Jet flow fracturing device and jet flow fracturing system

Abstract

The invention relates to the technical field of mining fracturing equipment, and provides a jet fracturing device and a jet fracturing system. The jet flow fracturing device comprises a core pipe assembly, a first sealing sleeve, a second sealing sleeve and two pairs of pushing blocks, and a first flow guide hole and a second flow guide hole are formed in the wall face of the core pipe assembly; the first sealing sleeve and the second sealing sleeve are sleeved outside the core tube assembly; the sliding sleeve assembly is arranged outside the core tube assembly in a sleeving mode and can drive the first sealing sleeve and the second sealing sleeve to move along the core tube assembly. The sliding sleeve assembly is provided with a first jet hole and a second jet hole. The two pairs of pushing blocks are connected with the inner wall of the sliding sleeve assembly, a second cavity is formed between one of each pair of pushing blocks and the core tube assembly, and when the sliding sleeve assembly slides, the first jet flow holes and the second jet flow holes can alternately spray liquid. According to the jet flow fracturing device, one tool has two functions, the jet flow fracturing device can have the cutting and fracturing effects only by switching abrasive materials or water sources in the actual operation process, distributed operation is not needed, and the construction efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of mining fracturing equipment technology, and in particular to a jet fracturing device and jet fracturing system. Background Technology

[0002] Hydraulic fracturing technology in coal mines is gradually replacing traditional blasting decompression methods due to its advantages such as precise control (it can achieve more uniform and predictable decompression effect by adjusting injection pressure, flow rate and liquid type) and good engineering adaptability (it can be safely constructed in complex geological conditions, high gas areas, sensitive areas such as adjacent goaf areas, and the construction process causes little disturbance to the surrounding rock of the roadway, which is conducive to maintaining roadway stability).

[0003] The first-generation rubber hose expansion sealing process suffers from limited single-point pressure range and low fracture propagation efficiency. While the second-generation high-pressure water jet pre-cutting + fracturing technology improves rock-breaking efficiency by first creating grooves with the jet and then fracturing and expanding the fracture, it is still limited by the time-consuming step-by-step process and the localized concentration of jet energy, requiring further breakthroughs in overall efficiency. The fundamental reason is that existing packers fail to effectively coordinate the two key steps of "cutting" and "fracturing"—the former relies on high-energy transient impact to form guiding fractures, while the latter requires continuous high-pressure fluid to drive the directional propagation of fractures.

[0004] Based on this, a new type of jet fracturing device is needed in the industry to achieve high-intensity initial rock breaking and directional fracture extension in a single operation. Summary of the Invention

[0005] This invention provides a jet fracturing device and a jet fracturing system to solve the problem of low operating efficiency caused by the distributed cutting and fracturing operations in the prior art.

[0006] This invention provides a jet fracturing device, comprising: a core tube assembly, a first end of which is connected to an abrasive mixing tank or a water source, the core tube assembly having an internal flow channel, a second end of which is a closed end, and a first guide hole and a second guide hole on the wall of the core tube assembly, both of which communicate with the flow channel; a first sleeve, fitted over the core tube assembly and movable along the core tube assembly; a second sleeve, fitted over the core tube assembly and movable along the core tube assembly; a sliding sleeve assembly, fitted over the core tube assembly, a portion of which is slidably connected to the core tube assembly, the sliding sleeve assembly having a first jet hole and a second jet hole, and a first cavity between the sliding sleeve assembly and the first and second sleeves; and two pairs of propulsion blocks. Located outside the core tube assembly, two pairs of propulsion blocks are connected to the inner wall of the sliding sleeve assembly. Each pair of propulsion blocks has a second cavity between itself and the core tube assembly. The first sleeve and the second sleeve are respectively disposed between each pair of propulsion blocks. When the sliding sleeve assembly moves along the first direction, the first sleeve moves away from the first guide hole. The first guide hole communicates with the first jet hole through the second cavity and the first cavity. The second sleeve blocks the second guide hole. When the sliding sleeve assembly moves in the opposite direction of the first direction, the first sleeve blocks the first guide hole. The second sleeve moves away from the second guide hole. The second guide hole communicates with the second jet hole through the second cavity and the first cavity.

[0007] According to a jet fracturing device provided by the present invention, each pair of propulsion blocks includes: a first propulsion block, sleeved outside the core tube assembly, having a second cavity between the first propulsion block and the core tube assembly, the first propulsion block being capable of pushing the first sleeve or the second sleeve to move along the first direction; and a second propulsion block, sleeved outside the core tube assembly, the second propulsion block being capable of pushing the first sleeve or the second sleeve to move in the opposite direction to the first direction.

[0008] According to a jet fracturing device provided by the present invention, the sliding sleeve assembly includes: a central sliding sleeve, which is sleeved outside the core tube assembly, and the two ends of the central sliding sleeve are respectively connected to two second propulsion blocks; a pair of first sliding sleeves, which are sleeved outside the core tube assembly and located on both sides of the central sliding sleeve, each first sliding sleeve being connected to a pair of propulsion blocks, and a first cavity being provided between the first sliding sleeve and the first or second sealing sleeve, one of the pair of first sliding sleeves being provided with a first jet hole and the other being provided with a second jet hole.

[0009] According to a jet fracturing device provided by the present invention, the central sliding sleeve is provided with a pair of third jet holes; the core tube assembly is provided with a third guide hole, the third guide hole is connected to the flow channel, and a third cavity is provided between the central sliding sleeve and the core tube assembly. The flow channel, the third guide hole, the third cavity, and the third jet holes are connected. When the first jet hole and the first guide hole, and the second jet hole and the second guide hole are in a critical state of imminent connection, the third cavity is filled with high-pressure liquid to cause the first propulsion block to separate from the first sleeve or the second sleeve.

[0010] According to a jet fracturing device provided by the present invention, the sliding sleeve assembly further includes: a pair of second sliding sleeves, which are sleeved on the outside of the core tube assembly and slidably connected to the core tube assembly; and a pair of buffer structures, the two ends of each buffer structure being connected to the second sliding sleeve and the first sliding sleeve, respectively.

[0011] According to the present invention, a jet fracturing device is provided, wherein the buffer structure is an elastic element.

[0012] According to a jet fracturing device provided by the present invention, the buffer structure includes: a third sliding sleeve, sleeved outside the core tube assembly, the two ends of the third sliding sleeve being connected to the first sliding sleeve and the second sliding sleeve respectively, a fourth cavity being provided between the third sliding sleeve and the core tube assembly, the fourth cavity being filled with liquid; a valve block, sleeved outside the core tube assembly and located inside the fourth cavity, the valve block being sealed to the third sliding sleeve, the valve block dividing the fourth cavity into a first space and a second space, the valve block having a first through hole communicating with the first space and the second space.

[0013] According to a jet fracturing device provided by the present invention, the core tube assembly includes: a positioning tube; a first valve core sleeved to a first end of the positioning tube, the first valve core having a first flow guide hole, a first sleeve sleeved outside the first valve core, and a second cavity formed between a first push block and the first valve core; a second valve core sleeved to a second end of the positioning tube, the second valve core having a second flow guide hole, a second sleeve sleeved outside the second valve core, and a second cavity formed between another first push block and the second valve core; a sliding sleeve assembly sleeved outside the first valve core, the positioning tube, and the second valve core, wherein when the sliding sleeve assembly slides along a first direction, the first sleeve can abut against the first end of the positioning tube, and when the sliding sleeve assembly moves in the opposite direction of the first direction, the second sleeve can abut against the second end of the positioning tube.

[0014] According to a jet fracturing device provided by the present invention, the core tube assembly further includes: a pair of guide tubes, each of the guide tubes communicating with the first valve core or the second valve core respectively; a pair of guide sleeves, each of the guide sleeves being sleeved with one of the guide tubes, and both ends of the sliding sleeve assembly being slidably connected to the pair of guide sleeves; a first packer, the first end of the first packer being used to connect to the abrasive mixing tank or water source, and the second end of the first packer being connected to one of the guide sleeves; and a second packer, the first end of the second packer being connected to one of the guide sleeves, and the second end of the second packer being a closed end.

[0015] The present invention also provides a jet fracturing system, comprising: an abrasive mixing tank, a high-pressure pump, and a jet fracturing device as described above, wherein the abrasive mixing tank, the high-pressure pump, and the jet fracturing device are connected by a first pipeline, the first pipeline being provided with a valve located between the abrasive mixing tank and the high-pressure pump; a second pipeline, one end of which is connected to a water source, and the other end of which is connected to the high-pressure pump; when the valve is in the open state, the water source is closed, and the jet fracturing device is used to cut the rock mass; when the valve is in the closed state, the water source is open, and the jet fracturing device is used to fracture the rock mass.

[0016] The jet fracturing device provided in this embodiment of the invention, by setting up a sliding sleeve assembly, a core tube assembly, a pair of sleeves and a pair of propulsion blocks, allows the first jet hole and the second jet hole to alternately conduct when the sliding sleeve assembly reciprocates, thereby cutting the rock mass between two boreholes. After cutting, the abrasive is switched to high-pressure water, and the first jet hole and the second jet hole alternately output water, which can fracture the initial pre-existing cracks. One tool has two functions. In actual operation, only the abrasive or water source needs to be switched to enable the jet fracturing device to perform cutting and fracturing functions, eliminating the need for distributed operations and improving construction efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the jet fracturing device provided by the present invention.

[0019] Figure 2 This is a cross-sectional view of the jet fracturing device provided by the present invention.

[0020] Figure 3 yes Figure 2 The enlarged view of point A shown in the image.

[0021] Figure 4 This is a cross-sectional view of the jet fracturing device provided by the present invention.

[0022] Figure 5 yes Figure 4 The enlarged view of point B shown in the image.

[0023] Figure 6 yes Figure 2 The diagram shows the structure of the valve core.

[0024] Figure label: 100. Central sliding sleeve; 101. Third jet orifice; 110. First sliding sleeve; 111. First jet orifice; 112. Second jet orifice; 113. First cavity; 121. First propulsion block; 122. Second propulsion block; 123. Second cavity; 130. Second sliding sleeve; 140. Third sliding sleeve; 141. Fourth cavity; 150. Valve block; 151. First through hole; 1411. First space; 1412. Second space; 200, Positioning tube; 201, Annular boss; 202, Third guide hole; 203, Third cavity; 204, Flow channel; 211, First valve core; 212, Second valve core; 220, Guide tube; 230, Guide sleeve; 231, Guide groove; 240, Connecting block; 251, First packer; 252, Second packer; 2111, First guide hole; 2112, Positioning groove; 2113, Sealing groove; 2121, Second guide hole; 300. First envelope; 310. Second envelope. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] The following is combined with Figures 1-6 The present invention describes a jet fracturing apparatus and a jet fracturing system.

[0027] like Figure 1 , Figure 2 and Figure 3As shown, in an embodiment of the present invention, the jet fracturing device includes: a core tube assembly, a first sleeve 300, a second sleeve 310, a sliding sleeve assembly, and two pairs of propulsion blocks. The first end of the core tube assembly is connected to an abrasive mixing tank or a water source, and the core tube assembly has a flow channel 204 inside. The second end of the core tube assembly is a closed end. The wall surface of the core tube assembly is provided with a first guide hole 2111 and a second guide hole 2121, both of which communicate with the flow channel 204. The first sleeve 300 and the second sleeve 310 are both fitted over the core tube assembly and are movable along the core tube assembly. In this embodiment, when the first sleeve 300 and the second sleeve 310 move, one of the first guide hole 2111 and the second guide hole 2121 can be opened, while the other is blocked.

[0028] A sliding sleeve assembly is fitted over the core tube assembly, with a portion of the sliding sleeve assembly slidably connected to the core tube assembly. The sliding sleeve assembly has a first jet hole 111 and a second jet hole 112. A first cavity 113 exists between the sliding sleeve assembly and the first sealing sleeve 300 and the second sealing sleeve 310. Two pairs of push blocks are fitted over the core tube assembly, with the push blocks connected to the inner wall of the sliding sleeve assembly. A second cavity 123 exists between one of the push blocks in each pair and the core tube assembly. The first sealing sleeve 300 and the second sealing sleeve 310 are respectively disposed between each pair of push blocks.

[0029] In this embodiment, when the sliding sleeve assembly slides along the core tube assembly, it can drive the propulsion block to slide along the core tube assembly as well. The propulsion block can push the first sleeve 300 and the second sleeve 310 to move, so that the first sleeve 300 moves away from or blocks the first guide hole 2111, and the second sleeve 310 moves away from or blocks the second guide hole 2121. During the sliding process of the sliding sleeve assembly, one of the first guide hole 2111 and the second guide hole 2121 is always in an unblocked state, while the other is in a blocked state. That is, only one of the first jet hole 111 and the second jet hole 112 can spray high-pressure abrasive.

[0030] Specifically, in this embodiment, each guide hole, jet hole, and sleeve is located between a pair of propulsion blocks. For ease of description, the two pairs of propulsion blocks are named the first pair of propulsion blocks and the second pair of propulsion blocks. When the sliding sleeve assembly slides along a first direction, in this embodiment, the first direction is to the right, and the opposite direction is to the left. The sliding sleeve assembly drives both the first pair of propulsion blocks and the second pair of propulsion blocks to slide to the right. The first pair of propulsion blocks pushes the first sleeve 300 to slide to the right, and the second pair of propulsion blocks pushes the second sleeve 310 to slide to the right. The first sleeve 300 moves away from the first guide hole 2111, and the second sleeve 310 blocks the second guide hole 2121. The high-pressure abrasive in the flow channel 204 can only enter the second cavity 123 through the first guide hole 2111. When the high-pressure abrasive fills the second cavity 123, the high-pressure abrasive pushes the first sleeve 300 to separate from the propulsion block. The high-pressure abrasive is then ejected through the first cavity 113 and the first jet hole 111 to cut the rock mass. Correspondingly, when the sliding sleeve assembly moves in the opposite direction to the first direction, i.e., to the left, the first pair of propellers push the first sleeve 300 to block the first guide hole 2111, while the second sleeve 310 moves away from the second guide hole 2121. The high-pressure abrasive enters the second cavity 123 between the second pair of propellers and the core tube assembly through the flow channel 204 and the second guide hole 2121. When the high-pressure abrasive fills the second cavity 123, it pushes the second sleeve 310 to separate from the propellers, and the high-pressure abrasive is ejected through the first cavity 113 and the second jet hole 112.

[0031] In the embodiments described above, the reciprocating sliding of the sliding sleeve assembly allows the first jet hole 111 and the second jet hole 112 to alternately expel fluid. During actual rock cutting, two holes need to be drilled longitudinally in the rock mass first, with the first jet hole 111 and the second jet hole 112 alternately expelling fluid. Cutting is then performed between the two holes to form an initial pre-fabricated fracture. Afterward, high-pressure water is introduced into the jet fracturing device, and the high-pressure water is alternately ejected from the first jet hole 111 and the second jet hole 112, causing the initial pre-fabricated fracture to continuously expand along the fracture tip.

[0032] The jet fracturing device provided in this embodiment of the invention, by setting up a sliding sleeve assembly, a core tube assembly, a pair of sleeves and a pair of propulsion blocks, allows the first jet hole and the second jet hole to alternately conduct when the sliding sleeve assembly reciprocates, thereby cutting the rock mass between two boreholes. After cutting, the abrasive is switched to high-pressure water, and the first jet hole and the second jet hole alternately output water, which can fracture the initial pre-existing cracks. One tool has two functions. In actual operation, only the abrasive or water source needs to be switched to enable the jet fracturing device to perform cutting and fracturing functions, eliminating the need for distributed operations and improving construction efficiency.

[0033] like Figure 3As shown, in an embodiment of the present invention, each pair of propulsion blocks includes a first propulsion block 121 and a second propulsion block 122. The first propulsion block 121 is sleeved on the outside of the core tube assembly, and a second cavity 123 is provided between the first propulsion block 121 and the core tube assembly. The first propulsion block 121 is capable of pushing the first sleeve 300 or the second sleeve 310 to move along a first direction. The second propulsion block 122 is sleeved on the outside of the core tube assembly, and the second propulsion block 122 is capable of pushing the first sleeve 300 or the second sleeve 310 to move in the opposite direction to the first direction.

[0034] Specifically, when the sliding sleeve assembly slides along the first direction, it drives both the first pair of push blocks and the second pair of push blocks to move along the first direction. At this time, the first push block 121 of the first pair of push blocks pushes the first cover 300 to move along the first direction, and the second push block 122 of the second pair of push blocks pushes the second cover 310 to move along the first direction. When the sliding sleeve assembly slides in the opposite direction of the first direction, the second push block 122 of the first pair of push blocks pushes the first cover 300 to move in the opposite direction of the first direction, and the first push block 121 of the second pair of push blocks pushes the second cover 310 to move in the opposite direction of the first direction. That is, in the embodiments of the present invention, the two pairs of push blocks are symmetrically arranged.

[0035] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the sliding sleeve assembly includes a central sliding sleeve 100 and a pair of first sliding sleeves 110. The two ends of the central sliding sleeve 100 are respectively connected to two second propulsion blocks 122. The pair of first sliding sleeves 110 are located on both sides of the central sliding sleeve 100. The inner wall of each first sliding sleeve 110 is connected to a first propulsion block 121 and a second propulsion block 122. The central sliding sleeve 100 and the pair of first sliding sleeves 110 are both sleeved outside the core tube assembly. A first cavity 113 is formed between the first sliding sleeve 110 and the first sealing sleeve 300 or the second sealing sleeve 310. One of the pair of first sliding sleeves 110 is provided with a first jet hole 111, and the other is provided with a second jet hole 112. In this embodiment, the pair of first sliding sleeves 110, the central sliding sleeve 100, the first propulsion block 121, and the second propulsion block 122 are connected as a whole and move together.

[0036] like Figure 2 and Figure 3As shown, in an embodiment of the present invention, the core tube assembly includes: a positioning tube 200, a first valve core 211, and a second valve core 212. The first valve core 211 is sleeved with a first end of the positioning tube 200, and the second valve core 212 is sleeved with a second end of the positioning tube 200, with both ends of the first valve core 211 and the second valve core 212 extending into the positioning tube 200. The first valve core 211 has a first guide hole 2111, a first sleeve 300 is sleeved on the outside of the first valve core 211, and a second cavity 123 is formed between a first push block 121 and the first valve core 211. The second valve core 212 has a second guide hole 2121, a second sleeve 310 is sleeved on the outside of the second valve core 212, and a second cavity 123 is formed between another first push block 121 and the second valve core 212.

[0037] Specifically, the outer surface of the positioning tube 200 is provided with an annular boss 201. The annular boss 201 is located in the middle of the positioning tube 200. When the sliding sleeve assembly moves, the second push block 122 can abut against the annular boss 201 to position the displacement of the sliding sleeve assembly during reciprocating movement, so as to ensure that one of the two sleeves can move away from one guide hole, while the other can block the other guide hole. Figure 3As shown, when the sliding sleeve assembly moves to the right, the first pusher block 121 of the first pair of pushers pushes the first sleeve 300 away from the first guide hole 2111. At this time, the flow channel 204, the first guide hole 2111, and the second cavity 123 are connected. The first cavity 113 is connected to the first jet hole 111, but the first cavity 113 is blocked from the second cavity 123. The second pusher block 122 of the first pair of pushers abuts against the annular boss 201, and the first sleeve 300 abuts against the first end of the positioning tube 200. At the same time, the second sleeve 310 blocks the second guide hole 2121 of the second valve core 212, and the flow channel 204 and the first cavity 113 between the first sliding sleeve 110 and the second sleeve 310 are blocked. The high-pressure liquid in the flow channel 204 enters the second cavity 123 through the first guide hole 2111. After the high-pressure liquid fills the second cavity 123, the first sleeve 300 cannot move further to the right because it is in contact with the positioning tube 200. Under the action of the high-pressure liquid, the first push block 121 of the first pair of push blocks moves to the left, causing the second cavity 123 to connect with the first cavity 113, and the liquid is ejected from the first jet hole 111. When the first push block 121 of the first pair of push blocks moves to the left, it will drive the first sliding sleeve 110, the central sliding sleeve 100 and the second pair of push blocks to move to the left together until the second push block 122 of the second pair of push blocks abuts against the annular boss 201. At this time, the first sleeve 300 blocks the first guide hole 2111, and the second sleeve 310 moves away from the second guide hole 2121. The flow channel 204, the second guide hole 2121, and the second cavity 123 are connected. The first cavity 113 is connected to the second jet hole 112, but the first cavity 113 is blocked from the second cavity 123. The second sleeve 310 abuts against the second end of the positioning tube 200. The high-pressure liquid in the flow channel 204 enters the second cavity 123 through the second guide hole 2121. When the high-pressure liquid fills the second cavity 123, the second sleeve 310 cannot continue to move to the left because it abuts against the positioning tube 200. Under the action of the high-pressure liquid, the first pusher block 121 of the second pair of pushers moves to the right, causing the second cavity 123 to connect with the first cavity 113, and the liquid is ejected from the second jet hole 112. At this time, when the first pusher block 121 of the second pair of pusher blocks moves to the right, it will drive the entire sliding sleeve assembly to move to the right, thereby causing the first jet hole 111 to spray liquid, while the second jet hole 112 does not spray liquid. Thus, the jet fracturing device provided in this embodiment of the invention does not require external force to drive it, and can realize the alternating liquid discharge and alternating cutting of the first jet hole 111 and the second jet hole 112, so as to improve the cutting efficiency.

[0038] like Figure 1 and Figure 2As shown, in an embodiment of the present invention, the core tube assembly further includes: a pair of guide tubes 220, a pair of guide sleeves 230, a first packer 251, and a second packer 252. One of the pair of guide tubes 220 is connected to the first valve core 211, and the other is connected to the second valve core 212. The pair of guide sleeves 230 are disposed on both sides of the pair of guide tubes 220, and each guide sleeve 230 is sleeved with one guide tube 220. The two ends of the sliding sleeve assembly are slidably connected to the pair of guide sleeves 230. The first end of the first packer 251 is used to connect to the abrasive mixing tank or a water source, and the second end of the first packer 251 is connected to one guide sleeve 230. The first end of the second packer 252 is connected to one guide sleeve 230, and the second end of the second packer 252 is a closed end.

[0039] In this embodiment, the left side of the positioning tube 200 is sequentially connected to a first valve core 211, a guide tube 220, a guide sleeve 230, and a first packer 251, while the right side of the positioning tube 200 is symmetrically provided with a second valve core 212, a guide tube 220, a guide sleeve 230, and a second packer 252. The internal connections of the above components form a flow channel 204.

[0040] Furthermore, such as Figure 1 and Figure 2 As shown, the core tube assembly also includes a connecting block 240. The first end of the connecting block 240 is connected to either the first packer 251 or the second packer 252, and the second end of the connecting block 240 is threadedly connected to the guide sleeve 230. In an embodiment of the invention, the surface of the guide sleeve 230 is provided with a guide groove 231, and the inner wall of the sliding sleeve assembly is provided with a slider, which can slide along the guide groove 231.

[0041] like Figure 6 As shown, in the embodiments of the present invention, the first valve core 211 and the second valve core 212 have the same structure. Taking the first valve core 211 as an example, the structure of the first valve core 211 and the second valve core 212 will be described in detail below. The first valve core 211 has a second through hole inside, which communicates with the inside of the positioning tube 200 to form a flow channel 204. The surface of the first valve core 211 has a first guide hole 2111, which can be one or two. Near both ends, the surface of the first valve core 211 also has a pair of positioning grooves 2112. One of the positioning grooves 2112 engages with the positioning tube 200, and the other engages with the guide tube 220. Simultaneously, the surface of the first valve core 211 also has a pair of sealing grooves 2113, so that the positioning tube 200 can be sealed to the first valve core 211, and the guide tube 220 can also be sealed to the first valve core 211. Optionally, in the embodiments of the present invention, the guide tube 220 can be a single unit or two tubes connected in series.

[0042] like Figure 3As shown, in an embodiment of the present invention, the central sliding sleeve 100 is provided with a pair of third jet holes 101. The positioning tube 200 is provided with a pair of third guide holes 202, which are located on both sides of the annular boss 201. The third guide holes 202 communicate with the flow channel 204, and a third cavity 203 is provided between the central sliding sleeve 100 and the positioning tube 200. The flow channel 204, the third guide holes 202, the third cavity 203, and the third jet holes 101 are connected.

[0043] Specifically, in Figure 3 In this process, the first jet hole 111 and the first guide hole 2111 are at a critical state of imminent connection. At this time, the first propulsion block 121, the first sleeve 300, and the positioning tube 200 abut in sequence. Theoretically, the first propulsion block 121 and the first sleeve 300 may be locked together and unable to separate. Based on this, a third guide hole 202 is provided on the positioning tube 200, and a third jet hole 101 is provided on the central sliding sleeve 100. When the second sleeve 310 blocks the second guide hole 2121, the liquid can enter the third cavity 203 through the flow channel 204 and the third guide hole 202. The large flow rate in the third cavity 203 will push the central sliding sleeve 100 to the left, so that the first propulsion block 121 and the first sleeve 300 will separate quickly. At this time, the third jet hole 101 will also spray high-pressure liquid. Accordingly, when the first push block 121 comes into contact with the second sleeve 310, the liquid in the third cavity 203 will cause the central sliding sleeve 100 to move to the right, so that the first push block 121 and the second sleeve 310 will quickly separate.

[0044] like Figure 2 , Figure 4 and Figure 5 As shown, in an embodiment of the present invention, the sliding sleeve assembly further includes: a pair of second sliding sleeves 130 and a pair of buffer structures. Each buffer structure has its two ends connected to the second sliding sleeve 130 and the first sliding sleeve 110, respectively. In this embodiment, the left side of the central sliding sleeve 100 is sequentially connected to the first sliding sleeve 110, the buffer structure, and the second sliding sleeve 130. Correspondingly, the right side of the central sliding sleeve 100 is symmetrically arranged with the first sliding sleeve 110, the buffer structure, and the second sliding sleeve 130. The two pairs of push blocks are also symmetrically arranged with the central sliding sleeve 100 as the center. In this embodiment, the second sliding sleeve 130, the buffer structure, the first sliding sleeve 110, and the central sliding sleeve 100 can all slide relative to the core tube assembly. In this embodiment, a buffer structure is provided between the second sliding sleeve 130 and the first sliding sleeve 110 to avoid high-pressure contact during axial movement of the first sliding sleeve 110 and the second sliding sleeve 130, thereby improving the service life of the jet fracturing device.

[0045] Optionally, in one embodiment of the present invention, the buffer structure is an elastic element, which is used to guide and compress the first sliding sleeve 110 during axial movement.

[0046] Optionally, in another embodiment of the present invention, the buffer structure includes a third sliding sleeve 140 and a valve block 150. The two ends of the third sliding sleeve 140 are respectively connected to the first sliding sleeve 110 and the second sliding sleeve 130. A fourth cavity 141, filled with liquid, is provided between the third sliding sleeve 140 and the guide pipe 220. The valve block 150 is sleeved around the guide pipe 220 and is sealed to the third sliding sleeve 140. When the third sliding sleeve 140 moves left and right, the valve block 150 remains stationary, but the volumes of the first space 1411 and the second space 1412 on the left and right sides of the valve block 150 change, resulting in different damping forces on both sides of the valve block 150. In this embodiment, the valve block 150 is provided with a first through hole 151, through which the first space 1411 communicates with the second space 1412. When the third sliding sleeve 140 moves, the liquid on both sides of the valve block 150 flows through the first through hole 151 to balance the damping on both sides of the valve block 150 and achieve a damping buffering effect. This buffering structure is stable and has a low failure rate, and is also unaffected by external pressure.

[0047] This invention also provides a jet fracturing system, comprising: an abrasive mixing tank, a high-pressure pump, a jet fracturing device, and a second pipeline. The abrasive mixing tank, the high-pressure pump, and the jet fracturing device are connected via a first pipeline, which is equipped with a valve located between the abrasive mixing tank and the high-pressure pump. The two ends of the second pipeline are connected to a water source and the high-pressure pump, respectively. When rock mass needs to be cut, the water source is closed, the valve is opened, and the abrasive in the abrasive mixing tank is pumped to the jet fracturing device by the high-pressure pump. The abrasive is then alternately ejected from the first jet orifice 111 and the second jet orifice 112 of the jet fracturing device to cut the rock mass. After cutting, the valve is closed, the water source is opened, and water is pumped to the jet fracturing device by the high-pressure pump. Water is then alternately ejected from the first jet orifice 111 and the second jet orifice 112 of the jet fracturing device to fracture the rock mass that has formed fractures.

[0048] Specifically, in actual use, a tracked, fully hydraulic tunnel drilling rig, a matching drill bit (Φ75mm), and a matching drill rod are used to drill a hole with a diameter of Φ75mm and an elevation angle of 75° on the roof of the tunnel.

[0049] The valve is opened, and the abrasive mixture is alternately sprayed out by the jet fracturing device, forming an initial pre-crack of a certain length and depth in the longitudinal direction of the borehole. The length of the pre-crack is 50±5 cm and the depth is 20±5 cm.

[0050] After the cutting is completed, the valve is closed and the water source is turned on. High-pressure water is alternately sprayed out through the jet fracturing device. The initial pre-fabricated crack continues to expand along the crack tip. When a large amount of water comes out of the adjacent borehole, or the pump pressure suddenly drops, or the fracturing time reaches 30 minutes, the high-pressure pump is turned off to complete the fracturing work of this segment.

[0051] The jet fracturing system provided in this embodiment of the invention can cut and fracture rock masses by setting up a jet fracturing device, thus having two functions. In actual operation, it is only necessary to switch the abrasive mixing tank or the water source to enable the jet fracturing device to perform both cutting and fracturing functions, eliminating the need for distributed operations and improving construction efficiency.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A jet fracturing device, characterized in that, include: A core tube assembly, wherein a first end of the core tube assembly is used to connect to an abrasive mixing tank or a water source, the core tube assembly has a flow channel inside, the second end of the core tube assembly is a closed end, and the wall surface of the core tube assembly is provided with a first flow guide hole and a second flow guide hole, both of which are connected to the flow channel; The first sleeve is fitted over the core tube assembly and is movable along the core tube assembly; The second sleeve is fitted over the core tube assembly and is movable along the core tube assembly; A sliding sleeve assembly is sleeved outside the core tube assembly. A portion of the sliding sleeve assembly is slidably connected to the core tube assembly. The sliding sleeve assembly is provided with a first jet hole and a second jet hole. A first cavity is formed between the sliding sleeve assembly and the first and second covers. Two pairs of push blocks are sleeved on the outside of the core tube assembly. Both pairs of push blocks are connected to the inner wall of the sliding sleeve assembly. One of the push blocks in each pair has a second cavity between it and the core tube assembly. The first sleeve and the second sleeve are respectively disposed between each pair of push blocks. When the sliding sleeve assembly moves along the first direction, the first sleeve moves away from the first guide hole, the first guide hole communicates with the first jet hole through the second cavity, and the second sleeve blocks the second guide hole; When the sliding sleeve assembly moves in the opposite direction to the first direction, the first sleeve blocks the first guide hole, the second sleeve moves away from the second guide hole, and the second guide hole communicates with the second jet hole through the second cavity and the first cavity.

2. The jet fracturing device according to claim 1, characterized in that, Each pair of the propulsion blocks includes: A first push block is sleeved on the outside of the core tube assembly. The first push block and the core tube assembly have a second cavity. The first push block can push the first sleeve or the second sleeve to move along the first direction. The second push block is sleeved on the outside of the core tube assembly. The second push block can push the first cover or the second cover to move in the opposite direction of the first direction.

3. The jet fracturing device according to claim 2, characterized in that, The sliding sleeve assembly includes: A central sliding sleeve is fitted over the core tube assembly, and both ends of the central sliding sleeve are respectively connected to two second push blocks; A pair of first sliding sleeves are sleeved on the outside of the core tube assembly and located on both sides of the central sliding sleeve. Each first sliding sleeve is connected to a pair of the propulsion blocks. There is a first cavity between the first sliding sleeve and the first or second sealing sleeve. One of the pair of first sliding sleeves is provided with the first jet hole, and the other is provided with the second jet hole.

4. The jet fracturing device according to claim 3, characterized in that, The central sliding sleeve is provided with a pair of third jet holes; The core tube assembly is provided with a third flow guide hole, which is connected to the flow channel. A third cavity is provided between the central sliding sleeve and the core tube assembly. The flow channel, the third flow guide hole, the third cavity, and the third jet hole are connected. When the first jet hole and the first guide hole, and the second jet hole and the second guide hole are in a critical state of imminent connection, the third cavity is filled with high-pressure liquid to cause the first propulsion block to separate from the first or second cover.

5. The jet fracturing device according to claim 3, characterized in that, The sliding sleeve assembly further includes: A pair of second sliding sleeves are fitted over the core tube assembly and slidably connected to the core tube assembly; A pair of buffer structures, each of which is connected at both ends to the second sliding sleeve and the first sliding sleeve, respectively.

6. The jet fracturing device according to claim 5, characterized in that, The buffer structure is an elastic element.

7. The jet fracturing device according to claim 5, characterized in that, The buffer structure includes: The third sliding sleeve is sleeved on the outside of the core tube assembly. The two ends of the third sliding sleeve are respectively connected to the first sliding sleeve and the second sliding sleeve. There is a fourth cavity between the third sliding sleeve and the core tube assembly, and the fourth cavity is filled with liquid. A valve block is sleeved on the outside of the core tube assembly and located in the fourth cavity. The valve block is sealed to the third sliding sleeve. The valve block divides the fourth cavity into a first space and a second space. The valve block is provided with a first through hole, which communicates with the first space and the second space.

8. The jet fracturing device according to claim 2, characterized in that, The core tube assembly includes: Positioning tube; A first valve core is sleeved with the first end of the positioning tube. The first valve core is provided with the first flow guide hole. The first sleeve is sleeved outside the first valve core. A second cavity is formed between a first push block and the first valve core. The second valve core is sleeved with the second end of the positioning tube. The second valve core is provided with the second flow guide hole. The second sleeve is sleeved outside the second valve core. The second cavity is formed between the other first push block and the second valve core. The sliding sleeve assembly is sleeved on the outside of the first valve core, the positioning tube and the second valve core. When the sliding sleeve assembly slides along the first direction, the first sleeve can abut against the first end of the positioning tube. When the sliding sleeve assembly moves in the opposite direction of the first direction, the second sleeve can abut against the second end of the positioning tube.

9. The jet fracturing device according to claim 8, characterized in that, The core tube assembly also includes: A pair of guide tubes, each of the guide tubes being connected to either the first valve core or the second valve core; A pair of guide sleeves, each of the guide sleeves being sleeved with one of the flow guide tubes, and the two ends of the sliding sleeve assembly being slidably connected to the pair of guide sleeves; A first packer, the first end of which is connected to the abrasive mixing tank or water source, and the second end of which is connected to a guide sleeve; The second packer has a first end connected to one of the guide sleeves, and a second end of the second packer is a closed end.

10. A jet fracturing system, characterized in that, include: The abrasive mixing tank, the high-pressure pump, and the jet fracturing device according to any one of claims 1-9, wherein the abrasive mixing tank, the high-pressure pump, and the jet fracturing device are connected by a first pipeline, and a valve is provided on the first pipeline, wherein the valve is located between the abrasive mixing tank and the high-pressure pump; The second pipeline has one end connected to a water source and the other end connected to the high-pressure pump. When the valve is in the open state, the water source is closed, and the jet fracturing device is used to cut the rock mass. When the valve is in the closed state, the water source is open, and the jet fracturing device is used to fracture the rock mass.

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