Porous perforation-oriented fracturing system and method

Abstract

This invention discloses a porous fracture-forming directional fracturing system and method. The porous fracture-forming directional fracturing system includes fracturing pipes, a pipe body, control components, and a sealing device. The pipe body is connected between two adjacent fracturing pipes, and the sidewall of the pipe body is provided with fracturing holes and jet hole groups. The jet hole groups include multiple jet holes spaced apart along the axial direction of the pipe body. The control components are connected to the pipe body and are used to control the opening of the fracturing holes so that the inner cavity of the pipe body and the external space outside the pipe body can be connected through the fracturing holes, or to control the closing of the fracturing holes so that the inner cavity of the pipe body and the external space outside the pipe body are not connected at the fracturing holes. The sealing device is located on the outside of the pipe body and / or the fracturing pipes, and the fracturing holes and jet hole groups are located between two adjacent sealing devices. This invention can first form a through fracture, and then further fracturing the through fracture to form a complex fracture network, improving the fracture development in the coal seam and reducing safety hazards in subsequent mining.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic fracturing technology, specifically relating to a porous fracturing directional fracturing system and method. Background Technology

[0002] my country is rich in coal resources. In some regions, the hard coal seams are harder than ordinary coal seams, with a hardness coefficient greater than 2. They are dense, have a complete overall structure, and often appear in blocky or layered forms. Joints and fractures are not well-developed, making them difficult to break into smaller pieces. Mining these hard coal seams presents challenges: low mining efficiency, significant difficulty in breaking the coal, and slow advance speeds for mining machines and other equipment. Equipment wear is high, and the mining process exacerbates the wear and tear on cutting tools, hydraulic supports, and other equipment, increasing maintenance costs. Furthermore, there are high safety risks, potentially leading to rock bursts (sudden coal and rock breaking and ejection), coal face spalling, and other disasters, severely impacting the safe and efficient mining of coal faces.

[0003] In related technologies, coal weakening is achieved through methods such as hydraulic weakening, blasting weakening, chemical agents, thermal weakening, and ultrasonic vibration. However, blasting, chemical agents, thermal weakening, and ultrasonic vibration can cause problems such as coal corrosion and spontaneous combustion. Hydraulic fracturing, a technique in this field, cannot effectively create complex fracture networks within the coal seam, thus limiting its ability to disrupt the integrity of the coal. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a porous fracture-forming directional fracturing system, which can first form a through fracture through jet, and then perform fracturing on the through fracture to form a complex fracture network, resulting in good fracturing effect.

[0006] The embodiments of the present invention propose a porous fracture directional fracturing method.

[0007] The porous fracturing directional fracturing system of this invention includes:

[0008] Fracturing tubing;

[0009] The pipe body is connected between two adjacent fracturing pipes. The side wall of the pipe body is provided with fracturing holes and a jet hole group. The jet hole group includes a plurality of jet holes spaced apart along the axial direction of the pipe body.

[0010] A control component is connected to the tube body. The control component is used to control the fracturing hole to open so that the inner cavity of the tube body and the outer space of the tube body can be connected through the fracturing hole, or to control the fracturing hole to close so that the inner cavity of the tube body and the outer space of the tube body are not connected at the fracturing hole.

[0011] A sealing device is provided on the outside of the tube body and / or the fracturing tube, and the fracturing hole and the jet hole are arranged between two adjacent sealing devices.

[0012] The multi-hole fracture directional fracturing system of this invention can first form multiple perforations on the sidewall of the borehole through a jet hole group. The multiple perforations are connected to form a through fracture. Then, a large flow of fluid flowing into the outside of the pipe body through the fracturing hole and the jet hole group further fractures the through fracture to form a complex fracture network, which improves the fracture development in the coal body, has a good fracturing effect, facilitates the subsequent mining of the coal body, and effectively reduces the safety hazards in subsequent mining.

[0013] In some embodiments, there are multiple jet orifice groups, and the multiple jet orifice groups are arranged circumferentially along the pipe body; there are multiple fracturing holes, and the multiple fracturing holes are arranged circumferentially along the pipe body.

[0014] In some embodiments, a rotating impeller is further included, the rotating impeller being disposed within the jet orifice so that the fluid forms a rotating fluid after passing through the jet orifice;

[0015] And / or, the tube body has connecting portions at both ends in its axial direction, and the tube body is detachably connected to the fracturing tube through the connecting portions.

[0016] In some embodiments, the control component includes a sleeve and a first elastic element, the sleeve being sleeved on the outside of the tube body and movable relative to the tube body along the axial direction of the tube body, and the first elastic element being disposed between the sleeve and the tube body.

[0017] In the initial state, the first elastic element is blocked by the sleeve to prevent the inner cavity of the tube body from communicating with the external space outside the tube body at the fracturing hole. When the fluid pressure in the external space outside the tube body is greater than a first threshold, the fluid drives the sleeve to move and deforms the first elastic element to open the fracturing hole.

[0018] In some embodiments, a fixing sleeve is further included, the fixing sleeve being sleeved on the outside of the tube body, the first end of the fixing sleeve being sealed between the outer wall of the tube body, the second end of the fixing sleeve being open to form a sliding cavity between the fixing sleeve and the tube body, the end of the sleeve adjacent to the first end of the fixing sleeve being provided with an end plate, the circumferential outer wall of the end plate being in contact with the inner wall of the fixing sleeve, and the first elastic member being disposed between the end plate and the first end of the fixing sleeve.

[0019] In some embodiments, a detection component is further included, which is used to detect the pressure of the fluid in the external space outside the tube body. A sealing cavity and a detection cavity are formed between the fixing sleeve and the tube body. The detection cavity communicates with the external space outside the tube body. The detection component is disposed in the sealing cavity, and the detection end of the detection component extends into the detection cavity.

[0020] In some embodiments, there are multiple tube bodies, each of which is provided with a fracturing hole, a jet hole group, and a control component. The multiple tube bodies are arranged at intervals along the length direction of the fracturing tube. At least a portion of the tube bodies are connected to a ball-launching drive component at their ends. The ball-launching drive component has a first state and a second state. In the first state, the inner cavity of the ball-launching drive component is open and the ball-launching drive component blocks the jet hole group on its corresponding tube body. In the second state, the inner cavity of the ball-launching drive component is blocked and the ball-launching drive component opens the jet hole group on its corresponding tube body.

[0021] In some embodiments, the pitching drive component includes:

[0022] A ball-launching tube, which is connected to the tube body and the fracturing tube;

[0023] A sliding cylinder is disposed inside the inner cavity of the ball-throwing tube and is movable along the axial direction of the ball-throwing tube. An installation cavity is defined between the sliding cylinder and the ball-throwing tube. The outer wall of the sliding cylinder is in contact with the inner wall of the ball-throwing tube. The middle part of the sliding cylinder has a ball-blocking part. A portion of the sliding cylinder is in contact with the inner wall of the corresponding tube body.

[0024] The second elastic element is disposed in the mounting cavity. In the initial state, the second elastic element blocks the jet hole group of the corresponding tube body of the sliding cylinder.

[0025] The ball dropped into the fracturing tube can abut against the ball-blocking part to block the inner cavity of the slide tube and drive the slide tube to move, thereby opening the corresponding jet hole group on the tube body.

[0026] This invention provides a porous fracture directional fracturing method, which utilizes the porous fracture directional fracturing system described in any of the above-mentioned embodiments for fracturing operations. The porous fracture directional fracturing method includes:

[0027] S101. Conduct directional drilling within the tunnel;

[0028] S102. Connect the porous fracture directional fracturing system and the pump group, and perform a water injection test on the porous fracture directional fracturing system.

[0029] S103. After the water injection test is completed, the multi-hole fracture directional fracturing system is placed into the directional borehole until the preset fracturing section is reached, and water is injected into the sealing device to achieve setting and sealing.

[0030] S104. Water is injected into the fracturing pipe, and the water flowing into the porous fracture directional fracturing system is ejected from the jet holes to form multiple perforations on the sidewall of the directional borehole. The multiple perforations are connected to form a through fracture.

[0031] S105. Continuously inject water to open the fracturing holes on the pipe body, and the fluid flows into the external space outside the pipe body through the fracturing holes and jet holes to carry out directional fracturing.

[0032] S106. After the previous preset fracturing section is completed, water is drained from the sealing device, and the multi-hole fracturing directional fracturing system is dragged to the next preset fracturing section. Water is injected into the sealing device to achieve setting and sealing, and steps S104 and S105 are repeated to carry out the fracturing operation of the fracturing section.

[0033] S107. Repeat the previous step until the fracturing operation of all fracturing sections is completed.

[0034] This invention provides a porous fracture directional fracturing method, which utilizes the aforementioned porous fracture directional fracturing system for fracturing operations. The porous fracture directional fracturing method includes:

[0035] S201. Directional drilling is carried out in the tunnel;

[0036] S202. Connect the porous fracture directional fracturing system and the pump group, and perform a water injection test on the porous fracture directional fracturing system.

[0037] S203. After the water injection test is completed, the multi-hole fracture directional fracturing system is placed into the directional borehole, and water is injected into the sealing device to achieve setting and form multiple independent fracturing sections.

[0038] S204. Water is injected into the fracturing pipe. The water flowing into the porous fracture directional fracturing system is ejected from the jet hole on the pipe body closest to the bottom of the directional borehole to form multiple perforations on the sidewall of the directional borehole. The multiple perforations are connected to form a through fracture.

[0039] S205. Continuously inject water to open the fracturing hole on the pipe body closest to the bottom of the directional borehole. Fluid flows into the external space outside the pipe body through the fracturing hole and the jet hole to perform directional fracturing.

[0040] S206. After the previous preset fracturing section is completed, a ball is placed into the fracturing pipe. The ball contacts the ball-throwing drive component that is closest to the bottom of the directional borehole, so that the inner cavity of the ball-throwing drive component is isolated and the jet hole group on the pipe body corresponding to the ball-throwing drive component is opened. Then, steps S204 and S205 are repeated to carry out the fracturing operation of the fracturing section.

[0041] S207. Repeat the previous step to perform fracturing operations on multiple fracturing sections sequentially along the direction from the bottom to the opening of the directional borehole. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a porous fracture directional fracturing system according to an embodiment of the present invention.

[0043] Figure 2 This is a cross-sectional schematic diagram of a porous fracture directional fracturing system according to an embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of the installation of the detection component in an embodiment of the present invention.

[0045] Figure 4 This is a cross-sectional schematic diagram of the tube body and control components in another embodiment of the present invention.

[0046] Figure 5 This is a cross-sectional schematic diagram of the rotating impeller in an embodiment of the present invention.

[0047] Figure 6 This is a cross-sectional schematic diagram of the ball-throwing drive component in an embodiment of the present invention.

[0048] Figure 7 This is a cross-sectional schematic diagram of a porous fracture directional fracturing system according to another embodiment of the present invention.

[0049] Figure label:

[0050] 100. Porous fracturing directional fracturing system;

[0051] 1. Fracturing pipe; 11. Plug;

[0052] 2. Pipe body; 21. Fracturing hole; 22. Jet hole; 23. Connecting part; 24. Sleeve; 25. First elastic element; 26. Fixing sleeve; 261. Sliding cavity; 262. Sealing cavity; 263. Detection cavity; 27. Detection component;

[0053] 3. Sealing device;

[0054] 4. Rotate the impeller;

[0055] 5. Throwing drive component; 51. Throwing tube; 52. Slide tube; 521. Body section; 522. First body section; 523. Second body section; 53. Second elastic element; 54. Ball blocking part; 55. Mounting cavity. Detailed Implementation

[0056] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0057] See Figures 1 to 7 The porous fracture directional fracturing system 100 of this invention includes a fracturing tube 1, a tube body 2, a control component, and a sealing device 3.

[0058] The pipe body 2 is connected between two adjacent fracturing pipes 1. The pipe body 2 can be a section of fracturing pipe 1, or the pipe body 2 and fracturing pipe 1 can be made of the same material, or the pipe body 2 can be made of other materials, such as metal, to meet the arrangement requirements of fracturing holes 21, jet orifice groups, and control components. A plug 11 is provided at one end of the fracturing pipe 1 near the bottom of the borehole. The fracturing pipe 1 consists of multiple sections, and the fracturing pipe 1 and pipe body 2 are connected in sequence. Fracturing holes 21 and jet orifice groups are provided on the side wall of the pipe body 2. The jet orifice group includes multiple jet orifices 22 spaced apart along the axial direction of the pipe body 2. There can be multiple fracturing holes 21. When high-flow fracturing is performed, more water will flow from the fracturing holes 21 to the external space outside the pipe body 2. The jet orifice group is used to make the fluid in the pipe body 2 flow at a high velocity to the external space outside the pipe body 2, and to impact the side wall of the borehole with high pressure, thereby forming a perforation. In this embodiment, multiple jet holes 22 are arranged along the axial direction of the pipe body 2. Therefore, after multiple jet holes arranged along the axial direction of the pipe body 2 are connected to each other, they can form a long strip-shaped through crack.

[0059] The jet hole group can also be multiple groups, which are set along the circumference of the pipe body 2. This can form multiple through cracks in the circumference of the borehole. After the through cracks are formed, further fracturing can make the through cracks expand further, improve the distribution of cracks in the rock wall in the circumference of the borehole, fully fracture the rock wall, facilitate subsequent construction, and reduce the safety risks of subsequent construction.

[0060] The control component is connected to the tube body 2. The control component is used to control the opening of the fracturing hole 21 so that the inner cavity of the tube body 2 and the outer space of the tube body 2 can be connected through the fracturing hole 21, or to control the closing of the fracturing hole 21 so that the inner cavity of the tube body 2 and the outer space of the tube body 2 are not connected at the fracturing hole 21.

[0061] The fracturing operation is divided into a perforation stage and a fracturing stage. In the perforation stage, the control component closes the fracturing hole 21, and the water in the fracturing pipe 1 flows into the inner cavity of the pipe body 2 and then flows to the outer space of the pipe body 2 through the jet hole group. Multiple perforations can be formed on the side wall of the drilled hole through the high-speed fluid. In the fracturing stage, as the water injection pressure continues to increase, the control component opens the fracturing hole 21. At this time, the water in the inner cavity of the pipe body 2 can flow to the outer space of the pipe body 2 through the fracturing hole 21 and the jet hole group at the same time, forming a large flow of fluid to fracture the through fracture.

[0062] In this embodiment, nozzles can be installed inside the jet holes 22 of the jet hole group, thereby forming a high-speed flowing fluid, which facilitates the formation of perforations on the rock wall.

[0063] The sealing device 3 is located on the outside of the pipe body 2 and / or the fracturing pipe 1, and the fracturing hole 21 and the jet hole group are located between two adjacent sealing devices 3.

[0064] The sealing device 3 is a sealing bag. After water is injected into the sealing device 3, the sealing device 3 expands. The outer wall of the sealing device 3 fits against the inner wall of the borehole. At the same time, the inner wall of the sealing device 3 fits against the outer wall of the pipe body 2 or the fracturing pipe 1. The aforementioned external space, namely the fracturing space, is formed between the inner wall of the borehole between the two sealing devices 3 and the outer wall of the fracturing pipe 1 and the pipe body 2.

[0065] The multi-hole fracture directional fracturing system 100 of this invention can first form multiple perforations on the sidewall of the borehole through a jet hole group. The multiple perforations are connected to form a through fracture. Then, a large flow of fluid flows into the outside of the pipe body 2 through the fracturing hole 21 and the jet hole group to further fracture the through fracture and form a complex fracture network. This improves the fracture development in the coal body, has a good fracturing effect, facilitates the subsequent mining of the coal body, and effectively reduces the safety hazards in subsequent mining.

[0066] In some embodiments, the multi-hole fracture directional fracturing system 100 includes a rotating impeller 4 disposed within a jet orifice 22 so that fluid forms a rotating fluid after passing through the jet orifice 22. It is understood that by arranging the rotating impeller 4 within the jet orifice 22, the fluid flowing out of the jet orifice 22 can be a high-speed, high-pressure rotating fluid, resulting in stronger cutting capabilities. This allows for cutting of the rock strata on the borehole sidewall, improving the speed and quality of perforation formation, and ensuring that through fractures can be formed between multiple perforations.

[0067] Since this embodiment has multiple jet hole groups, the perforations along the circumference of the pipe body 2 can also be connected, so that the perforations in the corresponding sections are intertwined, resulting in good crack formation quality and facilitating subsequent fracturing operations.

[0068] In some embodiments, the pipe body 2 has connecting portions 23 at both ends in the axial direction. The connecting portions 23 can be internal threaded joints or external threaded joints. For example, one end of the pipe body 2 is provided with an internal threaded joint and the other end with an external threaded joint, or both ends of the pipe body 2 are provided with external threaded joints. The pipe body 2 is detachably connected to the fracturing pipe 1 through the connecting portions 23, which facilitates the assembly of the pipe body 2 with the fracturing pipes 1 located at both ends, improves practicality, facilitates more flexible division of the length of the fracturing section for each operation, and also facilitates transportation.

[0069] In some embodiments, the control component includes a sleeve 24 and a first elastic element 25. The sleeve 24 is sleeved on the outside of the tube body 2, and the sleeve 24 is in contact with the outer wall of the tube body 2. The sleeve 24 is movable relative to the tube body 2 along the axial direction of the tube body 2. The first elastic element 25 is disposed between the sleeve 24 and the tube body 2. In the initial state, the sleeve 24 blocks the fracturing hole 21 so that the inner cavity of the tube body 2 and the external space outside the tube body 2 are not connected at the fracturing hole 21. When the fluid pressure in the external space outside the tube body 2 is greater than a first threshold, the fluid drives the sleeve 24 to move and deforms the first elastic element 25 to open the fracturing hole 21.

[0070] For example, when the casing 24 is opposite to the fracturing hole 21, the fracturing hole 21 can be blocked and closed. When the casing 24 is misaligned with the tube body 2, the fracturing hole 21 can be opened. The fracturing hole 21 can be used to connect the inner cavity of the tube body 2 and the outer space of the tube body 2.

[0071] Furthermore, the porous fracture directional fracturing system 100 also includes a fixing sleeve 26, which is sleeved on the outside of the tube body 2. The first end of the fixing sleeve 26 is sealed with the outer wall of the tube body 2, and the second end of the fixing sleeve 26 is open to form a sliding cavity 261 between the fixing sleeve 26 and the tube body 2. An end plate is provided at the end of the sleeve 24 adjacent to the first end of the fixing sleeve 26. The circumferential outer wall of the end plate is in contact with the inner wall of the fixing sleeve 26. A first elastic member 25 is provided between the end plate and the first end of the fixing sleeve 26.

[0072] The installation of the fixed sleeve 26, the sleeve 24, and the first elastic element 25 provides installation space, making the arrangement between components more stable and improving practicality.

[0073] In some embodiments, the porous fracturing directional fracturing system 100 further includes a detection component 27 for detecting the pressure of fluid in the external space outside the tube body 2. A sealing cavity 262 and a detection cavity 263 are formed between the fixing sleeve 26 and the tube body 2. The detection cavity 263 communicates with the external space outside the tube body 2. The detection component 27 is disposed in the sealing cavity 262, and the detection end of the detection component 27 extends into the detection cavity 263. The sealing cavity 262 and the detection cavity 263 are relatively independent and are both generally semi-circular. The sealing cavity 262 and the detection cavity 263 are arranged circumferentially on the tube body 2. A through hole can be provided on the detection cavity 263, thereby allowing fluid in the external space outside the tube body 2 to flow into the detection cavity 263 through the through hole.

[0074] The detection component 27 can be a pressure sensor. Of course, a power supply unit and a data storage unit can also be arranged in the sealed cavity 262. The power supply unit supplies power to the data storage unit and the detection component 27, and the data storage unit is used to store the data detected by the detection component 27.

[0075] The detection end of the detection component 27 has a probe that extends into the detection cavity 263 to detect the fluid pressure in the external space outside the tube body 2, accurately control the fluid pressure in the external space, and facilitate the guidance of the fracturing construction process.

[0076] In some embodiments, there are multiple tube bodies 2, each tube body 2 is provided with a fracturing hole 21, a jet hole group and a control component. The multiple tube bodies 2 are arranged at intervals along the length direction of the fracturing tube 1. At least some of the tube bodies 2 are connected to a ball-throwing drive component 5 at their ends. The ball-throwing drive component 5 has a first state and a second state. In the first state, the inner cavity of the ball-throwing drive component 5 is open and the ball-throwing drive component 5 blocks the jet hole group on its corresponding tube body 2. In the second state, the inner cavity of the ball-throwing drive component 5 is blocked and the ball-throwing drive component 5 opens the jet hole group on its corresponding tube body 2.

[0077] When a single pipe body 2 is installed, it is usually possible to fracturing only one fracturing section at a time. After the fracturing of the fracturing section is completed, the multi-hole fracturing directional fracturing system 100 needs to be dragged in the borehole to move to the next fracturing section, and then the sealing device 3 is re-set and the water injection pressure is increased.

[0078] When multiple pipe bodies 2 are installed, multiple setters can be used to simultaneously set the borehole, dividing it into multiple fracturing sections. These fracturing sections, from the bottom of the borehole to the borehole opening, are sequentially designated as the first fracturing section, the second fracturing section, the third fracturing section, and so on up to the Nth fracturing section. During water injection, the jet orifice group on the pipe body 2 closest to the bottom of the borehole is open, while the jet orifice groups on the other pipe bodies 2 are blocked by the corresponding ball-throwing drive components 5. Therefore, water will only flow out through the jet orifice group on the pipe body 2 closest to the bottom of the borehole, allowing for perforation and fracturing of the first fracturing section closest to the bottom of the borehole. After fracturing is completed in the first fracturing section, a ball is placed into the fracturing tube 1. The ball enters the ball-throwing drive component 5 on the front side of the tube body 2 corresponding to the first fracturing section. The inner cavity of the ball-throwing drive component 5 is blocked. At the same time, the fluid in the fracturing tube 1 will drive the ball-throwing drive component 5 to move and open the jet hole group on the front side (the side away from the bottom of the hole) of the tube body 2, so that the water in the fracturing hole 21 flows out through the jet hole group on the tube body 2, and perforation and fracturing are performed on the second fracturing section. After fracturing is completed in the second fracturing section, a ball (with an increased radius) is placed into the fracturing pipe 1. The ball enters the ball-throwing drive component 5 on the front side of the pipe body 2 corresponding to the second fracturing section. The inner cavity of the ball-throwing drive component 5 is blocked. At the same time, the fluid in the fracturing pipe 1 will push the ball-throwing drive component 5 to actuate and open the jet orifice group on the front side (the side away from the bottom of the hole) of the pipe body 2, allowing the water in the fracturing hole 21 to flow out through the jet orifice group on the pipe body 2, thus performing perforation and fracturing in the third fracturing section. This operation can be repeated to achieve sequential fracturing operations in N fracturing sections.

[0079] In some embodiments, the ball-throwing drive component 5 includes a ball-throwing tube 51, a slide 52, and a second elastic element 53.

[0080] The ball-throwing tube 51 is connected to the tube body 2 and the fracturing tube 1. The inner diameter of different sections of the ball-throwing tube 51 is different, and the inner cavity of the ball-throwing tube 51 has a flat U-shaped chamber. The slide cylinder 52 is located in the inner cavity of the ball-throwing tube 51 and is movable along the axial direction of the ball-throwing tube 51. The slide cylinder 52 includes a body section 521, a first body section 522 and a second body section 523. The first body section 522 and the second body section 523 are respectively located at both ends of the body section 521. The outer wall of the body section 521 slides against the inner wall of the ball-throwing tube 51. The first body section 522 is sleeved with the flat U-shaped chamber, thereby defining an installation cavity 55 between the slide cylinder 52 and the ball-throwing tube 51. The second elastic element 53 is located in the installation cavity 55.

[0081] The slide cylinder 52 has a ball-blocking part 54 in the middle of its main body section 521. After the ball is dropped, it can abut against the ball-blocking part 54 and seal the inner cavity of the main body section 521, thereby blocking the inner cavity of the ball-dropping drive component 5. The outer wall of the second set of body sections 523 of the slide cylinder 52 is in contact with the inner wall of the corresponding tube body 2. In the initial state, the second elastic member 53 blocks the jet hole group of the corresponding tube body 2 with the second set of body sections 523 of the slide cylinder 52. The ball dropped into the fracturing tube 1 can abut against the ball-blocking part 54 to block the inner cavity of the main body section 521 of the slide cylinder 52 and drive the slide cylinder 52 to move, thereby opening the jet hole group on the corresponding tube body 2. This embodiment can thus form a linkage structure. Under normal circumstances, the ball-throwing drive component 5 can block the jet hole group on the corresponding pipe body 2. After a ball with a certain outer diameter is thrown, the ball can come into contact with the ball-blocking part 54 and prevent water from flowing further towards the bottom of the borehole. At the same time, under the action of water, it can drive the slide cylinder 52 to move and open the jet hole group on the pipe body 2 located in front of it (the side away from the bottom of the borehole).

[0082] In this embodiment, both the first elastic element 25 and the second elastic element 53 can be columnar springs, and there can be multiple first elastic elements 25 and second elastic elements 53.

[0083] This invention provides a porous fracture directional fracturing method, which utilizes the porous fracture directional fracturing system 100 described above for fracturing operations. The porous fracture directional fracturing method includes:

[0084] S101. Constructing directional boreholes within the roadway. By setting up drilling sites within the roadway, drilling equipment is used to construct long directional boreholes inside the coal and rock mass.

[0085] S102. Connect the porous fracture directional fracturing system 100 and the pump set, and conduct a water injection test on the porous fracture directional fracturing system 100.

[0086] During the water injection test, the water injection pipe of the sealer 3 can be connected to the pump set first, and water can be injected into the sealer 3 to test the sealing performance of the sealer 3 and the water injection pipe. Then, the fracturing pipe 1 can be connected to the pump set, and water can be injected into the fracturing pipe 1 to test the connectivity of the fracturing system.

[0087] S103. After the water injection test is completed, the multi-hole fracture directional fracturing system 100 is placed into the directional borehole until the preset fracturing section is reached. Water is injected into the sealing device 3 to achieve setting and sealing. Initially, construction is carried out from the bottom section of the borehole. After each section is completed, the fracturing pipe 1 is pulled outward to carry out the construction of the next section until the fracturing construction of the entire directional borehole is completed.

[0088] S104. Water is injected into the fracturing pipe 1. The water flowing into the multi-hole fracture directional fracturing system 100 is ejected through the jet holes 22 to form multiple perforations on the sidewall of the directional borehole. These multiple perforations are interconnected to form a continuous fracture. During this process, the high-pressure fluid ejected from the jet holes 22 in the jet hole group impacts the rock wall of the directional borehole, forming a series of perforations on the upper and lower rock walls. The perforations are interconnected and form a continuous fracture, resulting in good fracture quality, which is beneficial to the formation of the fracture network in the subsequent fracturing process. Especially when a rotating impeller 4 is installed inside the jet hole 22, it forms a nozzle structure that can generate rotating fluid, resulting in better cutting effect and larger hole depth and radius in the formed perforations.

[0089] S105. Continuously inject water to open the fracturing hole 21 on the pipe body 2. Fluid flows into the external space outside the pipe body 2 through the fracturing hole 21 and the jet hole 22 for directional fracturing. After the through fracture is formed, the area of ​​the elongated prefabricated through fracture remains unchanged. Fluid accumulates in the closed space, the pressure rises, and the casing 24 is pushed and moved by the fluid. The first elastic element 25 is deformed and compressed, the fracturing hole 21 opens, and a large volume of fluid enters the elongated prefabricated through fracture hole 21 and jet hole 22 for directional fracturing.

[0090] S106. After the previous preset fracturing section is completed, water is drained from the sealing device 3, and the multi-hole fracturing directional fracturing system 100 is dragged to the next preset fracturing section. Water is injected into the sealing device 3 to achieve setting and sealing, and steps S104 and S105 are repeated to carry out the fracturing operation of the fracturing section.

[0091] S107. Repeat the previous step until the fracturing operation of all fracturing sections is completed.

[0092] This invention provides a porous fracture directional fracturing method, which utilizes the aforementioned porous fracture directional fracturing system 100 for fracturing operations. The porous fracture directional fracturing method includes:

[0093] S201. Constructing directional boreholes within the roadway. This involves setting up drilling sites within the roadway and using drilling equipment to construct long directional boreholes inside the coal and rock mass.

[0094] S202. Connect the porous fracture directional fracturing system 100 and the pump set, and conduct a water injection test on the porous fracture directional fracturing system 100. During the water injection test, the water injection pipe of the sealing device 3 can be connected to the pump set first, and water can be injected into the sealing device 3 to test the sealing performance of the sealing device 3 and the water injection pipe. Then, connect the fracturing pipe 1 and the pump set, and inject water into the fracturing pipe 1 to test the connectivity of the fracturing system.

[0095] S203. After the water injection test is completed, the multi-hole fractured directional fracturing system 100 is placed into the directional borehole, and water is injected into the sealing device 3 to achieve setting and form multiple independent fracturing sections. The multiple independent fracturing sections are sequentially named from the bottom of the directional borehole to the borehole opening as the first fracturing section, the second fracturing section, the third fracturing section, ... the Nth fracturing section.

[0096] S204. Water is injected into the fracturing pipe 1. The water flowing into the multi-hole fracture directional fracturing system 100 is ejected from the jet holes 22 on the pipe body 2 (corresponding to the first fracturing section) closest to the bottom of the directional borehole, forming multiple perforations on the sidewall of the directional borehole. These perforations are interconnected to form a continuous fracture. During this process, the high-pressure fluid ejected from the jet holes 22 impacts the rock wall of the directional borehole, forming a series of perforations on the upper and lower rock walls. The perforations are interconnected and form a continuous fracture, resulting in good fracture quality, which is beneficial to the formation of the fracture network in subsequent fracturing processes. Especially when a rotating impeller 4 is installed inside the jet hole 22, it forms a nozzle structure that can generate rotating fluid, resulting in better cutting effect and larger hole depth and radius in the formed perforations.

[0097] S205. Continuous water injection is performed to open the fracturing hole 21 on the pipe body 2 (corresponding to the first fracturing section) closest to the bottom of the directional borehole. Fluid flows into the external space outside the pipe body 2 through the fracturing hole 21 and the jet hole 22 for directional fracturing. After the through fracture is formed, the area of ​​the elongated prefabricated through fracture remains unchanged. Fluid accumulates in the closed space, the pressure rises, and the casing 24 is pushed and moved by the fluid. The first elastic element 25 is deformed and compressed, the fracturing hole 21 opens, and a large volume of fluid enters the elongated prefabricated through fracture hole 21 and jet hole 22 for directional fracturing.

[0098] S206. After the previous preset fracturing section is completed, a ball is placed into the fracturing pipe 1. The ball contacts the ball-throwing drive component 5, which is closest to the bottom of the directional borehole, so that the inner cavity of the ball-throwing drive component 5 is isolated and the jet hole group on the pipe body 2 corresponding to the ball-throwing drive component 5 is opened. Then, steps S204 and S205 are repeated to carry out the fracturing operation of the fracturing section.

[0099] S207. Repeat the previous step to perform fracturing operations on multiple fracturing sections sequentially along the direction from the bottom of the directional borehole to the borehole opening.

[0100] Understandably, when there are three or more pipe bodies and two or more ball-throwing drive components, the ball-throwing size corresponding to the ball-blocking parts in these multiple ball-throwing drive components will also be different. Along the direction from the bottom to the top of the directional borehole, the ball-throwing size corresponding to the ball-blocking parts of these multiple ball-throwing drive components continuously increases. This ensures that when placing the balls, the ball with the smallest outer diameter is placed first, and then the size of the placed balls is gradually increased, allowing multiple fracturing sections to be constructed sequentially from the bottom to the top of the directional borehole.

[0101] The embodiments of the present invention have a simple process, high construction efficiency, low labor intensity, and the ability to manually control multiple perforations to form prefabricated through-cracks and guide the fracturing through-cracks to form a complex fracture network. It has outstanding effects in weakening hard coal and is more practical.

[0102] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to 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, they should not be construed as limitations on this invention.

[0103] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0104] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0105] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0106] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0107] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A perforating fracturing system, comprising: include: At least two fracturing tubes; The pipe body is connected between two adjacent fracturing pipes. The side wall of the pipe body is provided with fracturing holes and a jet hole group. The jet hole group includes a plurality of jet holes spaced apart along the axial direction of the pipe body. A control component is connected to the tube body. The control component is used to control the fracturing hole to open so that the inner cavity of the tube body and the outer space of the tube body can be connected through the fracturing hole, or to control the fracturing hole to close so that the inner cavity of the tube body and the outer space of the tube body are not connected at the fracturing hole. A sealing device is provided on the outside of the tube body and / or the fracturing tube, and the fracturing hole and the jet hole are arranged between two adjacent sealing devices; There are multiple jet orifice groups, and the multiple jet orifice groups are arranged along the circumference of the pipe body; there are multiple fracturing holes, and the multiple fracturing holes are arranged along the circumference of the pipe body. It also includes a rotating impeller, which is disposed inside the jet hole so that the fluid forms a rotating fluid after passing through the jet hole; The tube body has connecting portions at both ends in the axial direction, and the tube body is detachably connected to the fracturing tube through the connecting portions; The control component includes a sleeve and a first elastic element. The sleeve is sleeved on the outside of the tube body and is movable relative to the tube body along the axial direction of the tube body. The first elastic element is disposed between the sleeve and the tube body. In the initial state, the first elastic element is blocked by the sleeve to prevent the inner cavity of the tube body from communicating with the external space outside the tube body at the fracturing hole. When the fluid pressure in the external space outside the tube body is greater than a first threshold, the fluid drives the sleeve to move and deforms the first elastic element to open the fracturing hole.

2. The perforating fracturing system of claim 1, wherein, It also includes a fixing sleeve, which is sleeved on the outside of the tube body. The first end of the fixing sleeve is sealed to the outer wall of the tube body, and the second end of the fixing sleeve is open to form a sliding cavity between the fixing sleeve and the tube body. An end plate is provided at the end of the sleeve adjacent to the first end of the fixing sleeve. The circumferential outer wall of the end plate fits against the inner wall of the fixing sleeve. The first elastic element is disposed between the end plate and the first end of the fixing sleeve.

3. The perforating fracturing system of claim 2, wherein, It also includes a detection component for detecting the pressure of the fluid in the external space outside the tube body. A sealing cavity and a detection cavity are formed between the fixing sleeve and the tube body. The detection cavity is connected to the external space outside the tube body. The detection component is disposed in the sealing cavity, and the detection end of the detection component extends into the detection cavity.

4. The perforating fracturing system of any of claims 1-3, wherein, The tube body comprises multiple tube bodies, each of which is provided with a fracturing hole, a jet hole group, and a control component. The multiple tube bodies are arranged at intervals along the length direction of the fracturing tube. At least some of the tube bodies are connected to a ball-launching drive component at their ends. The ball-launching drive component has a first state and a second state. In the first state, the inner cavity of the ball-launching drive component is open and the ball-launching drive component blocks the jet hole group on its corresponding tube body. In the second state, the inner cavity of the ball-launching drive component is blocked and the ball-launching drive component opens the jet hole group on its corresponding tube body.

5. The perforating fracturing system of claim 4, wherein, The ball-throwing drive component includes: A ball-launching tube, which is connected to the tube body and the fracturing tube; A sliding cylinder is disposed inside the inner cavity of the ball-throwing tube and is movable along the axial direction of the ball-throwing tube. An installation cavity is defined between the sliding cylinder and the ball-throwing tube. The outer wall of the sliding cylinder is in contact with the inner wall of the ball-throwing tube. The middle part of the sliding cylinder has a ball-blocking part. A portion of the sliding cylinder is in contact with the inner wall of the corresponding tube body. The second elastic element is disposed in the mounting cavity. In the initial state, the second elastic element blocks the jet hole group of the corresponding tube body of the sliding cylinder. The ball dropped into the fracturing tube can abut against the ball-blocking part to block the inner cavity of the slide tube and drive the slide tube to move, thereby opening the corresponding jet hole group on the tube body.

6. A method of perforation oriented fracturing, characterized in that, Fracturing operations are performed using the porous fracture directional fracturing system according to any one of claims 1 to 3, wherein the porous fracture directional fracturing method comprises: S101. Conduct directional drilling within the tunnel; S102. Connect the porous fracture directional fracturing system and the pump group, and perform a water injection test on the porous fracture directional fracturing system. S103. After the water injection test is completed, the multi-hole fracture directional fracturing system is placed into the directional borehole until the preset fracturing section is reached, and water is injected into the sealing device to achieve setting and sealing. S104. Water is injected into the fracturing pipe, and the water flowing into the porous fracture directional fracturing system is ejected from the jet holes to form multiple perforations on the sidewall of the directional borehole. The multiple perforations are connected to form a through fracture. S105. Continuously inject water to open the fracturing holes on the pipe body, and the fluid flows into the external space outside the pipe body through the fracturing holes and jet holes to carry out directional fracturing. S106. After the previous preset fracturing section is completed, water is drained from the sealing device, and the multi-hole fracturing directional fracturing system is dragged to the next preset fracturing section. Water is injected into the sealing device to achieve setting and sealing, and steps S104 and S105 are repeated to carry out the fracturing operation of the fracturing section. S107. Repeat the previous step until the fracturing operation of all fracturing sections is completed.

7. A porous, fractured, directional fracturing method, characterized in that, Fracturing operations are performed using the porous fracture directional fracturing system described in claim 4 or 5, wherein the porous fracture directional fracturing method includes: S201. Directional drilling is carried out in the tunnel; S202. Connect the porous fracture directional fracturing system and the pump group, and perform a water injection test on the porous fracture directional fracturing system. S203. After the water injection test is completed, the multi-hole fracture directional fracturing system is placed into the directional borehole, and water is injected into the sealing device to achieve setting and form multiple independent fracturing sections. S204. Water is injected into the fracturing pipe. The water flowing into the porous fracture directional fracturing system is ejected from the jet hole on the pipe body closest to the bottom of the directional borehole to form multiple perforations on the sidewall of the directional borehole. The multiple perforations are connected to form a through fracture. S205. Continuously inject water to open the fracturing hole on the pipe body closest to the bottom of the directional borehole. Fluid flows into the external space outside the pipe body through the fracturing hole and the jet hole to perform directional fracturing. S206. After the previous preset fracturing section is completed, a ball is placed into the fracturing pipe. The ball contacts the ball-throwing drive component that is closest to the bottom of the directional borehole, so that the inner cavity of the ball-throwing drive component is isolated and the jet hole group on the pipe body corresponding to the ball-throwing drive component is opened. Then, steps S204 and S205 are repeated to carry out the fracturing operation of the fracturing section. S207. Repeat the previous step to perform fracturing operations on multiple fracturing sections sequentially along the direction from the bottom to the opening of the directional borehole.

Images