Hydraulic fracturing device controllable in whole space in fracturing direction and operation method

Abstract

The invention relates to the technical field of mine pressure treatment, in particular to a hydraulic fracturing device controllable in the whole space in the fracturing direction and an operation method.The hydraulic fracturing device comprises a directional hydraulic fracturing packer, and the directional hydraulic fracturing packer comprises a front-end plugging air bag, a middle directional air bag and a rear-end plugging air bag which are sequentially connected; one end of the high-pressure water pump system is provided with a water injection assembly connected with the directional hydraulic fracturing packer; the middle directional air bag is of a double-layer air bag structure, openings are formed in the two sides of the middle directional air bag, the inner-layer high-pressure-resistant rubber layer prevents fracturing fluid from puncturing the air bag, the outer-layer aramid fiber reinforcing layer limits radial excessive expansion of the air bag, the stable shape of a flow guide channel is ensured, and the diffusion path of the fracturing fluid is limited; the crack is forced to expand in the direction perpendicular to the top plate, deflection along a primary weak plane is avoided, and it is ensured that the weakening range covers the whole thickness of a target rock stratum.

Description

Technical Field

[0001] This disclosure belongs to the field of mine pressure control technology, specifically relating to a hydraulic fracturing device and its operation method that allows for full-space control of the fracturing direction. Background Technology

[0002] During coal seam mining, thick, hard roofs are difficult to collapse naturally and in a timely manner, easily forming large-area overhangs. The traditional method is to inject fracturing fluid into the fracturing layers of the roof using a sealing device. After the fracturing fluid is injected, the fractures tend to extend along the original weak surfaces of the rock strata. However, hard rock strata only generate fracturing fractures in the circumferential direction of the fracturing borehole, making it difficult to form vertical fractures perpendicular to the roof, let alone fracturing fractures along the axial direction of the fracturing borehole. This prevents the fracturing fractures from intersecting in space, resulting in insufficient weakening of the roof and causing the hard roof to fail to collapse in a timely and effective manner.

[0003] To address these issues, those skilled in the art have proposed a hydraulic fracturing device and operating method with full spatial controllability in the fracturing direction. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this disclosure is to provide a hydraulic fracturing device and operating method with fully controllable fracturing direction in the entire space, which solves the problems in existing technologies where the direction of fracturing is uncontrollable, the fracturing fluid cannot make the fracturing fractures intersect in space, and the degree of weakening of the roof is insufficient.

[0005] The objective of this disclosure can be achieved through the following technical solutions: A hydraulic fracturing device with fully controllable fracturing direction throughout the space includes: A directional hydraulic fracturing packer, comprising a front-end plugging airbag, a middle directional airbag, and a rear-end plugging airbag connected in sequence; A high-pressure water pump system, one end of which is equipped with a water injection assembly connected to a directional hydraulic fracturing packer; The intermediate directional airbag is a double-layer airbag structure with openings on both sides and an intermediate directional fracturing rod inside. The intermediate directional fracturing rod has multiple fracturing fluid outlets. Both the front-end occlusion airbag and the rear-end occlusion airbag are single-layer airbags; The directional hydraulic fracturing packer is also equipped with a Y-shaped plugging airbag expansion rod for injecting water into the front plugging airbag and the rear plugging airbag, and an intermediate directional airbag expansion rod for injecting water into the intermediate directional airbag.

[0006] Preferably, the inner layer of the double-layered airbag of the intermediate directional airbag is a nitrile rubber layer and the outer layer is an aramid fiber reinforced layer. Its opening center axis is collinear with the fracturing fluid outlet center axis. After expansion, it forms a cylindrical directional flow channel with an inner diameter ≤ 2 mm different from the diameter of the fracturing fluid outlet.

[0007] Preferably, both the front-end sealing airbag and the rear-end sealing airbag are fitted with metal fixing clamps on their outer walls.

[0008] Preferably, the front end of the intermediate directional fracturing rod has a fracturing fluid inlet, the front end of the Y-shaped plugging airbag expansion rod has a plugging airbag high-pressure water inlet, and the front end of the intermediate directional airbag expansion rod has an intermediate directional airbag high-pressure water inlet.

[0009] Preferably, the water injection assembly includes a high-pressure water injection rod, one end of which is fixedly installed with a connecting slot, and one end of which is installed with a connecting block. One end of the connecting block is connected to the front end of the intermediate directional fracturing rod. Orientation marks are provided on the outer walls of the connecting slot and the connecting block. The orientation marks are red laser-etched lines aligned with the central axis of the fracturing fluid outlet.

[0010] Preferably, a directional compass is fixed to the outer wall of the connecting slot by a locking nut. The directional compass is used to adjust the angle with the direction of the roadway. The adjustment angle is 0-180°. After adjustment, the directional compass is fixed by the locking nut.

[0011] Preferably, the high-pressure water pump system includes a water pump, one end of which is fixedly connected to an intermediate directional fracturing rod connecting pipe, and one end of the intermediate directional fracturing rod connecting pipe is connected to a connecting slot.

[0012] Preferably, one end of the water pump is also fixedly connected to a Y-shaped sealing airbag expansion rod connecting hose, and one end of the Y-shaped sealing airbag expansion rod connecting hose is connected to the front end of the Y-shaped sealing airbag expansion rod.

[0013] Preferably, one end of the water pump is also fixedly connected to a central directional airbag expansion rod connecting hose, and one end of the central directional airbag expansion rod connecting hose is connected to the front end of the central directional airbag expansion rod.

[0014] A hydraulic fracturing operation method with full space controllability in the fracturing direction, based on the aforementioned hydraulic fracturing device with full space controllability in the fracturing direction, includes the following steps: S1. Assemble and position the equipment. Connect the directional hydraulic fracturing packer and the high-pressure water injection rod through connecting blocks and connecting slots to form a fracturing unit. Connect the connecting pipelines of each high-pressure water inlet and the high-pressure water pump system. After splicing multiple sections of high-pressure water injection rod to form an integral pipeline, open fracturing holes on the top plate that needs to be fracturing. Place the device in the fracturing holes so that the middle directional airbag of the device is located at the sealing section. Use directional marks and directional compasses to calibrate the direction of the fracturing fluid outlet and lock it in place. S2. Start the segmented rubber expansion sealing process. First, inject high-pressure water into the front and rear sealing airbags through the high-pressure water pump system to expand and anchor them to the wall of the fracturing borehole and maintain pressure to confirm. Then, inject high-pressure water into the middle directional airbag to form a directional flow channel and maintain pressure to seal. The expansion range of each airbag is constrained by metal fixing clamps. S3. Perform high-pressure fracturing fluid injection and fracture propagation operation. First, inject fracturing fluid at a set rate and pressure to achieve axial fracturing and generate axial fracturing fractures. Then, after releasing the pressure of the intermediate directional airbag, inject fracturing fluid while maintaining the sealed state of the plugging airbag to complete circumferential fracturing and generate circumferential fracturing fractures. S4. Carry out the equipment recycling and reuse process. Depressurize the equipment step by step in the order of front-end sealing airbag, middle directional airbag and rear-end sealing airbag, so that each rubber shrinks to its initial state. Disconnect the pipeline connection and recycle the device components in sections. After checking their integrity, use them for the next fracturing area.

[0015] The explanations of the nouns, conjunctions, or adjectives used in the above technical solutions are as follows: A fixed connection refers to a connection in which parts or components are fixed in place and there is no relative movement between them; A rotating connection is a connection between parts that allows the parts to rotate relative to each other. Threaded connections are a type of detachable fixed connection with advantages such as simple structure, reliable connection, and convenient assembly and disassembly. They are widely used in mechanical engineering and connection structure fields. A sliding connection is a connection between parts that allows the parts to slide against each other.

[0016] The beneficial effects of this disclosure are: This invention features a central directional airbag. The expansion of the central directional airbag forms a flow channel. The central directional airbag has a double-layer structure: an inner high-pressure resistant rubber layer prevents fracturing fluid from puncturing the airbag, while an outer aramid fiber reinforced layer limits excessive radial expansion, ensuring the stability of the flow channel shape and restricting the fracturing fluid diffusion path. This forces the fracture to extend perpendicularly to the top plate, avoiding deflection along the original weak surface and ensuring the weakened area covers the full thickness of the target rock layer. The openings on both sides are collinear with the fracturing fluid outlet, allowing the fracturing fluid to impact the top plate perpendicularly along the opening direction, forming axial fractures. After the axial fractures are formed, the central directional airbag is depressurized, and the fracturing fluid diffuses circumferentially along the borehole within the confined space. Utilizing the stress concentration effect of the axial fractures, circumferential fractures are rapidly formed, achieving spatial intersection. The connection of the two types of fractures enhances the fracturing effect and improves fracturing efficiency. This invention features a connecting slot and a connecting block. The high-pressure water injection rod achieves rapid splicing of multiple water pipe sections through the standardized nesting structure of the connecting slot and the connecting block, adapting to the needs of working in narrow spaces downhole. It first anchors the pipes using front-end and rear-end sealing airbags, and then orients them using the middle directional airbag, simplifying the construction process, reducing manual adjustment steps, and lowering operational risks. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a hydraulic fracturing device with full-space controllability in the fracturing direction; Figure 2 A schematic diagram of a directional hydraulic fracturing packer; Figure 3 A schematic diagram of the operation of a directional hydraulic fracturing packer; Figure 4 This is a schematic diagram of the high-pressure water injection rod. Figure 5 A schematic diagram of the high-pressure water injection rod, orientation marker, and orientation compass; Figure 6 A schematic diagram of the threaded connection method between the hose connecting the expansion rod of the intermediate directional airbag and the high-pressure water inlet of the intermediate directional airbag, and the Y-shaped sealing airbag expansion rod connecting the hose and the high-pressure water inlet of the sealing airbag; Figure 7 Diagram of the Y-type occlusion airbag expansion rod structure; Figure 8 Cross-sectional view of a hydraulic fracturing device with full-space controllability in the fracturing direction; Figure 9 A three-dimensional front view of a hydraulic fracturing device with full spatial controllability in the fracturing direction; Figure 10 A three-dimensional perspective view of a hydraulic fracturing device with full spatial controllability in the fracturing direction; Figure 11 A schematic diagram of axial fracturing using a hydraulic fracturing device with fully controllable fracturing direction throughout the entire space. Figure 12 A schematic diagram of a circumferential fracturing device for hydraulic fracturing in which the fracturing direction is fully controllable throughout the space. Figure 13 A schematic diagram of the spatially intersecting fractures in a hydraulic fracturing device where the fracturing direction is fully controllable throughout the space. Figure 14 This is a schematic diagram of a hydraulic fracturing operation method where the fracturing direction is fully controllable in the entire space.

[0019] In the picture: 1. Directional hydraulic fracturing packer; 101. Fracturing fluid inlet; 102. High-pressure water inlet of the plugging airbag; 103. High-pressure water inlet of the intermediate directional airbag; 104. Metal fixing clamp; 105. Front plugging airbag; 106. Fracturing fluid outlet; 107. Intermediate directional airbag; 108. Rear plugging airbag; 109. Intermediate directional fracturing rod; 1010. Y-type plugging airbag expansion rod; 1011. Intermediate directional airbag expansion rod; 2. High-pressure water injection rod; 201. Connecting slot; 202. Connecting block; 203. Orientation mark; 204. Orientation compass; 3. High-pressure water pump system; 301. Intermediate directional fracturing rod connecting pipe; 302. Y-type sealing airbag expansion rod connecting hose; 303. Intermediate directional airbag expansion rod connecting hose; 4. Fracturing borehole; 5. Fracturing borehole wall; 6. Sealing section; 7. Axial fracturing fracture; 8. Circumferential fracturing fracture. Detailed Implementation

[0020] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0021] Please refer to Figures 1 to 13 A hydraulic fracturing device with fully controllable fracturing direction in all spaces, comprising: The directional hydraulic fracturing packer 1 includes a front-end plugging airbag 105, a middle directional airbag 107 and a rear-end plugging airbag 108 connected in sequence. High-pressure water pump system 3, one end of which is equipped with a water injection assembly connected to directional hydraulic fracturing packer 1; The intermediate directional airbag 107 is a double-layer airbag structure with openings on both sides and an intermediate directional fracturing rod 109 inside. Multiple fracturing fluid outlets 106 are opened on the intermediate directional fracturing rod 109. Both the front-end occlusion airbag 105 and the rear-end occlusion airbag 108 are single-layer airbags; The directional hydraulic fracturing packer 1 is also equipped with a Y-shaped plugging airbag expansion rod 1010 for injecting water into the front plugging airbag 105 and the rear plugging airbag 108, and an intermediate directional airbag expansion rod 1011 for injecting water into the intermediate directional airbag 107.

[0022] When using, refer to Figure 11A fracturing borehole 4 is drilled in the top plate where fracturing is required. The device is extended upward into the fracturing borehole 4. High-pressure water is injected through the high-pressure water pump system 3. First, the high-pressure water is sent through the high-pressure water inlet 102 of the sealing airbag and through the Y-shaped sealing airbag expansion rod 1010 into the interior of the front sealing airbag 105 and the rear sealing airbag 108. The side walls of the front sealing airbag 105 and the rear sealing airbag 108 are attached to the borehole wall 5 of the fracturing borehole to achieve anchoring, thereby fixing the entire device inside the fracturing borehole 4. Then, the orientation of the fracturing fluid outlet 106 is calibrated, and then high-pressure water is injected into the middle directional airbag 107, causing the middle directional airbag 107 to expand and surround the fracturing fluid outlet 106 to form a directional flow channel, forming a three-section airbag structure of front sealing, middle directional and rear sealing, which can both anchor and seal, and constrain the direction of fracturing fluid.

[0023] As a feasible specific method: High-pressure water is injected using antifreeze hydraulic oil at a pressure of 3-5 MPa and a rate of 10-15 L / min. After expansion, the diameters of the front-end sealing airbag 105 and the rear-end sealing airbag 108 are 10%-15% larger than the borehole diameter. Pressure is maintained for 5-10 minutes to confirm secure anchoring. Then, the high-pressure water pump system 3 expands and injects high-pressure water into the intermediate directional airbag 107 to form a directional flow channel. After axial fracturing continues for 5-15 minutes and the system pressure stabilizes for more than 3 minutes, the intermediate directional airbag 107 is then... The water injection pressure is 2-3 MPa, the injection rate is 8-12 L / min, and the difference between the inner diameter of the expansion channel and the diameter of the fracturing fluid outlet is ≤2 mm. The pressure is maintained for 3-5 min to confirm the seal. The high-pressure water pump system injects fracturing fluid into the fracturing fluid inlet 101. The fracturing fluid impacts the top rock layer vertically through the fracturing fluid outlet 106. The intermediate directional airbag and the flow channel formed by 107 restrict the fluid diffusion path to achieve axial fracturing. The fracturing fluid injection rate is 20-30 L / min, the axial fracturing time is 5-15 min, and the pressure is stabilized at 25-35 MPa.

[0024] The high-pressure water pump system 3 releases high-pressure water through the high-pressure water inlet 103 of the intermediate directional airbag. The depressurization rate is ≤1MPa / min. When the pressure is depressurized to below 0.5MPa, the fracturing fluid diffusion path expands. At this time, the output pressure of the high-pressure water pump system 3 is adjusted to 15-25MPa, and fracturing fluid is injected into the fracturing fluid inlet 101 to achieve circumferential fracturing. During circumferential fracturing, the fracturing fluid injection rate is 15-25L / min, the fracturing time is 8-20min, and the pressure is stabilized at 15-25MPa.

[0025] Specifically, the inner layer of the double-layered airbag of the intermediate directional airbag 107 is a nitrile rubber layer and the outer layer is an aramid fiber reinforced layer. Its opening center axis is collinear with the center axis of the fracturing fluid outlet 106. After expansion, it forms a cylindrical directional flow channel with an inner diameter ≤2mm different from the diameter of the fracturing fluid outlet 106.

[0026] The intermediate directional airbag 107 adopts a double-layer structure. The inner high-pressure resistant rubber layer can withstand pressures of over 50MPa to prevent fracturing fluid from puncturing the airbag. The outer aramid fiber reinforced layer restricts excessive radial expansion of the airbag and ensures the stability of the flow channel shape. The openings on both sides are collinear with the fracturing fluid outlet 106, so that the fracturing fluid impacts the top plate perpendicularly along the opening direction, avoiding deflection along the original weak surface.

[0027] Furthermore, metal fixing clamps 104 are fitted onto the outer walls of both the front sealing airbag 105 and the rear sealing airbag 108.

[0028] The expansion range of the rubber in the front sealing airbag 105 and the rear sealing airbag 108 is constrained by the metal fixing clamp 104 to prevent excessive deformation from causing sealing failure.

[0029] It should be noted that the front end of the intermediate directional fracturing rod 109 has a fracturing fluid inlet 101, the front end of the Y-shaped plugging airbag expansion rod 1010 has a plugging airbag high-pressure water inlet 102, and the front end of the intermediate directional airbag expansion rod 1011 has an intermediate directional airbag high-pressure water inlet 103.

[0030] Furthermore, the water injection assembly includes a high-pressure water injection rod 2. One end of the high-pressure water injection rod 2 is fixedly installed with a connecting slot 201. One end of the connecting slot 201 is installed with a connecting block 202. One end of the connecting block 202 is connected to the front end of the intermediate directional fracturing rod 109. The outer walls of the connecting slot 201 and the connecting block 202 are provided with directional marks 203. The directional marks 203 are red laser-etched lines that are aligned with the central axis of the fracturing fluid outlet 106.

[0031] The standardized nested structure of the connecting slot 201 and the connecting block 202 enables rapid splicing of multiple water pipe sections, facilitates the connection of water injection components, and adapts to the needs of working in narrow downhole spaces. The directional mark 203 is aligned with the axis of the fracturing fluid outlet 106 to ensure that the fracturing orientation is consistent with the design direction.

[0032] Specifically, a directional compass 204 is fixed to the outer wall of the connecting slot 201 by a locking nut. The directional compass 204 is used to adjust the angle with the direction of the roadway. The angle can be adjusted from 0 to 180°. After adjustment, the directional compass 204 is fixed by the locking nut.

[0033] The directional compass 204 is used to adjust the fracturing orientation and to perform axial fracturing in different directions.

[0034] Specifically, the high-pressure water pump system 3 includes a water pump, one end of which is fixedly connected to an intermediate directional fracturing rod connecting pipe 301, and one end of the intermediate directional fracturing rod connecting pipe 301 is connected to a connecting slot 201.

[0035] The water pump is used to inject high-pressure water and fracturing fluid, and delivers them into the corresponding pipelines through the corresponding inlets.

[0036] Specifically, one end of the water pump is also fixedly connected to a Y-shaped sealing airbag expansion rod connecting hose 302, and one end of the Y-shaped sealing airbag expansion rod connecting hose 302 is connected to the front end of the Y-shaped sealing airbag expansion rod 1010.

[0037] Furthermore, one end of the water pump is also fixedly connected to a central directional airbag expansion rod connecting hose 303, and one end of the central directional airbag expansion rod connecting hose 303 is connected to the front end of the central directional airbag expansion rod 1011.

[0038] The water pump is connected to the intermediate directional airbag expansion rod 1011 via the intermediate directional airbag expansion rod connecting hose 303, and then connected to the intermediate directional airbag 107, which facilitates the injection of high-pressure water and fracturing fluid, thereby facilitating axial fracturing and circumferential fracturing operations.

[0039] Reference Figure 14 A hydraulic fracturing operation method with full space controllability in the fracturing direction, based on the aforementioned hydraulic fracturing device with full space controllability in the fracturing direction, includes the following steps: S1. Assemble and position the equipment. Connect the directional hydraulic fracturing packer 1 and the high-pressure water injection rod 2 through the connecting block 202 and the connecting slot 201 to form a fracturing unit. Connect the connecting pipelines of each high-pressure water inlet and the high-pressure water pump system. After splicing multiple sections of the high-pressure water injection rod 2 to form an integral pipeline, open a fracturing borehole 4 on the top plate that needs to be fracturing. Place the device in the fracturing borehole 4 so that the middle directional airbag 107 of the device is located at the position of the sealing section 6. Use the directional mark 203 and the directional compass 204 to calibrate the orientation of the fracturing fluid outlet 106 and lock it in place. S2. Start the segmented rubber expansion sealing process. First, inject high-pressure water into the front sealing airbag 105 and the rear sealing airbag 108 through the high-pressure water pump system to expand and anchor them to the fracturing borehole wall 5 and maintain pressure to confirm. Then, inject high-pressure water into the middle directional airbag 107 to form a directional flow channel and maintain pressure to seal. The expansion range of each airbag is constrained by the metal fixing hoop 104. S3. Perform high-pressure fracturing fluid injection and fracture propagation operation. First, inject fracturing fluid at a set rate and pressure to achieve axial fracturing and generate axial fracturing fracture 7. Then, after releasing the pressure of the intermediate directional airbag 107, inject fracturing fluid while maintaining the sealing state of the plugging airbag to complete circumferential fracturing and generate circumferential fracturing fracture 8. S4. Carry out the equipment recycling and reuse process. Depressurize in the order of front sealing airbag 105, middle directional airbag 107 and rear sealing airbag 108, so that each rubber shrinks to its initial state. Disconnect the pipeline connection and recycle the device components in sections. After checking the integrity, use them for the next fracturing area.

[0040] The following description, in conjunction with the accompanying drawings and embodiments, further illustrates the hydraulic fracturing device and operating method with full-space controllable fracturing direction provided by the present invention.

[0041] First, the directional hydraulic fracturing packer 1 and the high-pressure water injection rod 2 are nested together via connecting block 202 and connecting slot 201 to form an initial fracturing unit. The fracturing fluid inlet 101, the high-pressure water inlet 102 of the plugging airbag, and the high-pressure water inlet 103 of the intermediate directional airbag are connected to the intermediate directional fracturing rod connecting pipe 301, the Y-type plugging airbag expansion rod connecting hose 302, and the intermediate directional airbag expansion rod connecting hose 303, respectively. According to the target fracturing depth, multiple high-pressure water injection rods 2 are spliced ​​together in the same way to form an integral pipeline. The orientation of the fracturing fluid outlet 106 is calibrated by the directional mark 203 to ensure that its axis is perpendicular to the designed fracturing direction of the top plate. Subsequently, the fracturing orientation can be adjusted by the directional compass 204 to perform axial fracturing in different directions. During axial fracturing, multi-point axial fracturing can be performed by moving the device.

[0042] The high-pressure water pump system 3 injects high-pressure water into the high-pressure water inlet 102 of the sealing airbag through the Y-shaped sealing airbag expansion rod connecting hose 302, causing the front sealing airbag 105 and the rear sealing airbag 108 to expand axially and fit tightly against the borehole wall, forming a preliminary anchoring. The high-pressure water uses antifreeze hydraulic oil, with an injection pressure of 3-5 MPa and an injection rate of 10-15 L / min. After the front sealing airbag 105 and the rear sealing airbag 108 expand, their diameters are 10%-15% larger than the borehole diameter. The pressure is maintained for 5-10 minutes to confirm that the anchoring is firm.

[0043] After the sealing airbag is completely fixed, the high-pressure water pump system 3 injects high-pressure water into the high-pressure water inlet 103 of the intermediate directional airbag through the intermediate directional airbag expansion rod connecting hose 303, causing the intermediate directional airbag 107 to expand and surround the fracturing fluid outlet 106, forming a directional flow channel; the high-pressure water injection pressure of the intermediate directional airbag is 2-3MPa, the injection rate is 8-12L / min, and the difference between the inner diameter of the flow channel and the diameter of the fracturing fluid outlet after expansion is ≤2mm. The pressure is maintained for 3-5min to confirm the seal.

[0044] The high-pressure water pump system 3 injects fracturing fluid into the fracturing fluid inlet 101 through the intermediate directional fracturing rod connecting pipe 301. The fracturing fluid then vertically impacts the top rock formation through the fracturing fluid outlet 106. The flow channel formed by the intermediate directional airbag 107 restricts the fluid diffusion path, achieving axial fracturing. The fracturing fluid injection rate is 20-30 L / min, the axial fracturing time is 5-15 min, and the pressure is stabilized at 25-35 MPa. The high-pressure water pump system 3 releases fracturing fluid through the intermediate directional airbag expansion rod connecting hose 303. High-pressure water is released at a rate ≤1MPa / min until the pressure drops below 0.5MPa. The high-pressure water pump system injects fracturing fluid into the fracturing fluid inlet 101, and the fracturing fluid impacts the top rock layer vertically through the fracturing fluid outlet 106. The front-end plugging airbag 105 and the rear-end plugging airbag 108 form a sealed space with the rock wall to achieve circumferential fracturing. During circumferential fracturing, the fracturing fluid injection rate is 15-25L / min, the fracturing time is 8-20min, and the pressure is stabilized at 15-25MPa.

[0045] The high-pressure water pump system 3 depressurizes the front sealing airbag 105, the rear sealing airbag 108, and the intermediate directional airbag 107, causing the rubber to shrink to its initial state. During depressurization, the pressure of the intermediate directional airbag 107 is first released to 0 MPa, and then the pressure of the front sealing airbag 105 and the rear sealing airbag 108 is released to 0 MPa. The depressurization rate is ≤1 MPa / min to avoid damage to the airbags or impact to the components due to sudden pressure drop. The connection between the fracturing fluid inlet 101, the high-pressure water inlet 102 of the sealing airbag, and the high-pressure water inlet 103 of the intermediate directional airbag and the high-pressure water pump system 3 is disconnected. The connecting slot 201 and the connecting block 202 are disassembled, and the high-pressure water injection rod 2 and the directional hydraulic fracturing packer 1 are retrieved in sections. After checking the integrity of the components, they can be reassembled for use in the next fracturing area.

[0046] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of this disclosure. Those skilled in the art should understand that this disclosure is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this disclosure. Various changes and modifications can be made to this disclosure without departing from its spirit and scope, and all such changes and modifications fall within the scope of this disclosure as claimed.

Claims

1. A hydraulic fracturing device with fully controllable fracturing direction throughout space, characterized in that, include: A directional hydraulic fracturing packer (1) includes a front-end plugging airbag (105), a middle directional airbag (107), and a rear-end plugging airbag (108) connected in sequence. A high-pressure water pump system (3) is provided with a water injection assembly connected to a directional hydraulic fracturing packer (1) at one end of the high-pressure water pump system (3); The intermediate directional airbag (107) is a double-layer airbag structure with openings on both sides and an intermediate directional fracturing rod (109) inside. Multiple fracturing fluid outlets (106) are opened on the intermediate directional fracturing rod (109). Both the front-end occlusion airbag (105) and the rear-end occlusion airbag (108) are single-layer airbags; The directional hydraulic fracturing packer (1) is also provided with a Y-shaped plugging airbag expansion rod (1010) for injecting water into the front plugging airbag (105) and the rear plugging airbag (108), and an intermediate directional airbag expansion rod (1011) for injecting water into the intermediate directional airbag (107).

2. The hydraulic fracturing device with fully controllable fracturing direction in all spaces as described in claim 1, characterized in that: The inner layer of the double-layered airbag of the intermediate directional airbag (107) is a nitrile rubber layer and the outer layer is an aramid fiber reinforced layer. Its opening center axis is collinear with the center axis of the fracturing fluid outlet (106). After expansion, it forms a cylindrical directional flow channel with an inner diameter difference of ≤2mm from the diameter of the fracturing fluid outlet (106).

3. The hydraulic fracturing device with fully controllable fracturing direction in all spaces as described in claim 1, characterized in that: Metal fixing clamps (104) are fitted onto the outer walls of both the front sealing airbag (105) and the rear sealing airbag (108).

4. The hydraulic fracturing device with fully controllable fracturing direction in all spaces as described in claim 1, characterized in that: The front end of the intermediate directional fracturing rod (109) has a fracturing fluid inlet (101), the front end of the Y-shaped plugging airbag expansion rod (1010) has a plugging airbag high-pressure water inlet (102), and the front end of the intermediate directional airbag expansion rod (1011) has an intermediate directional airbag high-pressure water inlet (103).

5. The hydraulic fracturing device with fully controllable fracturing direction as described in claim 1, characterized in that: The water injection assembly includes a high-pressure water injection rod (2), one end of which is fixedly installed with a connecting slot (201), and one end of which is installed with a connecting block (202). One end of the connecting block (202) is connected to the front end of the intermediate directional fracturing rod (109). The outer walls of the connecting slot (201) and the connecting block (202) are provided with directional marks (203), which are red laser-etched lines aligned with the central axis of the fracturing fluid outlet (106).

6. The hydraulic fracturing device with fully controllable fracturing direction as described in claim 5, characterized in that: A directional compass (204) is fixed to the outer wall of the connecting slot (201) by a locking nut. The directional compass (204) is used to adjust the angle with the direction of the roadway. The angle is adjusted from 0 to 180°. After adjustment, the directional compass (204) is fixed by a locking nut.

7. The hydraulic fracturing device with fully controllable fracturing direction as described in claim 5, characterized in that: The high-pressure water pump system (3) includes a water pump, one end of which is fixedly connected to an intermediate directional fracturing rod connecting pipe (301), and one end of the intermediate directional fracturing rod connecting pipe (301) is connected to a connecting slot (201).

8. The hydraulic fracturing device with fully controllable fracturing direction in all spaces as described in claim 7, characterized in that: One end of the water pump is also fixedly connected to a Y-shaped sealing airbag expansion rod connecting hose (302), and one end of the Y-shaped sealing airbag expansion rod connecting hose (302) is connected to the front end of the Y-shaped sealing airbag expansion rod (1010).

9. The hydraulic fracturing device with fully controllable fracturing direction as described in claim 7, characterized in that: One end of the water pump is also fixedly connected to a central directional airbag expansion rod connecting hose (303), and one end of the central directional airbag expansion rod connecting hose (303) is connected to the front end of the central directional airbag expansion rod (1011).

10. A hydraulic fracturing operation method with full spatial controllability in the fracturing direction, characterized in that, A hydraulic fracturing device with fully controllable fracturing direction according to claim 9 includes the following steps: S1. Assemble and position the equipment. Connect the directional hydraulic fracturing packer (1) and the high-pressure water injection rod (2) through the connecting block (202) and the connecting slot (201) to form a fracturing unit. Connect the connecting pipelines of each high-pressure water inlet and the high-pressure water pump system. After splicing multiple sections of the high-pressure water injection rod (2) to form an integral pipeline, open a fracturing borehole (4) on the top plate that needs to be fracturing. Place the device in the fracturing borehole (4) so ​​that the middle directional airbag (107) of the device is located in the sealing section (6). Use the directional mark (203) and directional compass (204) to calibrate the orientation of the fracturing fluid outlet (106) and lock it in place. S2. Start the segmented rubber expansion sealing process. First, inject high-pressure water into the front sealing airbag (105) and the rear sealing airbag (108) through the high-pressure water pump system to expand and anchor them to the wall of the fracturing borehole (5) and maintain pressure to confirm. Then, inject high-pressure water into the middle directional airbag (107) to form a directional flow channel and maintain pressure to seal. The expansion range of each airbag is constrained by the metal fixing hoop (104). S3. Perform high-pressure fracturing fluid injection and fracture propagation operation. First, inject fracturing fluid at a set rate and pressure to achieve axial fracturing and generate axial fracturing fractures (7). Then, release the pressure of the intermediate directional airbag (107) and inject fracturing fluid while maintaining the sealing state of the plugging airbag to complete circumferential fracturing and generate circumferential fracturing fractures (8). S4. Carry out the equipment recycling and reuse process. Depressurize in the order of front sealing airbag (105), middle directional airbag (107) and rear sealing airbag (108) to shrink each rubber to the initial state, disconnect the pipeline connection and recycle the device components in sections. After checking the integrity, use them for the next fracturing area.

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