Intelligent tunneling-carbon sequestration integrated equipment and method for deep-sea deep rock-soil body

Abstract

The invention discloses intelligent tunneling-carbon sequestration integrated equipment and method for a deep-sea deep rock-soil body. Comprising a supply ship, an offshore injection platform, a CO2 injection pipeline, a CO2 capturing and conveying mechanism and a CO2 injection and storage device. The CO2 injection pipeline comprises a pneumatic conveying pump, a vertical pipe, a flow meter, a pressure sensor and a gas sensor, and the CO2 capturing and conveying mechanism comprises a CO2 capturing device, a liquid CO2 storage box and a CO2 liquefaction treatment device. The CO2 injection and storage device comprises a first jet nozzle, a second jet nozzle, a ground breaking and tunneling system, a high-pressure hose, a rock debris treatment device, a filter screen, an intelligent detection system and a power system; and the ground breaking and tunneling mechanism comprises a polycrystalline diamond compact drill bit, a bionic propulsion device and a rotary guide system. According to the directional intelligent tunneling equipment for deep-sea deep rock mass carbon sequestration and the liquid CO2 full-set injection sequestration method, long-term stability of deep-sea carbon sequestration is achieved, and the directional intelligent tunneling equipment and the liquid CO2 full-set injection sequestration method are of great significance to global environment 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 method for intelligent excavation and carbon storage of deep-sea rock and soil bodies. Background Art

[0002] In recent years, with the increasing global attention to climate change, reducing greenhouse gas emissions has become a global consensus. Carbon dioxide is one of the main greenhouse gases. Its excessive emissions will lead to an accelerated rise in global temperatures, which may cause a series of climate problems such as extreme heat and drought. According to the latest detection, the concentration of carbon dioxide, as the main greenhouse gas, in the atmosphere has reached 420 ppm, which has increased by nearly 50% compared with the pre-industrial level (about 280 ppm in the 17th century). In order to solve this problem, many countries and scientific research institutions have begun to explore carbon dioxide capture and storage technology, with the aim of capturing carbon dioxide from industrial sources (such as power plants, steel mills, etc.) and then storing it to prevent it from entering the atmosphere. Deep-sea carbon storage technology, as a form of carbon capture and storage, mainly injects captured carbon dioxide into the deep ocean and uses the unique environmental conditions of the deep sea for long-term storage.

[0003] The existing deep-sea carbon storage equipment and methods have the following problems: 1. Existing deep-sea carbon storage technology cannot inject and store large amounts of CO2 into deep-sea rock and soil for a long time. In addition, the equipment used for deep-sea CO2 injection and storage is relatively scarce, and generally requires reliance on other deep-sea operating equipment (such as submarine robots, etc.), which makes the time, quantity and effectiveness of deep-sea carbon storage very limited; 2. The current marine carbon storage technology directly discharges CO2 into the saline layer or the seabed surface. Although it has a certain storage effect, CO2 is likely to migrate with the changes in ocean currents and face the risk of leaving the ocean water and circulating again into the atmosphere. It is impossible to inject CO2 into the deep rock cracks under the seabed for permanent storage; 3. Directly discharging CO2 into the seabed or saltwater will change the pH value of seawater, leading to ocean acidification. This acidification will harm marine life, especially those that rely on carbonates (such as corals, shellfish, etc.). Long-term CO2 accumulation may also change the seabed ecological environment and affect the stability of the deep-sea food chain; 4. Existing deep-sea carbon storage equipment and processes will cause significant disturbances to the seabed environment, resulting in a large amount of bottom plumes on the seabed surface, causing serious damage to the seabed ecological environment. At present, there are no effective measures to reduce plume disturbances during deep-sea carbon storage. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide an integrated equipment and method for intelligent excavation and carbon storage in deep-sea rock and soil. The equipment can realize large-scale storage of CO2 in cracks or cavities in deep-sea rock and soil. The existing CO2 seabed storage devices are temporarily unable to penetrate deep into the deep rock mass under the seabed, and there is a risk of CO2 leakage on the seabed.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: Deep sea deep rock and soil body intelligent excavation - carbon sequestration integrated equipment and method, characterized by comprising 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 and 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 an injection pipeline, and receives monitoring data in real time, and monitors the injection flow of CO2 through flow meters at both ends of the CO2 injection pipeline; the energy supply system includes a main power source and a backup power source; 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 meter is arranged at the inlet and outlet of the CO2 injection pipeline, and 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 by the pressure sensor and the gas sensor 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 processing device; The CO2 injection and storage device includes a first jet nozzle, a second jet nozzle, a ground-breaking and excavation system, a high-pressure hose, a cuttings processing device, a filter, an intelligent detection system, a power system, and a plume suppression cover, and is connected to the offshore injection platform through a CO2 injection pipeline; there are a total of 4 first-type jet nozzles for CO2 injection and storage; there are a total of 2 second-type jet nozzles for excavation and ground-breaking and cuttings cleaning; the ground-breaking and excavation mechanism includes a polycrystalline diamond composite drill bit, a bionic propulsion device, and a rotary guide system; the bionic propulsion device includes a hydraulic compartment, 4 propulsion rings, and 3 retractable mechanisms; the retractable mechanisms include 3 retractable rings and 3 control push rods, which are controlled by The push rod presses the liquid CO2 in the hydraulic tank into the propulsion ring, causing the propulsion ring to expand, thereby providing an anchoring force for the CO2 injection and sealing device to move forward; the high-pressure hose is arranged inside the CO2 injection and sealing mechanism, and is used for the injection of liquid CO2; the rock cuttings processing device includes a suction pipeline and a water storage tank; the intelligent detection device includes a high-precision positioning and navigation system, a drill bit adaptive adjustment system, and an acoustic wave reflection detector, which uses low-frequency sound waves to emit sound waves to underground rock formations and records the reflected wave signals of the sound waves propagating in the rock formations; the power control system includes an active drive motor and a torque and speed control system; the plume suppression hood is installed at the connection between the CO2 injection and sealing device and the CO2 injection pipeline.

[0006] Furthermore, the CO2 injection pipeline is made of titanium alloy that can withstand a pressure of 50-100MPa, has a diameter of 2-5m, is laid in a J-shape on the seabed, and is suspended on an offshore injection platform. The lower end of the CO2 injection pipeline is connected to the CO2 injection and storage device through four high-pressure hoses with a diameter of 0.5-0.8m.

[0007] Furthermore, the polycrystalline diamond composite drill bit includes a polycrystalline diamond composite, a drill bit body, an elastic drill string, cutting teeth, blades, connecting parts, water holes, polycrystalline particles, and drill bit coolant, which is connected to the first thrust ring through the connecting part, and the drill bit coolant is transported to the drill bit body through the elastic drill string.

[0008] Furthermore, there are a total of four thrust rings, which are arranged at the front, middle and rear positions of the CO2 injection and storage device, respectively. The fourth thrust ring is located at the rear, the first thrust ring is located at the front, and the second and third thrust rings are located in the middle. The second, third and fourth thrust rings are the main sources of forward power. The first thrust ring maintains the stability of the polycrystalline diamond composite drill bit 6 during excavation and plays a transfer role for liquid CO2.

[0009] Furthermore, the first type of jet nozzle is arranged at the front end of the polycrystalline diamond composite sheet drill bit, and the rear end thereof is connected to the high-pressure hose.

[0010] Furthermore, there are three telescopic rings in total, 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.

[0011] Furthermore, the plume suppression cover is a retractable mechanism. As the excavation progresses deeper into the seabed, the plume suppression cover retracts along the drill bit body toward its installation position until the CO2 injection and storage device is completely excavated below the seabed.

[0012] Furthermore, the rotary steering system includes a direction sensor and a control system. The control system controls the drill bit to turn according to data fed back by the direction sensor.

[0013] Furthermore, the acoustic wave reflection detector uses low-frequency sound waves to transmit sound waves to underground rock formations, records the reflected wave signals of the sound waves propagating in the rock formations, and infers the distribution of rock cracks by analyzing the time, intensity and frequency of the sound wave reflection.

[0014] One object of the present invention is to provide a method for carbon sequestration in deep rock mass under the deep seabed, comprising 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, and stores it in a liquid CO2 storage tank. The liquid CO2 is then transported to the offshore injection platform by a supply ship, and injected into the deep sea rock and soil for storage through a pneumatic conveying pump, a riser, and a CO2 injection and storage 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 5000m, and the CO2 injection and sealing device are sealed and connected with the CO2 injection pipeline at the interface; S3. After the CO2 injection and storage device is connected to the CO2 injection pipeline and lowered to the seabed, the second jet nozzle located at the front end of the excavation mechanism of the CO2 injection and storage device starts to spray seawater to excavate the surface sediments of the seabed; S4. The plume diffusion caused by the groundbreaking process is suppressed by the plume suppression cover. As the groundbreaking depth increases, the plume suppression cover shrinks continuously and always stays above the seabed. When the CO2 injection storage device is completely excavated under the seabed, the plume suppression cover stops shrinking; 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 degree of destruction, the polycrystalline diamond composite drill bit at the front end of the earth-breaking and excavation system starts to work, and the drill bit adaptive adjustment system is used to adjust the drill bit speed according to the soil type. The specific steps are as follows: ① Soft soil layer: the jet speed is controlled at 6-8m / s. When the drill bit is sunk to a depth of more than 50cm, the speed is controlled at 60-80rpm; ②Medium-dense soil layer: The jet speed is controlled at 8-10m / s. When the drill bit sinks to a depth of more than 30cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts working at 80-100rpm; ③Hard soil layer: The jet speed is controlled at 10-12m / s. When the drill bit sinks to a depth of more than 20cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts to work at 100-150rpm; S6. When the CO2 injection storage device passes through the shallow soil to reach the rock layer, the intelligent detection system senses the change of the rock and soil type, and adjusts the jet speed and drill speed in real time according to the transition between different soil and rock layers. The specific steps are as follows: ①When the shallow soil turns into hard rock, the jet velocity is controlled to 15-20m / s and the drill speed is controlled to 80-100rpm; ② When the shallow soil turns into soft rock, the jet velocity is controlled to 12-15m / s and the drill speed is controlled to 60-80rpm; S7. Provide driving power for the CO2 injection and storage device through the hydraulic chamber, the propulsion ring, and the retractable mechanism. The steps are as follows: ① Release the liquid CO2 in the hydraulic chamber to the fourth propulsion ring. After the fourth propulsion ring is filled with liquid CO2 and expanded and anchored, control the push rod 3 to push out and make the third telescopic ring extend and move forward; 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; ③Continue 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; ④Finally, the liquid CO2 in the second propulsion ring is released into the first propulsion ring, and then the liquid CO2 is returned to the hydraulic chamber for use in the next excavation cycle; S8, loop S6, during the excavation process, CO2 is injected into the storage device, and the excavation is carried out under the seabed according to the preset path based on the high-precision positioning and navigation system, and the rotation angle of the drill bit is controlled to be between 0.5° and 3° through the rotary steering system; S9. During the CO2 injection into the storage device and excavation process, the suction pipeline sucks seawater into the water storage tank, and the seawater in the water storage tank is sprayed through the second jet nozzle to clean up the rock debris generated during the excavation process; S10. Upon reaching the preset sealing storage layer, the rock type and the distribution of rock cracks and cavities are detected by using an acoustic wave reflection detector, the reservoir characteristics are evaluated according to the porosity and permeability of the sealing storage layer, and the injection state of the CO2 injection and storage device is adjusted in real time by using an intelligent monitoring and control system; S11. When the porosity of the sealing storage layer is 20%-30% and the permeability is greater than 1000mD, it is judged as a good sealing environment and the injection rate and injection volume should be appropriately increased; when the porosity is 10%-20% and the permeability is 100-1000mD, it is judged as a general sealing environment and the injection rate and injection volume should be reduced; S12. After arriving at the preset storage location and completing the detection of rock mass fissures and passing the analysis, the liquid CO2 in the hydraulic tank is released through the jet nozzle, and the liquid CO2 is pumped into the CO2 injection pipeline at a pressure of ≥8MPa through the energy power supply system, and finally the liquid CO2 is injected into the rock mass fissures under the deep seabed through the CO2 storage injection device for storage; S13. During the carbon storage process, flow meters, pressure sensors, and gas sensors deployed on the offshore injection platform and CO2 injection pipeline start working to monitor the liquid CO2 injection flow, injection pressure, and CO2 concentration in real time to ensure that the liquid CO2 injection flow rate changes by no more than ±5%, the injection pressure changes by no more than ±3MPa, and the CO2 concentration is ≤1%.

[0015] Beneficial effects of the present invention: 1. Based on the feasibility of CO2 deep-sea rock and soil storage, the present invention provides intelligent excavation and storage integrated equipment and methods for injecting and sealing CO2 into deep-sea rock and soil, injecting CO2 into the cavity and cracks of deep rock and soil under the seabed, avoiding the risk of CO2 storage in the shallow seabed being recirculated to the atmosphere with the ocean current, and realizing the permanent storage of CO2 in deep-sea rock and soil; 2. The present invention uses liquid CO2 to provide power for the earth-breaking and excavation mechanism through a hydraulic chamber, a propulsion ring, and a retractable mechanism. During the excavation process, the expansion and anchoring of the propulsion ring also plays a certain role in the stability of the drill bit; 3. The present invention uses a drill bit adaptive adjustment system to adjust the drill bit speed according to different seabed rock and soil types immediately after the surface sediments reach the destruction level; 4. The present invention uses an intelligent monitoring and control system to classify the storage layer according to its porosity and permeability characteristics, and regulates the liquid CO2 injection rate and injection time, thereby achieving dynamic real-time regulation of the liquid CO2 injection and storage process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the structure of a polycrystalline diamond composite drill bit.

[0018] Figure 3 3D illustration of the CO2 injection storage device.

[0019] Figure 4 Schematic diagram of the middle cross-section of the CO2 injection storage device.

[0020] 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 composite sheet drill bit; 601, drill bit body; 602, connector; 603, blade; 604, cutting tooth; 605, polycrystalline diamond composite sheet; 606, polycrystalline particles; 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, the fourth propulsion ring; 8, the retractable mechanism; 801, the first retractable ring; 802, the second retractable ring; 803, the third retractable ring; 804, the third control push rod; 805, the second control push rod; 806, the first control push rod; 9, the pneumatic conveying pump; 10, the riser; 11, the flow meter; 12, the pressure sensor; 13, the gas sensor; 14, the high-pressure hose; 15, the suction pipeline; 16, the filter; 17, the hydraulic tank; 18, the water storage tank; 19, the active drive motor; 20, the acoustic wave reflection detector; 21, the plume suppression hood. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0023] like Figure 1 As shown, the deep rock carbon storage equipment under the deep seabed 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.

[0024] like Figure 1 As shown, the offshore injection platform includes a self-elevating platform 1, an energy and power supply system, and an intelligent monitoring and control system; the self-elevating platform 1 adopts a tension leg fixed platform; the intelligent monitoring and control system transports the compressed CO2 to the submarine reservoir through the injection pipeline and receives monitoring data in real time, and monitors the injection flow of CO2 through the flowmeter 10 at both ends of the CO2 injection pipeline; the energy supply system includes a main power source and a backup power supply to provide necessary power supply for the offshore injection platform. The CO2 injection pipeline includes a pneumatic conveying pump 9, a riser 10, a flowmeter 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 flowmeter 11 is arranged 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 by the pressure sensor 12 and the gas sensor 13, so as to realize the monitoring of the entire CO2 collection and injection process. If there is a leak, an alarm is given in time, so as to achieve control at 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 processing device 4.

[0025] like Figure 1-4 As shown, the CO2 injection and sealing device includes a first jet nozzle 607, a second jet nozzle 608, a ground-breaking and excavation system, a high-pressure hose 14, a rock cuttings processing device, a filter 16, an intelligent detection system, and a power system, which are connected to the offshore injection platform through a CO2 injection pipeline; there are a total of 4 first-type jet nozzles 607, which are used for CO2 injection and sealing; there are a total of 2 second-type jet nozzles, which are used for excavation and ground-breaking and rock cuttings cleaning; the ground-breaking and excavation mechanism includes a polycrystalline diamond composite piece drill bit 601, a bionic propulsion device, and a rotary guide system. The bionic propulsion device includes a hydraulic chamber 17, 4 propulsion rings 7, and 3 retractable mechanisms 8. The retractable mechanisms include 3 retractable rings and 3 control push rods. The push rod presses the liquid CO2 in the hydraulic tank into the propulsion ring, causing the propulsion ring to expand, providing anchoring force for the CO2 injection and sealing device to move forward; the high-pressure hose 14 is arranged inside the CO2 injection and sealing mechanism, and is used for the injection of liquid CO2 and the discharge of rock cuttings; the rock cuttings processing device includes a suction pipeline 15 and a water storage tank 18; the intelligent detection device includes a high-precision positioning and navigation system, a drill bit adaptive adjustment system, and an acoustic wave reflection detector 20, which uses low-frequency sound waves to emit sound waves to underground rock formations and record the reflected wave signals of the sound waves propagating in the rock formations; the power control system includes an active drive motor 19 and a torque and speed control system; the plume suppression hood 21 is installed at the connection between the CO2 injection and sealing device and the CO2 injection pipeline.

[0026] like Figure 1 As shown, the CO2 injection pipeline is made of titanium alloy that can withstand a pressure of 50-100MPa, has a diameter of 1.6m, is laid in a J-shape on the seabed, and is suspended on an offshore injection platform. The lower end of the CO2 injection pipeline is connected to the CO2 injection and storage device through four high-pressure hoses 14 with a diameter of 0.3m.

[0027] like Figure 2-3 As shown, the polycrystalline diamond composite drill bit includes a polycrystalline diamond composite 605, a drill body 601, an elastic drill string 609, cutting teeth 604, blades 603, a connector 602, polycrystalline particles 606, and a drill coolant. The drill bit is connected to the first thrust ring 701 through the connector 602, and the drill coolant is transported to the drill bit through the elastic drill string 609.

[0028] like Figure 1 As shown, there are four propulsion rings in total, which are arranged at the front, middle and rear positions of the CO2 injection and storage device respectively, among which 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 composite sheet drill bit 6 during excavation and plays a transfer role of liquid CO2.

[0029] like Figure 2 As shown, the four first-type jet nozzles 607 are arranged at the front end of the polycrystalline diamond composite drill bit, and the rear end thereof is connected to a high-pressure hose.

[0030] like Figure 1 As shown, there are three retractable mechanisms 8, which are arranged between two of the four propulsion rings.

[0031] like Figure 1 As shown, the plume suppression cover 21 is a retractable mechanism. As the excavation progresses deeper into the seabed, the plume suppression cover shrinks along the drill bit body toward its installation position until the CO2 injection and storage device is completely excavated below the seabed.

[0032] like Figure 1 As shown, the acoustic wave reflection detector 20 uses low-frequency sound waves to transmit sound waves to underground rock formations, records the reflected wave signals of the sound waves propagating in the rock formations, and infers the distribution of rock fractures by analyzing the time, intensity and frequency of the sound wave reflection. Example

[0033] The CO2 capture device captures gaseous CO2 from the CO2 emission source, liquefies the gaseous CO2 through the CO2 compression processing device, and stores it in a liquid CO2 storage tank. The liquid CO2 is then transported to the offshore injection platform by a supply ship, and injected into the deep sea rock and soil for storage through a pneumatic conveying pump, a riser, and a CO2 injection and storage device; 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 5000m, and the CO2 injection and sealing device are sealed and connected at the interface with the CO2 injection pipeline; The CO2 injection and storage device is connected to the CO2 injection pipeline and lowered to the seabed. First, the second jet nozzle located at the front end of the excavation mechanism of the CO2 injection and storage device starts to spray seawater to excavate the surface sediments of the seabed. The plume suppression cover is used to suppress the diffusion of plume caused by the groundbreaking process. As the groundbreaking depth increases, the plume suppression cover continues to shrink and always stays above the seabed. When the CO2 injection and storage device is completely excavated under the seabed, the plume suppression cover stops shrinking; The type of surface soil 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 degree of destruction, the polycrystalline diamond composite drill bit at the front end of the earth-breaking and excavation system starts to work, and the drill bit adaptive adjustment system adjusts the drill bit speed according to the soil type. The specific steps are as follows: ① Soft soil layer: the jet speed is controlled at 6-8m / s. When the drill bit is sunk to a depth of more than 50cm, the speed is controlled at 60-80rpm; ②Medium-dense soil layer: The jet speed is controlled at 8-10m / s. When the drill bit sinks to a depth of more than 30cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts working at 80-100rpm; ③Hard soil layer: The jet speed is controlled at 10-12m / s. When the drill bit sinks to a depth of more than 20cm, the polycrystalline diamond composite drill bit at the front end of the soil-breaking and excavation system starts to work at 100-150rpm; When the CO2 injection storage device passes through the shallow soil to reach the rock layer, the intelligent detection system senses the change of the rock and soil type, and adjusts the jet speed and drill speed in real time according to the transition between different soil and rock layers. The specific steps are as follows: ①When the shallow soil turns into hard rock, the jet velocity is controlled to 15-20m / s and the drill speed is controlled to 80-100rpm; ② When the shallow soil turns into soft rock, the jet velocity is controlled to 12-15m / s and the drill speed is controlled to 60-80rpm; The hydraulic chamber, propulsion ring and retractable mechanism are used to provide driving power for the CO2 injection and storage device. The steps are as follows: ① Release the liquid CO2 in the hydraulic chamber to the fourth propulsion ring. After the fourth propulsion ring is filled with liquid CO2 and expanded and anchored, control the push rod 3 to push out and make the third telescopic ring extend and move forward; 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; ③Continue 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; ④Finally, the liquid CO2 in the second propulsion ring is released into the first propulsion ring, and then the liquid CO2 is returned to the hydraulic chamber for use in the next excavation cycle; During the excavation process, CO2 is injected into the storage device, and the excavation proceeds under the seabed according to the preset path based on the high-precision positioning and navigation system. The rotation angle of the drill bit is controlled between 0.5° and 3° through the rotary steering system; During the CO2 injection into the storage device and excavation process, the suction pipeline sucks seawater into the water storage tank, and the seawater in the water storage tank is sprayed through the second jet nozzle to clean up the rock debris generated during the excavation process; When arriving at the preset sealing storage layer, the rock type and the distribution of rock cracks and cavities are detected through the acoustic reflection detector, the reservoir characteristics are evaluated according to the porosity and permeability of the sealing storage layer, and the injection status of the CO2 injection and storage device is adjusted in real time through the intelligent monitoring and control system; When the porosity of the sealing storage layer is 20%-30% and the permeability is greater than 1000mD, it is judged as a good sealing environment and the injection rate and injection volume should be appropriately increased; when the porosity is 10%-20% and the permeability is 100-1000mD, it is judged as a general sealing environment and the injection rate and injection volume should be reduced; After arriving at the preset storage location and completing the detection of rock fissures and passing the analysis, the liquid CO2 in the hydraulic tank is released through the jet nozzle, and the liquid CO2 is pumped into the CO2 injection pipeline at a pressure of ≥8MPa through the energy power supply system. Finally, the liquid CO2 is injected into the rock fissures under the deep seabed through the CO2 storage injection device for storage; During the carbon sequestration process, flow meters, pressure sensors, and gas sensors deployed on the offshore injection platform and CO2 injection pipeline start working to monitor the liquid CO2 injection flow, injection pressure, and CO2 concentration in real time to ensure that the liquid CO2 injection flow rate changes by no more than ±5%, the injection pressure changes by no more than ±3MPa, and the CO2 concentration is ≤1%.

Claims

1. Deep sea deep rock and soil body intelligent excavation - carbon sequestration integrated equipment and method, characterized by The steps include: S1. The CO2 capture device captures gaseous CO2 from the CO2 emission source, liquefies the gaseous CO2 through the CO2 compression processing device, and stores it in a liquid CO2 storage tank. The liquid CO2 is then transported to the offshore injection platform by a supply ship, and injected into the deep sea rock and soil for storage through a pneumatic conveying pump, a riser, and a CO2 injection and storage 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 5000m, and the CO2 injection and sealing device are sealed and connected with the CO2 injection pipeline at the interface; S3. After the CO2 injection and storage device is connected to the CO2 injection pipeline and lowered to the seabed, the second jet nozzle located at the front end of the excavation mechanism of the CO2 injection and storage device starts to spray seawater to excavate the surface sediments of the seabed; S4. The plume diffusion caused by the groundbreaking process is suppressed by the plume suppression cover. As the groundbreaking depth increases, the plume suppression cover shrinks continuously and always stays above the seabed. When the CO2 injection storage device is completely excavated under the seabed, the plume suppression cover stops shrinking; 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 degree of destruction, the polycrystalline diamond composite drill bit at the front end of the earth-breaking and excavation system starts to work, and the drill bit adaptive adjustment system is used to adjust the drill bit speed according to the soil type. The specific steps are as follows: ① Soft soil layer: 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 speed is controlled at 60-80 rpm. ②Medium-dense soil layer: The jet speed 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. ③Hard soil layer: The jet speed is controlled at 10-12 m / s. When the drill bit is sunk 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; S6. When the CO2 injection storage device passes through the shallow soil to reach the rock layer, the intelligent detection system senses the change of the rock and soil type, and adjusts the jet speed and drill speed in real time according to the transition between different soil and rock layers. The specific steps are as follows: ① When the shallow soil turns into hard rock, the jet velocity is controlled to 15-20 m / s and the drill speed is controlled to 80-100 rpm; ② When the shallow soil turns into soft rock, the jet velocity is controlled to 12-15 m / s and the drill speed is controlled to 60-80rpm; S7. Provide driving power for the CO2 injection and storage device through the hydraulic chamber, the propulsion ring, and the retractable mechanism. The steps are as follows: ① Release the liquid CO2 in the hydraulic chamber to the fourth propulsion ring. After the fourth propulsion ring is filled with liquid CO2 and expanded and anchored, control the push rod 3 to push out and make the third telescopic ring extend and move forward; 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; ③Continue 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; ④Finally, the liquid CO2 in the second propulsion ring is released into the first propulsion ring, and then the liquid CO2 is returned to the hydraulic chamber for use in the next excavation cycle; S8, loop S6, during the excavation process, CO2 is injected into the storage device, and the excavation is carried out under the seabed according to the preset path based on the high-precision positioning and navigation system, and the rotation angle of the drill bit is controlled to be between 0.5° and 3° through the rotary steering system; S9. During the CO2 injection into the storage device and excavation process, the suction pipeline sucks seawater into the water storage tank, and the seawater in the water storage tank is sprayed through the second jet nozzle to clean up the rock debris generated during the excavation process; S10. Upon reaching the preset sealing storage layer, the rock type and the distribution of rock cracks and cavities are detected by using an acoustic wave reflection detector, the reservoir characteristics are evaluated according to the porosity and permeability of the sealing storage layer, and the injection state of the CO2 injection and storage device is adjusted in real time by using an intelligent monitoring and control system; S11. When the porosity of the sealing storage layer is 20%-30% and the permeability is greater than 1000mD, it is judged as a good sealing environment and the injection rate and injection volume should be appropriately increased; when the porosity is 10%-20% and the permeability is 100-1000mD, it is judged as a general sealing environment and the injection rate and injection volume should be reduced; S12. After arriving at the preset storage location and completing the detection of rock mass fissures and passing the analysis, the liquid CO2 in the hydraulic tank is released through the jet nozzle, and the liquid CO2 is pumped into the CO2 injection pipeline at a pressure of ≥8MPa through the energy power supply system, and finally the liquid CO2 is injected into the rock mass fissures under the deep seabed through the CO2 storage injection device for storage; S13. During the carbon storage process, flow meters, pressure sensors, and gas sensors deployed on the offshore injection platform and CO2 injection pipeline start working to monitor the liquid CO2 injection flow, injection pressure, and CO2 concentration in real time to ensure that the liquid CO2 injection flow rate changes by no more than ±5%, the injection pressure changes by no more than ±3MPa, and the CO2 concentration is ≤1%.

2. According to claim 1, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: Including supply ships, offshore injection platforms, CO2 injection pipelines, CO2 capture and transportation mechanisms, and CO2 injection and storage devices; The offshore injection platform includes a jack-up platform, an energy and 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 an injection pipeline, and receives monitoring data in real time, and monitors the injection flow of CO2 through flow meters at both ends of the CO2 injection pipeline; the energy supply system includes a main power source and a backup power source; 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 meter is arranged at the inlet and outlet of the CO2 injection pipeline, and 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 by the pressure sensor and the gas sensor 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 processing device; The CO2 injection and storage device includes a first jet nozzle, a second jet nozzle, a ground-breaking and excavation system, a high-pressure hose, a cuttings processing device, a filter, an intelligent detection system, a power system, and a plume suppression cover, and is connected to the offshore injection platform through a CO2 injection pipeline; there are a total of 4 first-type jet nozzles for CO2 injection and storage; there are a total of 2 second-type jet nozzles for excavation and ground-breaking and cuttings cleaning; the ground-breaking and excavation mechanism includes a polycrystalline diamond composite drill bit, a bionic propulsion device, and a rotary guide system; the bionic propulsion device includes a hydraulic compartment, 4 propulsion rings, and 3 retractable mechanisms; the retractable mechanisms include 3 retractable rings and 3 control push rods, which are controlled by The push rod presses the liquid CO2 in the hydraulic tank into the propulsion ring, causing the propulsion ring to expand, thereby providing an anchoring force for the CO2 injection and sealing device to move forward; the high-pressure hose is arranged inside the CO2 injection and sealing mechanism, and is used for the injection of liquid CO2; the rock cuttings processing device includes a suction pipeline and a water storage tank; the intelligent detection device includes a high-precision positioning and navigation system, a drill bit adaptive adjustment system, and an acoustic wave reflection detector, which uses low-frequency sound waves to emit sound waves to underground rock formations and records the reflected wave signals of the sound waves propagating in the rock formations; the power control system includes an active drive motor and a torque and speed control system; the plume suppression hood is installed at the connection between the CO2 injection and sealing device and the CO2 injection pipeline.

3. According to claim 2, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: The CO2 injection pipeline is made of titanium alloy that can withstand a pressure of 50-100MPa, has a diameter of 2-5m, is laid in a J-shape on the seabed, and is suspended on an offshore injection platform. The lower end of the CO2 injection pipeline is connected to the CO2 injection and storage device through four high-pressure hoses with a diameter of 0.5-0.8m.

4. According to claim 2, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: The polycrystalline diamond composite drill bit comprises a polycrystalline diamond composite, a drill body, an elastic drill string, cutting teeth, blades, connecting pieces, water holes, polycrystalline particles, and drill coolant, which is connected to a first thrust ring via the connecting piece, and the drill coolant is transported to the drill body via the elastic drill string.

5. According to claim 2, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: There are four thrust rings in total, which are arranged at the front, middle and rear positions of the CO2 injection and storage device respectively, among which the fourth thrust ring is located at the rear, the first thrust ring is located at the front, and the second and third thrust rings are located in the middle. The second, third and fourth thrust rings are the main sources of forward power. The first thrust ring maintains the stability of the polycrystalline diamond composite sheet drill bit 6 during excavation and plays a transfer role of liquid CO2.

6. According to claim 2, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: The first type of jet nozzle is arranged at the front end of the polycrystalline diamond composite sheet drill bit, and the rear end thereof is connected to a high-pressure hose.

7. According to claim 2, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: There are three telescopic rings in total, 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. According to claim 2, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: The plume suppression cover is a retractable mechanism. As the excavation continues to go deeper into the seabed, the plume suppression cover shrinks along the drill bit body toward its installation position until the CO2 injection and storage device is completely excavated below the seabed.

9. According to claim 2, the deep-sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: The rotary steering system includes a direction sensor and a control system. The control system controls the drill bit to turn according to data fed back by the direction sensor.

10. According to claim 2, the deep sea deep rock and soil body intelligent excavation-carbon sequestration integrated equipment and method is characterized in that: The acoustic wave reflection detector uses low-frequency sound waves to transmit sound waves to underground rock formations, records the reflected wave signals of the sound waves propagating in the rock formations, and infers the distribution of rock mass cracks by analyzing the time, intensity and frequency of the sound wave reflections.

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