resource drilling ship according to the present invention; FIG. 1 is an explanatory view showing an embodiment of a submarine resource drilling ship according to the present invention; FIG.

The submarine resource drilling ship 1 according to the present invention places the drilling body 23 in contact with the seabed S2 while holding the tubular tube 21 between the right ship 11 and the left ship 12, and drills around the drilling unit 20 by the rotating screw 15. The main feature is that the excavating body 23 is rotated by rotating the ship body 10 to excavate the seabed S2.
An embodiment of a submarine resource drilling ship 1 according to the present invention will be described below with reference to the drawings.

The submarine resource drilling ship 1 according to the present invention is not particularly limited to the embodiments described below. It can be changed as appropriate within the range of.

FIG. 1 is an overall view showing an embodiment of a submarine resource drilling ship 1 according to the present invention. Moreover, FIG. 2 is an enlarged view of a main part showing an embodiment of the submarine resource drilling ship 1 according to the present invention. Furthermore, FIG. 3 is an explanatory diagram showing an embodiment of the submarine resource drilling ship 1 according to the present invention. Furthermore, FIG. 4 is an explanatory diagram showing an embodiment of the submarine resource drilling ship 1 according to the present invention.
A submarine resource drilling ship 1 according to the present invention mainly comprises a drilling ship body 10 and a drilling unit 20 equipped on the drilling ship body 10 .

The drilling vessel body 10 includes a ballast unit 13 capable of taking in ballast water (seawater). A rotary screw 15 capable of rotating the hull is provided at a predetermined location on the hull.
The hull structure of the drilling vessel body 10 is not particularly limited, but in order to adjust the contact with the seabed S2 with the ballast unit 13, the height above the sea surface is about 20 m to 50 m, and the hull is rotated. Since excavation is performed by the excavation unit 20 interlocked with movement, it is preferable to have a total length of at least about 200 m to 300 m. By adopting this mode, the rotational force generated by the drilling vessel body 10 on the sea is reliably transmitted to the drilling body 23 in contact with the seabed S2, contributing to smooth drilling.

The drilling vessel body 10 has a hull structure that can be divided into a right vessel 11 and a left vessel 12 at approximately the center in the lateral direction. The right ship 11 and the left ship 12 function as ships capable of sailing individually, and the right ship 11 and the left ship 12 are combined to form one drilling ship main body 10 . there is The hull fixing means 18 for fixing the right boat 11 and the left boat 12 together is not particularly limited.
Since the drilling ship body 10 can be separated into the right ship 11 and the left ship 12 in this way, a connecting rail of a required length is interposed between the right ship 11 and the left ship 12, and the drilling vessel is divided on the connecting rail. It is possible to transport the drilling unit 20 (cylindrical tube 21) transported at the resource drilling site to the site in a state in which a number of cylindrical tubes 21 are placed thereon. It is also possible to use the ballast unit 13 to vertically sink either the right vessel 11 or the left vessel 12 with the bow or stern downward, thereby assisting the sinking of the drilling unit 20 (cylindrical tube 21). be.

The right ship 11 and the left ship 12 are respectively provided with recesses at positions facing each other so that the cylindrical tube 21 can be sandwiched in a combined state. Together, they form a tubular tube clamping portion 16 . The shape of the concave portion is not particularly limited, and various shapes such as a substantially semicircular shape and a polygonal shape in plan view can be adopted.

The ballast units 13 are provided at predetermined positions inside the right ship 11 and the left ship 12 of the drilling vessel body 10. Sea water flows into and out of the ballast units 13, causing the hull to float and sink, thereby adjusting the position of the drilling unit 20. Stability during navigation will be achieved.
Further, by appropriately entering water into the ballast unit 13 during excavation, the excavated body 23 can be kept in contact with the seabed S2. Furthermore, when the drilling unit 20 after drilling is lifted from the seabed S2, the seawater in the ballast unit 13 is appropriately drained, thereby increasing the buoyancy of the drillship body 10 and moving the drillship in the direction opposite to that during drilling. By rotating the drilling body 23, it becomes possible to pull back the drilling body 23 from the inside of the methane hydrate layer to the sea S1, so that the pulling-up work can be performed smoothly.

It is preferable that the ballast units 13 provided on the right ship 11 and the left ship 12 are configured so that the amount of seawater can be confirmed numerically on both ships. By adopting this mode, when the ballast unit 13 is filled and discharged during the rotation of the drilling ship, it is possible to automatically or manually perform the filling and discharging of the ballast unit 13 while balancing the right and left ships 11 and 12. It will contribute to excavation.

The rotating screws 15 are provided at predetermined positions on the right ship 11 and the left ship 12 of the drilling ship main body 10, and are screws for turning the hull. The shape and size of the rotary screw 15 are not particularly limited, and it is sufficient to use conventional means for ship screws. Also, the position of the rotary screw 15 is not particularly limited. For example, one or more rotary screws 15 are provided at locations such as the bow, stern, and hull that are flooded with seawater.

Regarding the position of the rotating screw 15, for example, the rotating screw 15 is provided in the vicinity of the hull of either or both of the right ship 11 and the left ship 12, and the rotation operation by operating the propulsion screw provided at the stern and the hull It is conceivable that the driving force in the short direction (horizontal direction) by the rotary screw 15 of the part causes the rotary operation around the excavating unit 20 . At that time, in order to equalize the amount of energy generated in the right ship 11 and the left ship 12, the number of rotations or the amount of kinetic energy in each screw is digitized, and the number of rotations for rotation is adjusted automatically or manually. A mode of performing can also be adopted. This aspect contributes to the stable rotation of the drilling ship, and even if a problem such as an abnormality in the rotation speed of a screw occurs, it is possible to quickly respond by suppressing the rotation speed of other screws.

The drilling unit 20 includes a tubular tube 21 that can extend to the seabed S2, a tubular tube holding portion that connects the tubular tube 21 and the drilling vessel main body 10, and a tubular tube 21 provided at the tip of the tubular tube 21 for drilling the seabed S2. a possible excavation body 23, a combustion chamber 24 provided in the vicinity of the excavation body 23, an exhaust heat pipe 25 for thermally conducting the exhaust heat discharged from the combustion chamber 24 to the tip region of the tubular tube 21, and an upper end. is provided around the outer peripheral surface of the cylindrical tube 21 and has a funnel shape that expands downward, and is capable of recovering the methane gas G that has surfaced from the seabed S2, and a resource recovery tank 28 that stores the recovered methane gas G. , consists of

The cylindrical tube 21 has a tubular structure with a hollow inside, and the tip is narrowed in a conical shape that can be pierced into the seabed S2. A possible drilling body 23 is provided, for example a helical blade or a helical groove. The cylindrical tube 21 has a structure in which the upper region thereof is sandwiched between the right ship 11 and the left ship 12 and can be connected to the drilling vessel body 10 by the cylindrical tube holding portion. The connected tubular pipe 21 extends from the drillship main body 10 to the seabed S2, and the tip of the tubular pipe 21 abuts on the seabed S2. adjusted. As a result, the tubular tube 21 rotates at the same time as the drilling vessel body 10 rotates, and the drilling body 23 also rotates accordingly to perform drilling. A combustion chamber 24 is disposed at the tip of the hollow interior of the cylindrical tube 21, and the resource recovery pipe 30, the combustion pipe 31, and the exhaust pipe 32 are passed through. If seawater is allowed to flow into the cylindrical pipe 21, it is assumed that these devices may malfunction or malfunction. Therefore, it is preferable that the cylindrical tube 21 has watertightness and has a structure that does not allow seawater to flow into the hollow interior.

The material, size, and shape of the cylindrical tube 21 are not particularly limited, but since it extends to the seabed S2 at a depth of 1000 m or more, a material that can withstand water pressure, such as steel or aluminum alloy, is preferable. Regarding the length of the cylindrical tube 21, it is necessary to have a suitable length to extend to the seabed S2 at a water depth of 1000 m or more. The total length of the pipe 21 is about 1100-1200m. In addition, considering the transportability to the resource excavation site, the cylindrical tube 21 is divided into several parts at predetermined locations in the longitudinal direction, and the divided parts are connected as appropriate on site to extend to the seabed S2. It is preferable to configure the tubular tube 21 with a length that can be obtained. At that time, in order to easily adjust the length corresponding to the water depth up to the seabed S2 which varies depending on the location, the parts connected to the proximal end of the cylindrical tube 21 are relatively short (eg, 10 to 30 m). It is desirable to prepare parts that are divided into parts of about 10m. It becomes possible to fit within, and workability is improved. In addition, in order to withstand the pressure caused by water pressure, ocean currents, etc. when submerged, it is preferable to increase the thickness or weight of the cylindrical tube 21 gradually toward the tip.

The cylindrical tube holder is a structure for connecting and fixing the vertically extending cylindrical tube 21 to the drilling vessel body 10 in a state where the upper region of the cylindrical tube 21 is held between the right ship 11 and the left ship 12. The specific structure thereof is not particularly limited. It is conceivable that the inner wall of the concave portion forming 16 is tightly bound by a predetermined means. As another structural example, as shown in FIG. A recess 17 into which the arm 29 is fitted may be provided, and in a state where the connecting arm 29 is fitted into the recess 17, it may be connected and fixed with bolts, nuts, or the like. According to this aspect, the turning force of the drilling vessel body 10 is transmitted via the connecting arm 29, which contributes to efficient rotation of the cylindrical tube 21 like the principle of leverage. When the connecting arm 29 is provided, it is desirable that the mounting height position of the connecting arm 29 on the cylindrical pipe 21 can be varied according to the depth of the cylindrical pipe 21 to the seabed S2.

As the structure of the tubular tube holding portion, a plurality of T-shaped projections are formed on the outer peripheral surface of the tubular tube 21, and a surface that abuts on the outer peripheral surface of the tubular tube 21 (in the previous example, the tubular tube holding portion 16 It is also preferable to form the same number of T-shaped recessed grooves that can engage the T-shaped projections in a fitting manner at positions opposite to the T-shaped projections on the inner wall surface of the cylinder or the inner wall surface of the cylindrical plate. In this manner, the T-shaped projection and the T-shaped groove are firmly engaged, and the kinetic energy generated by the rotation of the drilling vessel body 10 can be efficiently transmitted to the cylindrical tube 21 . The shape of the projection is not limited to the T shape, but may be an inverted T shape, an L shape, an H shape, a V shape, other various shapes, or a combination thereof. The shape of the concave groove can also take various shapes according to the shape of the projection.

As shown in FIG. 4, as a structure of the cylindrical tube holding portion, a plurality of connecting arms 41 having different height positions are provided as separate bodies from the cylindrical tube 21 so as to face each other and extend outward. An aspect using the outer tube 40 can be adopted. By providing a plurality of connecting arms 41 with different heights, it becomes easy to connect the cylindrical tube 21 and the drilling ship main body 10 at different height positions without changing the attachment positions of the connecting arms 41 . On the outer peripheral surface of the upper region of the tubular tube 21, there are at least two projecting pieces 22 of a predetermined length which are partially divided and extend in the vertical direction with a plurality of gaps 22a at predetermined intervals. are provided. Further, the inner peripheral surface of the outer tube 40 is provided with a vertically extending groove 42 penetrating vertically at a location corresponding to the protrusion 22. At a predetermined intermediate location of the groove 42, One or a plurality of openings 44 are formed so as to pass through in a substantially horizontal direction through which the fitting 43 can be inserted. When the outer tube 40 is inserted into the cylindrical tube 21 from above, the outer tube 40 is fitted into the cylindrical tube 40 by fitting the protruding piece 22 of the cylindrical tube 21 with the concave groove 42 of the outer tube 40 . 21 is fixed without sliding in the circumferential direction. Also, by aligning the position of the opening 44 in the concave groove 42 of the outer tube 40 with the position of the divided gap 22a in the convex piece 22 of the cylindrical tube 21 and inserting the fitting 43 into the opening 44, , the fitting 43 is fitted into the gap 22a, and the outer tube 40 is fixed without sliding in the longitudinal direction of the cylindrical tube 21. As shown in FIG. At this time, since a plurality of gaps 22a are formed in the projecting piece 22, by changing the gaps 22a corresponding to the openings 44, along with changing the attachment position of the connecting arm 41, the tubular pipe 21 and the excavation can be separated. It is possible to more finely set the connection at different height positions with the ship body 10 .

4, pulleys 45 are provided at the tip of the uppermost connecting arm 41 in the outer tube 40 and at predetermined positions on the outer periphery of the cylindrical tube 21. As shown in FIG. The pulley 45 is used for alignment when connecting the tubular tube 21 to the drilling ship main body 10. Specifically, a wire is passed through the pulley 45 and pulled or loosened by a winch or the like to loosen the tubular tube. While finely adjusting the position and inclination of the tube 21, the tube 21 is finally connected to the drillship main body 10 in an accurate position and in a vertical state. Such a pulley 45 can also be used as a portion through which a wire is passed when the tubular tube 21 is pulled up.

Regarding the tubular tube holding portion that connects the drilling vessel body 10 and the tubular tube 21, it is assumed that the drilling body 23 may be caught in a hard rock during excavation and cannot rotate. It is also possible to employ a mode in which the connection between the drilling vessel body 10 and the tubular tube 21 is automatically released in order to prevent damage to the hull and the drilling unit 20 when a load exceeding a certain level occurs. be. For example, when there is an obstacle in the excavated object and the rotation is delayed, if a certain load or more is applied to the tubular tube holding section connecting the drilling vessel body 10 and the tubular tube 21, the tubular tube automatically rotates. The connection structure at the tube holding portion is disengaged, whereby the connection between the drillship body 10 and the tubular tube 21 is released, and even if the drillship body 10 rotates, the tubular tube 21 does not rotate, and the tubular tube clamping portion It is a configuration mode that idles at 16 . In addition, it is desirable that the disconnection between the drillship main body 10 and the tubular pipe 21 is notified to the operator as an abnormality report. Stop the useless rotation of the ship, stop the ship, check and repair the abnormal state, and judge the continuation of excavation at the relevant place.

An excavating body 23 capable of excavating the seabed S2 is provided on the outer peripheral surface of the tip portion of the tubular tube 21 . The shape and structure of the excavating body 23 are not particularly limited. A structure is adopted in which an excavating body 23 capable of excavating S2, for example, a spiral blade or a spiral groove capable of excavating by rotation is provided. With the tip of the cylindrical tube 21 in contact with the seabed S2, which is the excavation point, the cylindrical tube 21 rotates in conjunction with the rotation of the drilling vessel body 10 on the sea, so that the drilling body 23 moves to the seabed S2. Excavation will be carried out to enter. The material of the excavating body 23 is not particularly limited, but since there is a possibility of excavating a hard bedrock, a material resistant to wear such as a composite material of steel or tungsten is suitable.

A combustion chamber 24 is provided inside the tip of the tubular tube 21 . The combustion chamber 24 burns the combustible gas to generate high-temperature exhaust heat, and the exhaust heat passes through the exhaust heat pipe 25 to It raises the temperature. Then, the rise in ambient seawater temperature due to the heated tip of the cylindrical tube 21 and the drilling body 23 accelerates the melting of the methane hydrate present on and near the drilled surface. The methane gas G that has become bubbles due to the melting of the methane hydrate is recovered by the resource recovery unit 26, which will be described later. After passing through the exhaust heat pipe 25, the exhaust gas whose temperature has been lowered is discharged into the atmosphere from the chimney 33 of the drilling vessel main body 10 via the exhaust pipe 32, which will be described later.

The structure of the combustion chamber 24 is not particularly limited. The route for laying the heat exhaust pipe 25 is not particularly limited, but for example, in the case where the excavation body 23 has a spiral structure, the route along the formed spiral shape is used as a flow path, and the entire spiral structure is heated to heat the surroundings. It is possible to employ a mode in which the temperature of the seawater and the temperature of the methane hydrate layer that is in close contact during excavation are increased. In addition, in order to grasp the operating state of the combustion chamber 24 on the drilling vessel body 10, a temperature sensor is provided in the combustion chamber 24, and control of the combustion chamber 24 (starting, stopping, temperature setting, etc.) can be performed automatically or manually. It is preferable to use a mode in which an instruction can be given by

A resource recovery unit 26 is provided at a predetermined intermediate position of the tubular tube 21 . The resource recovery unit 26 recovers the methane gas G generated from the excavated methane hydrate layer. It has a funnel-like or umbrella-like shape. By expanding the lower end in a funnel shape or an umbrella shape, it is possible to collect bubbles of methane gas G released into the sea S1 by melting methane hydrate after excavating the seabed S2 over a wide range. The methane gas G recovered by the resource recovery unit 26 flows into a resource recovery pipe 30, which will be described later, through a recovery window 27 opened in the cylindrical tube 21, passes through the resource recovery pipe 30, and is recovered on the sea. It will be transferred to the tank 28 . Therefore, the position where the resource recovery unit 26 is provided around the tubular tube 21 is the peripheral edge directly above the recovery window 27 .
By the way, as shown in FIG. 2, it is conceivable that a plurality of collection windows 27 are opened at different height positions of the tubular tube 21 . That is, as the excavation of the seabed S2 progresses, the cylindrical pipe 21 sinks downward. This is to deal with The collection window 27 when not in use is closed to prevent seawater from entering, and is opened only when in use.

Since the shape of the resource recovery unit 26 is funnel-shaped, there is a possibility that when the resource recovery unit 26 is submerged in the sea S1, an air pool is generated above the resource recovery unit 26, and buoyancy is generated to interfere with the subsidence work. Therefore, it is preferable to close the lower part of the resource recovery unit 26 when it sinks and open the lower part automatically or manually in the vicinity of the scheduled resource recovery point. The method of closing and expanding the lower part is not particularly limited. Alternatively, the lower part of the frame may be attracted to the outer peripheral surface of the cylindrical tube 21 by means of magnetic force or a fastening band, and the frame may be submerged in the sea S1. At this time, an umbrella-like surface material made of a material impermeable to methane gas is covered between the frames, and is expanded and closed in conjunction with the frames. Then, in the vicinity of the planned methane gas recovery site, the magnetic force at the lower end of the frame is extinguished, the tightening of the fastening band is released, and a predetermined part of the frame is pulled upward with a wire rope. Then, the frame and the umbrella-shaped surface member are expanded in a funnel shape. Further, when the tubular tube 21 is pulled up after the recovery of methane gas, it is preferable to automatically or manually close the frame and the umbrella-shaped surface material, so that the water resistance generated when the tubular tube 21 is pulled up can be reduced. This will contribute to mitigation.

A resource recovery tank 28 is equipped as the excavation unit 20 . The resource recovery tank 28 is installed on the deck of the drillship body 10 for the purpose of storing the recovered methane gas G. As shown in FIG. That is, the methane gas G recovered by the resource recovery unit 26 is transferred to the resource recovery tank 28 through the resource recovery pipe 30, which will be described later, and stored therein. With respect to the structure and material of the resource recovery tank 28, it is sufficient to employ conventional means, and there is no particular limitation.

A resource recovery pipe 30 , a combustion pipe 31 , and an exhaust pipe 32 are inserted through the hollow portion of the cylindrical tube 21 . The resource recovery pipe 30 is for transferring the methane gas G recovered by the resource recovery unit 26 to the resource recovery tank 28, and is provided between the resource recovery tank 28 laid on the drilling ship body 10 and the resource recovery unit 26. are connected in a continuous manner. The combustion pipe 31 is for sending fuel to the combustion chamber 24, and connects the combustion chamber 24 and the fuel tank laid on the drillship main body 10 in a communicative manner. Further, the exhaust pipe 32 is for sending the exhaust gas discharged from the heat exhaust pipe 25, and connects the chimney portion 33 laid on the drilling ship main body 10 and the heat exhaust pipe 25 in a communicating manner. there is The material of each pipe is not particularly limited, and it is conceivable to use a material such as copper or an aluminum alloy, for example. Also, the shape of each pipe is not particularly limited, but since the drilling vessel main body 10, the resource recovery unit 26, the combustion chamber 24, and the exhaust heat pipe 25 are connected in a communicating manner, there is considerable It is required to form an elongated shape. At this time, it is preferable that each long pipe is equipped with transfer means such as a pump and a propeller for smoothly transferring fuel, gas, and exhaust gas.

By the way, it is possible to employ a mode in which part of the collected methane gas G is flowed into the combustion chamber 24 through the combustion pipe 31 and the methane gas G is burned in the combustion chamber 24 . In this embodiment, the methane gas G recovered by the resource recovery unit 26 is once made to flow into the resource recovery tank through the resource recovery pipe 30, and part of the inflowing methane gas G is taken out from the resource recovery tank. , to the combustion chamber 24 via the combustion pipe 31 . By adopting such a mode, there is no need to prepare a new combustible material for the combustion chamber 24, which contributes to a reduction in energy costs for excavation.

The submarine resource drilling ship 1 according to the present invention is configured by the above components. The submarine resource drilling ship 1 according to the present invention has a tubular tube 21 having an excavating body 23 at its tip, with the tip of the tubular tube 21 in contact with the seabed S2, and the upper region of the tubular tube 21 being attached to the drilling vessel main body 10. The drilling vessel body 10 is fixedly connected via a tubular tube holding portion at the tubular tube clamping portion 16 provided, and the rotary screw 15 is used to rotate the drilling vessel body 10 about the tubular tube 21, which is interlocked therewith. As a result, the cylindrical tube 21 is also rotated to rotate the excavating body 23 at the tip, thereby excavating the seabed S2. At that time, the high temperature exhaust heat generated in the combustion chamber 24 raises the outer peripheral surface of the tip of the cylindrical tube 21 and the surface temperature of the drilling body 23, thereby raising the ambient seawater temperature and promoting the melting of methane hydrate. , the methane gas G that has become bubbles is recovered by the resource recovery unit 26 and stored in the resource recovery tank 28 .

An example of the mode of use of the submarine resource drilling ship 1 according to the present invention, that is, a series of flow of drilling work of a methane hydrate layer, will be described in order with reference to FIG.
As a preliminary preparation, an acoustic survey of the position of the surface methane hydrate layer is performed using an echo sounder (measurement fish finder), SEABAT (sea bottom sounding device), and the like.
A submarine resource drilling vessel 1 having a drilling vessel body 10 equipped with a drilling unit 20 is moved directly above the shallow methane hydrate layer found by the acoustic survey. At this time, the cylindrical tube 21 in the drilling unit 20 moves while being placed sideways on the drilling vessel body 10 .
Considering the length and weight of the tubular tube 21, it is difficult to place the tubular tube 21 on the drilling vessel body 10 and move it. Therefore, it is also preferable to place the cylindrical tube 21 on a separate buoyant body such as a rubber boat or a foam body and tow the drilling vessel body 10 on the sea. At that time, it is also possible to separate the drilling vessel body 10 into a right ship 11 and a left ship 12, one of which is towed on the front side of the buoyant body, and the other of which is on the rear side of the buoyant body and controls direction correction. It contributes to the navigation of the ship, the approach to the side, fine adjustment of the position, etc.

When it arrives directly above the shallow methane hydrate layer, it stops there, and the drilling vessel main body 10 and the drilling unit 20 are connected at the stopping point. Specifically, the hull fixing means 18 is removed, the drilling vessel body 10 is separated into the right vessel 11 and the left vessel 12, and the mounted cylindrical tube 21 is obliquely submerged from the tip side into the sea S1, and finally approximately Allow to settle vertically. At this time, as shown in the figure, by separating either the bow side or the stern side of the right ship 11 and the left ship 12 so as to open the other while closing the other, flooding from the tip side of the cylindrical tube 21 is possible. is. When the cylindrical pipe 21 is divided into several parts with a predetermined length, the cylindrical pipe 21 having the excavation body 23 and the combustion chamber 24 is placed at the forefront, and the resource recovery pipe 30 existing inside. , the combustion pipe 31, and the exhaust pipe 32 are aligned so as not to be connected to different pipes, and connected as needed to sink. A resource recovery unit 26 is also provided at a predetermined intermediate position of the tubular tube 21 .

When the tip of the tubular tube 21, that is, the excavating body 23 contacts the seabed S2, the proximal end of the tubular tube 21 is connected and fixed to the tubular tube holding portion. Specifically, the upper region of the cylindrical tube 21 is sandwiched between the concave portions of the right ship 11 and the left ship 12, and is firmly fastened by a predetermined fixing means. Then, the right ship 11 and the left ship 12 are connected and integrated by the hull fixing means 18 so that the right ship 11 and the left ship 12 are not separated while holding the cylindrical tube 21 therebetween.

Seawater is injected into the ballast unit 13 provided in the drilling vessel body 10, and the drilling vessel body 10 is rotated by the rotating screw 15 and the propulsion screw 14 while applying a downward load to the tubular tube 21. - 特許庁At this time, the drilling vessel body 10 rotates around the cylindrical tube 21 , and in conjunction with the rotation of the drilling vessel body 10 , the fixed cylindrical tube 21 also rotates. As a result, the excavating body 23 located at the tip of the tubular tube 21 excavates the methane hydrate layer of the seabed S2 while rotating.
When the seabed S2 is excavated so that the tip of the cylindrical tube 21 is no longer in contact with the seabed S2 and becomes floating, seawater is injected into the ballast unit 13 provided in the drillship body 10, and the drillship body 10 By sinking slightly, the tip of the cylindrical tube 21 can be brought into contact with the seabed S2 again. Alternatively, with the tip of the tubular tube 21 floating, the rotation of the drilling vessel main body 10 is once stopped, and the tip of the tubular tube 21 moves a little to the place where it abuts the seabed S2, and drilling is started again. is also possible.

In the vicinity of the excavated body 23, a combustion chamber 24 and an exhaust heat pipe 25 for conducting heat exhaust heat discharged from the combustion chamber 24 are provided. , is sent to the exhaust heat pipe 25 . The temperature of the methane hydrate drilled by the rotation of the drilling vessel 10 rises along with the ambient seawater temperature due to heat conduction in the tip region of the cylindrical tube 21, and the methane hydrate is decomposed into methane gas G and water, which is a gaseous body. G will surface toward the sea.
The exhaust after heat exhaust is discharged into the atmosphere from a chimney 33 provided on the drilling ship body 10 through an exhaust pipe 32 connected to the heat exhaust pipe 25 .

The methane gas G decomposed from the methane hydrate and floating to the surface enters the interior of the resource recovery unit 26 from the expanded lower part of the resource recovery unit 26 provided at a predetermined position of the cylindrical tube 21, and is provided near the upper part of the resource recovery unit 26. The methane gas G flows into the resource recovery pipe 30 provided in the cylindrical tube 21 from the recovery window 27 in the cylindrical tube 21, and the methane gas G having a low specific gravity rises in the resource recovery pipe 30 and is installed on the drilling ship main body 10. It will be collected in the resource recovery tank that was designed.
In addition, a part of the methane gas G is sent to the combustion chamber 24 provided near the excavation body 23 by the combustion pipe 31 connected to a predetermined location of the resource recovery tank, and is used as combustion gas in the combustion chamber 24. It is also conceivable that the

The recovered methane gas G is stored in the vicinity of the upper part of the resource recovery unit 26, and then flows into the resource recovery pipe 30 in the tubular tube 21 through the recovery window 27, and the methane gas G rises inside the resource recovery pipe 30. As a result, it is stored in a resource recovery tank, but the resource recovery tank may be provided in a follower ship or the like that has transported the tubular tube 21 other than the drilling vessel main body 10 . In addition, the storage method in the resource recovery tank is not particularly limited, and it is also conceivable to liquefy the recovered methane gas G on board, store it in the resource recovery tank, and transfer it.
In addition, since the methane gas G is likely to cause accidents such as fires and explosions due to static electricity, explosion-proof treatment is essential for resource recovery tanks and piping leading to resource recovery tanks. This explosion-proof treatment is not particularly limited, and accidents can be prevented by using conventionally known techniques such as wrapping the outer layer of the tank with an explosion-proof layer filled with nitrogen.

In the vicinity of the resource recovery unit 26 or in the resource recovery pipe 30, disasters such as static electricity and spontaneous combustion occur due to friction between the methane gases G and contact between the methane gas G and structures such as the resource recovery pipe 30. there is a possibility. Therefore, it is conceivable to attach a plurality of anti-disaster devices, such as a static eliminator, a temperature sensor, and a flame-extinguishing net, to predetermined portions of the resource recovery pipe 30 . The disaster prevention device is not particularly limited, and a conventionally known structure is used to suppress the occurrence of the disaster described above.

When the drilling and recovery of methane gas G are completed and the drilling vessel is withdrawn, it is sufficient to perform the procedure in reverse to the described flow up to the drilling. After the drilling body 23 appears on the seabed at the drilling location due to the reverse rotation of 10, the drilling vessel is separated from the right vessel 11 and the left vessel 12 by disconnecting the tubular tube holding portion and removing the hull fixing means 18. A winch or the like provided on the main body 10 is used to pull up the tubular tube 21, the tubular tube 21 is placed on the drilling vessel main body 10, and the right and left vessels 11 and 12 are combined to form a hull fixing means. 18 and return to the ship.

An example of the mode of use of the submarine resource drilling ship 1 according to the present invention has been described above, but the mode of use is not necessarily limited to the mode of use described above, and the following modes can also be considered.
For example, regarding the method of installing the cylindrical pipe 21 at the planned excavation site, one or more winches provided on the right ship 11 and the left ship 12 are used, and the drilling body 23 connected to the tip of the cylindrical pipe 21 is used. While gradually dropping into the sea S1 from the bottom, the next cylindrical pipe 21 is connected to the proximal end of the cylindrical pipe 21 until it reaches the vicinity of the planned excavation depth, and the excavating body 23 contacts the seabed S2. A mode in which the drilling vessel and the tubular tube 21 are connected to each other at a tubular tube holding portion later, or a tubular tube 21 extending to the vicinity of the planned excavation depth while connecting the drilling body 23 to the tip is prepared in advance. Then, at the scheduled drilling site, the drilling body 23 is gradually thrown into the sea S1. It is conceivable to use one or a plurality of winches to connect the tubular tube 21 of insufficient length or disconnect the connection of unnecessary length.

Further, it is conceivable that the submarine resource drilling ship 1 moves to the next drilling site as soon as the submarine S2 drilling at the scheduled drilling site is completed. At that time, it is preferable to move with a part of the excavating unit 20 contracted or removed depending on the moving distance to the scheduled point and the seafloor topography. By adopting this moving method, it is possible to shorten the work time and reduce the work load, which contributes to efficient excavation of seabed resources.

When the drilling unit 20 is pulled up, it is conceivable that the drilling unit 20 is pulled up by winches provided at a plurality of predetermined locations on the drilling ship in a state where the left ship 12 and the right ship 11 are separated. Furthermore, when pulling up in this mode, it is preferable to dismantle the portion connecting the cylindrical tubes 21 of a predetermined length and load them on the accompanying ship. By adopting this mode, the cylindrical pipe 21 is transferred to the companion ship at regular intervals, and the burden on the winch accompanying the lifting of the drilling unit 20 can be reduced, and the cylindrical pipe pulled up from the sea S1 can be used. It is also possible to prevent bending of the tubular tube 21 due to the gravity applied to the tube 21 and its own weight.

Although the basic configuration and operation of the submarine resource drilling ship 1 according to the present invention have been described above, the present invention is not limited to the above-described embodiment or the configuration shown in the drawings. In the present invention, the drilling vessel main body 10 is described, but it does not necessarily have to be in the shape of a ship. It is also possible to adopt a mode in which As for the heat generation method of the drilling body 23, a method other than gas combustion, for example, a mode in which the drilling body 23 is heated by power transmission from a drilling ship to heat a heating wire is conceivable.

It is also conceivable to use the ballast units 13 of the right ship 11 and/or the left ship 12 to tilt the hull to assist the sinking or lifting of the tubular tube 21 . In this embodiment, the seawater is discharged to the ballast units 13 of the right ship 11 and/or the left ship 12 to float the hull, and the floating hull and the tubular tube 21 in the air are fixed at predetermined points, and / Alternatively, by injecting seawater from the ballast unit 13 of the left ship 12, the hull can sink and the cylindrical tube 21 fixed to the hull can sink into the sea S1. Conversely, by injecting seawater into the ballast units 13 of the right ship 11 and/or the left ship 12, the hulls sink, and the submerged hulls and the tubular pipes 21 in the sea S1 are fixed at predetermined locations, and / Alternatively, by discharging seawater from the ballast unit 13 of the left ship 12, the hull can float and the tubular tube 21 fixed to the hull can be pulled up from the sea S1. By repeating this operation, it is possible to expect the effect of facilitating sinking and lifting of the tubular tube 21 that has become elongated in the longitudinal direction.

As described above, according to the submarine resource drilling ship 1 according to the present invention, the drilling ship body 10 is separated into the right ship 11 and the left ship 12, and the tubular tube 21 is fixed by the tubular tube holding portion. The drilling body 23, which is connected to the tip of the tubular tube 21 due to the subsidence of the ballast unit 13, is brought into contact with the seabed S2. At the same time as the drilling vessel body 10 rotates around the tubular tube 21, the tubular tube 21 and the drilling body 23 rotate in conjunction with the drilling vessel body 10, so that the drilling body comes into contact with the seabed S2. The seabed S2 is excavated by the tip of the excavation body 23, and the exhaust heat of the combustion chamber 24 provided in the excavation body 23 heats the excavation body 23, thereby melting the surrounding methane hydrate and generating methane gas G, which is cylindrical. After the methane gas G that has surfaced is recovered by the resource recovery unit 26 provided at a predetermined position of the pipe 21, it can be stored in the resource recovery tank 28 on board.

INDUSTRIAL APPLICABILITY The present invention can be used not only for excavating surface methane hydrate layers lying in the sea around Japan, but also for excavating other marine resources, excavating lakes and marshes, and the like. Therefore, it is considered that the industrial applicability of the "submarine resource drilling ship" according to the present invention is great.

1 Submarine Resource Drilling Vessel 10 Drilling Vessel Body 11 Right Vessel 12 Left Vessel 13 Ballast Unit 14 Propulsion Screw 15 Rotating Screw 16 Cylindrical Tube Clamping Part 17 Recess 18 Hull Fixing Means 20 Drilling Unit 21 Cylindrical Tube 22 Protruding Piece 22a Gap 23 Excavation Body 24 Combustion chamber 25 Exhaust heat pipe 26 Resource recovery unit 27 Recovery window 28 Resource recovery tank 29 Connection arm 30 Resource recovery pipe 31 Combustion pipe 32 Exhaust pipe 33 Chimney 40 Mantle pipe 41 Connection arm 42 Groove 43 Fitting 44 opening 45 pulley G methane gas S1 underwater S2 seabed

Claims (2)

A submarine resource drilling vessel capable of mining a methane hydrate layer buried in the seafloor,
A drilling vessel body equipped with a ballast unit and a rotating screw provided at a predetermined location on the hull and capable of rotating the hull; and a drilling unit equipped on the drilling vessel body,
The main body of the drilling vessel has a hull structure that can be divided into right and left vessels at the center in the transverse direction,
The drilling unit includes a tubular tube that can extend to the seabed, a tubular tube holding portion that connects the tubular tube and the drilling vessel body, a drilling body that is provided at the tip of the tubular tube and is capable of drilling the seabed, and a drilling unit. A combustion chamber provided near the body, an exhaust heat pipe for conducting heat exhaust heat discharged from the combustion chamber to the tip region of the cylindrical tube, and an upper end portion extending downward around the outer peripheral surface of the cylindrical tube. Equipped with an expanded funnel-shaped resource recovery unit that can recover methane gas that has surfaced from the seabed, and a resource recovery tank that stores the recovered methane gas,
A resource recovery pipe for sending the recovered methane gas to the resource recovery tank, a combustion pipe for sending fuel to the combustion chamber, and an exhaust pipe for sending the exhaust gas discharged from the exhaust heat pipe are inserted through the cylindrical pipe. consists of
The drilling body is brought into contact with the seabed while the tubular tube is sandwiched between the right and left ships. After fixing the drilling vessel body and the tubular tube with the tubular tube holding part, the drilling unit is rotated by the rotating screw of the drilling vessel body. A submarine resource drilling vessel characterized by rotating a hull around a to excavate the seabed by rotating a drilling body, and recovering methane gas after drilling by a resource recovery unit. 2. The submarine resource drilling ship according to claim 1, wherein said combustion pipe is connected to a resource recovery tank so that part of the recovered methane gas can be flowed into the combustion chamber as fuel.

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