Shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis

Abstract

This invention discloses a shale oil extraction method based on multi-stage pulsed gas fracturing and synergistic nanocatalysis, belonging to the field of oilfield development technology. The method includes the following steps: S1, determining the optimal drilling location of the target shale formation and conducting drilling operations; S2, using a high-frequency solenoid valve to control and generate an adjustable pulsed pressure wave of 0.1–10 Hz, injecting fracturing media mixed with functionalized nanoparticles into the formation via a fracturing pump, adjusting the pulse frequency of the high-frequency solenoid valve to perform staged pulsed fracturing operations, forming a fracture network; S3, after each stage of fracturing, injecting a mixture of proppant and fracturing fluid into the formation fractures; S4, after the fracturing operation is completed, applying a microwave field to the formation to maintain the formation temperature within a set range. This invention significantly reduces the environmental impact by using a mixture of gas fracturing media and functionalized nanoparticles for fracturing, and substantially improves the recovery rate of shale oil through the combined action of multi-stage pulsed fracturing, composite proppant, and microwave field.

Description

Technical Field

[0001] This invention relates to the field of oilfield development technology, and in particular to a shale oil extraction method based on the synergy of multi-stage pulsed gas fracturing and nanocatalysis. Background Technology

[0002] In-situ extraction technology for oil shale aligns with current green and low-carbon extraction principles and is a popular research direction in oil shale extraction technology. However, oil shale itself is a type of shale with extremely low porosity and permeability, making it difficult to efficiently extract shale oil and pyrolysis gas simply through heating. Typical in-situ heating techniques for oil shale require combination with hydraulic fracturing to create fractures, but traditional hydraulic fracturing techniques suffer from high water consumption, severe reservoir damage, and uneven proppant distribution. While existing gas fracturing technology is environmentally friendly, it has drawbacks such as difficulty in controlling fracture propagation and insufficient improvement in crude oil fluidity.

[0003] To address the aforementioned issues, a shale oil extraction method based on the synergistic effect of multi-stage pulsed gas fracturing and nanocatalysis is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy, so as to solve the problems in the background art.

[0005] To achieve the above objectives, this invention provides a shale oil extraction method based on the synergistic effect of multi-stage pulsed gas fracturing and nanocatalysis, comprising the following steps:

[0006] S1. Conduct geological exploration of the target shale oil reservoir, determine the optimal drilling location of the target shale layer, and carry out drilling operations;

[0007] S2. A high-frequency solenoid valve is used to control the formation of an adjustable pulse pressure wave of 0.1 to 10 Hz. The fracturing medium mixed with functionalized nanoparticles is injected into the formation through a fracturing pump. The pulse frequency of the high-frequency solenoid valve is adjusted to carry out staged pulse fracturing operations and form a fracture network.

[0008] S3. After each stage of fracturing operation is completed, the mixture of proppant and fracturing fluid is injected into the formation fractures using a pumping device.

[0009] S4. After the fracturing operation is completed, a microwave field is applied to the formation to maintain the formation temperature within the set range and improve the extraction efficiency of shale oil.

[0010] Preferably, step S2 specifically includes the following steps:

[0011] S21. First stage fracturing: Adjust the pulse frequency of the high-frequency solenoid valve to 0.5-2Hz, and inject fracturing medium mixed with functionalized nanoparticles into the formation at a pressure of 8-12MPa through the fracturing pump. Continuously apply low-frequency pulse pressure waves to form a main fracture network in the shale layer.

[0012] S22. Second stage fracturing: After the first stage fracturing is completed, increase the pressure of the fracturing pump to 15-20 MPa, adjust the pulse frequency of the high-frequency solenoid valve to 3-5 Hz, and use the medium-frequency pulse pressure wave to expand the secondary fracture.

[0013] S23. Third stage fracturing: After the second stage is completed, the fracturing pump pressure is increased to 25-30 MPa, and the pulse frequency of the high-frequency solenoid valve is adjusted to 8-10 Hz. Under the action of the high-frequency pulse pressure wave, the micro-fracture is connected.

[0014] Preferably, the fracturing medium is a mixture of liquid CO2 and nitrogen in a volume ratio of 3:1; the functionalized nanoparticles are Fe3O4@SiO2 core-shell structured functionalized nanoparticles with a particle size of 50-80 nm.

[0015] Preferably, the preparation steps of the functionalized nanoparticles are as follows: surface modification of Fe3O4@SiO2 core-shell structured nanoparticles to introduce amino groups and load transition metal catalyst Ni-Mo, and then coating the surface of the obtained nanoparticles with a temperature-sensitive polymer coating to obtain functionalized nanoparticles.

[0016] Preferably, in step S3, the proppant is a composite proppant with ceramsite as the matrix material, an outer coating of a shape memory polymer layer, and an inner pH-responsive microcapsule; the composite proppant has an embedded RFID chip.

[0017] The particle size of the ceramic granules is 0.3–0.6 mm, the thickness of the shape memory polymer layer is 50–100 μm, and the diameter of the pH-responsive microcapsules is 10 μm.

[0018] Preferably, in step S3, after each stage of fracturing operation is completed, composite proppant with different particle sizes is injected sequentially.

[0019] The specific steps are as follows:

[0020] 1) After the first stage of fracturing is completed, inject small-diameter proppant: Add the quality-inspected composite proppant and fracturing fluid to the mixing equipment in a predetermined ratio, turn on the stirring device, and stir thoroughly to make the composite proppant evenly dispersed in the fracturing fluid to obtain a mixture;

[0021] Start the wellhead injection pump at a rate of 5-10m. 3 The mixture is injected into the formation at an injection rate of / h;

[0022] 2) After the second stage of fracturing is completed, inject medium-sized proppant according to the method in step 1), at an injection rate of 10–15 m / s. 3 / h;

[0023] 3) After the third stage of fracturing is completed, inject large-diameter proppant according to the method in step 1), at an injection rate of 15–20 m / s. 3 / h.

[0024] Preferably, the specific steps of S4 are as follows:

[0025] S41. Install microwave transmitters and microwave radiators at predetermined locations and connect them using microwave transmission pipes, and simultaneously install downhole fiber optic temperature measurement systems.

[0026] S42. Start the microwave transmitter and apply a microwave field to the formation for 30-60 minutes. Use a downhole fiber optic temperature measurement system to monitor the formation temperature in real time and adjust the microwave output precisely according to the temperature changes.

[0027] Preferably, the microwave field emitted by the microwave transmitting device has an output frequency of 2.45 GHz and an output power of 5–10 kW / m. 3 The downhole fiber optic temperature measurement system consists of fiber optic sensors and is deployed near the fracturing area.

[0028] Preferably, the control conditions of the downhole fiber optic temperature measurement system are as follows:

[0029] 1) When the temperature is >120℃, reduce the microwave output power or stop microwave transmission to prevent excessively high formation temperature from damaging the shale formation structure and mining equipment;

[0030] 2) When the temperature is <80℃, increase the microwave output power and improve the energy intensity of the microwave field to promote further cracking and flow of shale oil.

[0031] Therefore, the shale oil extraction method based on the synergistic effect of multi-stage pulsed gas fracturing and nanocatalysis of the present invention has the following beneficial effects:

[0032] (1) In this invention, a mixture of liquid CO2 and nitrogen is used as the fracturing medium. Combined with high-frequency solenoid valve control, an adjustable pulse pressure wave is formed, which can effectively avoid environmental problems such as water consumption and formation pollution caused by traditional hydraulic fracturing. Using gas as the fracturing medium reduces damage to the formation and avoids the problem of expansion of water-sensitive minerals. At the same time, the three-stage fracturing design gradually increases the complexity of the fracture network. The multi-stage pulse design can flexibly adjust parameters according to different geological conditions, which helps to improve the recovery rate of shale oil.

[0033] (2) In this invention, functionalized nanoparticles are mixed with fracturing media and injected into the formation. The small size of the nanoparticles allows them to penetrate deep into the microfractures and play a catalytic role. The introduction of amino groups on the surface enhances the bonding force between the nanoparticles and the shale surface. The supported transition metal catalyst Ni-Mo can promote the cracking and upgrading of crude oil, which helps to crack heavy oil into light oil and improve the fluidity of shale oil. The temperature-sensitive polymer coating enables controlled release. The temperature-sensitive characteristics ensure that the catalyst can play its role at the appropriate temperature, which improves efficiency and reduces waste.

[0034] (3) The composite proppant in this invention combines multiple functions such as ceramic matrix, shape memory polymer coating layer, pH-responsive microcapsule and RFID chip, which can adapt to complex fracture morphology, improve the support effect and provide real-time monitoring data; among them, the softening properties of shape memory polymer at high temperature enable it to better fit the fracture wall, while pH-responsive microcapsule can release surfactant when it encounters crude oil, reduce the oil-water interfacial tension, help improve the fluidity of shale oil and increase the recovery rate.

[0035] (4) In this invention, microwave field is used to provide a new means for heating and flowing shale oil. Microwave heating is fast and can quickly increase the temperature of shale layer and promote the flow of crude oil. Precise energy control is achieved through downhole fiber optic temperature measurement system, which ensures the safety and efficiency of microwave field and can effectively avoid the problem of overheating or underheating. At the same time, it ensures the uniform coverage of microwave field on target area.

[0036] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0037] Figure 1 This is a flowchart of an embodiment of the present invention. Detailed Implementation

[0038] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0040] Example

[0041] The method of this invention for shale oil extraction in a certain block specifically includes the following steps:

[0042] S1. The following information was obtained through geological mapping and seismic exploration:

[0043] Target stratigraphy: Lower Jurassic Qianfoya Formation, Section 1 (J2q1);

[0044] Reservoir characteristics: Rich in organic matter, low porosity, and extremely low permeability, it is a typical tight shale oil reservoir;

[0045] The target shale layer was determined to be between 2,500 and 3,000 meters deep and approximately 80 meters thick, and drilling operations were carried out accordingly.

[0046] S2-S3: A high-frequency solenoid valve is used to control and generate an adjustable pulse pressure wave of 0.1–10 Hz. A fracturing medium mixed with functionalized nanoparticles is injected into the formation via a fracturing pump. The pulse frequency of the high-frequency solenoid valve is adjusted to perform staged pulse fracturing operations, forming a fracture network. After each stage of fracturing is completed, a mixture of proppant and fracturing fluid is injected into the formation fractures using a pumping device. Details are as follows:

[0047] 1) Preparatory work:

[0048] Preparation of fracturing medium: Liquid CO2 and nitrogen are mixed in a volume ratio of 3:1, ensuring the mixing process is carried out in a safe and controlled environment to guarantee thorough and homogeneous mixing of the two gases to obtain the fracturing medium. The mixed fracturing medium is stored in a specialized pressure vessel to ensure its stability during storage and transportation.

[0049] Customized or prepared Fe3O4@SiO2 core-shell structured functionalized nanoparticles are prepared by using existing methods to synthesize Fe3O4@SiO2 core-shell structured nanoparticles, controlling their particle size within the range of 50-80 nm, and ensuring uniform particle size and stable structure of nanoparticles by precisely controlling the synthesis process parameters.

[0050] Then, the nanoparticles are surface modified: amino groups are introduced onto the surface of the nanoparticles through chemical methods to enhance their adsorption capacity on the shale surface. In this embodiment, a silane coupling agent is used to chemically react with SiO2 on the surface of the nanoparticles, thereby grafting amino groups onto them.

[0051] Then, the transition metal catalyst Ni-Mo is loaded: the solution containing Ni-Mo metal ions is mixed with nanoparticles by impregnation, and Ni-Mo metal is loaded onto the surface of nanoparticles by existing methods to promote the cracking reaction of crude oil.

[0052] Finally, a temperature-sensitive polymer coating with a low critical solution temperature (LCST) of 60°C is coated onto the surface of the obtained nanoparticles. In this embodiment, a solution coating process is used to ensure that the temperature-sensitive polymer is uniformly covered on the surface of the nanoparticles, enabling the controlled release of the nanoparticles.

[0053] The aforementioned nanoparticles are mixed into fracturing gas in a predetermined ratio and then applied to fracturing operations.

[0054] Preparation of the composite proppant: First, ceramsite with a particle size of 0.3–0.6 mm is selected as the proppant matrix. A layer of shape memory polymer with a thickness of 50–100 μm is coated on the surface of the ceramsite. In this embodiment, a thermal spraying method is used to ensure that the shape memory polymer is uniformly covered on the surface of the ceramsite. The shape memory polymer can change shape at a specific temperature, thereby adapting to the morphology of the crack;

[0055] Then, pH-responsive microcapsules with a diameter of 10 μm were introduced into the proppant. In this embodiment, the microcapsules were uniformly distributed in the proppant through physical mixing. The microcapsules contain surfactants, which rupture upon contact with crude oil, releasing the surfactants, reducing the surface tension of the crude oil, and improving its fluidity.

[0056] Finally, an RFID chip is embedded in the obtained proppant for real-time monitoring of its distribution within the fracture. In this embodiment, existing encapsulation technology is used to fix the RFID chip inside the proppant, ensuring that the chip can function properly in fracturing and formation environments.

[0057] Composite proppant with diameters of 0.3 mm, 0.05 mm, and 0.08 mm was prepared using the above method. The proppant was then mixed with fracturing fluid at a volume ratio of 3% to ensure uniform dispersion of the proppant in the fracturing fluid.

[0058] 2) Perform staged fracturing operations and inject composite proppant: During fracturing gas injection, simultaneously inject nanofluid mixed with functionalized nanoparticles, with the concentration controlled at 0.5 wt%. Inject the fracturing medium mixed with functionalized nanoparticles into the fracturing string via a high-pressure pump, activate the high-frequency solenoid valve, and perform fracturing operations in three stages according to the preset program, as follows:

[0059] ① First-stage fracturing: The pulse frequency of the high-frequency solenoid valve is adjusted to 0.5-2Hz. The fracturing medium mixed with functionalized nanoparticles is injected into the formation at a pressure of 8-12MPa through the fracturing pump. Low-frequency pulse pressure waves are continuously applied. Through the action of the low-frequency pulse pressure waves, the periodic changes in pressure cause stress concentration in the shale layer in different directions, thereby gradually forming interconnected main fractures. In this stage, a preliminary main fracture network is successfully formed in the shale layer, and the extension of fractures in different directions is observed through downhole monitoring equipment.

[0060] The mixture of composite proppant with a particle size of 0.3 mm and fracturing fluid was prepared at an 8m... 3At an injection rate of / h, small-diameter proppant is injected into the formation. During this stage, the proppant mainly enters the narrower fractures formed in the early stage of fracturing, initially establishing a support structure and providing a foundation for the subsequent injection of large-diameter proppant.

[0061] ② Second-stage fracturing: After the first-stage fracturing is completed, the pressure of the fracturing pump is increased to 15-20 MPa, and the pulse frequency of the high-frequency solenoid valve is adjusted to 3-5 Hz. The secondary fractures are expanded using medium-frequency pulse pressure waves. During this process, based on the formation of the main fracture network, the medium-frequency pulse pressure waves can further destroy the rock structure of the shale layer, causing a large number of secondary fractures to appear around the main fractures. The complexity of the fracture network increases significantly, the connectivity of the fractures increases, and the permeability of the shale layer is improved.

[0062] The mixture of composite proppant with a particle size of 0.5 mm and fracturing fluid was prepared at a flow rate of 12 m. 3 Injected into the formation at an injection rate of / h, this stage allows medium-sized proppant to further fill fractures, enhance propping strength, and expand propping range on the basis of existing small-sized proppant;

[0063] S23. Third-stage fracturing: After the second stage is completed, the fracturing pump pressure is increased to 25-30 MPa, and the pulse frequency of the high-frequency solenoid valve is adjusted to 8-10 Hz. Under the action of high-frequency pulse pressure waves, micro-fractures are connected. During this process, the high-frequency pressure waves can further promote the development and expansion of micro-fractures on the basis of secondary fractures, enabling the micro-fractures in the shale layer to connect with each other, forming a denser fracture network, thereby improving the seepage channels of shale oil.

[0064] The mixture of composite proppant with a particle size of 0.8 mm and fracturing fluid was prepared at 18 m... 3 At an injection rate of / h, large-diameter proppant is injected into the formation. During this stage, it primarily fills the widest parts of the fractures, forming a stable support framework to ensure the fractures remain open during long-term production, providing a continuous channel for shale oil flow. Throughout the injection process, parameters such as wellhead pressure and injection flow rate must be closely monitored, and the injection rate and the proppant-to-fracturing fluid mixing ratio should be adjusted promptly based on formation feedback.

[0065] During the above process, the nanoparticles enter the shale fractures along with the fracturing gas, and their surface amino groups are rapidly adsorbed onto the shale surface, enhancing the bonding force between the nanoparticles and the shale. When the downhole temperature reaches 60°C, the temperature-sensitive polymer coating undergoes a phase transition, releasing the supported Ni-Mo catalyst. Under the action of the catalyst, the crude oil begins to undergo a cracking reaction, with large molecular hydrocarbons gradually transforming into small molecular hydrocarbons, reducing the viscosity of the crude oil and improving its fluidity.

[0066] As downhole temperatures rise above 80°C, the shape memory polymer coating softens, allowing the proppant to adapt to fracture morphology changes and maintain effective support. When crude oil comes into contact with the proppant, pH-responsive microcapsules release surfactants, reducing the surface tension of the crude oil and promoting its flow. Furthermore, the distribution of the proppant within the fractures is monitored in real-time using RFID readers on the surface, allowing for adjustments to subsequent production parameters based on the monitoring data.

[0067] S4. After the composite proppant injection is completed, a microwave field is applied to the formation to maintain the formation temperature within a set range, thereby improving the shale oil extraction efficiency. Specifically:

[0068] Microwave transmitters and microwave radiators are installed at predetermined locations and connected via microwave transmission pipes, while an underground fiber optic temperature measurement system is installed simultaneously.

[0069] The microwave transmitter was activated, applying an output frequency of 2.45 GHz and an output power of 5–10 kW / m into the formation. 3 The microwave field lasts for 45 minutes. The formation temperature is monitored in real time using a downhole fiber optic temperature measurement system. The microwave output is precisely controlled according to the temperature changes to maintain the reservoir temperature within the range of 80 to 120°C.

[0070] 1) When the temperature is >120℃, reduce the microwave output power or stop microwave transmission to prevent excessively high formation temperature from damaging the shale formation structure and mining equipment;

[0071] 2) When the temperature is <80℃, increase the microwave output power and improve the energy intensity of the microwave field to promote further cracking and flow of shale oil.

[0072] An assessment of the effectiveness of mining operations in the area:

[0073] After adopting this extraction method, the daily oil production per shale well in the region increased from approximately 5 tons to over 12.5 tons, a significant increase. It is estimated that the total shale oil production in the entire extraction area will increase by 2 to 3 times compared to the original level. Furthermore, during this process, CO2 sequestration increased by 40%, and water consumption per ton of crude oil decreased to 0.5 m³. 3 The nanocatalyst has a recovery rate of >85%, reduces operating costs by 30%, and reduces carbon emissions by 45%.

[0074] Analysis of the crude oil composition revealed that, through the action of the nano-catalytic upgrading system, the content of light components in the extracted crude oil increased, the API gravity of the crude oil increased by 5-8°, the viscosity decreased by 60-70%, the quality was significantly improved, and the market value of the crude oil was increased.

[0075] RFID monitoring data showed that the proppant was evenly distributed in the fractures, with no obvious displacement or collapse. This is because the composite proppant effectively maintained the open state of the fractures, ensuring the long-term stability of shale oil extraction.

[0076] Therefore, the present invention provides a shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis. By mixing gas fracturing media and functionalized nanoparticles for fracturing, the environmental impact is significantly reduced. The combined effect of multi-stage pulsed fracturing, composite proppant, and microwave field greatly improves the recovery rate of shale oil.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy, characterized in that, Includes the following steps: S1. Conduct geological exploration of the target shale oil reservoir, determine the optimal drilling location of the target shale layer, and carry out drilling operations; S2. A high-frequency solenoid valve is used to control and generate an adjustable pulse pressure wave of 0.1-10Hz. The fracturing medium mixed with functionalized nanoparticles is injected into the formation through a fracturing pump. The pulse frequency of the high-frequency solenoid valve is adjusted to perform staged pulse fracturing operations and form a fracture network. The functionalized nanoparticles are Fe3O4@SiO2 core-shell structure functionalized nanoparticles. The preparation steps of the functionalized nanoparticles are as follows: the Fe3O4@SiO2 core-shell structure nanoparticles are surface modified to introduce amino groups and loaded with a transition metal catalyst Ni-Mo. Then, a temperature-sensitive polymer coating is coated on the surface of the obtained nanoparticles to obtain functionalized nanoparticles. S3. After each stage of fracturing operation is completed, the mixture of proppant and fracturing fluid is injected into the formation fractures using a pumping device. S4. After the fracturing operation is completed, a microwave field is applied to the formation to maintain the formation temperature within the set range and improve the extraction efficiency of shale oil.

2. The shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy according to claim 1, characterized in that: S2 specifically includes the following steps: S21. First stage fracturing: Adjust the pulse frequency of the high-frequency solenoid valve to 0.5-2Hz, and inject fracturing medium mixed with functionalized nanoparticles into the formation at a pressure of 8-12MPa through the fracturing pump. Continuously apply low-frequency pulse pressure waves to form a main fracture network in the shale layer. S22. Second stage fracturing: After the first stage fracturing is completed, increase the pressure of the fracturing pump to 15-20 MPa, adjust the pulse frequency of the high-frequency solenoid valve to 3-5 Hz, and use the medium-frequency pulse pressure wave to expand the secondary fracture. S23. Third stage fracturing: After the second stage is completed, the fracturing pump pressure is increased to 25-30 MPa, and the pulse frequency of the high-frequency solenoid valve is adjusted to 8-10 Hz. Under the action of the high-frequency pulse pressure wave, the micro-fracture is connected.

3. The shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy according to claim 2, characterized in that: The fracturing medium is a mixture of liquid CO2 and nitrogen in a volume ratio of 3:1; the functionalized nanoparticles have a particle size of 50-80 nm.

4. The shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy according to claim 1, characterized in that: In S3, the proppant is a composite proppant with ceramic particles as the matrix material, an outer coating of a shape memory polymer layer, and an inner pH-responsive microcapsule; the composite proppant has an embedded RFID chip.

5. The shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy according to claim 4, characterized in that: In S3, after each stage of fracturing operation is completed, composite proppant with different particle sizes is injected sequentially.

6. The shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy according to claim 1, characterized in that: The specific steps of S4 are as follows: S41. Install microwave transmitters and microwave radiators at predetermined locations and connect them using microwave transmission pipes, and simultaneously install downhole fiber optic temperature measurement systems. S42. Start the microwave transmitter and apply a microwave field to the formation for 30-60 minutes. Use a downhole fiber optic temperature measurement system to monitor the formation temperature in real time and adjust the microwave output precisely according to the temperature changes.

7. A shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy according to claim 6, characterized in that: The microwave transmitting device emits a microwave field with an output frequency of 2.45 GHz and an output power of 5–10 kW / m. 3 The downhole fiber optic temperature measurement system consists of fiber optic sensors and is deployed near the fracturing area.

8. A shale oil extraction method based on multi-stage pulsed gas fracturing and nanocatalysis synergy according to claim 6, characterized in that: The control conditions for the downhole fiber optic temperature measurement system are as follows: 1) When the temperature is >120℃, reduce the microwave output power or stop microwave transmission to prevent excessively high formation temperature from damaging the shale formation structure and mining equipment; 2) When the temperature is <80℃, increase the microwave output power and improve the energy intensity of the microwave field to promote further cracking and flow of shale oil.

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