Fracturing system and control method for automatic pressure maintaining and remote pressure releasing

Abstract

The application discloses a fracturing system and a control method for automatic pressure maintenance and remote pressure relief. The system comprises first, second and third through-paths which are coaxial and sequentially communicated in the water flow direction; the first through-path is connected with a fracturing water pump through a high-pressure rubber pipe; the third through-path is connected with a screen pipe through a sealed fracturing pipe column and a hole sealing section; the second through-path has a larger diameter than the first through-path; a ring-shaped spring base is connected with a water outlet of the second through-path; a strong spring is fixed on the ring-shaped spring base and faces the water inlet of the second through-path; a free end of the strong spring is fixedly connected with a plugging steel ball; the diameter of the plugging steel ball is slightly larger than the diameter of the first through-path; the second through-path is communicated with the outside through a pressure relief pipeline provided with an electromagnetic valve; the electromagnetic valve is electrically connected with a control terminal; the control terminal is electrically connected with the fracturing water pump; the control terminal collects pressure signals in the second through-path through a pressure flow sensor and controls the fracturing pump to be closed according to the pressure signals. The scheme can accurately and timely maintain and release pressure and improves the fracturing efficiency.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic fracturing in coal mines, and relates to a fracturing system and control method with automatic pressure maintenance and remote pressure relief. Background Technology

[0002] In the extraction of coalbed methane, the coal seam has low permeability, small extraction radius, and high extraction difficulty. The gas extraction concentration, extraction rate, and extraction efficiency are all relatively low. Improving the permeability of the coal seam has become a technical problem that urgently needs to be solved for efficient extraction of coalbed methane.

[0003] Hydraulic fracturing is a major method of hydraulic permeability enhancement, boasting advantages such as a wide permeability enhancement range and excellent permeability improvement effect. Its principle involves using a high-pressure pump on the surface to inject fracturing fluid into the reservoir through the wellbore. When the injection rate of the fracturing fluid exceeds the reservoir's absorption capacity, a very high pressure is created. When this pressure exceeds the fracturing pressure of the coal and rock near the bottom of the well, the coal and rock are forced open, creating fractures. Continued injection of fracturing fluid causes the fractures to propagate further into the reservoir. Next, proppant-carrying fluid is injected. This proppant-carrying fluid, once inside the fractures, allows the fractures to extend further and supports the already opened fractures, preventing them from closing. Finally, displacement fluid is injected to displace all the proppant-carrying fluid from the wellbore into the fractures. The proppant then supports the fractures, establishing a new fluid channel between the reservoir and the wellbore.

[0004] In fracturing, existing technologies typically employ check valves for pressure holding and release, offering advantages such as low fluid resistance and minimal torque required for opening and closing. However, as the orifice pressure continuously increases during fracturing, the water pressure in the check valve becomes high when pressure holding is required. Closing the check valve at this point can generate water hammer pressure in the pipeline, easily leading to valve damage, shortening valve lifespan, requiring frequent maintenance or replacement, and increasing labor and time costs. Furthermore, existing fracturing units require extensive on-site manual labor, and fracturing fluid poses serious health hazards, not only creating safety risks but also making it difficult to accurately determine and promptly control pressure release, resulting in frequent damage to the pressure holding and release devices and impacting fracturing efficiency. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an automatic pressure holding and remote pressure relief fracturing system and control method, which reduces the degree of human involvement in the fracturing process, enables precise and timely pressure relief, reduces damage to the pressure holding and pressure relief device, increases the service life of the pressure holding and pressure relief device, and improves fracturing efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An automatic pressure-maintaining and remote pressure-relieving fracturing system includes an orifice device located outside a sealing section. The orifice device comprises a first, second, and third orifice connected sequentially in the direction of injected water flow. The axes of the first, second, and third orifices are collinear. The first orifice is connected to a fracturing water pump via a high-pressure hose, and the third orifice passes through the sealing section via a sealed fracturing tubing and connects to a screen pipe. The diameter of the third orifice is larger than that of the second orifice, and the diameter of the second orifice is larger than that of the first orifice. The outlet of the second orifice is fixed. A ring-shaped spring base is connected to the system, and a strong spring is fixed on the ring-shaped spring base, facing the inlet of the second flow path. The free end of the strong spring is fixedly connected to a sealing steel ball. The diameter of the sealing steel ball is between the diameter of the first flow path and the diameter of the second flow path. The second flow path is also equipped with a pressure relief pipeline, which is connected to the outside via a solenoid valve. The second flow path is equipped with a pressure and flow sensor. The solenoid valve is electrically connected to an integrated control terminal via a solenoid valve signal line, and the integrated control terminal is electrically connected to a fracturing pump via a fracturing pump control signal line.

[0008] The pressure and flow sensor collects the pressure signal in the second pipe and transmits the pressure signal to the integrated control terminal; the integrated control terminal controls the fracturing water pump to shut down and the solenoid valve to open and close according to the pressure signal; the integrated control terminal communicates with a remote mobile terminal through a wireless communication module.

[0009] Furthermore, the connection between the first and second orifices is a transitional arc surface. Compared to structures with sharp edges, this design makes the sealing ball more securely locked at the inlet of the second orifice, and prevents wear and tear caused by collisions between the sealing ball and sharp edges, resulting in a longer service life and avoiding affecting the sealing effect during pressure holding. Since the second orifice also includes the sealing ball and the annular spring base, the powerful spring is initially in a slightly compressed state. This allows the sealing ball to be held in place at the inlet of the second orifice by the elastic force of the spring's recovery deformation before fracturing. This design uses a longer spring, resulting in greater spring compression and a tighter seal, thus preventing coalbed methane leakage through the orifice device during installation.

[0010] Furthermore, the length of the strong spring when it is not under force is greater than the length of the second bore.

[0011] An automatic pressure holding and remote pressure relief fracturing control method, applied to the automatic pressure holding and remote pressure relief fracturing system described above, includes the following steps:

[0012] S1. After confirming that the system is connected and powered on, send a start signal to the integrated control terminal via the remote mobile terminal;

[0013] S2. The integrated control terminal receives the start signal and controls the fracturing water pump to start under zero load;

[0014] S3. The pressure signal in the second duct is collected in real time by the pressure and flow sensor. It is determined whether the pressure signal is greater than or equal to the pressure holding condition threshold. If not, the fracturing water pump is adjusted to gradually increase the pressure until the pressure signal is greater than or equal to the pressure holding condition threshold. If so, the fracturing water pump is controlled to gradually decrease until it is turned off, and the pressure holding time is started at the same time.

[0015] S4. If the pressure holding time is greater than or equal to the preset pressure holding time, the integrated control terminal controls the solenoid valve to open and release pressure.

[0016] Furthermore, the fracturing water pump is equipped with a temperature sensor in the reciprocating pump to collect the oil temperature of the reciprocating pump; in step S2, if the oil temperature of the reciprocating pump is greater than a preset oil temperature threshold, the integrated control terminal controls the fracturing water pump to stop.

[0017] Furthermore, a pump injection pressure sensor and a pump regulating valve are installed at the outlet of the fracturing water pump. The pump regulating valve is electrically connected to the integrated control terminal. The pump injection pressure is collected by the pump injection pressure sensor and transmitted to the integrated control terminal. In step S2, if the pump injection pressure is less than the safe fracturing threshold, the integrated control terminal controls the pump regulating valve to increase the pump injection pressure.

[0018] Furthermore, in S2, if the pumping pressure is greater than the safe fracturing threshold, the integrated control terminal determines whether pipeline blockage has occurred based on the changing trend of the pumping pressure exceeding the safe fracturing threshold. If the changing trend is greater than the steep slope threshold, the fracturing pump is controlled to stop; if the changing trend is less than the steep slope threshold, the pump regulating valve is controlled to reduce the pumping pressure.

[0019] Furthermore, in step S4, the pressure and flow sensor also collects flow information of the second flow path. If the flow information is greater than the preset water injection volume, the integrated terminal sends an early warning to the remote mobile terminal and controls the solenoid valve to open and release pressure.

[0020] Furthermore, in step S4, if the pressure signal is greater than a preset pressure relief threshold, the integrated control terminal controls the solenoid valve to open for emergency pressure relief.

[0021] Furthermore, it also includes S5, after the fracturing is completed, the integrated control terminal generates a fracturing process traceability report and sends it to a remote mobile terminal; the fracturing process traceability report includes pressure and flow curves, and analyzes to obtain coal seam fracturing parameters and pressure peak fracturing parameters.

[0022] The beneficial effects of this invention are as follows:

[0023] This solution enables automatic pressure maintenance and depressurization during fracturing, eliminating the need for on-site personnel intervention and reducing the health hazards of fracturing fluid to workers. Furthermore, it monitors changes in various parameters during fracturing, preventing abnormal situations that could lead to fracturing accidents and improving fracturing safety. Simultaneously, this solution analyzes abnormal fracturing parameters within the borehole, automatically diagnoses and adjusts these parameters, and issues optimal fracturing commands, thereby improving fracturing efficiency.

[0024] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0026] Figure 1 This is a schematic diagram of a fracturing system with automatic pressure holding and remote pressure relief according to the present invention;

[0027] Figure 2 This is a schematic diagram showing the state of the orifice device during fracturing;

[0028] Figure 3 This is a schematic diagram showing the state of the orifice device during pressure holding;

[0029] Figure 4 This is a schematic diagram of a ring-shaped spring base;

[0030] Figure 5 This is a schematic diagram of the control principle of a fracturing system with automatic pressure holding and remote pressure relief.

[0031] Figure reference numerals: 1. Fracturing coal seam; 2. Fracturing borehole; 3. Screen pipe; 4. Sealing fracturing tubing string; 5. Sealing section; 6. Threaded thread of sealing tubing string for borehole device; 7. Pressure and flow sensor; 8. Power spring; 9. Sealing steel ball; 10. Annular spring base; 11. Solenoid valve; 12. DN connector for borehole device; 13. High-pressure hose; 14. Solenoid valve signal line; 15. Fracturing pump control signal line; 16. Display screen; 17. Integrated computer; 18. Water tank; 19. Fracturing pump; 20. Remote explosion-proof control mobile phone. Detailed Implementation

[0032] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0033] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0034] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0035] Please see Figures 1-5This is an automatic pressure-maintaining and remote pressure-relieving fracturing system, comprising an orifice device located outside the sealing section of the fracturing borehole 2. The orifice device includes a first, second, and third borehole connected sequentially in the direction of injected water flow; the axes of the first, second, and third boreholes are collinear. The orifice device has a DN connector 12 at the inlet of the first borehole, which connects to a high-pressure hose 13. The high-pressure hose 13 connects to a fracturing water pump, which consists of a fracturing pump 19 and a water tank 18. The fracturing pump 19 provides the pumping power to pump water from the water tank 18. The third borehole has a sealing threaded connection 6 for the orifice device, which securely connects the third borehole to a sealing fracturing string 4. The third borehole passes through the sealing fracturing string 4 and connects to a screen pipe 3 via the sealing section 5. The third bore has a larger diameter than the second bore, increasing the water flow rate into the sealed fracturing string and thus improving fracturing efficiency. Furthermore, the third bore gradually increases in diameter from the inlet to the outlet, preventing excessive changes in diameter between the second and third bores that could lead to pressure fluctuations and improving water pressure stability when water enters the third bore. The second bore has a larger diameter than the first bore. A ring-shaped spring base 10 is fixedly connected to the outlet of the second bore, and a strong spring 8 is fixed to the ring-shaped spring base 10, facing the inlet of the second bore. A sealing steel ball 9 is fixedly connected to the free end of the strong spring 8. The diameter of the sealing steel ball 9 is between the diameters of the first and second bores. The connection between the first and second bores is a transition arc surface. The second bore also has a pressure relief pipeline, which is connected to the outside via a solenoid valve 11.

[0036] The second passage is equipped with a pressure and flow sensor; the solenoid valve 11 is electrically connected to the integrated computer 17 (i.e., the integrated control terminal) through the solenoid valve signal line 14, and the integrated computer 17 is electrically connected to the fracturing pump 19 through the fracturing pump control signal line 14.

[0037] The pressure and flow sensor 7 collects the pressure signal in the second passage and transmits the pressure signal to the integrated computer 17. The integrated computer 17 controls the fracturing pump 19 to shut down and the solenoid valve 11 to open and close according to the pressure signal. The integrated computer 17 communicates with the remote explosion-proof control mobile phone 20 (i.e., the remote mobile terminal) through a wireless communication module (e.g., a WIFI module, a 5G communication module, etc.) to receive instructions sent by the remote explosion-proof control mobile phone 20, or to send monitoring data and control results to the remote explosion-proof control mobile phone 20.

[0038] In this embodiment, the length of the high-strength spring 8 when not under force is equal to or slightly greater than the length of the second passage. Since the second passage also includes a sealing steel ball 9 and a ring spring base 10, both of which occupy a certain space, the high-strength spring 8 is initially in a slightly compressed state. Before fracturing, the sealing steel ball 9 is held in place at the water inlet of the second passage by the elastic force of the high-strength spring 8 as it recovers its deformation, thereby preventing coalbed methane leakage through the orifice device when it is installed. Compared with other sealing materials, this solution uses a sealing steel ball 9, which allows the sealing material to move more smoothly in the second passage. Furthermore, the ball has a smaller contact area with the closed part of the second passage compared to other structures, creating more space for high-pressure water to pass through when the ball moves. This results in a larger water flow rate during high-pressure water impact, thus reaching the required fracturing pressure more quickly and improving fracturing efficiency.

[0039] The fracturing control method with automatic pressure holding and remote pressure relief includes the following steps:

[0040] S1. After confirming the system connection and power-on, a start signal is sent to the integrated computer 17 via the remote explosion-proof control mobile phone 20.

[0041] S2. After receiving the start signal, the integrated computer 17 controls the fracturing pump 19 to start under zero load.

[0042] At this time, the fracturing pump 19 pumps water out of the water tank 18 and delivers it to the first passage through the high-pressure hose 13, so that the water pressure in the first passage gradually increases. When the water pressure in the first passage is greater than the elastic force of the strong spring 8 on the sealing steel ball 9, the sealing steel ball 9 is pushed to the left by the high-pressure water flow, so that the strong spring 8 is further compressed. The high-pressure water passes through the gap between the sealing steel ball 9 and the second passage, and enters the third passage. It then enters the fracturing borehole 2 through the sealed fracturing tubing string 4 and the screen pipe 3, and begins fracturing in the fracturing coal seam 1.

[0043] S3. The pressure and flow signals in the second pipe are collected in real time by the pressure and flow sensor 7; it is determined whether the pressure signal is greater than or equal to the pressure holding condition threshold. If not, the pressure of the fracturing pump 19 is gradually increased until the pressure signal is greater than or equal to the pressure holding condition threshold. If so, the pressure of the fracturing pump 19 is gradually reduced to shut down, and the pressure holding time is started at the same time.

[0044] When the pressure signal is greater than or equal to the pressure holding threshold, the pressure conditions required for fracturing have been met. The fracturing pump 19 no longer provides high-pressure water flow. The integrated computer 17 controls the fracturing pump 19 to stop via the fracturing pump control signal line 15. The pressure on the first port side returns to normal. At this time, the water pressure inside the fracturing tube is greater than the water pressure on the first port side. The pressure of the high-pressure water, plus the elastic force of the strong spring 8 itself, pushes the sealing steel ball 9 to move towards the first port side. With greater pressure, the sealing steel ball 9 is fixed at the connection between the first and second ports to prevent fracturing fluid from flowing out, thereby realizing the automatic pressure holding function. This design utilizes a pressure relief pipeline for pressure release, distributing the pressure holding and pressure relief functions of a check valve to two separate structures. This reduces water hammer pressure during high-pressure water injection and pressure holding. If a sealing steel ball is used as the sealing material, its spherical shape allows water to flow smoothly through the gaps on both sides, further minimizing water hammer pressure and significantly reducing the impact on the inner wall of the orifice device compared to a check valve, thus preventing excessive force and damage to the device. Furthermore, during pressure relief, since the solenoid valve is initially closed, opening it under higher water pressure is easier than closing it under higher pressure, causing less damage to the valve itself and making it safer and more durable than a check valve.

[0045] S4. Determine whether pressure relief is needed based on pressure and flow signals; specifically including:

[0046] Excess water volume pressure relief: Determine whether the flow rate information is greater than the preset water injection volume. If so, the integrated computer 17 sends a warning to the remote explosion-proof control mobile phone 20 and controls the solenoid valve 11 to open and relieve pressure; if not, continue to maintain pressure.

[0047] Emergency pressure relief: Determine whether the pressure signal is greater than a preset pressure relief threshold (i.e., Figure 5 The pressure holding condition at the orifice (taken as 0.5 MPa in this implementation) is as follows: if so, the integrated computer 17 sends a warning signal to the remote explosion-proof control mobile phone 20 and sends an instruction through the remote explosion-proof control mobile phone 20 to remotely control the solenoid valve 11 to open for emergency pressure relief; otherwise, the pressure holding continues.

[0048] Pressure relief upon meeting the pressure holding time: Determine whether the pressure holding time is greater than or equal to the preset pressure holding time, and the integrated computer 17 controls the solenoid valve 11 to open and relieve pressure.

[0049] S5. After fracturing is completed, the integrated computer 17 generates a fracturing process traceability report and sends it to the remote explosion-proof control mobile phone 20. The fracturing process traceability report includes pressure and flow curves, and analyzes and obtains the fracturing parameters for initiation and peak pressure of the coal seam. The integrated computer 17 displays the results on the display screen 16.

[0050] The fracturing water pump is equipped with a temperature sensor in the reciprocating pump to collect the oil temperature of the reciprocating pump; a pump injection pressure sensor and a pump regulating valve are installed at the outlet of the fracturing water pump, and the pump regulating valve is electrically connected to the integrated control terminal. The pump injection pressure is collected by the pump injection pressure sensor and transmitted to the integrated control terminal.

[0051] In S2 (i.e., during the fracturing process), the integrated computer also performs anomaly analysis based on the collected parameters such as motor shaft temperature, reciprocating pump oil temperature, and pump injection pressure, automatically identifies the state of fracturing pump 19, and makes a judgment, thereby performing optimal fracturing control and improving fracturing efficiency.

[0052] If the oil temperature of the reciprocating pump is greater than the preset oil temperature threshold, the integrated control terminal controls the fracturing water pump to stop. In this embodiment, the preset oil temperature threshold is 70°C.

[0053] If the pump injection pressure is less than the safe fracturing threshold (40 MPa in this embodiment), the integrated control terminal controls the pump regulating valve to increase the pump injection pressure; if the pump injection pressure is greater than the safe fracturing threshold, the integrated control terminal determines whether pipeline blockage has occurred based on the trend of the pump injection pressure exceeding the safe fracturing threshold. If the trend is greater than the steep slope threshold, the fracturing pump is stopped; if the trend is less than the steep slope threshold, the pump regulating valve is controlled to decrease the pump injection pressure.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. 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 be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A fracturing control method with automatic pressure holding and remote pressure relief, characterized in that: It is applied to a fracturing system with automatic pressure holding and remote pressure relief. The system includes an orifice device located outside the sealing section. The orifice device includes a first, second, and third orifice connected sequentially in the direction of injected water flow. The axes of the first, second, and third orifices are collinear. The first orifice is connected to a fracturing water pump via a high-pressure hose, and the third orifice passes through the sealing section via a sealed fracturing tubing and is connected to a screen pipe. The diameter of the third orifice is larger than that of the second orifice, and the diameter of the second orifice is larger than that of the first orifice. The outlet of the second orifice... A ring-shaped spring base is fixedly connected to the water inlet, and a strong spring facing the water inlet of the second diameter is fixedly fixed on the ring-shaped spring base. The free end of the strong spring is fixedly connected to a sealing steel ball. The diameter of the sealing steel ball is between the diameter of the first diameter and the diameter of the second diameter. The second diameter is also provided with a pressure relief pipeline, which is connected to the outside through a solenoid valve. The second diameter is provided with a pressure and flow sensor. The solenoid valve is electrically connected to an integrated control terminal through a solenoid valve signal line, and the integrated control terminal is electrically connected to a fracturing pump through a fracturing pump control signal line. The pressure and flow sensor collects the pressure signal in the second pipe and transmits the pressure signal to the integrated control terminal; the integrated control terminal controls the fracturing water pump to shut down and controls the solenoid valve to open and close according to the pressure signal; the integrated control terminal communicates with a remote mobile terminal through a wireless communication module. The method includes the following steps: S1. After confirming that the system is connected and powered on, send a start signal to the integrated control terminal via the remote mobile terminal; S2. The integrated control terminal receives the start signal and controls the fracturing water pump to start under zero load; S3. The pressure signal in the second duct is collected in real time by the pressure and flow sensor. It is determined whether the pressure signal is greater than or equal to the pressure holding condition threshold. If not, the fracturing water pump is adjusted to gradually increase the pressure until the pressure signal is greater than or equal to the pressure holding condition threshold. If so, the fracturing water pump is controlled to gradually decrease until it is turned off, and the pressure holding time is started at the same time. S4. If the pressure holding time is greater than or equal to the preset pressure holding time, the integrated control terminal controls the solenoid valve to open and release pressure. A pump injection pressure sensor and a pump regulating valve are installed at the outlet of the fracturing water pump. The pump regulating valve is electrically connected to the integrated control terminal. The pump injection pressure is collected by the pump injection pressure sensor and transmitted to the integrated control terminal. In step S2, if the pump injection pressure is less than the safe fracturing threshold, the integrated control terminal controls the pump regulating valve to increase the pump injection pressure. In step S2, if the pump injection pressure is greater than the safe fracturing threshold, the integrated control terminal determines whether pipeline blockage has occurred based on the trend of the pump injection pressure exceeding the safe fracturing threshold. If the trend is greater than the slope threshold of drastic change, the fracturing pump is stopped. If the trend is less than the slope threshold of drastic change, the pump regulating valve is controlled to reduce the pump injection pressure.

2. The fracturing control method with automatic pressure holding and remote pressure relief as described in claim 1, characterized in that: The connection between the first and second bores is a transition arc surface.

3. The fracturing control method with automatic pressure holding and remote pressure relief as described in claim 1, characterized in that: The length of the high-strength spring when it is not under force is greater than the length of the second bore.

4. The fracturing control method with automatic pressure holding and remote pressure relief as described in claim 1, characterized in that: The reciprocating pump of the fracturing water pump is equipped with a temperature sensor to collect the oil temperature of the reciprocating pump; in step S2, if the oil temperature of the reciprocating pump is greater than a preset oil temperature threshold, the integrated control terminal controls the fracturing water pump to stop.

5. The fracturing control method for automatic pressure holding and remote pressure relief as described in claim 1, characterized in that: In step S4, the pressure and flow sensor also collects flow information of the second flow path. If the flow information is greater than the preset water injection volume, the integrated control terminal sends an early warning to the remote mobile terminal and controls the solenoid valve to open and release pressure.

6. The fracturing control method for automatic pressure holding and remote pressure relief as described in claim 1, characterized in that: In step S4, if the pressure signal is greater than the preset pressure relief threshold, the integrated control terminal controls the solenoid valve to open for emergency pressure relief.

7. The fracturing control method for automatic pressure holding and remote pressure relief as described in claim 1, characterized in that: It also includes S5. After the fracturing is completed, the integrated control terminal generates a fracturing process traceability report and sends it to a remote mobile terminal. The fracturing process traceability report includes pressure and flow curves, and analyzes to obtain the coal seam fracturing parameters and pressure peak fracturing parameters.

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