A movable cold spring leakage point bubble collection device and control method thereof

Abstract

The present invention belongs to the technical field of submarine natural gas collection, and discloses a movable cold spring leakage point bubble collection device and its control method. The device includes a frame structure to support the overall structure; a special collection cover, which is suspended and installed inside the frame structure, covers the cold spring leakage point and stores natural gas hydrates; a base, which is tightly attached to the lower end of the frame structure, supports and counterweights the overall structure, and a check valve array is installed on the bottom surface of the base to allow bubbles to enter the special collection cover; a propulsion module, which is installed on the outside of the base, uses a propeller to push the overall device to move; a position detection module, which is installed on the outside of the base, uses an acoustic wave sensor to detect the position of the leakage point; a control system, which is installed on the outer wall of the base, controls the operation of the overall device; and a battery pack, which is installed on the outer wall of the base, provides power for the overall device. The present invention can safely and continuously collect natural gas from cold spring leakage points in submarine hydrate stable areas.

Description

Technical Field

[0001] The invention belongs to the technical field of submarine natural gas collection, and in particular relates to a movable cold spring leakage point bubble collection device and a control method thereof. Background Art

[0002] At present, in nature, submarine natural gas hydrates are widely found in submarine sediments that meet temperature and pressure conditions outside the continental margin, with a seabed depth of 400-800 meters and a seawater temperature of about 15 degrees Celsius or less. The amount of submarine natural gas hydrate resources accounts for about 97% of the world's total resources. The occurrence environment of submarine natural gas hydrates is affected by factors such as changes in ocean circulation, submarine landslides, and submarine earthquakes, which can cause changes in temperature and pressure conditions, thereby destroying the stability of natural gas hydrates and forming cold spring seepage areas. During the seepage period, the flux of a single cold spring seepage point is generally between 3.5mL / min and 13.9L / min. So far, about 30,000 cold spring seepage areas have been found on the continental margin, and about 0.8Gt of natural gas leaks each year.

[0003] Due to the uneven distribution of seabed natural gas hydrates, currently, drilling and exploitation of hydrates are mainly carried out in hydrate-rich areas, while the collection of natural gas leaking from cold spring seepage areas is ignored. Limited by existing exploration technology, it is impossible to accurately explore hydrate-rich areas, which easily leads to uncertainty in the economic value of exploitation. In addition, there are related scientific problems and challenges such as difficulties in preventing and controlling geological disasters and difficulties in predicting the impact on development safety and global climate change during drilling and exploitation.

[0004] In summary, the shortcomings and problems of the prior art mainly include:

[0005] 1) Insufficient collection: At present, the main method of drilling for seabed natural gas hydrates is to collect natural gas leaking from cold springs, which leads to insufficient collection of natural gas resources and the inability to fully utilize and develop them.

[0006] 2) Low exploration accuracy: Current exploration technology cannot accurately identify hydrate-rich areas, which can easily lead to uncertainty in the economic value of mining and prevent effective resource management and utilization.

[0007] 3) High risk of geological disasters: During the drilling and mining process, due to the complex geological conditions on the seabed, it is difficult to prevent and control geological disasters, such as submarine landslides and earthquakes, which can easily cause safety accidents and environmental pollution.

[0008] 4) Environmental impacts are difficult to predict: The exploitation and utilization of submarine natural gas hydrates will have certain impacts on the environment, such as climate change, but these impacts cannot be accurately predicted and assessed at present, making it difficult to achieve sustainable development and environmental protection.

[0009] In summary, the main problems with existing technologies are insufficient collection, low exploration accuracy, high risk of geological disasters and unpredictable environmental impacts. These problems need to be solved through technological innovation and development to achieve the effective utilization and sustainable development of seabed natural gas hydrates. Summary of the invention

[0010] Due to a series of problems existing in the existing mining technology, the present invention considers collecting the natural gas leaking from the cold spring leakage area, and provides a movable cold spring leakage point bubble collection device and a control method thereof.

[0011] The present invention is implemented in this way: a movable cold spring leakage point bubble collection device comprises:

[0012] The frame structure is used to support the overall structure;

[0013] Special collection cover, suspended and installed inside the frame structure, used to cover the cold spring leakage point and store natural gas hydrate;

[0014] The base is tightly attached to the lower end of the frame structure and is used to support and balance the overall structure.

[0015] A check valve array, mounted on the bottom surface of the base, is used to allow air bubbles to enter the special collection hood;

[0016] A propulsion module is installed on the outside of the base and is used to propel the entire device to move using a propeller;

[0017] A position detection module is installed on the outside of the base and is used to detect the position of the leakage point using an acoustic wave sensor;

[0018] A control system, installed inside the outer wall of the base, for controlling the operation of the entire device;

[0019] The battery pack is installed inside the outer wall of the base and is used to provide electrical energy for the entire device.

[0020] Furthermore, the upper bottom of the frame structure is connected with a rope, the upper part of the rope is connected to the suspension ball, the lower bottom of the frame structure is clamped on the base with a buckle, the control system is connected with a cable, and the other end of the cable is fixed in the suspension ball.

[0021] Furthermore, the upper and lower bottoms of the frame structure are in the shape of closed loops, the radius of the upper bottom closed loop is much smaller than that of the lower bottom closed loop, the two closed loops are connected by equally spaced curved rods, a buckle is installed on the lower side of the curved rod for connecting to the lower base, and symmetrically distributed small rings are connected to the outer side of the upper bottom closed loop for connecting ropes.

[0022] Furthermore, the base is cylindrical as a whole, and the shape of the upper bottom of the base is the same as the shape of the lower bottom of the frame structure. The outer radius of the cylinder wall at the upper bottom opening of the base gradually increases and then remains unchanged at a fixed value. The closed loop of the lower bottom of the frame is between the inner and outer radii of the upper bottom opening of the cylinder wall of the base, and is used to firmly and tightly clamp the frame structure on the base.

[0023] Furthermore, the base as a whole maintains a certain weight to prevent the whole device from floating unstably after the special collection cover is filled.

[0024] Furthermore, the special collecting cover is composed of three layers of materials, including an outer high-strength waterproof fabric, a middle thermal insulation fabric and an inner smooth waterproof polymer bonding fabric.

[0025] Furthermore, the special collecting cover is suspended in the frame structure with a fixing device, the lower bottom surface of the special collecting cover is the same shape as the lower bottom surface of the frame structure, the top of the special collecting cover is connected to a waterproof fabric tube, both ends of the waterproof fabric tube are open, and the radius of the waterproof fabric tube is smaller than the closed loop radius of the upper bottom of the frame structure.

[0026] Furthermore, the check valve array is composed of a plurality of sheet-like check valves placed on the bottom surface of the base, and a sheet-like check valve controller of the sheet-like check valve is built into the base. The plurality of sheet-like check valves have equal widths and different lengths, are parallel to the bottom surface of the base and cover the entire bottom surface.

[0027] Furthermore, a plurality of identical propellers are installed on the outer side of the base, and the plurality of propellers are at equal distances from the bottom surface of the base and are evenly distributed on the outer wall.

[0028] Furthermore, a plurality of acoustic wave sensors are installed on the outer side of the base, and the plurality of acoustic wave sensors are equidistant from the bottom surface of the base and are evenly distributed on the outer wall.

[0029] Another object of the present invention is to provide a control method for a movable cold spring leakage point bubble collection device, the control method comprising:

[0030] Step 1: In the hydrate stability area on the seabed, the whole device is lowered by ropes on the sea surface. Seawater flows through the check valve array, the special collection cover, and the waterproof cloth tube. When lowering, the waterproof cloth tube is perpendicular to the upper bottom surface of the frame;

[0031] Step 2: The acoustic wave sensor detects the location of the leakage point, and the propeller pushes the entire device to adjust its position so that the entire device lands accurately on the leakage point, and then the waterproof fabric tube naturally droops to close the upper channel of the special collection cover;

[0032] Step 3: The check valve controller opens the check valve array, and the bubbles enter the special collection cover through the check valve array, and gather at the upper part of the special collection cover to form hydrates;

[0033] Step 4: After collecting for a period of time, all check valve arrays are closed and the entire device is recovered by ropes.

[0034] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0035] First, the present invention collects natural gas leaking from cold spring leakage points and deploys the whole device in the sea area where natural gas hydrates are stable. The waterproof cloth tube is kept lowered stably, the acoustic sensor detects the position of the leakage point, and the propeller adjusts the lowering direction so that the whole device lands accurately on the leakage point. Then the waterproof cloth tube naturally droops to close the special collection cover channel, and the check valve controller opens the check valve array to allow the bubbles at the cold spring leakage point to enter the special collection cover. The bubbles become hydrates inside the special collection cover, and the inside of the special collection cover is gradually filled with hydrates. The check valve array is closed, and the whole device is recovered by ropes. The whole device maintains a certain rising speed in the seawater, so that the waterproof cloth tube is pressed tightly against the outside of the special collection cover, and the temperature and pressure inside the special collection cover are kept stable to prevent the decomposition of hydrates inside the special collection cover, and finally the whole device is recovered.

[0036] The device of the present invention collects leaked natural gas in the submarine cold spring leakage area and can be used in both hydrate-enriched areas and non-enriched areas, thus greatly expanding the scope of submarine natural gas collection.

[0037] Second, the present invention can safely and continuously collect natural gas from cold spring leakage points in the seabed hydrate stable zone without destroying the seabed environment. The present invention does not require drilling, greatly saves costs, and does not cause problems such as geological landslides caused by drilling and mining. The present invention can be repeatedly used to collect leaking natural gas at various leakage points in the seabed cold spring leakage zone, and a large amount of natural gas in the form of hydrate can be collected, greatly improving the natural gas storage efficiency.

[0038] Third, the movable cold spring seepage point bubble collection device of the present invention can be reused at various cold spring seepage points. The cost of use is the electricity for controlling the propeller, the acoustic sensor and the check valve array. The maximum volume of natural gas collected can reach 120πr 3 , where r is the radius of the sphere in the frame. When r is 3.25 m, the volume of the collected hydrate after decomposition at standard atmospheric pressure is about 120πr 3 =12934.6m 3 , the economic benefits are huge.

[0039] Fourthly, the movable cold spring seepage point bubble collection device provided by the present invention fills the gap in the field of natural gas collection at cold spring seepage points at home and abroad, and shifts the mining target from drilling and mining hydrates in seabed sediments to collecting leaking bubbles in cold spring seepage areas on the seabed surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of a movable cold spring leakage point bubble collection device provided by an embodiment of the present invention;

[0041] Figure 2 is a bottom view of a movable cold spring leakage point bubble collection device provided by an embodiment of the present invention;

[0042] Figure 3 is a top view of a movable cold spring leakage point bubble collection device provided by an embodiment of the present invention;

[0043] Figure 4 is a structural schematic diagram of a framework structure provided by an embodiment of the present invention;

[0044] Figure 5 It is a structural schematic diagram of a special collection cover provided by an embodiment of the present invention;

[0045] Figure 6 is a schematic structural diagram of a side surface of a base provided by an embodiment of the present invention;

[0046] Figure 7 is an axial cross-sectional detail diagram of the connection between the frame structure and the base provided by an embodiment of the present invention;

[0047] Figure 8 It is a detailed structural diagram of a single check valve plate in the check valve array provided by an embodiment of the present invention;

[0048] In the figure: 1. frame structure; 2. special collection cover; 3. rope; 4. base; 5. buckle; 6. thruster; 7. battery pack; 8. control system; 9. check valve controller; 10. acoustic wave sensor; 11. suspension ball; 12. cable; 13. small ring; 14. fastener; 15. buckle; 16. waterproof cloth tube; 17. check valve array; 18. upper bottom closed loop; 19. curved rod; 20. lower bottom closed loop; 21. sheet check valve. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] like Figure 1 Shown is a structural diagram of the present invention; Figure 2 Shown is a bottom view of the present invention; Figure 3The movable cold spring seepage point bubble collection device provided by the embodiment of the present invention comprises: a frame structure 1, a special collection cover 2 suspended in the frame structure 1, a base 4 connected to the bottom of the special collection cover 2 through a plurality of buckles 5, a check valve array 17 mounted on the bottom surface of the base 4, a plurality of thrusters 6 and a plurality of acoustic wave sensors 10 installed on the outside of the base 4, and a battery pack 7 and a control system 8 installed in the outer wall of the base 4.

[0051] like Figure 4 As shown, the upper and lower bottoms of the frame structure 1 are in the shape of circular rings, the radius of the upper bottom circular ring 18 is much smaller than the radius of the lower bottom circular ring 20, and the two circular rings are connected by multiple curved rods 19. A buckle 15 is installed on the lower side of the curved rod 19 for connecting to the lower base 4. The outer side of the upper bottom circular ring 18 is connected to symmetrically distributed small circular rings 13 for connecting the rope 3.

[0052] The base 4 is cylindrical as a whole. At the upper bottom opening of the base 4, the outer radius of the cylinder wall gradually increases and then remains unchanged. The radius of the frame bottom ring 20 is between the inner and outer radii of the upper bottom opening of the cylinder wall of the base 4, so that the frame 1 can be firmly and tightly clamped on the base 4.

[0053] The special collecting cover 2 in the embodiment of the present invention is composed of three layers of materials, an outer high-strength waterproof fabric, a middle thermal insulation fabric and an inner smooth waterproof compound bonding fabric.

[0054] The special collection cover 2 is suspended in the frame structure 1 by a fixing device 14. The bottom surface of the special collection cover 2 has the same shape as the bottom surface of the frame structure 1. The top of the special collection cover 2 is connected to a waterproof cloth tube 16. The two ends of the waterproof cloth tube 16 are open. The radius of the waterproof cloth tube 16 is smaller than the radius of the bottom circular ring 18 of the frame. Figure 5 shown.

[0055] like Figure 6 As shown, a plurality of thrusters 6 are installed on the outside of the base 4, a plurality of acoustic wave sensors 10 are installed on the outside of the base, a check valve array 17 is installed on the bottom of the base, a battery pack 7 is installed on the outer wall of the base, a control system 8 is installed on the outer wall of the base, the control system is connected to a cable 12, and the other end of the cable 12 is fixed in a suspension ball 11.

[0056] The upper bottom of the frame structure is connected to a rope 3, the upper part of the rope 3 is connected to a suspension ball 11, a special collection cover 2 is suspended inside the frame structure, and the lower bottom of the frame structure is clamped on the base 4 with multiple buckles 5, such as Figure 7 shown.

[0057] like Figure 8As shown, the check valve array 17 is composed of a plurality of sheet-like check valves 21 placed on the lower bottom surface of the base 4. The sheet-like check valve controller 9 of the sheet-like check valve 21 is built into the base 4. The sheet-like check valves 21 have equal widths and different lengths, are parallel to the bottom surface of the base and cover the entire bottom surface.

[0058] In the embodiment of the present invention, 4 to 8 thrusters 6 of the same model are installed on the outside of the base 4, and the 4 to 8 thrusters 6 of the same model are equidistant from the bottom surface of the base 4 and evenly distributed on the outer wall. Four acoustic wave sensors 10 are installed on the outside of the base 4, and the 4 acoustic wave sensors 10 are equidistant from the bottom surface of the base 4 and evenly distributed on the outer wall. A battery pack 7 and a control system 8 are installed inside the outer wall of the base. The installation positions of the thrusters 6, acoustic wave sensors 10, battery packs 7 and control systems 8 should keep the mass distribution of the collection device centrally symmetrical.

[0059] In the stable area of ​​seabed hydrate, the whole device is lowered by rope 3, and seawater flows through check valve array 17, special collection cover 2 and waterproof cloth tube 16. The diameter of waterproof cloth tube 16 is much smaller than the inner diameter of the base, so that the collection device remains stable when lowered in seawater. The acoustic sensor 10 detects the position of the leakage point, and the thruster 6 adjusts the orientation of the whole device so that the whole device lands accurately on the leakage point. Then the waterproof cloth tube 16 naturally droops to close the upper channel of the special collection cover 2, and the check valve controller 9 opens the check valve array 17 to allow bubbles to enter through the check valve array 17. The bubbles collected in the upper part of the special collecting cover 2 gradually form hydrates. After a period of time, a large amount of hydrates are collected inside the special collecting cover 2, and the whole device is recovered by ropes. During the recovery, the check valve array 17 is completely closed to maintain a certain recovery speed of the whole equipment in the seawater so that the waterproof cloth tube 16 is pressed against the outer surface of the special collecting cover 2 to prevent seawater from entering the special collecting cover 2, and to keep the temperature and pressure inside the special collecting cover 2 relatively stable to keep the hydrates stable.

[0060] It should be noted that the thruster 6 , the check valve array, and the acoustic wave sensor may be automatically controlled by the control system 8 , or may be manually controlled via a cable connected to the suspension ball 11 .

[0061] When the radius of the inscribed circle of the special collection cover is 3.25m, the volume of the collected hydrate after decomposition under standard atmospheric pressure is about 120πr 3 =12934.6m 3, which is equivalent to the leakage of a single cold spring leakage point with an average flux of 8.7mL / min in one day. At the three cold spring leakage points, bubble collection devices with an inscribed circle radius of 3.25m were placed respectively, and the total amount of natural gas collected was greater than the daily gas production of 28,700 cubic meters in the second round of trial production of natural gas hydrates in China's waters on March 18, 2022. 122 cold spring leakage points with an average flux of about 8.7mL / min were found on the seabed, which can maintain the daily collection volume at 28,700 cubic meters throughout the year. The production and maintenance costs of the bubble collection device are much lower than the cost of drilling and mining of natural gas hydrates in the sea.

[0062] The working principle of the movable cold spring leakage point bubble collection device provided by the embodiment of the present invention is as follows:

[0063] 1) Frame structure: used to support the overall structure, ensure the stability of the entire device, and avoid instability during movement and collection.

[0064] 2) Special collection cover: It is suspended and installed inside the frame structure to cover the cold spring leakage point and store natural gas hydrate. When the bubbles enter the special collection cover, they will re-form hydrate inside the cover, which is convenient for collection and storage.

[0065] 3) Base: Closely attached to the lower end of the frame structure, used to support and balance the overall structure.

[0066] 4) Check valve array: installed on the bottom surface of the base, used to open and close the bottom surface of the base, allowing the bubbles to enter the special collection cover when collecting bubbles, and closing the bottom surface of the base when recovering the entire device.

[0067] 5) Propulsion module: Installed on the outside of the base, using the propeller to push the entire device to move. The propulsion module can be adjusted and controlled as needed to ensure the movement direction of the entire device.

[0068] 6) Position detection module: installed on the outside of the base, using an acoustic sensor to detect the location of the leak. The position detection module can monitor the location of the leak in real time and determine the location of the collection point so that the device can land accurately at the leak.

[0069] 7) Control system: installed inside the outer wall of the base, used to control the operation of the entire device. The control system can control the check valve array and the propulsion module based on the feedback information of the position detection module.

[0070] 8) Battery pack: installed inside the outer wall of the base, used to provide power for the entire device. The battery pack can ensure that the device can operate continuously when working in the field without being restricted by external conditions.

[0071] In summary, the device uses the position detection module to monitor the leakage point in real time, and controls the movement of the propulsion module to make the bubbles at the leakage point enter the special collection cover, thereby realizing the collection of bubbles at the cold spring leakage point. At the same time, the device is mobile and autonomous, and can adapt to different collection environments and conditions, improving collection efficiency and accuracy.

[0072] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0073] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A movable cold spring seepage point bubble collection device, characterized in that: The device comprises: The frame structure is used to support the overall structure; Special collection cover, suspended and installed inside the frame structure, used to cover the cold spring leakage point and store natural gas hydrate; The base is tightly attached to the lower end of the frame structure and is used to support and balance the overall structure. A check valve array, mounted on the bottom surface of the base, is used to allow air bubbles to enter the special collection hood; A propulsion module is installed on the outside of the base and is used to propel the entire device to move using a propeller; A position detection module is installed on the outside of the base and is used to detect the position of the leakage point using an acoustic wave sensor; A control system, installed inside the outer wall of the base, for controlling the operation of the entire device; A battery pack, mounted inside the outer wall of the base, for providing electrical energy to the entire device; The upper bottom of the frame structure is connected with a rope, the upper part of the rope is connected with a suspension ball, the lower bottom of the frame structure is clamped on the base with a buckle, the control system is connected with a cable, and the other end of the cable is fixed in the suspension ball; The upper and lower bottoms of the frame structure are in the shape of closed loops, the radius of the upper bottom closed loop is much smaller than that of the lower bottom closed loop, the two closed loops are connected by equally spaced curved rods, buckles are installed on the lower side of the curved rods for connecting to the lower base, and symmetrically distributed small circular rings are connected to the outer side of the upper bottom closed loop for connecting ropes; The base is cylindrical as a whole, and the shape of the upper bottom of the base is the same as the shape of the lower bottom of the frame structure. The outer radius of the cylinder wall at the upper bottom opening of the base gradually increases and then remains unchanged at a fixed value. The closed loop of the lower bottom of the frame is between the inner and outer radii of the upper bottom opening of the cylinder wall of the base, and is used to firmly and tightly clamp the frame structure on the base; The special collection cover is composed of three layers of materials, including an outer high-strength waterproof fabric, an intermediate thermal insulation fabric, and an inner smooth waterproof compound bonding fabric; The special collection cover is suspended in the frame structure by a fixing device, the lower bottom surface of the special collection cover is the same shape as the lower bottom surface of the frame structure, the top of the special collection cover is connected to a waterproof cloth tube, the two ends of the waterproof cloth tube are open, and the radius of the waterproof cloth tube is smaller than the closed loop radius of the upper bottom of the frame structure; The check valve array is composed of a plurality of sheet-shaped check valves placed on the bottom surface of the base, a sheet-shaped check valve controller of the sheet-shaped check valve is built into the base, and the plurality of sheet-shaped check valves have equal widths and different lengths, are parallel to the bottom surface of the base and cover the entire bottom surface; A plurality of identical propellers are installed on the outside of the base, the plurality of propellers are at an equal distance from the bottom surface of the base and are evenly distributed on the outer wall; a plurality of acoustic wave sensors are installed on the outside of the base, the plurality of acoustic wave sensors are at an equal distance from the bottom surface of the base and are evenly distributed on the outer wall.

2. The movable cold spring leakage point bubble collection device according to claim 1, characterized in that: The base as a whole maintains a certain weight to prevent the whole equipment from floating unstably after the special collection cover is filled.

3. A control method for implementing the movable cold spring seepage point bubble collection device according to any one of claims 1 to 2, the control method comprising: Step 1: In the hydrate stability area on the seabed, the whole device is lowered by ropes on the sea surface. Seawater flows through the check valve array, the special collection cover, and the waterproof cloth tube. When lowering, the waterproof cloth tube is perpendicular to the upper bottom surface of the frame; Step 2: The acoustic wave sensor detects the location of the leakage point, and the propeller pushes the entire device to adjust its position so that the entire device lands accurately on the leakage point, and then the waterproof fabric tube naturally droops to close the upper channel of the special collection cover; Step 3: The check valve controller opens the check valve array, and the bubbles enter the special collection cover through the check valve array, and gather at the upper part of the special collection cover to form hydrates; Step 4: After collecting for a period of time, all check valve arrays are closed and the entire device is recovered by ropes.

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