Intelligent tunneling - carbon sequestration integrated equipment and method for deep - sea deep geotechnical bodies

Abstract

The present invention discloses an integrated equipment and method for intelligent tunneling - carbon sequestration of deep - sea deep geotechnical bodies. It includes a supply ship, an offshore injection platform, a CO2 injection pipeline, a CO2 capture and transportation mechanism, and a CO2 injection and sequestration device. The CO2 injection pipeline includes a pneumatic conveying pump, a riser pipe, a flowmeter, a pressure sensor, and a gas sensor. The CO2 capture and transportation mechanism includes a CO2 capture device, a liquid CO2 storage tank, and a CO2 liquefaction treatment device. The CO2 injection and sequestration device includes a first type of jet nozzle, a second type of jet nozzle, a soil - breaking tunneling system, a high - pressure hose, a cuttings treatment device, a filter screen, an intelligent detection system, and a power system. The soil - breaking tunneling mechanism includes a polycrystalline diamond compact bit, a bionic propulsion device, and a rotary steering system. The present invention provides an orientation - intelligent tunneling equipment for deep - sea deep rock mass carbon sequestration and a complete set of liquid CO2 injection and sequestration methods, achieving long - term stability of deep - sea carbon sequestration and being of great significance to global environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine engineering and deep-sea carbon dioxide storage, and specifically relates to integrated equipment and methods for intelligent excavation and carbon sequestration of deep-sea rock and soil bodies. Background Art

[0002] In recent years, with growing global concern about climate change, reducing greenhouse gas emissions has become a global consensus. Carbon dioxide, a major greenhouse gas, is a key greenhouse gas. Excessive emissions of it can accelerate global temperature rises, potentially triggering a range of climate-related issues, including extreme heat waves and droughts. Recent measurements indicate that the atmospheric concentration of carbon dioxide, a major greenhouse gas, has reached 420 ppm, a nearly 50% increase compared to pre-industrial levels (from 280 ppm in the 17th century). To address this issue, many countries and research institutions have begun exploring carbon dioxide capture and storage technologies. The goal is to capture and store carbon dioxide from industrial sources (such as power plants and steel mills) to prevent it from entering the atmosphere. Deep-sea carbon storage, a form of carbon capture and storage, primarily involves injecting captured carbon dioxide into the deep ocean, exploiting the unique environmental conditions of the deep sea for long-term storage.

[0003] Existing deep-sea carbon storage equipment and methods have the following problems:

[0004] 1. Existing deep-sea carbon storage technologies are unable to inject and store large quantities of CO2 into deep-sea rock and soil over a long period of time. Furthermore, the equipment required for deep-sea CO2 injection and storage is relatively scarce, and generally requires reliance on other deep-sea operating equipment (such as submarine robots). This severely limits the duration, quantity, and effectiveness of deep-sea carbon storage.

[0005] 2. Current marine carbon storage technology directly releases CO2 into saline aquifers or the seabed. While this has a certain storage effect, CO2 is likely to migrate with ocean currents, risking recirculation from the ocean waters into the atmosphere. It is not possible to permanently store CO2 by injecting it into deep rock fissures beneath the seabed.

[0006] 3. Directly discharging CO2 onto the seabed or saltwater layers will alter the pH of seawater, leading to ocean acidification. This acidification is harmful to marine life, especially those that rely on carbonates (such as corals and shellfish). Long-term CO2 accumulation may also alter the seabed ecosystem and affect the stability of deep-sea food chains.

[0007] 4. Existing deep-sea carbon storage equipment and processes significantly disturb the seafloor environment, creating large amounts of bottom plumes on the seabed surface and causing serious damage to the seabed ecosystem. Currently, there are no effective measures to reduce plume disturbance during deep-sea carbon storage. Summary of the Invention

[0008] Aiming at the deficiencies of the above-mentioned existing technologies, the purpose of the present invention is to provide an integrated equipment and method for intelligent tunneling and carbon sequestration in deep-sea deep geotechnical bodies. This equipment can achieve a large amount of CO2 sequestration in positions such as fractures or cavities in deep-sea deep geotechnical bodies. The existing CO2 submarine sequestration devices cannot penetrate deep into the deep rock mass under the seabed for the time being, and there is a risk of CO2 leakage on the seabed.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0010] An integrated equipment and method for intelligent tunneling and carbon sequestration in deep-sea deep geotechnical bodies, characterized in that it includes a supply ship, an offshore injection platform, a CO2 injection pipeline, a CO2 capture and transportation mechanism, and a CO2 injection and sequestration device;

[0011] The offshore injection platform includes a jack-up platform, an energy power supply system, an intelligent monitoring and control system, and a pneumatic conveying system; the jack-up platform adopts a tension leg fixed platform; the intelligent monitoring and control system transports the compressed CO2 to the seabed reservoir through the injection pipeline and receives the monitoring data in real time, and monitors the injection flow rate of CO2 through the flow meters at both ends of the CO2 injection pipeline; the energy supply system includes a main power source and a backup power supply;

[0012] The CO2 injection pipeline includes a pneumatic conveying pump, a riser, a flow meter, a pressure sensor, and a gas sensor. The pneumatic conveying pump is arranged at the connection between the riser and the offshore injection platform; the flow meters are arranged at the inlet and outlet of the CO2 injection pipeline, and the pressure sensors and gas sensors are arranged every 10 meters on the CO2 injection pipeline. The pressure and concentration of the injection pipeline and the reservoir are monitored through the pressure sensors and gas sensors to realize the monitoring of the entire CO2 collection and injection process. The CO2 capture and transportation mechanism includes a CO2 capture device, a liquid CO2 storage tank, and a CO2 liquefaction treatment device;

[0013] The CO2 injection and storage device includes a first jet nozzle, a second jet nozzle, an earth-breaking and tunneling system, a high-pressure hose, a cuttings treatment device, a filter screen, an intelligent detection system, a power system, and a plume suppression cover, and is connected to an offshore injection platform through a CO2 injection pipeline; there are 4 first jet nozzles in total, which are used for CO2 injection and storage; there are 2 second jet nozzles in total, which are used for earth-breaking and cuttings cleaning; the earth-breaking and tunneling mechanism includes a polycrystalline diamond compact bit, a bionic propulsion device, and a rotary steering system. The bionic propulsion device includes a hydraulic chamber, 4 propulsion rings, and 3 telescopic mechanisms. The telescopic mechanism includes 3 telescopic rings and 3 control push rods. The liquid CO2 in the hydraulic chamber is pressed into the propulsion ring through the control push rod to expand the propulsion ring and provide an anchoring force for the advancement of the CO2 injection and storage device; the high-pressure hose is arranged inside the CO2 injection and storage mechanism and is used for the injection of liquid CO2; the cuttings treatment device includes a suction pipeline and a water storage chamber; the intelligent detection device includes a high-precision positioning and navigation system, a bit adaptive adjustment system, and an acoustic reflection detector, which emits acoustic waves to the underground rock formation using low-frequency acoustic waves and records the reflected wave signals of the acoustic waves propagating in the rock formation; the power control system includes 1 active drive motor and a torque and speed control system; the plume suppression cover is installed at the connection between the CO2 injection and storage device and the CO2 injection pipeline.

[0014] Further, the CO2 injection pipeline is made of titanium alloy material that can withstand a pressure of 50-100 MPa, with a diameter of 2-5 m. It is laid in a J shape to the seabed and suspended on the offshore injection platform. At the lower end of the CO2 injection pipeline, it is connected to the CO2 injection and storage device through 4 high-pressure hoses with a diameter of 0.5-0.8 m.

[0015] Further, the polycrystalline diamond compact bit includes a polycrystalline diamond compact, a bit body, 1 elastic drill string, cutting teeth, cutter wings, a connector, a water hole, polycrystalline grains, and bit coolant. It is connected to the first propulsion ring through a connector, and the bit coolant is transported to the bit body through the elastic drill string.

[0016] Further, there are 4 propulsion rings in total, which are respectively arranged at the front, middle, and rear positions of the CO2 injection and storage device. The fourth propulsion ring is located at the rear, the first propulsion ring is located at the front, and the second and third propulsion rings are located in the middle. The second, third, and fourth propulsion rings are the main sources of forward power, and the first propulsion ring maintains the stability of the polycrystalline diamond compact bit 6 during tunneling and the transfer function of liquid CO2.

[0017] Further, the first jet nozzle is arranged at the front end of the polycrystalline diamond compact bit, and its rear end is connected to the high-pressure hose.

[0018] Further, there are three telescopic rings in total. The first telescopic ring is disposed between the first propulsion ring and the second propulsion ring, the second telescopic ring is disposed between the second propulsion ring and the third propulsion ring, and the third telescopic ring is disposed between the third propulsion ring and the fourth propulsion ring.

[0019] Further, the plume suppression cover is a retractable mechanism. As the tunneling continuously deepens into the seabed, the plume suppression cover contracts along the drill bit body towards its installation position until the CO2 injection and storage device is completely tunnelled below the seabed.

[0020] Further, the rotary steering system includes a direction sensor and a control system. The control system controls the drill bit to turn based on the data fed back by the direction sensor.

[0021] Further, the acoustic wave reflection detector emits acoustic waves into the underground rock formation using low-frequency acoustic waves, records the reflected wave signals of the acoustic waves propagating in the rock formation, and infers the distribution of rock mass fractures by analyzing the time, intensity, and frequency of the acoustic wave reflection.

[0022] An object of the present invention is to propose an integrated equipment and method for intelligent tunneling - carbon sequestration of deep - sea deep geotechnical bodies, including the following steps:

[0023] S1. The CO2 capture device captures gaseous CO2 from the CO2 emission source, liquefies the gaseous CO2 through the CO2 compression processing device, stores it in the liquid CO2 storage tank, and then transports the liquid CO2 to the offshore injection platform through a supply ship. The liquid CO2 is injected into the deep - sea deep geotechnical body for sequestration through a pneumatic conveying pump, a riser pipe, and the CO2 injection and storage device.

[0024] S2. After the liquid CO2 is transported to the offshore injection platform, a small amount of liquid CO2 is first injected into the hydraulic chamber of the CO2 injection and storage device. The CO2 injection and storage device and the CO2 injection pipeline are lowered to the seabed below 5000 m, and the interface between the CO2 injection and storage device and the CO2 injection pipeline is sealed.

[0025] S3. After the CO2 injection and storage device is connected to the CO2 injection pipeline and lowered to the seabed, the second jet nozzle at the front end of the earth - breaking tunneling mechanism of the CO2 injection and storage device starts to spray seawater to excavate the surface sediment of the seabed.

[0026] S4. The plume suppression cover suppresses the plume diffusion caused during the earth - breaking process. As the earth - breaking depth increases, the plume suppression cover continuously contracts and always stays above the seabed. When the CO2 injection and storage device is completely tunnelled under the seabed, the plume suppression cover stops contracting.

[0027] S5. The surface soil type is sensed through the intelligent detection system, and the jet breaking parameters are adjusted according to the shallow soil type. When the shallow seabed soil reaches the destruction level, the polycrystalline diamond composite drill bit at the front end of the earth-breaking and excavation system starts working, and the drill bit adaptive adjustment system adjusts the drill bit speed according to the soil type. The specific steps are as follows:

[0028] ① Soft soil: The jet velocity is controlled at 6-8 m / s. When the drill bit is sunk to a depth of more than 50 cm, the rotation speed is controlled at 60-80 rpm.

[0029] ② Medium-density soil layer: The jet velocity is controlled at 8-10 m / s. When the drill bit is sunk to a depth of more than 30 cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts working at 80-100 rpm.

[0030] ③Hard soil layer: The jet velocity is controlled at 10-12 m / s. When the drill bit sinks to a depth of more than 20 cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts to work at 100-150 rpm.

[0031] S6. When the CO2 injection storage device passes through the shallow soil and reaches the rock layer, the intelligent detection system senses the changes in the rock and soil types and adjusts the jet speed and drill bit speed in real time according to the transition between different soil and rock layers. The specific steps are as follows:

[0032] ① When the shallow soil turns into hard rock, control the jet velocity to 15-20 m / s and the drill speed to 80-100 rpm;

[0033] ② When the shallow soil turns into soft rock, control the jet velocity to 12-15 m / s and the drill speed to 60-80 rpm;

[0034] S7. Provide driving force for the CO2 injection and storage device through the hydraulic chamber, propulsion ring, and retractable mechanism. The steps are as follows:

[0035] ① Release the liquid CO2 in the hydraulic chamber to the 4th propulsion ring. After the 4th propulsion ring is filled with liquid CO2 and expanded and anchored, control the push rod 3 to push out and make the 3rd telescopic ring extend and move forward;

[0036] ② Continue to release the liquid CO2 in the fourth propulsion ring into the third propulsion ring, so that the third propulsion ring expands and anchors, and control the push rod 2 to push out, so that the second telescopic ring extends and moves forward;

[0037] ③ Continue to release the liquid CO2 in the third propulsion ring into the second propulsion ring, so that the second propulsion ring expands and anchors, and control the push rod 1 to push out, so that the first telescopic ring extends and moves forward;

[0038] ④Finally, release the liquid CO2 in the second propulsion ring into the first propulsion ring, and then return the liquid CO2 to the hydraulic chamber for use in the next tunneling cycle;

[0039] S8. Repeat S6. During tunneling, the CO2 injection and storage device injects CO2 and tunnels under the seabed along a preset path according to the high-precision positioning and navigation system. The rotation angle of the drill bit is controlled between 0.5° and 3° by the rotary steering system;

[0040] S9. During the process of injecting CO2 into the CO2 injection and storage device and tunneling, the suction pipeline sucks seawater into the water storage chamber, and the seawater in the water storage chamber is ejected through the second jet nozzle to clean the rock debris generated during tunneling;

[0041] S10. When reaching the preset storage layer, use the acoustic wave reflection detector to detect the rock type, rock fractures, and cavity distribution. Evaluate the reservoir characteristics according to the porosity and permeability of the storage layer, and adjust the injection state of the CO2 injection and storage device in real time through the intelligent monitoring and control system;

[0042] S11. When the porosity of the storage layer is 20% - 30% and the permeability > 1000 mD, it is determined as a good storage environment, and the injection rate and injection volume are appropriately increased; when the porosity is 10% - 20% and the permeability is 100 - 1000 mD, it is determined as an average storage environment, and the injection rate and injection volume are reduced;

[0043] S12. After reaching the preset storage location, detecting the rock fractures and analyzing them to be qualified, release the liquid CO2 in the hydraulic chamber through the first jet nozzle, pump the liquid CO2 into the CO2 injection pipeline at a pressure of ≥ 8 MPa through the energy and power supply system, and finally inject the liquid CO2 into the rock fractures under the deep seabed through the CO2 storage injection device for storage;

[0044] S13. During the carbon storage process, the flow meters, pressure sensors, and gas sensors arranged on the offshore injection platform and the CO2 injection pipeline start to work to monitor the injection flow rate, injection pressure, and CO2 concentration of the liquid CO2 in real time, ensuring that the change in the injection flow rate of the liquid CO2 does not exceed ± 5%, the change in the injection pressure does not exceed ± 3 MPa, and the CO2 concentration ≤ 1%.

[0045] Advantages of the present invention:

[0046] 1. Based on the feasibility of deep - sea deep geotechnical carbon storage of CO2, the present invention provides an intelligent tunneling and storage integrated equipment and method for injecting and storing CO2 in deep - sea geotechnical bodies. Injecting CO2 into the cavity fractures of deep geotechnical bodies under the seabed avoids the risk of the recycled CO2 in the shallow - sea seabed storage process returning to the atmosphere with ocean currents, and realizes the permanent storage of CO2 in deep - sea deep geotechnical bodies;

[0047] 2. The present invention uses a hydraulic chamber, a propulsion ring, and a telescopic mechanism to provide power for the soil-breaking tunneling mechanism by using liquid CO2. During the tunneling process, the expansion and anchoring of the propulsion ring also play a certain role in the stability of the drill bit.

[0048] 3. The present invention adjusts the rotational speed of the drill bit immediately according to different types of seabed rock and soil masses through the drill bit adaptive adjustment system after the surface sediment reaches the degree of damage.

[0049] 4. The present invention classifies according to the porosity and permeability characteristics of the storage layer and regulates the injection rate and injection time of liquid CO2 through the intelligent monitoring and control system, realizing the dynamic real-time control of the liquid CO2 injection and storage process. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0051] Figure 2 It is a schematic diagram of the structure of a polycrystalline diamond compact bit.

[0052] Figure 3 It is a three-dimensional view of the CO2 injection and storage device.

[0053] Figure 4 It is a schematic diagram of the middle cross-section of the CO2 injection and storage device.

[0054] In the figure, 1. Jack-up platform; 2. Supply ship; 3. CO2 capture device; 4. CO2 liquefaction treatment device; 5. Liquid CO2 storage tank; 6. Polycrystalline diamond compact bit; 601. Bit body; 602. Connector; 603. Blade; 604. Cutting tooth; 605. Polycrystalline diamond compact; 606. Polycrystalline particle; 607. First jet nozzle; 608. Second jet nozzle; 609 Flexible drill string; 7. Propulsion ring; 701. First propulsion ring; 702. Second propulsion ring; 703. Third propulsion ring; 704. Fourth propulsion ring; 8. Telescopic mechanism; 801. First telescopic ring; 802. Second telescopic ring; 803. Third telescopic ring; 804. Third control push rod; 805. Second control push rod; 806. First control push rod; 9. Pneumatic conveying pump; 10. Standpipe; 11. Flowmeter; 12. Pressure sensor; 13. Gas sensor; 14. High-pressure hose; 15. Suction pipeline; 16. Filter screen; 17. Hydraulic chamber; 18. Water storage chamber; 19. Active drive motor; 20. Acoustic reflection detector; 21. Plume suppression cover. DETAILED DESCRIPTION OF THE INVENTION

[0055] The present invention will be further described below with reference to the drawings and embodiments.

[0056] The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope in which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0057] As Figure 1 shown, the deep - sea seabed deep - rock mass carbon sequestration equipment includes a supply ship, an offshore injection platform, a CO2 injection pipeline, a CO2 capture and transportation mechanism, and a CO2 injection and sequestration device.

[0058] As Figure 1 shown, the offshore injection platform includes a jack - up platform 1, an energy power supply system, and an intelligent monitoring and control system; the jack - up platform 1 adopts a tension - leg fixed platform; the intelligent monitoring and control system transports the compressed CO2 to the seabed reservoir through the injection pipeline and receives monitoring data in real - time, and monitors the injection flow rate of CO2 through the flow meters 10 at both ends of the CO2 injection pipeline; the energy supply system includes a main power source and a backup power supply, which provides necessary power supply for the offshore injection platform. The CO2 injection pipeline includes a pneumatic conveying pump 9, a riser 10, a flow meter 11, a pressure sensor 12, and a gas sensor 13. The pneumatic conveying pump 9 is arranged at the connection between the riser 10 and the offshore injection platform 1. The flow meter 11 is set at the inlet and outlet of the CO2 injection pipeline. The pressure sensor and the gas sensor are arranged every 10 meters on the CO2 injection pipeline. The pressure and concentration of the injection pipeline and the reservoir are monitored through the pressure sensor 12 and the gas sensor 13 to monitor the entire process of CO2 collection and injection. If there is a leak, an alarm will be given in time to achieve control in the first time. The CO2 capture and transportation mechanism includes a CO2 capture device 3, a liquid CO2 storage tank 5, and a CO2 liquefaction treatment device 4.

[0059] As Figures 1-4As shown in the figure, the CO2 injection and storage device includes a first type of jet nozzle 607, a second type of jet nozzle 608, an earth-breaking and tunneling system, a high-pressure hose 14, a cuttings treatment device, a filter screen 16, an intelligent detection system, and a power system, which is connected to an offshore injection platform through a CO2 injection pipeline; there are 4 first type of jet nozzles 607 for CO2 injection and storage; there are 2 second type of jet nozzles for tunneling and cuttings cleaning; the earth-breaking and tunneling mechanism includes a polycrystalline diamond compact bit 601, a bionic propulsion device, and a rotary steering system. The bionic propulsion device includes a hydraulic chamber 17, 4 propulsion rings 7, and 3 telescopic mechanisms 8. The telescopic mechanism includes 3 telescopic rings and 3 control push rods. The liquid CO2 in the hydraulic chamber is pressed into the propulsion rings through the control push rods to expand the propulsion rings and provide an anchoring force for the advancement of the CO2 injection and storage device; the high-pressure hose 14 is arranged inside the CO2 injection and storage mechanism for the injection of liquid CO2 and the discharge of cuttings; the cuttings treatment device includes a suction pipeline 15 and a water storage chamber 18; the intelligent detection device includes a high-precision positioning and navigation system, a bit adaptive adjustment system, and an acoustic wave reflection detector 20, which emits acoustic waves to the underground rock formation using low-frequency acoustic waves and records the reflected wave signals of the acoustic waves propagating in the rock formation; the power control system includes 1 active drive motor 19 and a torque and speed control system; the plume suppression cover 21 is installed at the connection between the CO2 injection and storage device and the CO2 injection pipeline.

[0060] As Figure 1 shown, the CO2 injection pipeline is made of titanium alloy material that can withstand a pressure of 50 - 100 MPa, with a diameter of 1.6 m, laid in a J shape to the seabed, suspended from the offshore injection platform, and connected to the CO2 injection and storage device through 4 high-pressure hoses 14 with a diameter of 0.3 m at the lower end of the CO2 injection pipeline.

[0061] As Figures 2-3 shown, the polycrystalline diamond compact bit includes a polycrystalline diamond compact 605, a bit body 601, 1 elastic drill string 609, cutting teeth 604, cutter wings 603, a connecting piece 602, polycrystalline grains 606, and bit coolant, and is connected to the first propulsion ring 701 through the connecting piece 602. The bit coolant is delivered to the bit through the elastic drill string 609.

[0062] As Figure 1 shown, there are 4 propulsion rings in total, which are respectively arranged at the front, middle, and rear positions of the CO2 injection and storage device. Among them, the fourth propulsion ring 704 is located at the rear, the first propulsion ring 701 is located at the front, the second propulsion ring 702 and the third propulsion ring 703 are located in the middle. The second propulsion ring 702, the third propulsion ring 703, and the fourth propulsion ring 704 are the main sources of forward power, and the first propulsion ring 701 maintains the stability of the polycrystalline diamond compact bit 6 during tunneling and the role of liquid CO2 transfer.

[0063] As shown Figure 2 in the figure, the four first - type jet nozzles 607 are arranged at the front end of the polycrystalline diamond compact bit, and their rear ends are connected to the high - pressure hoses.

[0064] As shown Figure 1 in the figure, there are a total of three telescopic mechanisms 8, which are respectively arranged between every two of the four propulsion rings.

[0065] As shown Figure 1 in the figure, the plume suppression cover 21 is a retractable mechanism. As the tunneling continuously penetrates deeper into the seabed, the plume suppression cover contracts along the drill bit body towards its installation position until the CO2 injection and storage device is completely tunnelled below the seabed.

[0066] As shown Figure 1 in the figure, the acoustic wave reflection detector 20 emits acoustic waves to the underground rock formation using low - frequency acoustic waves, records the reflected wave signals of the acoustic waves propagating in the rock formation, and infers the distribution of rock mass fractures by analyzing the time, intensity, and frequency of the acoustic wave reflection. Embodiment

[0067] The CO2 capture device captures gaseous CO2 from the CO2 emission source, liquefies the gaseous CO2 through the CO2 compression treatment device, stores it in the liquid CO2 storage tank, and then transports the liquid CO2 to the offshore injection platform through a supply ship. The liquid CO2 is injected into the deep - sea deep geotechnical body for storage through a pneumatic conveying pump, a riser pipe, and a CO2 injection and storage device;

[0068] After the liquid CO2 is transported to the offshore injection platform, a small amount of liquid CO2 is first injected into the hydraulic chamber of the CO2 injection and storage device. The CO2 injection and storage device and the CO2 injection pipeline are lowered to the seabed below 5000 m, and the interface between the CO2 injection and storage device and the CO2 injection pipeline is sealed and connected;

[0069] After the CO2 injection and storage device is connected to the CO2 injection pipeline and lowered to the seabed, the second - type jet nozzles located at the front end of the earth - breaking tunneling mechanism of the CO2 injection and storage device start to spray seawater to break and excavate the surface sediments of the seabed;

[0070] The plume suppression cover suppresses the plume diffusion caused during the earth - breaking process. As the earth - breaking depth increases, the plume suppression cover continuously contracts and always stays above the seabed. When the CO2 injection and storage device is completely tunnelled under the seabed, the plume suppression cover stops contracting;

[0071] The intelligent detection system senses the surface soil type and adjusts the jet breaking parameters according to the shallow soil type. When the shallow seabed soil reaches the destruction level, the polycrystalline diamond composite drill bit at the front end of the excavation system starts working. The drill bit adaptive adjustment system adjusts the drill bit speed according to the soil type. The specific steps are as follows:

[0072] ① Soft soil: The jet velocity is controlled at 6-8 m / s. When the drill bit is sunk to a depth of more than 50 cm, the rotation speed is controlled at 60-80 rpm.

[0073] ② Medium-density soil layer: The jet velocity is controlled at 8-10 m / s. When the drill bit is sunk to a depth of more than 30 cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts working at 80-100 rpm.

[0074] ③Hard soil layer: The jet velocity is controlled at 10-12 m / s. When the drill bit sinks to a depth of more than 20 cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts to work at 100-150 rpm.

[0075] When the CO2 injection storage device passes through the shallow soil and reaches the rock layer, the intelligent detection system senses the changes in the rock and soil types and adjusts the jet speed and drill bit speed in real time according to the transition between different soil and rock layers. The specific steps are as follows:

[0076] ① When the shallow soil turns into hard rock, control the jet velocity to 15-20 m / s and the drill speed to 80-100 rpm;

[0077] ② When the shallow soil turns into soft rock, control the jet velocity to 12-15 m / s and the drill speed to 60-80 rpm;

[0078] The hydraulic chamber, propulsion ring, and retractable mechanism provide driving force for the CO2 injection and storage device. The steps are as follows:

[0079] ① Release the liquid CO2 in the hydraulic chamber to the 4th propulsion ring. After the 4th propulsion ring is filled with liquid CO2 and expanded and anchored, control the push rod 3 to push out and make the 3rd telescopic ring extend and move forward;

[0080] ② Continue to release the liquid CO2 in the fourth propulsion ring into the third propulsion ring, so that the third propulsion ring expands and anchors, and control the push rod 2 to push out, so that the second telescopic ring extends and moves forward;

[0081] ③ Continue to release the liquid CO2 in the third propulsion ring into the second propulsion ring, so that the second propulsion ring expands and anchors, and control the push rod 1 to push out, so that the first telescopic ring extends and moves forward;

[0082] ④Finally, release the liquid CO2 in the second propulsion ring into the first propulsion ring, and then return the liquid CO2 to the hydraulic chamber for use in the next tunneling cycle;

[0083] During tunneling, the CO2 injection and storage device tunnels under the seabed along a preset path according to the high-precision positioning and navigation system, and controls the rotation angle of the drill bit between 0.5° and 3° through the rotary steering system;

[0084] During the process of injecting and storing CO2 and tunneling, the suction pipeline sucks seawater into the water storage chamber, and the seawater in the water storage chamber is sprayed through the second jet nozzle to clean the rock debris generated during tunneling;

[0085] When reaching the preset storage layer, use the acoustic reflection detector to detect the rock type, rock fractures and cavity distribution, evaluate the reservoir characteristics according to the porosity and permeability of the storage layer, and adjust the injection state of the CO2 injection and storage device in real time through the intelligent monitoring and control system;

[0086] When the porosity of the storage layer is 20%-30% and the permeability > 1000 mD, it is determined as a good storage environment, and the injection rate and injection volume are appropriately increased; when the porosity is 10%-20% and the permeability is 100-1000 mD, it is determined as a general storage environment, and the injection rate and injection volume are reduced;

[0087] After reaching the preset storage location, detecting the rock fractures and analyzing them qualified, release the liquid CO2 in the hydraulic chamber through the first jet nozzle, pump the liquid CO2 into the CO2 injection pipeline at a pressure of ≥8 MPa through the energy power supply system, and finally inject the liquid CO2 into the rock fractures under the deep-sea seabed through the CO2 storage injection device for storage;

[0088] During carbon storage, the flow meters, pressure sensors and gas sensors installed on the offshore injection platform and the CO2 injection pipeline start to work to monitor the injection flow rate, injection pressure and CO2 concentration of the liquid CO2 in real time, ensuring that the change in the injection flow rate of the liquid CO2 does not exceed ±5%, the change in the injection pressure does not exceed ±3 MPa, and the CO2 concentration ≤ 1%.

Claims

1. An integrated method for intelligent tunneling and carbon sequestration of deep marine geotechnical bodies, characterized in that It includes the following steps: S1. The CO2 capture device captures gaseous CO2 from the CO2 emission source, liquefies the gaseous CO2 through the CO2 compression processing device, stores it in the liquid CO2 storage tank, then transports the liquid CO2 to the offshore injection platform through a supply ship, and injects the liquid CO2 into the deep-sea deep geotechnical body for storage through a pneumatic conveying pump, a riser pipe, and a CO2 injection and sealing device; S2. After the liquid CO2 is transported to the offshore injection platform, a small amount of liquid CO2 is first injected into the hydraulic chamber of the CO2 injection and sealing device, and the CO2 injection and sealing device and the CO2 injection pipeline are lowered to the seabed below 5000 m, and the interface between the CO2 injection and sealing device and the CO2 injection pipeline is sealed and connected; S3. After the CO2 injection and sealing device is connected to the CO2 injection pipeline and lowered to the seabed, the second jet nozzle at the front end of the soil-breaking tunneling mechanism of the CO2 injection and sealing device starts to spray seawater to excavate the surface sediment of the seabed; S4. The plume suppression cover suppresses the plume diffusion caused during the soil-breaking process. As the soil-breaking depth increases, the plume suppression cover continuously shrinks and always stays above the seabed. When the CO2 injection and sealing device is completely tunneled under the seabed, the plume suppression cover stops shrinking; S5. The intelligent detection system senses the type of surface soil mass, regulates the jet soil-breaking parameters according to the type of shallow soil mass, and when the shallow seabed soil mass reaches the damaged degree, the polycrystalline diamond compact bit at the front end of the soil-breaking tunneling system starts to work, and the bit rotation speed is adjusted according to the soil mass type through the bit adaptive adjustment system. The specific steps are as follows: ① Soft soil layer: The jet velocity is controlled at 6 - 8 m / s. When the bit penetration depth reaches more than 50 cm, the rotation speed is controlled at 60 - 80 rpm; ② Medium-dense soil layer: The jet velocity is controlled at 8 - 10 m / s. When the bit penetration depth reaches more than 30 cm, the polycrystalline diamond compact bit at the front end of the soil-breaking tunneling system starts to work, 80 - 100 rpm; ③ Hard soil layer: The jet velocity is controlled at 10 - 12 m / s. When the bit penetration depth reaches more than 20 cm, the polycrystalline diamond compact bit at the front end of the soil-breaking tunneling system starts to work, 100 - 150 rpm; S6. When the CO2 injection and sealing device passes through the shallow soil layer and reaches the rock stratum, the intelligent detection system senses the change of the geotechnical body type, and adjusts the jet velocity and the bit rotation speed in real time according to the transition between different soil layers and rock strata. The specific steps are as follows: ① When the shallow soil layer turns into a hard rock stratum, the jet velocity is controlled at 15 - 20 m / s, and the bit rotation speed is controlled at 80 - 100 rpm; ② When the shallow soil layer turns into a soft rock stratum, the jet velocity is controlled at 12 - 15 m / s, and the bit speed is controlled at 60 - 80 rpm; S7. The hydraulic chamber, the propulsion ring, and the telescopic mechanism provide the tunneling power for the CO2 injection and sealing device. The steps are as follows: ① Release the liquid CO2 in the hydraulic chamber to the 4th propulsion ring. After the 4th propulsion ring is filled with liquid CO2 and expands and anchors, control the push rod 3 to push out, and make the 3rd telescopic ring extend and advance; ②Continue to release the liquid CO2 in the fourth propulsion ring into the third propulsion ring, causing the third propulsion ring to expand and anchor, controlling the push rod 2 to push out, and causing the second telescopic ring to extend forward; ③Continue to release the liquid CO2 in the third propulsion ring into the second propulsion ring, causing the second propulsion ring to expand and anchor, controlling the push rod 1 to push out, and causing the first telescopic ring to extend forward; ④Finally, release the liquid CO2 in the second propulsion ring into the first propulsion ring, and then return the liquid CO2 to the hydraulic chamber for use in the next tunneling cycle; S8. Cycle S6. During tunneling, the CO2 injection and storage device injects CO2 into the seabed according to the preset path by the high-precision positioning and navigation system, and controls the rotation angle of the drill bit between 0.5° and 3° through the rotary steering system; S9. During the process of injecting CO2 into the CO2 injection and storage device and tunneling, the suction pipeline sucks seawater into the water storage chamber, and sprays the seawater in the water storage chamber through the second jet nozzle to clean the rock debris generated during tunneling; S10. When reaching the preset storage layer, use the acoustic reflection detector to detect the rock type, rock fractures, and cavity distribution, evaluate the reservoir characteristics according to the porosity and permeability of the storage layer, and use the intelligent monitoring and control system to adjust the injection state of the CO2 injection and storage device in real time; S11. When the porosity of the storage layer is 20%-30% and the permeability > 1000 mD, it is determined as a good storage environment, and the injection rate and injection volume are appropriately increased; when the porosity is 10%-20% and the permeability is 100-1000 mD, it is determined as a general storage environment, and the injection rate and injection volume are reduced; S12. After reaching the preset storage location, detecting the rock fractures and analyzing them to be qualified, release the liquid CO2 in the hydraulic chamber through the first jet nozzle, pump the liquid CO2 into the CO2 injection pipeline at a pressure of ≥8 MPa through the energy power supply system, and finally inject the liquid CO2 into the rock fractures under the deep-sea seabed through the CO2 storage injection device for storage; S13. During the carbon storage process, the flow meters, pressure sensors, and gas sensors arranged on the offshore injection platform and the CO2 injection pipeline start to work to monitor the injection flow rate, injection pressure, and CO2 concentration of the liquid CO2 in real time, ensuring that the change in the injection flow rate of the liquid CO2 does not exceed ±5%, the change in the injection pressure does not exceed ±3 MPa, and the CO2 concentration ≤1%; 2. Equipment for the integrated method of intelligent tunneling and carbon sequestration in deep-sea deep geotechnical bodies according to claim 1, characterized in that, It includes a supply ship, an offshore injection platform, a CO2 injection pipeline, a CO2 capture and transportation mechanism, and a CO2 injection and storage device; The offshore injection platform includes a jack-up platform, an energy power supply system, an intelligent monitoring and control system, and a pneumatic conveying system; the jack-up platform uses a tension leg fixed platform; the intelligent monitoring and control system transports the compressed CO2 to the seabed reservoir through the injection pipeline and receives monitoring data in real time, and monitors the injection flow rate of CO2 through the flow meters at both ends of the CO2 injection pipeline; the energy power supply system includes a main power source and a standby power supply; The CO2 injection pipeline includes a pneumatic conveying pump, a riser pipe, a flowmeter, a pressure sensor, and a gas sensor. The pneumatic conveying pump is arranged at the connection between the riser pipe and the offshore injection platform. The flowmeter is set at the inlet and outlet of the CO2 injection pipeline. The pressure sensor and the gas sensor are arranged every 10 meters on the CO2 injection pipeline. The pressure and concentration of the injection pipeline and the reservoir are monitored through the pressure sensor and the gas sensor to monitor the entire process of CO2 collection and injection. The CO2 capture and transportation mechanism includes a CO2 capture device, a liquid CO2 storage tank, and a CO2 liquefaction treatment device. The CO2 injection and sequestration device includes a first type of jet nozzle, a second type of jet nozzle, a soil-breaking and tunneling system, a high-pressure hose, a cuttings treatment device, a filter screen, an intelligent detection system, a power system, and a plume suppression hood, which is connected to the offshore injection platform through the CO2 injection pipeline. There are 4 first type of jet nozzles for CO2 injection and sequestration. There are 2 second type of jet nozzles for soil breaking and cuttings cleaning. The soil-breaking and tunneling mechanism includes a polycrystalline diamond compact bit, a bionic propulsion device, and a rotary steering system. The bionic propulsion device includes a hydraulic chamber, 4 propulsion rings, and 3 telescopic mechanisms. The telescopic mechanism includes 3 telescopic rings and 3 control push rods. The liquid CO2 in the hydraulic chamber is pressed into the propulsion ring through the control push rod to expand the propulsion ring and provide an anchoring force for the forward movement of the CO2 injection and sequestration device. The high-pressure hose is arranged inside the CO2 injection and sequestration mechanism for the injection of liquid CO2. The cuttings treatment device includes a suction pipeline and a water storage chamber. The intelligent detection system includes a high-precision positioning and navigation system, a bit adaptive adjustment system, and an acoustic reflection detector, which emits acoustic waves to the underground rock formation using low-frequency acoustic waves and records the reflected wave signals of the acoustic waves propagating in the rock formation. The power control system includes 1 active drive motor and a torque and speed control system. The plume suppression hood is installed at the connection between the CO2 injection and sequestration device and the CO2 injection pipeline.

3. The equipment for the integrated method of intelligent tunneling - carbon sequestration of deep - sea deep geotechnical bodies according to claim 2, characterized in that, The material of the CO2 injection pipeline is titanium alloy that can withstand a pressure of 50 - 100 MPa, with a diameter of 2 - 5 m. It is laid in a J shape to the seabed and suspended from the offshore injection platform. At the lower end of the CO2 injection pipeline, it is connected to the CO2 injection and sequestration device through 4 high-pressure hoses with a diameter of 0.5 - 0.8 m.

4. The equipment for the integrated method of intelligent tunneling - carbon sequestration in deep - sea deep geotechnical bodies according to claim 2, characterized in that, The polycrystalline diamond compact bit includes a polycrystalline diamond compact, a bit body, 1 elastic drill string, cutting teeth, blade wings, a connector, a water hole, polycrystalline grains, and bit coolant. It is connected to the first propulsion ring through the connector, and the bit coolant is transported to the bit body through the elastic drill string.

5. The equipment for the integrated method of intelligent tunneling - carbon sequestration in deep - sea deep geotechnical bodies according to claim 2, characterized in that, There are 4 propulsion rings in total, which are respectively arranged at the front, middle, and rear positions of the CO2 injection and sequestration device. The fourth propulsion ring is located at the rear, the first propulsion ring is located at the front, and the second and third propulsion rings are located in the middle. The second, third, and fourth propulsion rings are the main sources of forward power, and the first propulsion ring maintains the stability of the polycrystalline diamond compact bit during tunneling and the role of liquid CO2 transfer.

6. The equipment for the integrated method of intelligent tunneling and carbon sequestration of deep-sea deep geotechnical body according to claim 2, characterized in that The first jet nozzle is arranged at the front end of the polycrystalline diamond compact bit, and its rear end is connected to a high-pressure hose.

7. The equipment for the integrated method of intelligent tunneling and carbon sequestration in deep-sea deep geotechnical bodies according to claim 2, characterized in that, There are a total of 3 telescopic rings. The first telescopic ring is arranged between the first propulsion ring and the second propulsion ring, the second telescopic ring is arranged between the second propulsion ring and the third propulsion ring, and the third telescopic ring is arranged between the third propulsion ring and the fourth propulsion ring.

8. The equipment for the integrated method of intelligent tunneling - carbon sequestration in deep - sea deep geotechnical bodies according to claim 2, characterized in that, The plume suppression cover is a retractable mechanism. As the tunneling continuously deepens into the seabed, the plume suppression cover shrinks along the drill bit body towards its installation position until the CO2 injection and storage device is completely tunnelled below the seabed.

9. The equipment for the integrated method of intelligent tunneling - carbon sequestration in deep - sea deep geotechnical bodies according to claim 2, characterized in that, The rotary steering system includes a direction sensor and a control system. Based on the data fed back by the direction sensor, the control system controls the drill bit to turn.

10. The equipment for the integrated method of intelligent tunneling - carbon sequestration in deep - sea deep geotechnical bodies according to claim 2, characterized in that, The acoustic wave reflection detector emits acoustic waves to the underground rock formation using low-frequency acoustic waves, records the reflected wave signals of the acoustic waves propagating in the rock formation, and infers the distribution of rock mass fractures by analyzing the time, intensity, and frequency of the acoustic wave reflections.

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