A dual supercritical treatment system and method for oil-based drilling cuttings

Abstract

The present application belongs to the technical field of oil-based drilling cuttings treatment, and particularly relates to a double-supercritical treatment system and method for oil-based drilling cuttings. The method comprises the following steps: feeding the oil-based drilling cuttings into a device for supercritical extraction of carbon dioxide, and supercritically extracting white oil; allowing the white oil in the supercritical carbon dioxide gas to be precipitated; then, cooling the precipitated carbon dioxide gas, and pressurizing it to a supercritical state for subsequent extraction; supercritically hydrothermally combusting the extracted oil-based drilling cuttings in a reactor to oxidize the residual substances in the drilling cuttings, and driving a turbine to work and drive a compressor to pressurize the carbon dioxide gas by using the supercritical water vapor generated by combustion; cooling the steam to liquid water, pressurizing it to a specified pressure or above, and then heating it to a supercritical state, with a part of the supercritical water being used for supercritical hydrothermal combustion, and the other part being used for providing heat energy for white oil precipitation, and using the combusted drilling cuttings as a heat source. The method can not only recover resources in the drilling cuttings, but also reduce energy consumption, and can more thoroughly treat the oil-based drilling cuttings.

Description

Technical Field

[0001] This invention belongs to the field of oil-based drilling cuttings treatment technology, specifically relating to a dual supercritical treatment system and method for oil-based drilling cuttings. Background Technology

[0002] With the exploitation of shale oil and gas and offshore oil and gas, the protection of producing formations has become increasingly important. Oil-based drilling fluids are also being used more widely. Compared to traditional water-based drilling fluids, oil-based drilling fluids are more difficult to process. In particular, the remaining oil-based drill cuttings contain various harmful organic and inorganic substances, including petroleum hydrocarbons, heavy metals, and water-soluble salts. Improper treatment can cause serious problems to the environment and human health; therefore, the efficient and harmless treatment and resource utilization of oil-based drill cuttings has become a current research hotspot.

[0003] Currently, methods for treating oil-based drill cuttings include surfactant washing, supercritical carbon dioxide extraction, supercritical / subcritical water treatment, pyrolysis adsorption, and microwave heating. Each method has its own distinct advantages and disadvantages: surfactant washing is simple, mild, and low-cost, but it results in low oil recovery rates, high oil content in the residue, and a tendency for secondary pollution from oily wastewater; supercritical carbon dioxide extraction has low material costs and can utilize the oil in the drill cuttings, with a short processing cycle, no pollution, and low oil content in the residue, but it consumes a lot of energy; supercritical water oxidation can completely convert organic pollutants into harmless inorganic small molecules, has a short processing time, and uses compact, portable equipment, but suffers from poor resource recovery. Other methods also exhibit similar problems such as poor resource recovery (low or no oil recovery rate), high energy consumption, and incomplete treatment.

[0004] As can be seen from existing technologies, it is difficult for any single technology to meet user needs. Summary of the Invention

[0005] One of the objectives of this invention is to provide a dual supercritical treatment method for oil-based drilling cuttings, which can recover resources from the cuttings as much as possible, reduce energy consumption, and more thoroughly treat oil-based drilling cuttings.

[0006] The method includes:

[0007] Step 1: The oil-based drill cuttings to be processed are fed into the equipment for supercritical carbon dioxide extraction, and carbon dioxide gas pressurized to the supercritical state and at the ideal extraction temperature and pressurized carrier are added in a certain proportion.

[0008] Step 2: Supercritical extraction of white oil from oil-based drill cuttings under the combined action of supercritical carbon dioxide and carrier.

[0009] Step 3: Transform the supercritical carbon dioxide that dissolves the white oil into a subcritical state and maintain a certain temperature to promote the precipitation of the white oil dissolved in the carbon dioxide gas.

[0010] The desorbed carbon dioxide gas is then cooled, pressurized to a supercritical state, and finally adjusted to the ideal temperature for carbon dioxide extraction for subsequent extraction; the pressurization process is performed by a compressor.

[0011] Step 4: The oil-based drill cuttings after extraction are directly fed into a reactor suitable for supercritical hydrothermal combustion, while heated supercritical steam and pure oxygen are introduced.

[0012] The residual material in the drill cuttings is oxidized by supercritical hydrothermal combustion in the reactor, which generates a large amount of heat and supercritical water vapor with high temperature and pressure.

[0013] Step 5: Use the supercritical steam generated by the aforementioned supercritical hydrothermal combustion to drive the steam turbine, and use the steam turbine to drive the compressor to pressurize the carbon dioxide gas;

[0014] Step 6: Cool the exhaust steam after the drive turbine has done work into liquid water, and pressurize the liquid water to a pressure above a specified level, while replenishing the water lost in the previous process from the outside.

[0015] Step 7: Heat the pressurized water to a supercritical state. Part of the water is used for subsequent supercritical hydrothermal combustion, and the other part is used to provide heat energy for the heat preservation of the aforementioned white oil precipitation process.

[0016] The heating process is completed by a heat exchanger assembly, which also introduces drill cuttings that have undergone supercritical hydrothermal combustion as a heat source.

[0017] Preferably, the heat exchanger group adopts a heat storage heating method, including multiple heat exchanger groups that operate alternately.

[0018] Preferably, in step 1, the pressurized oil-based drill cuttings are fed into a supercritical carbon dioxide extraction device.

[0019] Preferably, in step 2, the working pressure inside the equipment used for supercritical carbon dioxide extraction is 10-30 MPa.

[0020] Preferably, in step 2, the operating temperature inside the equipment used for supercritical carbon dioxide extraction is 30-70°C.

[0021] Preferably, in step 2, stirring extraction is used in the equipment for supercritical carbon dioxide extraction for 10 to 30 minutes.

[0022] Preferably, in step 2, the white oil dissolution rate is greater than 85%.

[0023] Preferably, in step 3, the analysis process is carried out under a pressure of 2.3 MPa.

[0024] Preferably, in step 3, the analysis process is carried out at a temperature of 225°C.

[0025] Preferably, in step 6, the liquid water is pressurized to above 22.1 MPa.

[0026] The method described in this invention involves a dual treatment of supercritical carbon dioxide extraction and supercritical hydrothermal oxidation of oil-based drill cuttings. This process not only utilizes the oil in the cuttings but also ensures their complete and harmless disposal. During this process, the energy required for pressurizing the supercritical carbon dioxide comes entirely from the supercritical water vapor produced during the supercritical hydrothermal oxidation process. The heat required to heat the liquid water comes from the residual heat energy on the oil-based drill cuttings after supercritical hydrothermal oxidation. Part of the supercritical water produced is used for supercritical hydrothermal combustion, and the other part is used to maintain the ambient temperature for the precipitation of white oil. Therefore, only the pressurization of the liquid water requires external energy input, and this energy is transferred to the supercritical water vapor produced during the supercritical hydrothermal oxidation process, which is then used for further pressurization of carbon dioxide. Furthermore, the chemical energy of the organic matter remaining on the oil-based drill cuttings is released through combustion and fully utilized throughout the process. Thus, thanks to the fact that the most energy-consuming supercritical carbon dioxide extraction section no longer requires external energy, and that the chemical energy of the residual organic matter is fully utilized, the total energy consumption of the entire process is greatly reduced.

[0027] In addition, since the oil-based rock cuttings undergo supercritical carbon dioxide extraction, the amount of organic matter that needs to be processed is reduced, which in turn reduces the amount of pure cation and pressurized water required in the supercritical hydrothermal oxidation process.

[0028] In some embodiments of the present invention, the heat exchanger group is a sealed tank regenerative heat exchanger. The high-temperature rock cuttings after supercritical hydrothermal combustion are sent into multiple heat exchanger groups. Each heat exchanger group adopts a regenerative heating method, alternately heating the high-pressure water. The use of regenerative heating instead of direct heating allows the high-temperature rock cuttings to have sufficient heat exchange time, improving the utilization efficiency of the residual heat energy on the rock cuttings.

[0029] Another object of the present invention is to provide a dual supercritical treatment system for oil-based drilling cuttings, comprising an oil-based cuttings conveyor, a supercritical CO2 extraction device, a carrier storage device, a carrier metering device, a carrier pressurizing pump, a pressure reducing valve, an oil separation device, a supercritical hydrothermal combustion reactor, a high-pressure water pump, a steam turbine, a heat exchanger assembly, a high-temperature feed conveyor, a CO2 compressor, a high-pressure CO2 cooling device, a low-pressure CO2 cooling device, a steam condensation device, and a low-pressure makeup water pump;

[0030] The oil-based drill cuttings conveyor is used to feed oil-based drill cuttings to be processed into the CO2 supercritical extraction equipment.

[0031] The supercritical CO2 extraction device, carrier meter, carrier pressurization pump, and carrier storage device are connected in sequence to form a pathway for quantitatively inputting pressurized carrier into the supercritical CO2 extraction device.

[0032] The CO2 compressor is used to pressurize the input carbon dioxide to a supercritical state and send it into the CO2 supercritical extraction equipment;

[0033] The supercritical CO2 extraction equipment is used to provide a working environment for supercritical carbon dioxide to extract white oil from oil-based drill cuttings with the help of a carrier.

[0034] The outlet of the supercritical CO2 extraction equipment used to output supercritical carbon dioxide is connected to the oil separation equipment via the pressure reducing valve.

[0035] The pressure reducing valve is used to convert the passing supercritical carbon dioxide into a subcritical state.

[0036] The oil separation equipment is used to provide a certain temperature environment for the precipitation of white oil by introducing supercritical water as a heat source, and can maintain a certain internal pressure.

[0037] The outlet for discharging oil-based drill cuttings on the CO2 supercritical extraction equipment is connected to the supercritical hydrothermal combustion reactor via a high-temperature feed conveyor.

[0038] The supercritical hydrothermal combustion reactor can be supplied with pure oxygen and supercritical water to produce supercritical hydrothermal combustion of supplied oil-based drill cuttings, pure oxygen, and supercritical water, thereby generating heat energy and supercritical steam with high temperature and high pressure.

[0039] The outlet of the supercritical hydrothermal combustion reactor for discharging supercritical steam is connected to the inlet of the steam turbine. The power output of the steam turbine is connected to the power input of the CO2 compressor. The outlet of the steam turbine for discharging exhaust steam is connected to the steam condensation equipment. The outlet of the steam condensation equipment is connected to the inlet of the high-pressure water pump. The outlet of the low-pressure makeup water pump is also connected to the inlet of the high-pressure water pump.

[0040] The steam turbine is used to drive the CO2 compressor using the energy of the introduced supercritical steam; the high-pressure water pump is used to pressurize the input liquid water to a certain pressure; and the low-pressure water supply pump is used to supply liquid water from the outside to the high-pressure water pump.

[0041] The outlet for carbon dioxide gas discharge on the oil separation equipment is connected to the inlet of the CO2 compressor via a high-pressure CO2 cooling device. The high-pressure CO2 cooling device is used to cool the carbon dioxide gas input to the CO2 compressor. The outlet of the CO2 compressor is connected to the supercritical carbon dioxide input of the supercritical CO2 extraction equipment via a low-pressure CO2 cooling device. The low-pressure CO2 cooling device is used to adjust the input supercritical carbon dioxide gas to the ideal temperature.

[0042] The outlet of the supercritical hydrothermal combustion reactor for discharging oil-based drill cuttings is connected to the heat energy input end of the heat exchanger group. The liquid water input end of the heat exchanger group is connected to the water outlet end of the high-pressure water pump. The heat exchanger group is used to heat the input liquid water into supercritical water vapor using the residual heat energy on the oil-based drill cuttings.

[0043] The outlet of the heat exchanger assembly is connected to the supercritical steam inlet of the supercritical hydrothermal combustion reactor on one hand, and to the steam inlet of the oil separation equipment on the other hand.

[0044] The system processes oil-based drill cuttings according to the aforementioned method and steps.

[0045] Preferably, the supercritical hydrothermal combustion reactor is a supercritical hydrothermal combustion continuous tubular reactor.

[0046] Furthermore, it also includes a solid-liquid separator connected between the supercritical hydrothermal combustion reactor and the steam turbine, used to remove solid impurities mixed in the input supercritical steam. Attached Figure Description

[0047] Figure 1 This is a schematic block diagram of a dual supercritical oil-based drilling cuttings treatment system according to an embodiment of the present invention.

[0048] The reference numerals in the accompanying drawings of the instruction manual include: 1. High-pressure water pump; 2A. First heat exchanger group; 2B. Second heat exchanger group; 3. Supercritical hydrothermal combustion continuous tubular reactor; 4. High-temperature feed conveyor; 5. Supercritical CO2 extraction tank; 6. Carrier metering device; 7. Carrier pressurization pump; 8. Carrier storage tank; 9. Recovered oil tank; 10. Oil separation vessel; 11. Pressure reducing valve; 12. Oil-based drill cuttings conveyor; 13. CO2 compressor; 14. Industrial steam turbine; 15. High-pressure CO2 air cooler; 16. Low-pressure CO2 air cooler; 17. Steam air cooler; 18. Solid-liquid separator; 19. Low-pressure makeup water pump. Detailed Implementation

[0049] The oil-based drilling cuttings dual supercritical processing system in this embodiment is basically as follows: Figure 1 As shown, it includes:

[0050] 1. High-pressure water pump; 2A and 2B of first and second heat exchanger groups; 3. Supercritical hydrothermal combustion continuous tubular reactor; 4. High-temperature feed conveyor; 5. Supercritical CO2 extraction tank; 6. Carrier metering device; 7. Carrier pressurization pump; 8. Carrier storage tank; 9. Recovered oil tank; 10. Oil separation vessel; 11. Pressure reducing valve; 12. Oil-based drill cuttings conveyor; 13. CO2 compressor; 14. Industrial steam turbine; 15. High-pressure CO2 air cooler; 16. Low-pressure CO2 air cooler; 17. Steam air cooler; 18. Solid-liquid separator; 19. Low-pressure makeup water pump.

[0051] Oil-based drill cuttings conveyor 12 is used to feed oil-based drill cuttings to be processed into the O2 supercritical extraction equipment;

[0052] The CO2 supercritical extraction tank 5, as an O2 supercritical extraction device, is sequentially connected to the carrier metering device 6, the carrier pressurization pump 7, and the carrier storage tank 8, as a carrier storage device, to form a pathway for quantitatively inputting pressurized carrier into the O2 supercritical extraction device.

[0053] CO2 compressor 13 is used to pressurize the input carbon dioxide to a supercritical state and send it into the CO2 supercritical extraction tank 5;

[0054] The CO2 supercritical extraction tank 5 is used to provide a working environment for supercritical carbon dioxide to extract white oil from oil-based drill cuttings with the help of a carrier.

[0055] The outlet of the supercritical CO2 extraction tank 5, which is used to output supercritical carbon dioxide, is connected to the oil separation vessel 10, which is an oil separation device, via a pressure reducing valve 11. The oil separation vessel 10 is also connected to the recovery oil tank 9.

[0056] Pressure reducing valve 11 is used to convert the passing supercritical carbon dioxide into a subcritical state.

[0057] The oil separation vessel 1 is used to provide a certain temperature environment for the precipitation of white oil by introducing supercritical water as a heat source, and can maintain a certain internal pressure.

[0058] The outlet of the CO2 supercritical extraction tank 5, used to deliver oil-based drill cuttings, is connected to the supercritical hydrothermal combustion continuous tubular reactor 3 via a high-temperature feed conveyor 14.

[0059] The supercritical hydrothermal combustion continuous tubular reactor 3 can introduce pure oxygen and supercritical steam to supply oil-based drill cuttings, pure oxygen, and supercritical steam for supercritical hydrothermal combustion to generate heat energy and supercritical steam with high temperature and high pressure.

[0060] The outlet of the supercritical hydrothermal combustion continuous tubular reactor 3, used to discharge supercritical steam, is connected to the inlet of the industrial steam turbine 14. A solid-liquid separator 18 is also provided between the supercritical hydrothermal combustion reactor and the industrial steam turbine to remove solid impurities mixed in the input supercritical steam. The power output of the industrial steam turbine 14 is connected to the power input of the CO2 compressor 13. The outlet of the exhaust steam from the industrial steam turbine 14 is connected to the steam air cooler 17, which serves as a steam condensation device. The outlet of the steam air cooler 17 is connected to the inlet of the high-pressure water pump 1, and the outlet of the low-pressure makeup water pump 19 is also connected to the inlet of the high-pressure water pump 1.

[0061] The industrial steam turbine 14 is used to drive the CO2 compressor to work using the energy of the supercritical steam. The CO2 compressor is used to pressurize the input carbon dioxide gas to a supercritical state. The high-pressure water pump 1 is used to pressurize the input liquid water to a specified pressure. The low-pressure water pump 19 is used to replenish the high-pressure water pump from the outside.

[0062] The outlet for carbon dioxide gas discharge on the oil separator 10 is connected to the inlet of the CO2 compressor 13 via a high-pressure CO2 air cooler 15, which serves as a high-pressure CO2 cooling device. The high-pressure CO2 air cooler 15 is used to cool the carbon dioxide gas input to the CO2 compressor 13. The outlet of the CO2 compressor 13 is connected to the supercritical carbon dioxide input of the supercritical CO2 extraction tank 5 via a low-pressure CO2 air cooler 16, which serves as a low-pressure CO2 cooling device. The low-pressure CO2 air cooler 16 is used to adjust the input supercritical carbon dioxide gas to an ideal temperature. The outlet of the supercritical hydrothermal combustion continuous tubular reactor 3, used to discharge oil-based drill cuttings, is connected to the heat energy input end of the heat exchanger group. The liquid water input end of the heat exchanger group is connected to the water outlet end of the high-pressure water pump 1. The heat exchanger group is used to heat the input liquid water into supercritical water vapor using the residual heat energy on the oil-based drill cuttings. It is worth noting that the feeding device that sends the oil-based rock cuttings that have undergone supercritical hydrothermal combustion into the heat exchanger group should be a feeding device that can withstand a certain high temperature, such as a high-temperature feed conveyor 4. The specific settings are well known to those skilled in the art and will not be described here.

[0063] The outlet of the heat exchanger assembly is connected to the supercritical steam inlet of the supercritical hydrothermal combustion continuous tubular reactor 3 on one hand, and to the steam inlet of the oil separator 10 on the other.

[0064] The connecting pipelines used for gas and liquid flow between different devices in the system are well known to those skilled in the art and will not be described here.

[0065] In this embodiment, the oil-based drilling cuttings dual supercritical treatment method specifically implemented using this system is as follows:

[0066] 1) The oil-based drill cuttings to be processed are pressurized by the oil-based drill cuttings conveyor 12 and enter the CO2 supercritical extraction tank 5. At the same time, carbon dioxide gas, which is pressurized to the supercritical state by the CO2 compressor 13, is added in a certain proportion, and the carrier is conveyed by the carrier pressurization pump 7 and measured by the carrier meter 6.

[0067] 2) Supercritical extraction is performed under the combined action of the aforementioned oil-based drill cuttings, supercritical carbon dioxide, and a carrier. Under supercritical conditions and with the help of the carrier, the white oil in the oil-based drill cuttings dissolves into the supercritical carbon dioxide fluid. Typical operating conditions are a working pressure of 10-30 MPa, a working temperature of 30-70℃, and stirring extraction for 10-30 minutes, achieving a white oil dissolution rate greater than 85%. The shorter the dissolution time, the lower the white oil dissolution rate. In this step, the working efficiency can be improved by adjusting the time.

[0068] 3) The supercritical CO2 that dissolves the white oil is converted to a subcritical state after passing through a pressure reducing valve. Under a certain temperature within the oil separation vessel 10, the subcritical CO2 hardly dissolves the white oil. Therefore, the white oil originally dissolved in the CO2 gas precipitates out and flows into the recovery oil tank 9. The decomposed CO2 gas then enters the CO2 compressor 13 and is pressurized again. The heat required during the decomposition process is provided by the first heat exchanger group 2A and the second heat exchanger group 2B, eliminating the need for external energy. Typical decomposition conditions are 2.3 MPa and 225℃.

[0069] 4) After being cooled by the low-pressure CO2 air cooler 16, the decomposed carbon dioxide is compressed to a supercritical state by the CO2 compressor 13, and then adjusted to the ideal temperature for carbon dioxide extraction by the high-pressure CO2 air cooler 15. The compressor 12 in the compression process is directly driven by the industrial steam turbine 14, so no external energy is required.

[0070] 5) The treated oil-based drill cuttings from the CO2 supercritical extraction tank 5 contain a small amount of white oil, carrier residues, and other organic matter that cannot be dissolved in supercritical carbon dioxide. They are directly transported to the supercritical hydrothermal combustion continuous tubular reactor 3 by the high-temperature feed conveyor 4. At the same time, supercritical steam heated from the first heat exchanger group 2A and the second heat exchanger group 2B is introduced, and pure oxygen is added at an appropriate position. Then, through supercritical hydrothermal combustion, the oil stains, carrier residues, and other residues in the drill cuttings are completely oxidized, and a large amount of heat is generated at the same time. The supercritical steam with high temperature and high pressure is discharged from the upper outlet of the supercritical hydrothermal combustion continuous tubular reactor 3.

[0071] 6) The supercritical steam discharged from the upper outlet of reactor 3 is separated by solid-liquid separator 18 to remove the mixed solid impurities and enters industrial steam turbine 14 to drive it to rotate at high speed. Industrial steam turbine 14 is used to drive CO2 compressor 13 to work, and no external energy is needed.

[0072] 7) The exhaust steam after doing work in the steam turbine 14 is fed into the steam air cooler 17 to be cooled into liquid water, and then enters the high-pressure water pump 1, which is responsible for pressurizing the condensate to above 22.1 MPa. Some of the water lost is replenished by the low-pressure water supply pump 19.

[0073] 8) The high-pressure water from high-pressure water pump 1 is heated to a supercritical state through the first heat exchanger group 2A and the second heat exchanger group 2B. Both heat exchanger groups are regenerative heat exchangers. High-temperature rock cuttings, after being treated by supercritical hydrothermal combustion, are sent from the continuous tubular reactor 3 into the first heat exchanger group 2A and the second heat exchanger group 2B, along with some supercritical water contained in these high-temperature rock cuttings. The two heat exchanger groups use a regenerative heating method to alternately heat the high-pressure water. The high-pressure water is heated to a supercritical state by the rock cuttings after the reaction, and at the same time, the rock cuttings are cooled. After the rock cuttings in one heat exchanger are cooled, the process switches to the other heat exchanger group for continued heating. After the cooled rock cuttings are discharged, they continue to be cooled to room temperature in the air, thus completing the harmless resource recovery and treatment of oil-based rock cuttings.

[0074] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A dual supercritical treatment method for oil-based drilling cuttings, characterized in that, include: Step 1: The oil-based drill cuttings to be processed are fed into the equipment for supercritical carbon dioxide extraction, and carbon dioxide gas pressurized to the supercritical state and at the ideal extraction temperature and pressurized carrier are added in a certain proportion. Step 2: Supercritical extraction of white oil from oil-based drill cuttings under the combined action of supercritical carbon dioxide and carrier. Step 3: Transform the supercritical carbon dioxide that dissolves the white oil into a subcritical state and maintain a certain temperature to promote the precipitation of the white oil dissolved in the carbon dioxide gas. The desorbed carbon dioxide gas is then cooled, pressurized to a supercritical state, and finally adjusted to the ideal temperature for carbon dioxide extraction for subsequent extraction; the pressurization process is performed by a compressor. Step 4: The oil-based drill cuttings after extraction are directly fed into a reactor suitable for supercritical hydrothermal combustion, while heated supercritical steam and pure oxygen are introduced. The residual material in the drill cuttings is oxidized by supercritical hydrothermal combustion in the reactor, which generates a large amount of heat and supercritical water vapor with high temperature and pressure. Step 5: Use the supercritical steam generated by the aforementioned supercritical hydrothermal combustion to drive the steam turbine, and use the steam turbine to drive the compressor to pressurize the carbon dioxide gas; Step 6: Cool the exhaust steam after the drive turbine has done work into liquid water, and pressurize the liquid water to a pressure above a specified level, while replenishing the water lost in the previous process from the outside. Step 7: Heat the pressurized water to a supercritical state. Part of the water is used for subsequent supercritical hydrothermal combustion, and the other part is used to provide heat energy for the heat preservation of the aforementioned white oil precipitation process. The heating process is completed by a heat exchanger assembly, which also introduces drill cuttings that have undergone supercritical hydrothermal combustion as a heat source.

2. The method according to claim 1, characterized in that, The heat exchanger group adopts a heat storage heating method and includes multiple heat exchanger groups that work alternately.

3. The method according to claim 1, characterized in that, In step 2, the working pressure inside the equipment used for supercritical carbon dioxide extraction is 10-30 MPa.

4. The method according to claim 1, characterized in that, In step 2, the operating temperature inside the equipment used for supercritical carbon dioxide extraction is 30-70℃.

5. The method according to claim 1, characterized in that, In step 2, stirring extraction is used in the equipment for supercritical carbon dioxide extraction for 10-30 minutes.

6. The method according to claim 1, characterized in that, In step 3, the analysis process is carried out under a pressure of 2.3 MPa.

7. The method according to claim 1, characterized in that, In step 3, the analysis process is carried out at a temperature of 225℃.

8. The method according to claim 1, characterized in that, In step 6, the liquid water is pressurized to above 22.1 MPa.

9. A dual supercritical processing system for oil-based drilling cuttings, characterized in that, This includes oil-based drill cuttings conveyors, supercritical CO2 extraction equipment, carrier storage equipment, carrier metering devices, carrier pressurization pumps, pressure reducing valves, oil separation equipment, supercritical hydrothermal combustion reactors, high-pressure water pumps, steam turbines, heat exchanger units, high-temperature feed conveyors, CO2 compressors, high-pressure CO2 cooling equipment, low-pressure CO2 cooling equipment, steam condensation equipment, and low-pressure makeup water pumps; The oil-based drill cuttings conveyor is used to feed oil-based drill cuttings to be processed into the CO2 supercritical extraction equipment. The supercritical CO2 extraction device, carrier meter, carrier pressurization pump, and carrier storage device are connected in sequence to form a pathway for quantitatively inputting pressurized carrier into the supercritical CO2 extraction device. The CO2 compressor is used to pressurize the input carbon dioxide to a supercritical state and send it into the CO2 supercritical extraction equipment; The supercritical CO2 extraction equipment is used to provide a working environment for supercritical carbon dioxide to extract white oil from oil-based drill cuttings with the help of a carrier. The outlet of the supercritical CO2 extraction equipment used to output supercritical carbon dioxide is connected to the oil separation equipment via the pressure reducing valve. The pressure reducing valve is used to convert the passing supercritical carbon dioxide into a subcritical state. The oil separation equipment is used to provide a certain temperature environment for the precipitation of white oil by introducing supercritical water as a heat source, and can maintain a certain internal pressure. The outlet for discharging oil-based drill cuttings on the CO2 supercritical extraction equipment is connected to the supercritical hydrothermal combustion reactor via a high-temperature feed conveyor. The supercritical hydrothermal combustion reactor can be supplied with pure oxygen and supercritical water to produce supercritical hydrothermal combustion of supplied oil-based drill cuttings, pure oxygen, and supercritical water, thereby generating heat energy and supercritical steam with high temperature and high pressure. The outlet of the supercritical hydrothermal combustion reactor for discharging supercritical steam is connected to the inlet of the steam turbine. The power output of the steam turbine is connected to the power input of the CO2 compressor. The outlet of the steam turbine for discharging exhaust steam is connected to the steam condensation equipment. The outlet of the steam condensation equipment is connected to the inlet of the high-pressure water pump. The outlet of the low-pressure makeup water pump is also connected to the inlet of the high-pressure water pump. The steam turbine is used to drive the CO2 compressor using the energy of the introduced supercritical steam; the high-pressure water pump is used to pressurize the input liquid water to a certain pressure; and the low-pressure water supply pump is used to supply liquid water from the outside to the high-pressure water pump. The outlet for carbon dioxide gas discharge on the oil separation equipment is connected to the inlet of the CO2 compressor via a high-pressure CO2 cooling device. The high-pressure CO2 cooling device is used to cool the carbon dioxide gas input to the CO2 compressor. The outlet of the CO2 compressor is connected to the supercritical carbon dioxide input of the supercritical CO2 extraction equipment via a low-pressure CO2 cooling device. The low-pressure CO2 cooling device is used to adjust the input supercritical carbon dioxide gas to the ideal temperature. The outlet of the supercritical hydrothermal combustion reactor for discharging oil-based drill cuttings is connected to the heat energy input end of the heat exchanger group. The liquid water input end of the heat exchanger group is connected to the water outlet end of the high-pressure water pump. The heat exchanger group is used to heat the input liquid water into supercritical water vapor using the residual heat energy on the oil-based drill cuttings. The outlet of the heat exchanger assembly is connected to the supercritical steam inlet of the supercritical hydrothermal combustion reactor on one hand, and to the steam inlet of the oil separation equipment on the other hand. The system processes oil-based drill cuttings according to the steps of any one of the methods described in claims 1-8.

10. The system according to claim 9, characterized in that, It also includes a solid-liquid separator connected between the supercritical hydrothermal combustion reactor and the steam turbine, used to remove solid impurities mixed in the input supercritical steam.

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