Fracturing equipment and hydraulic fracturing method of "drilling-fracture-cutting-excitation"

Abstract

The present invention belongs to the technical field of coal mining, and specifically relates to a fracturing device and a hydraulic fracturing method of "drill-crack-cut-excite". The present invention installs a hydraulic fracturing component in the fracturing device, and uses a directional perforating component and an ultrasonic excitation component for auxiliary permeability enhancement. Through the technology of combining "hydraulic fracturing and hydraulic slitting", multiple cracks are generated inside the part to be fractured, and the ultrasonic excitation component is used to stimulate the internal crack water of the part to be fractured, thereby expanding the range of wetting of the internal crack water of the part to be fractured, and then completing the "drill-crack-cut-excite" operation of the part to be fractured, so that crack branches are formed inside the part to be fractured, thereby effectively enhancing the technical effect of hydraulic fracturing and solving the technical problem of poor hydraulic fracturing permeability enhancement effect in the prior art.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mining, and in particular, relates to a fracturing device and a "drill-crack-cut-excite" hydraulic fracturing method. Background Art

[0002] At present, hydraulic fracturing in underground coal mines is a technical measure to increase the permeability of underground coal seams during coal mining. It has the characteristics of a large permeability increase range and significant permeability increase effect, and can significantly improve the extraction efficiency of coal seam gas. Hydraulic fracturing technology is becoming more and more widely used in mining.

[0003] However, the hydraulic fracturing technology in the prior art is not stable, and there are problems such as serious filtration loss. The direction of the hydraulic fracture is mainly affected by the stress distribution of the part to be fractured. Therefore, during the hydraulic fracturing process, only one main fracture controlled by stress is often formed, and it is difficult to form fracture branches around the main fracture, so that the hydraulic fracture cannot evenly control the range of the coal seam, and the hydraulic fracturing permeability enhancement effect is poor. Summary of the invention

[0004] The purpose of the present invention is to provide a fracturing device and a "drill-fracture-cut-excite" hydraulic fracturing method to solve the technical problem of poor hydraulic fracturing permeability enhancement effect in the prior art.

[0005] In order to achieve the above purpose, the technical solution adopted is:

[0006] A fracturing device, comprising a controller, a water tank, a pressure detection component, a high-pressure pump, a hydraulic fracturing component, and a guide, wherein the water tank contains water containing an organic solvent, and further comprises a directional perforating component and an ultrasonic excitation component;

[0007] The directional perforating assembly includes a fracturing pipeline and a directional slotter, and the ultrasonic excitation assembly includes an ultrasonic driving power supply and an ultrasonic transducer;

[0008] The water tank is connected to a high-pressure pump, the high-pressure pump is connected to a fracturing pipeline via a high-pressure hose, and a pressure detection component is installed at the outlet of the high-pressure pump;

[0009] The fracturing pipeline is connected to a hydraulic fracturing assembly or a directional slotter, and the other end of the hydraulic fracturing assembly or the directional slotter is connected to the guide. When the fracturing pipeline is connected to the directional slotter, the ultrasonic transducer is installed at one end of the fracturing pipeline connected to the directional slotter;

[0010] The ultrasonic transducer is connected to an ultrasonic driving power supply through a transmission cable, and the ultrasonic driving power supply, the pressure detection element, and the high-pressure pump are connected to a controller through a connecting line, and the controller controls the opening or closing of the fracturing device. The controller can be a computer or software installed in the computer, and the controller can be used to directly open or close each component and receive data and other information.

[0011] Preferably, the high-pressure pump is connected to a control cabinet to control the pressure of the high-pressure pump. The control cabinet can be set up on-site in the well, and the purpose of setting it up separately is to ensure that the opening and closing of the pump can be adjusted on-site during the hydraulic fracturing process.

[0012] Preferably, the outer side of the ultrasonic transducer is wrapped with a pressure-resistant protective shell.

[0013] Preferably, the hydraulic fracturing assembly includes a packer, a throttle, a packer, and a one-way valve. The packers include two. The fracturing pipeline is connected to the packer, the throttle, the packer, and the one-way valve in sequence, and the front end is connected to the guide.

[0014] A "drill-crack-cut-excite" hydraulic fracturing method, using the above-mentioned fracturing equipment, the method comprises the following steps:

[0015] (1) drilling a fracturing borehole into the coal seam at the location to be fractured;

[0016] (2) installing hydraulic fracturing components and guides on the fracturing pipeline in sequence, extending the installed fracturing pipeline, hydraulic fracturing components and guides into the fracturing borehole, and performing hydraulic fracturing on the part to be fractured;

[0017] (3) After the hydraulic fracturing is completed, the hydraulic pressure assembly and the guide are disassembled, and the directional slotter and the guide are installed in sequence, and then an ultrasonic transducer is installed on the end of one side of the fracturing pipeline where the directional slotter is installed; the installed fracturing pipeline, directional slotter, and guide are extended into the fracturing borehole to perform high-pressure hydraulic slotting on the part to be fractured;

[0018] (4) Using an ultrasonic excitation component to perform ultrasonic excitation fracturing on the site to be fractured.

[0019] Preferably, in step (2), the high-pressure pump is turned on to inject high-pressure water into the hydraulic fracturing assembly, so that the packers on both sides of the throttle of the hydraulic fracturing assembly are expanded, and the water outlet of the throttle of the hydraulic fracturing assembly is opened under the expansion effect of the two packers.

[0020] Preferably, the pressure detection component can detect the pressure at the outlet of the high-pressure pump, and the pressure at the outlet of the high-pressure pump can be adjusted by adjusting the control cabinet as needed.

[0021] Preferably, in step (3), the directional slotting device includes a perforating hole, and the high-pressure pump is turned on to perform high-pressure slotting on the part to be fractured using high-pressure water ejected from the perforating hole of the directional slotting device. The high-pressure water can be water with an organic solvent added, such as tetrahydrofuran, or geological water used in mining. If the coal mine contains hydrogen sulfide, sodium carbonate, sodium bicarbonate, etc. can be added to the high-pressure water. In short, the solvent added to the high-pressure water needs to be determined according to the actual working conditions.

[0022] Preferably, in step (4), the ultrasonic excitation component performs ultrasonic excitation fracturing on the part to be fractured, comprising:

[0023] Obtaining pressure changes at the water outlet of the high-pressure pump;

[0024] When the pressure value at the water outlet of the high-pressure pump rises to the perforating pressure of the directional slotter, the ultrasonic transducer is started, and an ultrasonic signal is emitted to the periphery of the directional slotter through the ultrasonic transducer to stimulate and increase fracturing of the part to be fractured.

[0025] Compared with the prior art, the present invention is beneficial in that:

[0026] The present invention installs a hydraulic fracturing component in the fracturing equipment, and uses a directional perforating component and an ultrasonic excitation component to assist in permeability enhancement, and performs a "drill-fracture-cut-excite" operation on the part to be fractured, which can form crack branches inside the part to be fractured, thereby effectively enhancing the technical effect of hydraulic fracturing and solving the technical problem of poor hydraulic fracturing permeability enhancement effect in the prior art.

[0027] The present invention innovatively combines hydraulic slitting with ultrasonic excitation. After the hydraulic fracturing is completed on the part to be fractured, uncontrollable cracks affected by the maximum principal stress already exist inside the part to be fractured. The hydraulic slitting process is used again to perform high-pressure water slitting on the part to be fractured, and a controllable crack perpendicular to the borehole is generated inside the structure to be cut. The "hydraulic fracturing-hydraulic slitting" technology is combined to generate multiple cracks inside the part to be fractured, and the ultrasonic excitation component is used to excite the internal fracture water of the part to be fractured, thereby expanding the range of water wetting inside the fractures of the part to be fractured.

[0028] The present invention innovatively proposes a main crack guided by the main stress generated by "hydraulic fracturing" inside the part to be fractured, and a main crack perpendicular to the borehole generated by "hydraulic cutting", thereby improving the permeability enhancement effect of the part to be fractured, and using ultrasonic waves to excite the internal cracks of the part to be fractured to increase its internal water wetting and permeability enhancement range. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a fracturing device connected to a hydraulic fracturing assembly provided in Embodiment 1 of the invention;

[0030] Figure 2 A schematic diagram of the structure of a fracturing device connecting a directional perforating assembly and an ultrasonic excitation assembly provided in Embodiment 1 of the invention.

[0031] In the figure, the reference numerals represent:

[0032] 1. Water tank; 2. Control cabinet; 3. Pressure detection component; 4. High-pressure pump; 5. High-pressure hose; 6. Fracturing pipeline; 7. Packer; 8. Choke; 9. Guide; 10. Controller; 11. Ultrasonic drive power supply; 12. Transmission cable; 13. Ultrasonic transducer; 14. Directional slotter; 15. Check valve. DETAILED DESCRIPTION

[0033] The drawings are for illustrative purposes only. To better illustrate the present embodiment, some parts of the drawings are omitted, enlarged or reduced, and do not represent the size of the actual product. The terms "upper", "lower", "left", "right", "side", "outer", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, and 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0034] For those skilled in the art, some well-known structures and their descriptions in the drawings may be omitted, and therefore, they should not be understood as limitations of the present invention.

[0035] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Example 1

[0037] A fracturing device, comprising a controller 10, a water tank 1, a pressure detection component 3, a high-pressure pump 4, a hydraulic fracturing component, and a guide 9. The water tank 1 contains water containing an organic solvent. The fracturing device also includes a directional perforating component and an ultrasonic excitation component.

[0038] The directional perforating assembly includes a fracturing pipeline 6 and a directional slotter 14, and the ultrasonic excitation assembly includes an ultrasonic driving power supply 11 and an ultrasonic transducer 13;

[0039] The water tank 1 is connected to the high-pressure pump 4. The water tank 1 contains the required solvent-added water or mining geological water, which is converted into the required high-pressure water by the high-pressure pump 4. The high-pressure pump 4 is connected to the fracturing pipeline 6 through the high-pressure hose 5, and the pressure detection component 3 is installed at the outlet of the high-pressure pump 4; the high-pressure pump 4 is also connected to the control cabinet 2, and the pressure of the high-pressure pump can be adjusted through the control cabinet 2 to ensure its operation.

[0040] like Figure 1 As shown, the fracturing pipeline 6 is connected to the hydraulic fracturing assembly. The hydraulic fracturing assembly has a fracturing pipeline 6 extending into the part to be fractured, the fracturing pipeline 6 is connected to the high-pressure hose 5 and the packer 7, and the throttle 8 is connected to a packer 7 at both ends to fractur the part to be fractured through the high-pressure fluid in the throttle section 8.

[0041] like Figure 2 As shown, the directional slotter 14 is connected to the fracturing pipeline 6, and the other end is connected to the guide bevel 9. The high-pressure water generated by the high-pressure pump 4 flows out of the directional slotter 14 to cut the fracturing structure. The ultrasonic transducer 13 in the ultrasonic excitation component is arranged at the head end of the directional slotter 14. The electric energy generated by the ultrasonic driving power supply 11 is transmitted to the ultrasonic transducer 13 through the transmission cable 12, and the ultrasonic wave finally emitted is used to stimulate the fracturing of the part to be fractured. The outer side of the ultrasonic transducer 13 is also wrapped with a protective shell made of pressure-resistant metal material to prevent excessive pressure from damaging the ultrasonic transducer 13.

[0042] The controller controls the opening or closing of the fracturing equipment. The controller 10 may be a computer. The controller 10 is installed with an intelligent recognition program, and the controller 10 recognizes the pressure data change characteristics of the pressure detection meter 3 in real time. The controller 10 controls the opening and closing of the high-pressure pump 4 and the ultrasonic driving power supply 11 according to the pressure data change characteristics.

[0043] By adopting such a configuration, by simultaneously arranging a hydraulic fracturing assembly, a directional perforating assembly and an ultrasonic excitation assembly in the fracturing equipment, it is possible to achieve a synergistic fracturing effect of hydraulic cutting and ultrasonic excitation through the directional perforating assembly and the ultrasonic excitation assembly while hydraulic fracturing the part to be fractured, thereby effectively solving the technical problem of poor hydraulic fracturing permeability enhancement effect in the prior art.

[0044] In this embodiment, the hydraulic fracturing assembly includes a one-way valve 15, a guide deflector 9, a throttle 8 and packers 7 on both sides. The throttle 8 is arranged between the two packers 7. With such an arrangement, the packers 7 at both ends can be pressed against the part to be fractured, and a closed space can be formed between the two packers 7. The fracturing fluid (the water in the water tank is the same as the high-pressure water delivered by the high-pressure pump) is supplied into the closed space through the throttle 8, and the hydraulic fracturing work of the part to be fractured can be achieved in this way.

[0045] In this embodiment, the ultrasonic transducer 13 is connected to the ultrasonic driving power supply 11 through the transmission cable 12. During installation, the transmission cable 12 is arranged on the outside of the fracturing pipeline 6, and the ultrasonic transducer 13 is installed at one end of the fracturing pipeline 6 connected to the directional slotter 14. The ultrasonic transducer 13 forms the energy emitting part of the ultrasonic excitation component. With such a setting, the ultrasonic driving power supply 11 can provide electric energy to the ultrasonic transducer 13 through the transmission cable 12, and the ultrasonic transducer 13 can convert the electric energy into ultrasonic energy, so that the ultrasonic transducer 13 can emit ultrasonic waves to the part to be fractured and stimulate the fracturing of the part to be fractured.

[0046] In this embodiment, the pressure detection component 3 is arranged at the water outlet of the high-pressure pump 4. The hydraulic fracturing component, the directional perforating component, the ultrasonic excitation component and the pressure detection component 3 are all connected to the controller 10 (that is, the ultrasonic drive power supply, the pressure detection component, and the high-pressure pump are connected to the controller through a connecting line), so that the controller 10 controls the hydraulic fracturing component, the directional perforating component and the ultrasonic excitation component according to the pressure conditions detected by the pressure detection component 3. With such a setting, the pressure detection component 3 can detect the pressure at the water outlet of the high-pressure pump, and the controller 10 can automatically judge the situation in the part to be fractured, and control the fracturing process in real time, which can improve the intelligence and automation of the fracturing equipment, and thus improve the fracturing efficiency of the fracturing equipment. Specifically, the pressure detection component 3 is a pressure sensor.

[0047] The controller 10 may be a computer with an intelligent recognition program installed therein, and the controller 10 recognizes the pressure data change characteristics of the pressure detection meter 3 in real time, and controls the opening and closing of the high pressure pump 4 and the ultrasonic driving power supply 11 according to the pressure data change characteristics.

[0048] The present invention also provides a "drill-fracture-cut-excite" hydraulic fracturing method, wherein the fracturing method uses the above-mentioned fracturing equipment to fracture the part to be fractured, and the fracturing method comprises:

[0049] A fracturing borehole is drilled into the coal seam at the location to be fractured, and the fracturing equipment is extended into the fracturing borehole; the location to be fractured is first hydraulically fractured using the installed hydraulic fracturing assembly, and then the hydraulic fracturing assembly is removed and a directional perforating assembly is installed, and the directional perforating assembly is used to perform high-pressure hydraulic slits at the location to be fractured, and then the ultrasonic excitation assembly of the fracturing equipment is used to perform ultrasonic excitation fracturing at the location to be fractured.

[0050] By adopting this method, by sequentially opening the hydraulic fracturing assembly, the directional perforating assembly and the ultrasonic excitation assembly, the fracturing equipment can have different working stages and can adopt different working modes according to different conditions in the fracturing borehole, thereby better fracturing the fracturing site.

[0051] Specifically, after drilling a fracturing hole into the coal seam, first install the water tank 1, the high-pressure pump 4, and the pressure detection component 3 in sequence, connect the fracturing pipeline through the high-pressure hose 5, and then connect the packer 7, the throttle 8, the packer 7, the one-way valve 15, and the guide 9; the method of using the hydraulic fracturing assembly to perform hydraulic fracturing on the part to be fractured includes: using the high-pressure pump 4 to inject high-pressure water into the fracturing pipeline 6, when the water injection pressure exceeds 5MPa, the ball in the one-way valve 15 blocks the water outlet to increase the pressure in the fracturing assembly, so that the two packers 7 expand, and the water outlet of the throttle 8 in the hydraulic fracturing assembly is opened under the action of the expansion of the packers 7 on both sides. Since the expansion of the packer 7 will open the water outlet of the throttle 8, the packer 7 can expand and press the wall of the fracturing borehole to form a closed space between the packers 7 on both sides, and the throttle 8 can also supply high-pressure water to the outside. Such a control method can simplify the structure.

[0052] After hydraulic fracturing, the hydraulic fracturing assembly is removed, a directional slotter 14 is installed on the fracturing pipeline, a guide angle 9 is installed at the end, and then the ultrasonic excitation assembly is installed. The method of high-pressure hydraulic slotting of the part to be fractured includes: after the hydraulic fracturing of the hydraulic fracturing assembly is completed, there is a part of cracks in the part to be fractured. In order to further improve the crack development inside the fracturing structure, the directional slotter in the directional perforating assembly is used to extend into the borehole in the part to be fractured, and the high-pressure pump 4 is used to inject high-pressure water into the fracturing pipeline 6. Finally, the high-pressure water is ejected through the perforation hole of the directional slotter 14, and acts on the inner wall of the borehole to cut the part to be fractured.

[0053] The method of using an ultrasonic excitation component to perform ultrasonic fracturing on a part to be fractured includes: obtaining the pressure change at the fracturing borehole; when the pressure value of the high-pressure pump 4 rises to the perforating pressure value of the directional slotter 14, the pressure detection component 3 receives the signal and transmits it to the controller 10, and the controller 10 turns on the ultrasonic excitation component and transmits an ultrasonic signal to the vicinity of the directional slotter through the ultrasonic transducer 13 of the ultrasonic excitation component. With this method, since the ultrasonic wave can make the internal molecules of the high-pressure water containing organic solvent move again, the fracturing effect of the fracturing equipment is further improved.

[0054] Example 2

[0055] A "drill-crack-cut-excite" hydraulic fracturing method is applied to a tunnel in a coal mining area. The specific method includes the following steps:

[0056] Step 1: According to the layout of the tunnels and the coal mining method in a coal mining area, combined with the characteristics of the coal seam occurrence, drill the fracturing drill into the top coal and use hydraulic fracturing to relieve the pressure and increase the permeability of the top coal. At the same time, the length of the pressure drill hole and the pressure required for fracturing are determined according to the development and length of the top coal.

[0057] Step 2: Connect the end of the high-pressure hose 5 to the fracturing string (including the fracturing pipeline 6, the packers 7 on both sides, the throttle 8, the one-way valve 15, and the guide 9), and then extend it into the fracturing borehole.

[0058] Turn on the high-pressure pump 4 and inject high-pressure water into the fracturing string through the high-pressure hose 5. When the water injection pressure exceeds 5MPa, the ball in the one-way valve 15 blocks the water outlet, causing the pressure in the fracturing string to increase, causing the packers 7 on both sides to expand, and the packers 7 at both ends of the throttle 8 to expand, thereby pulling open the water outlet of the throttle 8, so that the water in the fracturing string flows out of the throttle 8, thereby generating water pressure between the packers 7 on both sides, and then the part to be fractured can be fractured. The pressure sensor 3 monitors the pressure at the outlet of the high-pressure pump 4 in real time and feeds it back to the controller 10 through the pressure detection component 3. The controller 10 identifies the pressure data change characteristics of the pressure detection component 3 in real time, where:

[0059] a. After the high-pressure pump is turned on, the packers 7 on both sides expand and pressurize the borehole, and the pressure around the throttle 8 begins to rise, indicating that the pressure water fills the fracturing borehole and enters the initial stage;

[0060] b. When the pressure at the outlet of the high-pressure pump exceeds the fracturing pressure of the part to be fractured, the pressure around the throttle 8 drops, indicating that the fracturing stage has begun;

[0061] c. When the pressure value at the outlet of the high-pressure pump no longer rises to the fracture initiation pressure value of the part to be fractured, but remains at a low pressure stage, it means that the hydraulic fracturing is completed and the hydraulic fracturing assembly is exited;

[0062] Step 3: Remove the fracturing string, install the directional perforating assembly, the guide angle 9 and the ultrasonic transducer assembly. Push the directional perforating assembly into the borehole at the site to be fractured, turn on the high-pressure pump 4, and inject high-pressure water into the directional perforating assembly through the high-pressure hose 5. When the water injection pressure exceeds the perforating pressure value of the directional slotting device, the perforating eye of the directional slotting device opens, and high-pressure water is ejected to perform slotting on the site to be fractured. When the pressure detection component 3 monitors the pressure at the outlet of the high-pressure pump 4 in real time and feeds back to the controller 10 through the pressure detection component 3, the controller 10 recognizes the pressure data change characteristics of the pressure detection component 3 in real time.

[0063] Step 4: When the pressure at the outlet of the high-pressure pump reaches the perforating pressure of the directional slotter 14, the controller 10 controls to turn on the ultrasonic driving power supply 11, and then enters the ultrasonic excitation stage. The ultrasonic driving power supply 11 generates a high-frequency AC signal and transmits it to the ultrasonic transducer 13 through the transmission cable 12. The ultrasonic transducer 13 converts the high-frequency AC signal into an ultrasonic signal and transmits it to the part to be fracturing around the directional slotter 14. During the excitation stage, the pressure at the outlet of the high-pressure pump 4 fluctuates slightly.

[0064] Ultrasonic waves can produce cavitation, mechanical and thermal effects in organic solvents. The cavitation effect is the dynamic process of the growth and collapse of the cavitation nucleus sound pressure at a certain value when the ultrasonic sound field acts on the organic solvent. Ultrasonic waves will form bubbles in the organic solvent. When the bubbles are completely closed, the rapid energy in the bubbles will be released outward in the form of shock waves. At the same time, a large amount of heat will be generated to impact the part to be fractured, which can weaken or even destroy the internal structure of the part to be fractured, thereby increasing the porosity of the part to be fractured, improving the connectivity between the pores inside the part to be fractured, and optimizing the permeability of the part to be fractured. During the propagation of ultrasonic waves, a series of mechanical effects are generated due to the reflection of sound waves, which can cause the state of the particles in the medium inside the part to be fractured to change from static to alternating vibration. The effect of the boundary layer in the pores or pore throats will be weakened by the ultrasonic mechanical vibration effect, which can effectively overcome the constraints of related particles in the part to be fractured and improve the relative permeability of the part to be fractured. During the excitation phase, the pressurized water in the pores and cracks of the micropores around the fracturing borehole generates new microcracks and pores under the action of ultrasound, and the pressure sensor 21 monitors the pressure fluctuations in the water injection borehole during the excitation phase;

[0065] Under the action of ultrasonic excitation, the wetting range of the inside of the part to be fractured will expand along the cracks produced by hydraulic fracturing and directional perforation cutting, and then secondary fracturing will occur. As the length of the cracks produced by directional drilling cutting increases to the maximum range, the pressure at the water outlet of the high-pressure pump 4 will no longer increase.

[0066] After the high-pressure pump 4 is turned off, the pressure in the fracturing pipeline 6 gradually decreases to zero, thereby completing a "drill-fracture-cut-excite" hydraulic fracturing. According to the actual needs of the test project, several "drill-fracture-cut-excite" hydraulic fracturing can be completed by switching pressure components in the same borehole.

[0067] Other unmentioned places are the same as those in Example 1.

[0068] It can be seen from the technical scheme of the above embodiment 2 that the present invention can first perform hydraulic fracturing on the part to be fractured by setting a hydraulic fracturing assembly, and use a directional perforating assembly and an ultrasonic excitation assembly to perform collaborative and efficient fracturing according to different working conditions, which can effectively solve the technical problem of poor hydraulic fracturing permeability enhancement effect in the prior art. And in the process of fracturing, the pressure detection part 3 monitors the change of the pressure data of the water outlet of the high-pressure pump 4 in real time, and then the controller 10 judges the opening and closing of the automatic control of the high-pressure pump 4 and the ultrasonic drive power supply 11, so that high-pressure water can enter the original connected cracks, hydraulic fracturing secondary cracks, directional slit cracks and secondary secondary cracks of the part to be fractured in sequence, which significantly improves the effect of hydraulic fracturing. And in the whole hydraulic fracturing process, by real-time monitoring of the pressure data changes in the fracturing borehole, the automatic control of the ultrasonic wave and the automatic switch of the high-pressure pump 4 are realized, without manual intervention, the process flow is simplified, the consumption of energy consumption and water resources is reduced, and the cost investment of construction is saved.

[0069] The present invention innovatively combines hydraulic slitting with ultrasonic excitation. After the hydraulic fracturing of the part to be fractured is completed, uncontrollable cracks affected by the maximum principal stress already exist inside the part to be fractured. The hydraulic slitting process is used again to perform high-pressure water slitting on the structure to be fractured, and a controllable crack perpendicular to the borehole is generated inside the structure to be fractured. The "hydraulic fracturing-hydraulic slitting" technology is combined to generate multiple cracks inside the structure to be fractured, and ultrasonic excitation technology is used to excite the internal fracture water of the part to be fractured, thereby expanding the range of water wetting in the fractures of the part to be fractured. Under the condition of applying the same pressure, the permeability-enhancing and fracturing range of the part to be fractured by the present invention is much larger than the range that can be fractured by the prior art.

[0070] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0071] Unless specifically stated otherwise, the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0072] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] Other matters not mentioned adopt the common practices in the prior art and will not be described in detail here.

[0074] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A "drill-crack-cut-excite" hydraulic fracturing method, using a fracturing device, characterized in that: The fracturing equipment includes a controller, a water tank, a pressure detection component, a high-pressure pump, a hydraulic fracturing component, and a deflection guide, and is characterized in that it also includes a directional perforating component and an ultrasonic excitation component; The directional perforating assembly includes a fracturing pipeline and a directional slotter, and the ultrasonic excitation assembly includes an ultrasonic driving power supply and an ultrasonic transducer; the outer side of the ultrasonic transducer is wrapped with a pressure-resistant protective shell; The hydraulic fracturing assembly includes a packer, a throttle, a packer, and a one-way valve. The packers include two. The fracturing pipeline is connected to the packer, the throttle, the packer, and the one-way valve in sequence, and the front end is connected to the guide bevel; The water tank is connected to a high-pressure pump, the high-pressure pump is connected to a fracturing pipeline via a high-pressure hose, and a pressure detection component is installed at the outlet of the high-pressure pump; The fracturing pipeline is connected to a hydraulic fracturing assembly or a directional slotter, and the other end of the hydraulic fracturing assembly or the directional slotter is connected to the guide. When the fracturing pipeline is connected to the directional slotter, the ultrasonic transducer is installed at one end of the fracturing pipeline connected to the directional slotter; The ultrasonic transducer is connected to an ultrasonic driving power supply through a transmission cable, and the ultrasonic driving power supply, the pressure detection element, and the high-pressure pump are connected to a controller through a connecting line, and the controller controls the opening or closing of the fracturing equipment; The fracturing method comprises the following steps: (1) Drilling a fracturing borehole into the coal seam at the location to be fractured; (2) installing hydraulic fracturing components and guide bends on the fracturing pipeline in sequence, extending the installed fracturing pipeline, hydraulic fracturing components and guide bends into the fracturing borehole, and performing hydraulic fracturing on the part to be fractured; Turning on the high-pressure pump to inject high-pressure water into the hydraulic fracturing assembly, so that the packers on both sides of the throttle of the hydraulic fracturing assembly expand, and opening the water outlet of the throttle of the hydraulic fracturing assembly under the expansion effect of the two packers; (3) After the hydraulic fracturing is completed, the hydraulic fracturing components and the guide are disassembled, and the directional slotter and the guide are installed in sequence, and then an ultrasonic transducer is installed at one end of the fracturing pipeline where the directional slotter is installed; the installed fracturing pipeline, directional slotter, and guide are extended into the fracturing borehole to perform hydraulic slot cutting at the part to be fractured; (4) Using an ultrasonic excitation component to ultrasonically excite and enhance the fracturing of the part to be fractured, the ultrasonic excitation component to ultrasonically excite and enhance the fracturing of the part to be fractured includes: Obtaining pressure changes at the water outlet of the high-pressure pump; When the pressure value at the water outlet of the high-pressure pump rises to the perforating pressure of the directional slotter, the ultrasonic transducer is started, and an ultrasonic signal is emitted to the periphery of the directional slotter through the ultrasonic transducer to stimulate and increase fracturing of the part to be fractured.

2. A "drill-crack-cut-excite" hydraulic fracturing method according to claim 1, characterized in that: The high-pressure pump is connected to a control cabinet to control the pressure of the high-pressure pump.

3. A "drill-crack-cut-excite" hydraulic fracturing method according to claim 1, characterized in that: The pressure detection element can detect the pressure at the outlet of the high-pressure pump, and the pressure at the outlet of the high-pressure pump can be adjusted by adjusting the control cabinet as needed.

4. A "drill-crack-cut-excite" hydraulic fracturing method according to claim 1, characterized in that: In the step (3), the high-pressure pump is turned on, and the high-pressure water ejected by the directional slotting device is used to perform high-pressure hydraulic slotting on the site to be fractured.

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