Deep-sea methane hydrate mining and carbon dioxide storage integrated operation tools and methods

Abstract

The present invention discloses an integrated deep-sea methane hydrate mining and carbon dioxide storage injection tool, which is mainly composed of a safety joint mechanism, a mechanical self-locking mechanism, an anchoring mechanism, a sealing mechanism, and an injection mechanism. The mechanical self-locking mechanism includes a switching self-locking joint, a bevel guide ring, and a spring I, which realizes the switching and locking of different functions and improves the practicality of the tool; the anchoring mechanism is equipped with an upper slip, a tooth shaft I, a two-stroke piston cylinder I, a two-stroke piston cylinder II, a tooth shaft II, and a lower slip, which enhances the anchoring ability and ensures operational stability; the present invention realizes the switching and locking of drilling, mining, injection and storage functions through the change of the movement stroke of the mechanical self-locking mechanism, and realizes the mutual combination of multiple natural gas hydrate mining methods, fracturing transformation, and hydrate carbon fixation; the combination of various mechanisms achieves integration; and the combined process method prevents the risk of carbon dioxide hydrate downhole blockage and increases carbon storage capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas hydrate mining and carbon sequestration, and in particular to an integrated operation tool and method for deep-sea combustible ice mining and carbon dioxide sequestration injection. Background Art

[0002] Deep-sea methane hydrate mining is one of the untapped unconventional natural gas resources with the greatest potential. Compared to traditional oil and gas reservoirs, safe and efficient development presents significant challenges. Currently, the main methods for deep-sea methane hydrate mining include thermal shock mining, pressure reduction mining, and carbon dioxide displacement mining. Furthermore, due to the weak cementation, lack of dense caprocks, and non-diagenetic properties of deep-sea methane hydrate in my country's marine environment, researchers have proposed a solid-state fluidization mining method.

[0003] Subsea carbon dioxide storage technology refers to the technology of storing carbon dioxide in the form of solid hydrates in the shallow seabed. This technology usually injects liquid carbon dioxide into seabed sediments, allowing it to form stable solid hydrates under specific temperature and pressure conditions, thereby achieving long-term carbon storage. The principle of subsea carbon dioxide storage technology is similar to the formation mechanism of natural gas hydrates. In the shallow seabed environment, gases such as methane can combine with water molecules to form hydrates. This process is called hydration. Similarly, carbon dioxide can also form hydrates with water molecules under specific conditions. These hydrates are relatively stable in the shallow seabed environment and can store carbon dioxide for a long time.

[0004] Currently, the integration of deep-sea methane hydrate extraction and carbon dioxide storage has become a research hotspot, and its feasibility has been demonstrated in theory and experiments. However, when applying these technologies to practical projects, there is a lack of tools specifically designed for this integration. Existing deep-sea methane hydrate extraction tools are often repurposed for carbon dioxide storage. This generalization of non-specialized tools has a significant impact on deep-sea methane hydrate extraction, carbon sequestration efficiency, and safety. Therefore, there is an urgent need to develop a dedicated tool to meet the needs of this integration project, and it must meet the following specific functional requirements: ① the ability to combine multiple natural gas hydrate extraction methods, fracturing and reforming methods, and hydrate carbon sequestration methods; ② the ability to achieve isolation and anchoring functions during liquid carbon dioxide injection; and ③ the ability to effectively prevent the risk of carbon dioxide hydrate downhole blockage.

[0005] Comprehensive and in-depth market and product research revealed that no downhole tool currently meets all of the aforementioned functional requirements. Therefore, there is an urgent need to develop a tool that integrates deep-sea methane hydrate extraction and CO2 storage and injection. Summary of the Invention

[0006] The purpose of the present invention is to provide an integrated deep-sea methane hydrate mining and carbon dioxide storage injection operation tool, in response to the specific functional requirements of deep-sea methane hydrate mining and carbon dioxide storage projects. The tool is mainly composed of a safety joint mechanism, a mechanical self-locking mechanism, an anchoring mechanism, a sealing mechanism, and an injection mechanism. The mechanical self-locking mechanism includes a switching self-locking joint, a bevel guide ring, and a spring I, which realizes the switching and locking of different functions and improves the practicality of the tool. The anchoring mechanism is equipped with an upper slip, a tooth shaft I, a two-stroke piston cylinder I, a two-stroke piston cylinder II, a tooth shaft II, and a lower slip, which enhances the anchoring ability and ensures operational stability. The present invention realizes the switching and locking of drilling, mining, injection and storage functions through the change of the movement stroke of the mechanical self-locking mechanism, and realizes the mutual combination of multiple natural gas hydrate mining methods, fracturing transformation, and hydrate carbon fixation. The combination of various mechanisms achieves integration. By combining process methods, the risk of carbon dioxide hydrate downhole blockage is prevented and the carbon storage capacity is increased.

[0007] The present invention solves the technical problem by adopting the following technical solution: a deep-sea combustible ice mining and carbon dioxide storage injection integrated operation tool, mainly composed of a safety joint mechanism, a mechanical self-locking mechanism, an anchoring mechanism, a sealing mechanism, and an injection mechanism, characterized by:

[0008] The safety joint mechanism consists of a coiled tubing joint, an O-ring I, a set screw, a connecting fixture, a shear pin, and a movable core: a sealing groove I is provided at the head end of the coiled tubing joint, a positioning installation groove is provided at the front, a shear pin groove is provided in the middle, and a conical boss is provided inside. The coiled tubing joint is installed inside the end of the coiled tubing, the O-ring I is installed in the sealing groove I of the coiled tubing joint, the connecting fixture is installed outside the end of the coiled tubing, the set screw is installed on the connecting fixture, the shear pin is installed in the shear pin groove in the middle of the coiled tubing joint, and the head end of the movable core contacts the conical boss of the coiled tubing joint.

[0009] The mechanical self-locking mechanism consists of a switching self-locking joint, a bevel guide ring, a thrust bearing, and spring I. The head end of the switching self-locking joint is installed inside the coiled tubing joint. The tail end of the bevel guide ring is provided with a tail groove and is sleeved on the head end of the movable barrel core. The thrust bearing is installed in the tail groove of the bevel guide ring. Spring I is sleeved on the outside of the movable barrel core, with the head end in contact with the thrust bearing.

[0010] The anchoring mechanism consists of an upper cone joint, a slip cover Ⅰ, a spring Ⅱ, an upper slip, a tooth shaft Ⅰ, a two-stroke piston cylinder Ⅰ, a two-stroke piston cylinder Ⅱ, a tooth shaft Ⅱ, a slip cover Ⅱ, a spring Ⅲ, a lower slip, and a lower cone joint: the upper cone joint is sleeved on the outside of the movable cylinder core, the head end is connected to the outer layer of the switching self-locking joint, a boss is provided inside to contact the end of the spring Ⅰ, an inclined surface Ⅰ is provided outside to contact the upper slip, and a concave platform Ⅰ is also provided in the middle, the two-stroke piston cylinder Ⅰ is installed on the outside of the upper cone joint, the head end of the tooth shaft Ⅰ is in contact with the tail of the upper slip, and its tail end is installed on the two-stroke movable cylinder. Inside the head end of the plug cylinder I, the head end of the slip cover I is connected to the middle concave platform I of the upper cone joint, and the tail end is connected to the head end of the two-stroke piston cylinder I. The spring II is installed between the upper slip and the slip cover I. The lower cone joint is sleeved outside the movable cylinder core, the head end is connected to the tail end of the upper cone joint, the outside is provided with an inclined surface II that contacts the tail end of the lower slip, and the middle is provided with a concave platform II. The two-stroke piston cylinder II is installed on the outside of the lower cone joint, the head end of the tooth shaft II contacts the tail end of the lower slip, and the tail end is installed inside the head end of the two-stroke piston cylinder II, and the spring III is installed between the lower slip and the slip cover II.

[0011] The sealing mechanism consists of a piston shaft I, a rubber cylinder, a spacer ring, a piston shaft II, and an O-ring II: the rubber cylinder is sleeved on the tail end of the upper cone joint, the spacer ring is installed between the rubber cylinders and sleeved on the tail end of the upper cone joint, the piston shaft I contacts the rubber cylinder at its head end, and the tail end is installed inside the end of the double-stroke piston cylinder I, the piston shaft II contacts the rubber cylinder at its head end, and the tail end is installed inside the end of the double-stroke piston cylinder II, and the O-ring II are installed in pairs on the movable cylinder core.

[0012] The injection mechanism consists of an injection connector and a throttling plug: the head end of the injection connector is connected to the tail end of the lower cone joint, and the throttling plug is installed inside the tail end of the injection connector;

[0013] Several limiting bosses are provided at equal angles on the outside of the head end of the movable cylinder core, and a pressure drop slope is provided inside the head end. Several valve core holes I, several valve core holes II, several valve core holes III, and several valve core holes IV are provided at equal angles on the circumference of different axial sections of the movable cylinder core valve body, and several groups of sealing grooves II are provided on different axial sections of the movable cylinder core valve body.

[0014] Switching self-locking joint, with a self-locking shoulder at the head end, a shear pin groove in the middle, and self-locking guide bevels of different lengths at the tail end to match the bevel guide ring;

[0015] The injection connector is provided with a plurality of groups of jet injection holes in an axial direction, which are arranged in a circumferential spiral. A jet injection cavity is provided inside the connector. The jet injection holes are connected to the jet injection cavity. A throttling plug mounting platform is provided inside the end.

[0016] The middle part of the throttle plug is provided with a number of interconnected holes at equal angles, the head end is provided with a through hole connected to the circumferential interconnected holes in the middle part, and the tail end is provided with a mounting bolt;

[0017] A limit groove I is opened in the middle of the upper slip, and a spring II mounting groove I is opened in the middle of the limit groove; a limit groove II is opened in the middle of the lower slip, and a spring III mounting groove II is opened in the middle of the limit groove;

[0018] The middle part of the two-stroke piston cylinder I is provided with a liquid inlet and outlet port I and an anti-blocking net. The upper cone joint is provided with a plurality of communicating holes at equal angles in the circumference, and the communicating holes coincide with the position of the liquid inlet and outlet port I of the two-stroke piston cylinder I. The middle part of the two-stroke piston cylinder II is provided with a liquid inlet and outlet port II and an anti-blocking net. The lower cone joint is provided with a plurality of communicating holes at equal angles in the circumference, and the communicating holes coincide with the position of the liquid inlet and outlet port II of the two-stroke piston cylinder II.

[0019] The present invention also provides a method for integrated operation of deep-sea methane hydrate mining and carbon dioxide storage injection, which is characterized by using any of the above-mentioned integrated operation tools for deep-sea methane hydrate mining and carbon dioxide storage injection, including the following steps:

[0020] SⅠ. Drilling into a natural gas hydrate reservoir specifically includes the following steps:

[0021] Sa. Running tools: Install the lift pump, deep-sea methane hydrate mining and CO2 storage injection integrated operation tool, and hydrate drill bit on the coiled tubing, and run them into the casing through the coiled tubing storage mechanism on the drilling and production platform to the designated layer;

[0022] Sb. Vertical drilling: Drilling fluid enters the tool through the coiled tubing, passes through the oil safety joint and the movable core, and reaches the hydrate drill bit, which controls the hydrate drill bit to drill to the target layer of the natural gas hydrate reservoir.

[0023] SⅡ, natural gas hydrate mining, specifically includes the following steps:

[0024] Sc. Solid fluidized production: The drilling fluid flow rate is changed, the movable core moves, the valve core holes III and IV coincide with the injection cavity inside the injection connector, the throttling plug enters the movable core, sealing the tail end of the movable core. The tool switches to the solid fluidized production mode, the drilling fluid is ejected through the jet injection hole on the injection connector, the hydrate slurry is returned by the lift pump, and the coiled tubing is pulled back to complete the solid fluidized cavity creation operation in the natural gas hydrate reservoir;

[0025] Sd. Post-fracture decompression production: After completing the solid fluidization cavitation operation in the natural gas hydrate reservoir, the fracturing agent is injected from the coiled tubing and sprayed out through the jet injection holes on the injection connector to perform fracturing transformation on the target layer of the natural gas hydrate reservoir. After the fracturing transformation is completed, decompression production is carried out.

[0026] SIII, carbon dioxide hydrate storage, specifically includes the following steps:

[0027] Sd, anchoring and sealing: Drag the deep-sea methane hydrate mining and carbon dioxide storage injection integrated operation tool back to the designated position at the lower end of the casing, change the drilling fluid flow, move the movable barrel core, and the front end of the throttling plug enters the movable barrel core. The drilling fluid flows out from the middle intercommunication hole through the through hole at the head end of the throttling plug. The valve core hole I coincides with the inlet and outlet port I of the two-stroke piston cylinder I, and the valve core hole II coincides with the inlet and outlet port I of the two-stroke piston cylinder II. The tool is switched to the anchoring and sealing working mode, and the drilling fluid enters the two-stroke piston cylinder I and the two-stroke piston cylinder II. The pressure in the cylinder increases, pushing the tooth shaft I, tooth shaft II, piston shaft I, and piston shaft II to overcome spring II and spring III respectively, squeezing the upper slips, lower slips, and rubber cylinder to complete the anchoring and sealing operations of the tool;

[0028] Se. Injection and sealing: After the tool is anchored and sealed, the drilling fluid flow rate is changed, the movable barrel core moves, the valve core hole III and the valve core hole IV coincide with the injection cavity inside the injection connector, the throttling plug enters the movable barrel core, the tail end is sealed, and the tool is switched to the carbon sequestration working mode. Liquid carbon dioxide is injected through the continuous oil tubing and ejected through the jet injection hole on the injection connector to generate carbon dioxide hydrate in the cavity created by solid fluidization of the natural gas hydrate reservoir, completing the carbon dioxide hydrate sealing operation.

[0029] 1. This integrated tool was developed to address the engineering needs of deep-sea natural gas hydrate extraction and deep-sea carbon dioxide hydrate sequestration. It addresses the urgent need for specialized tools and improves the efficiency and safety of natural gas hydrate extraction and sequestration.

[0030] 2. This integrated tool utilizes the travel of a mechanical self-locking mechanism to switch and lock the tool's drilling, cavity creation, and injection and storage functions. This significantly improves the efficiency of deep-sea methane hydrate extraction and carbon sequestration, and significantly optimizes deep-sea natural gas hydrate extraction and carbon dioxide hydrate sequestration. The provision of anchoring and sealing mechanisms enhances anchoring and sealing capabilities, ensures operational stability and reliability, and improves the tool's practicality.

[0031] 3. By combining process methods, this tool can inject liquid carbon dioxide into the solid fluidized cavity, which not only strengthens the cavity structure, but also prevents the risk of carbon dioxide hydrate blockage downhole and enhances carbon storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the appearance diagram of the present invention;

[0033] Figure 2 This is a diagram of the mechanical self-locking mechanism of the present invention;

[0034] Figure 3 This is a diagram of the anchoring mechanism and the packing mechanism of the present invention;

[0035] Figure 4 This is a plan view of the anchoring mechanism and the packing mechanism of the present invention;

[0036] Figure 5 This is a diagram of a coiled tubing joint of the present invention;

[0037] Figure 6 This is a plan view of the coiled tubing joint of the present invention;

[0038] Figure 7 This is a diagram of a self-locking joint switch according to the present invention;

[0039] Figure 8 FIG outer cylinder of the present invention;

[0040] Figure 9 Plane surface view of the outer cylinder of the present invention;

[0041] Figure 10 This is a diagram of the inclined guide ring of the present invention;

[0042] Figure 11 This is a diagram of the injection connector of the present invention;

[0043] Figure 12 This is a planed view of the injection connector of the present invention

[0044] Figure 13 This is a diagram of a throttling plug according to the present invention;

[0045] Figure 14 This is a planed view of the throttling plug of the present invention;

[0046] Figure 15 The movable core diagram of the present invention;

[0047] Figure 16 Partial planing diagram of the movable core of the present invention;

[0048] Figure 17 For the present invention on Kavatu;

[0049] Figure 18 Schematic diagram of the present invention's deep-sea natural gas hydrate solid fluidization mining and deep-sea carbon dioxide hydrate carbon fixation process;

[0050] Figure 19 It is a process flow chart of the present invention.

[0051] In the figure, 1-coiled tubing joint, 101-sealing groove, 102-positioning installation groove, 103-shear pin groove, 104-conical boss, 2-O-ring I, 3-set screw, 4-connecting tool, 5-movable cylinder core, 501-limiting boss, 502-valve core hole I, 503-valve core hole II, 504-valve core hole III, 505-valve core hole IV, 506-sealing groove II, 507-pressure drop slope, 6-switch self-locking joint, 6 01-Self-locking shoulder, 602-Shear pin groove, 603-Self-locking guide bevel, 7-Bevel guide ring, 701-Tail groove, 8-Thrust bearing, 9-Spring I, 10-Piston shaft I, 11-Rubber cylinder, 12-Spacer ring, 13-Piston shaft II, 14-Injection connector, 1401-Jet injection hole, 1402-Jet injection chamber, 1403-Mounting platform, 15-O-ring II, 16-Throttle plug, 1601-Interconnecting hole, 1602-through hole, 17-upper cone joint, 1701-connecting hole, 18-slip cover I, 19-spring II, 20-upper slip, 2001-limiting groove I, 2002-installation groove II, 21-horse tooth shaft I, 22-two-stroke piston cylinder I, 2201-liquid inlet and outlet I, 2202-anti-blocking net I, 23-two-stroke piston cylinder II, 2301-liquid inlet and outlet II, 2302-anti-blocking net II, 24-horse tooth shaft II, 25-slip cover Ⅱ, 26-spring III, 27-lower slip, 2701-limiting groove II, 2702-installing groove II, 28-lower cone joint, 2801-connecting hole, 29-shear pin, 30-carbon dioxide hydrate, 31-coiled tubing, 32-casing, 33-lift pump, 34-liquid carbon dioxide, 35-solid fluidization cavity creation, 36-hydrate drill bit, 37-carbon dioxide hydrate, 38-natural gas hydrate reservoir, 39-drilling and production platform. DETAILED DESCRIPTION

[0052] The present invention is further described below with reference to the accompanying drawings, and the protection scope of the present invention is not limited to the following:

[0053] like Figures 1 to 19 As shown, a deep-sea methane hydrate mining and carbon dioxide storage injection integrated operation tool is mainly composed of a safety joint mechanism, a mechanical self-locking mechanism, an anchoring mechanism, a sealing mechanism, and an injection mechanism, and is characterized by:

[0054] like Figure 1As shown, the safety joint mechanism consists of a coiled tubing joint 1, an O-ring I2, a set screw 3, a connecting fixture 4, a shear pin 29, and a movable core 5: the coiled tubing joint 1 has a sealing groove I 101 at its head end, a positioning and mounting groove 102 at its front end, a shear pin groove 103 in its middle, and a conical boss 104 inside. The coiled tubing joint 1 is installed inside the end of the coiled tubing 31, the O-ring I2 is installed in the sealing groove I 101 of the coiled tubing joint 1, the connecting fixture 4 is installed outside the end of the coiled tubing 31, the set screw 3 is installed on the connecting fixture 4, the shear pin 29 is installed in the shear pin groove 103 in the middle of the coiled tubing joint 1, and the head end of the movable core 5 contacts the conical boss 104 of the coiled tubing joint 1.

[0055] like Figure 2 As shown, the mechanical self-locking mechanism consists of a switching self-locking joint 6, a ramp guide ring 7, a thrust bearing 8, and a spring I 9: the head end of the switching self-locking joint 6 is installed inside the coiled tubing joint 1, the tail end of the ramp guide ring 7 is provided with a tail groove 701, which is sleeved on the head end of the movable barrel core 5, the thrust bearing 8 is installed in the tail groove 701 of the ramp guide ring 7, and the spring I 9 is sleeved on the outside of the movable barrel core 5, with the head end in contact with the thrust bearing 8;

[0056] like Figures 3 and 4 As shown, the anchoring mechanism consists of an upper cone joint 17, a slip cover I 18, a spring II 19, an upper slip 20, a tooth shaft I 21, a double-stroke piston cylinder I 22, a double-stroke piston cylinder II 23, a tooth shaft II 24, a slip cover II 25, a spring III 26, a lower slip 27, and a lower cone joint 28: the upper cone joint 17 is sleeved on the outside of the movable cylinder core 5, and the head end is connected to the outer layer of the switching self-locking joint 6. A boss 1704 is provided inside to contact the end of the spring I 9, and an inclined surface I 1703 is provided outside to contact the upper slip 20. A concave platform I 1702 is also provided in the middle. The double-stroke piston cylinder I 22 is installed on the outside of the upper cone joint 17. The head end of the tooth shaft I 21 contacts the tail of the upper slip 20, and its tail end is installed on the double Inside the head end of the stroke piston cylinder Ⅰ 22, the head end of the slip cover Ⅰ 18 is connected to the middle concave platform Ⅰ 1702 of the upper cone joint 17, and the tail end is connected to the head end of the double-stroke piston cylinder Ⅰ 22. The spring Ⅱ 19 is installed between the upper slip 20 and the slip cover Ⅰ 18. The lower cone joint 28 is sleeved on the outside of the movable cylinder core 5. The head end is connected to the tail end of the upper cone joint 17. The outside is provided with an inclined surface Ⅱ 2803 that contacts the tail end of the lower slip 27. The middle part is provided with a concave platform Ⅱ 2802. The double-stroke piston cylinder Ⅱ 23 is installed on the outside of the lower cone joint 28. The head end of the tooth shaft Ⅱ 24 contacts the tail end of the lower slip 27, and the tail end is installed inside the head end of the double-stroke piston cylinder Ⅱ 23. The spring Ⅲ 26 is installed between the lower slip 27 and the slip cover Ⅱ 25.

[0057] The sealing mechanism consists of a piston shaft I 10, a rubber cylinder 11, a spacer ring 12, a piston shaft II 13, and an O-ring II 15. The rubber cylinder 11 is sleeved on the tail end of the upper cone joint 17. The spacer ring 12 is installed between the rubber cylinders 11 and sleeved on the tail end of the upper cone joint 17. The piston shaft I 10 contacts the rubber cylinder 11 at its head end, and is installed inside the end of the two-stroke piston cylinder I 22 at its tail end. The piston shaft II 13 contacts the rubber cylinder 11 at its head end, and is installed inside the end of the two-stroke piston cylinder II 23 at its tail end. The O-rings II 15 are arranged in groups of two and are respectively installed on the movable cylinder core 5.

[0058] The injection mechanism consists of an injection connector 14 and a throttle plug 16 : the head end of the injection connector 14 is connected to the tail end of the lower cone joint 28 , and the throttle plug 16 is installed inside the tail end of the injection connector 14 .

[0059] like Figures 15 and 16 As shown, a plurality of limiting bosses 501 are provided at equal angles on the outside of the head end of the movable cylinder core 5, a pressure drop inclined surface 507 is provided on the inside of the head end, a plurality of valve core holes I 502, a plurality of valve core holes II 503, a plurality of valve core holes III 504, and a plurality of valve core holes IV 505 are provided at equal angles on the circumference of different axial sections of the valve body of the movable cylinder core 5, and a plurality of groups of sealing grooves II 506 are provided on different axial sections of the valve body of the movable cylinder core 5;

[0060] like Figure 10 As shown, the switching self-locking joint 6 has a self-locking shoulder 601 at the head end, a shear pin groove 602 in the middle, and a self-locking guide bevel 603 of different lengths at the tail end to cooperate with the bevel guide ring 7;

[0061] like Figures 11-12 As shown, the injection connector 14 is axially provided with a plurality of groups of jet injection holes 1401, which are arranged in a circumferential spiral. A jet injection cavity 1402 is provided inside the connector. The jet injection holes 1401 are connected to the jet injection cavity 1402. A mounting base 1403 for the throttling plug 16 is provided inside the end.

[0062] like Figures 13 and 14 As shown, the throttle plug 16 has a plurality of interconnected holes 1601 at equal angles in the middle, a through hole 1602 is opened at the head end to communicate with the circumferential interconnected holes 1601 in the middle, and a mounting bolt 1603 is provided at the tail end;

[0063] like Figure 17 As shown, a limiting groove I 2001 is formed in the middle of the upper slip 20, and a mounting groove I 2002 for the spring II 19 is formed in the middle of the limiting groove. A limiting groove II 2701 is formed in the middle of the lower slip 27, and a mounting groove II 2702 for the spring III 26 is formed in the middle of the limiting groove.

[0064] The middle part of the double-stroke piston cylinder Ⅰ 22 is provided with a liquid inlet and outlet Ⅰ 2201 and an anti-blocking net 2202, and the upper cone joint 17 is provided with a plurality of connecting holes 1701 at equal angles in the circumference. Figure 7 As shown, the communicating hole 1701 coincides with the liquid inlet and outlet port I 2201 of the two-stroke piston cylinder I 22, and the middle part of the two-stroke piston cylinder II 23 is provided with a liquid inlet and outlet port II 2301 and an anti-blocking net 2302. The lower cone joint 28 is provided with a plurality of communicating holes 2801 at equal angles in the circumferential direction, and the communicating holes 2801 coincide with the liquid inlet and outlet port II 2301 of the two-stroke piston cylinder II 23;

[0065] like Figures 18 and 19 As shown, a tool and method for integrating deep-sea methane hydrate mining and carbon dioxide storage injection is characterized in that, in specific engineering implementation, it includes the following steps:

[0066] SⅠ. Drilling into a natural gas hydrate reservoir specifically includes the following steps:

[0067] Sa. Running tools: Install the lift pump 33, the deep-sea methane hydrate mining and CO2 storage injection integrated operation tool, and the hydrate drill bit 36 ​​on the coiled tubing 31, and run them into the casing 32 through the coiled tubing storage mechanism 30 on the drilling and production platform 39 to the designated layer;

[0068] Sb. Vertical drilling: Drilling fluid enters the tool through the coiled tubing 31 , passes through the oil safety joint 1 and the movable core 5 , and reaches the hydrate drill bit 36 ​​, which is controlled to drill to the target layer of the natural gas hydrate reservoir 38 .

[0069] SⅡ, natural gas hydrate mining, specifically includes the following steps:

[0070] Sc. Solid fluidized production: The drilling fluid flow rate is changed, the movable core 5 moves, the valve core hole III 503 and the valve core hole IV 504 coincide with the injection cavity 1402 inside the injection connector 14, the throttle plug 16 enters the movable core 5, blocks the tail end of the movable core 5, and the tool switches to the solid fluidized production mode. The drilling fluid is ejected through the jet injection hole 1401 on the injection connector 14, the hydrate slurry is returned upward by the lift pump 33, and the coiled tubing 31 is pulled back to complete the solid fluidized cavity creation 35 operation of the natural gas hydrate reservoir. Figure 12 As shown;

[0071] Sd. Post-fracture decompression production: After the solid fluidization cavitation 35 operation in the natural gas hydrate reservoir is completed, the fracturing agent is injected from the coiled tubing 31 and ejected through the jet injection holes 1401 on the injection connector 14 to perform fracturing transformation on the target layer of the natural gas hydrate reservoir. After the fracturing transformation is completed, decompression production is performed;

[0072] SIII, carbon dioxide hydrate storage, specifically includes the following steps:

[0073] Sd. Anchoring and sealing: Drag the deep-sea methane hydrate mining and carbon dioxide storage injection integrated operation tool back to the designated position at the lower end of the casing 32, change the drilling fluid flow, move the movable barrel core 5, and the front end of the throttling plug 16 enters the movable barrel core 5. The drilling fluid flows out from the middle intercommunication hole 1601 through the through hole 1602 at the head end of the throttling plug 16. The valve core hole I501 coincides with the inlet and outlet port I2201 of the double-stroke piston cylinder I22, and the valve core hole II 502 coincides with the position of the liquid inlet and outlet port I2301 of the two-stroke piston cylinder II 23, and the tool switches to the anchoring and sealing working mode. The drilling fluid enters the two-stroke piston cylinder I 22 and the two-stroke piston cylinder II 23. The pressure in the cylinder increases, pushing the tooth shaft I 21, the tooth shaft II 24, the piston shaft I 10, and the piston shaft II 13 to overcome the spring II 19 and the spring III 26 respectively, squeezing the upper slip 20, the lower slip 27, and the rubber cylinder 11 to complete the anchoring and sealing operations of the tool;

[0074] Se. Injection and sealing: After the tool is anchored and sealed, the drilling fluid flow rate is changed, the movable barrel core 5 moves, the valve core hole III 503 and the valve core hole IV 504 coincide with the injection cavity 1402 inside the injection connector 14, the throttling plug 16 enters the movable barrel core 5, blocks the tail end, and the tool switches to the carbon sequestration working mode, and the liquid carbon dioxide 34 is injected through the coiled tubing 31 and ejected through the jet injection hole 1401 on the injection connector 14, generating carbon dioxide hydrate 37 in the cavity 35 created by solid fluidization of the natural gas hydrate reservoir 38, completing the carbon dioxide hydrate sequestration operation.

[0075] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0076] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" are based on the directions or positional relationships described in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0077] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0078] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0079] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications can be made based on the above descriptions. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A deep-sea combustible ice mining and carbon dioxide storage integrated operation tool, including a safety joint mechanism, a mechanical self-locking mechanism, an anchoring mechanism, a sealing mechanism, and an injection mechanism, characterized by: The safety joint mechanism consists of a coiled tubing joint, an O-ring I, a set screw, a connecting fixture, a shear pin, and a movable core: a sealing groove I is provided at the head end of the coiled tubing joint, a positioning installation groove is provided at the front, a shear pin groove is provided in the middle, and a conical boss is provided inside. The coiled tubing joint is installed inside the end of the coiled tubing, the O-ring I is installed in the sealing groove I of the coiled tubing joint, the connecting fixture is installed outside the end of the coiled tubing, the set screw is installed on the connecting fixture, the shear pin is installed in the shear pin groove in the middle of the coiled tubing joint, and the head end of the movable core contacts the conical boss of the coiled tubing joint. The mechanical self-locking mechanism consists of a switching self-locking joint, a bevel guide ring, a thrust bearing, and spring I. The head end of the switching self-locking joint is installed inside the coiled tubing joint. The tail end of the bevel guide ring is provided with a tail groove and is sleeved on the head end of the movable barrel core. The thrust bearing is installed in the tail groove of the bevel guide ring. Spring I is sleeved on the outside of the movable barrel core, with the head end in contact with the thrust bearing. The anchoring mechanism consists of an upper cone joint, a slip cover Ⅰ, a spring Ⅱ, an upper slip, a tooth shaft Ⅰ, a two-stroke piston cylinder Ⅰ, a two-stroke piston cylinder Ⅱ, a tooth shaft Ⅱ, a slip cover Ⅱ, a spring Ⅲ, a lower slip, and a lower cone joint: the upper cone joint is sleeved on the outside of the movable cylinder core, the head end is connected to the outer layer of the switching self-locking joint, a boss is provided inside to contact the end of the spring Ⅰ, an inclined surface Ⅰ is provided outside to contact the upper slip, and a concave platform Ⅰ is also provided in the middle, the two-stroke piston cylinder Ⅰ is installed on the outside of the upper cone joint, the head end of the tooth shaft Ⅰ is in contact with the tail of the upper slip, and its tail end is installed on the two-stroke Inside the front end of the piston cylinder I, the front end of the slip cover I is connected to the middle concave platform I of the upper cone joint, and the rear end is connected to the front end of the two-stroke piston cylinder I. The spring II is installed between the upper slip and the slip cover I. The lower cone joint is sleeved outside the movable cylinder core, the front end is connected to the rear end of the upper cone joint, the outside is provided with an inclined surface II that contacts the rear end of the lower slip, and the middle is provided with a concave platform II. The two-stroke piston cylinder II is installed on the outside of the lower cone joint, the front end of the tooth shaft II contacts the rear end of the lower slip, and the rear end is installed inside the front end of the two-stroke piston cylinder II, and the spring III is installed between the lower slip and the slip cover; The sealing mechanism consists of a piston shaft I, a rubber cylinder, a spacer ring, a piston shaft II, and an O-ring II: the rubber cylinder is sleeved on the tail of the upper cone joint, the spacer ring is installed between the rubber cylinders and sleeved on the tail of the upper cone joint, the head end of the piston shaft I contacts the rubber cylinder, and the tail end is installed inside the end of the double-stroke piston cylinder I, the head end of the piston shaft II contacts the rubber cylinder, and the tail end is installed inside the end of the double-stroke piston cylinder II, O-rings II are arranged in groups of two and are respectively installed on the movable cylinder core, the middle part of the double-stroke piston cylinder I is provided with a liquid inlet and outlet I and an anti-blocking net, a number of connecting holes are opened at equal angles in the circumference of the upper cone joint, and the connecting holes coincide with the position of the liquid inlet and outlet I of the double-stroke piston cylinder I, a liquid inlet and outlet II and an anti-blocking net are opened in the middle part of the double-stroke piston cylinder II, a number of connecting holes are opened at equal angles in the circumference of the lower cone joint, and the connecting holes coincide with the position of the liquid inlet and outlet II of the double-stroke piston cylinder II; The injection mechanism consists of an injection connector and a throttling plug: the head end of the injection connector is connected to the tail end of the lower cone joint, the throttling plug is installed inside the end of the injection connector, and a number of interconnected holes are opened at equal angles in the middle of the throttling plug. A through hole is opened at the head end to connect with the circumferential interconnected holes in the middle, and a mounting bolt is provided at the tail end.

2. The deep-sea methane hydrate mining and carbon dioxide storage integrated operation tool according to claim 1, characterized in that: Several limiting bosses are provided at equal angles on the outside of the head end of the movable cylinder core, a pressure drop inclined surface is provided inside the head end, and several valve core holes I, several valve core holes II, several valve core holes III, and several valve core holes IV are provided at equal angles on the circumference of different axial sections of the movable cylinder core valve body, and several groups of sealing grooves II are provided on different axial sections of the movable cylinder core valve body.

3. The deep-sea methane hydrate mining and carbon dioxide storage integrated operation tool according to claim 1 is characterized by: The switching self-locking joint has a self-locking shoulder at the head end, a shear pin groove in the middle, and self-locking guide bevels of different lengths at the tail end to match the bevel guide ring.

4. The deep-sea methane hydrate mining and carbon dioxide storage integrated operation tool according to claim 1 is characterized by: The injection connector is axially provided with several groups of jet injection holes, which are arranged in a circumferential spiral. A jet injection cavity is provided inside. The jet injection holes are connected to the jet injection cavity, and a throttling plug mounting platform is provided inside the end.

5. The deep-sea methane hydrate mining and carbon dioxide storage integrated operation tool according to claim 1 is characterized by: A limit groove I is opened in the middle of the upper slip, and a spring II mounting groove I is opened in the middle of the limit groove; a limit groove II is opened in the middle of the lower slip, and a spring III mounting groove II is opened in the middle of the limit groove.

6. A method for integrating deep-sea methane hydrate mining and carbon dioxide storage, characterized by: The deep-sea methane hydrate mining and carbon dioxide storage injection integrated operation tool according to claim 5 includes the following steps: SⅠ. Drilling into a natural gas hydrate reservoir specifically includes the following steps: Sa. Running tools: Install the lift pump, deep-sea methane hydrate mining and CO2 storage injection integrated operation tool, and hydrate drill bit on the coiled tubing, and run them into the casing through the coiled tubing storage mechanism on the drilling and production platform to the designated layer; Sb. Vertical drilling: Drilling fluid enters the tool through the coiled tubing, passes through the oil safety joint and the movable core, and reaches the hydrate drill bit, which controls the hydrate drill bit to drill to the target layer of the natural gas hydrate reservoir; SⅡ, natural gas hydrate mining, specifically includes the following steps: Sc. Solid fluidized production: The drilling fluid flow rate is changed, the movable core moves, the valve core holes III and IV coincide with the injection cavity inside the injection connector, the throttling plug enters the movable core, sealing the tail end of the movable core. The tool switches to the solid fluidized production mode, the drilling fluid is ejected through the jet injection hole on the injection connector, the hydrate slurry is returned by the lift pump, and the coiled tubing is pulled back to complete the solid fluidized cavity creation operation in the natural gas hydrate reservoir; Sd, post-fracture decompression production: After completing the solid fluidization cavitation operation in the natural gas hydrate reservoir, the fracturing agent is injected from the coiled tubing and sprayed out through the jet injection holes on the injection connector to perform fracturing transformation on the target layer of the natural gas hydrate reservoir. After the fracturing transformation is completed, decompression production is carried out; SIII, carbon dioxide hydrate storage, specifically includes the following steps: Sd, anchoring and sealing: Drag the deep-sea methane hydrate mining and carbon dioxide storage injection integrated operation tool back to the designated position at the lower end of the casing, change the drilling fluid flow, move the movable barrel core, and the front end of the throttling plug enters the movable barrel core. The drilling fluid flows out from the middle intercommunication hole through the through hole at the head end of the throttling plug. The valve core hole I coincides with the inlet and outlet port I of the two-stroke piston cylinder I, and the valve core hole II coincides with the inlet and outlet port I of the two-stroke piston cylinder II. The tool is switched to the anchoring and sealing working mode, and the drilling fluid enters the two-stroke piston cylinder I and the two-stroke piston cylinder II. The pressure in the cylinder increases, pushing the tooth shaft I, tooth shaft II, piston shaft I, and piston shaft II to overcome spring II and spring III respectively, squeezing the upper slips, lower slips, and rubber cylinder to complete the anchoring and sealing operations of the tool; Se. Injection and sealing: After the tool is anchored and sealed, the drilling fluid flow rate is changed, the movable barrel core moves, the valve core hole III and the valve core hole IV coincide with the injection cavity inside the injection connector, the throttling plug enters the movable barrel core, the tail end is sealed, and the tool is switched to the carbon sequestration working mode. Liquid carbon dioxide is injected through the continuous oil tubing and ejected through the jet injection hole on the injection connector to generate carbon dioxide hydrate in the cavity created by solid fluidization of the natural gas hydrate reservoir, completing the carbon dioxide hydrate sealing operation.

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