Abrasive water jet type slotting and fracturing equipment

Abstract

The invention relates to the technical field of underground mining equipment, and provides abrasive water jet type slotting and fracturing equipment which comprises an extending outer pipe, and the extending outer pipe is used for extending into and sliding in a passage formed in a well wall in the extending direction; a plurality of jet flow holes are formed in the circumferential wall, extending into the outer pipe, of the outer pipe in the circumferential direction in a penetrating mode and used for jetting out liquid flow to conduct jet flow fracturing on the well wall. Two sets of expansion pipes are further arranged on the outer wall extending into the outer pipe, the jet flow hole is located between the two sets of expansion pipes, and the two sets of expansion pipes abut against the well wall to define an isolation operation space. The supporting assembly is arranged on the outer wall extending into the outer pipe in a sleeving mode and comprises a plurality of outer abutting strips arranged in the circumferential direction. The supporting assembly stably supports the extending outer pipe, it can be guaranteed that the expansion pipe is accurately aligned with the well wall during expansion, the sealing performance of an isolation operation space is enhanced, and the technical problems that in the prior art, abrasive water jet type slotting fracturing equipment possibly has pipeline abrasion and deflection, and sealing of a packer fails are solved.

Description

Technical Field

[0001] This invention relates to the field of downhole mining equipment technology, specifically to abrasive waterjet fracturing equipment. Background Technology

[0002] Abrasive waterjet fracturing equipment is a key piece of equipment used in the extraction of underground resources such as coal mines and oil and gas fields for coal and rock pressure relief, gas extraction, and reservoir stimulation. It uses a high-pressure pump set to mix abrasive with high-pressure water to create a high-pressure abrasive waterjet, which is then transported through pipelines to the nozzle. During the fracturing stage, it cuts the coal and rock to form fractures. During the fracturing stage, a stop-and-close device seals the borehole annulus, utilizing the pressure-locking effect to expand the coal and rock fractures, improve reservoir permeability, or relieve in-situ stress. In actual operations, the equipment piping needs to frequently switch between feed and stationary packer fracturing states, which presents significant problems: during feed, the piping moving along the borehole is prone to outer wall wear, inner wall grooves, and skew deformation; during stationary packer states, piping wear and skew can lead to packer seal failure and pressure leakage. The switching between these two states creates a vicious cycle, exacerbating piping damage and packer aging, affecting operational efficiency and safety. Existing equipment uses a single material or simple wear-resistant treatment, which cannot simultaneously address skew resistance and sealing compatibility. The packer design does not consider dynamic piping wear, and reliability decreases significantly over operating time. Summary of the Invention

[0003] To overcome the above-mentioned defects, embodiments of the present invention provide an abrasive waterjet slotting fracturing device, which solves the technical problems that may occur in the prior art abrasive waterjet slotting fracturing device, such as pipeline wear, misalignment and packer sealing failure.

[0004] According to one aspect, at least one embodiment of the present invention provides an abrasive waterjet fracturing apparatus for jet fracturing of a wellbore, comprising: An outer tube is inserted into and slides along the extension direction within a passageway opened in the well wall; The outer tube has several jet holes that are circumferentially opened on its peripheral wall for jetting fluid to perform jet fracturing on the well wall. Two sets of expansion tubes are also provided on the outer wall of the inserted outer tube. The jet hole is located between the two sets of expansion tubes. After the two sets of expansion tubes are configured to deform and expand, the two sets of expansion tubes abut against the well wall and together with the well wall form an isolated working space. A support assembly is sleeved on the outer wall of the inserted outer tube. The support assembly includes a plurality of circumferentially arranged outer abutment strips, each of which is used to abut against the well wall.

[0005] As a further technical solution, it also includes: An inner flow tube is disposed inside the outer tube. The inner flow tube is used to provide a flow path for liquid flow, and a liquid injection jacket is formed between the inner flow tube and the outer tube. The liquid injection jacket is connected to the outside through the jet hole. A first communication port is provided on the tube wall of the inner flow tube. The first communication port is used to connect the inside of the inner flow tube and the liquid injection jacket. A sliding stop is provided and slidably disposed within the inner flow pipe. The sliding stop is configured to block or unblock the first communication port after sliding.

[0006] As a further technical solution, it also includes: The first blocking ball slides within the inner flow tube and is located upstream of the sliding block; A downstream blocking elastic element, one end of which acts on the sliding block and the other end of which acts on the inner wall of the inner flow pipe downstream of the sliding block, the downstream blocking elastic element is used to provide the sliding block to slide upstream to block the first communication port; An elastic spacer is provided, with its two ends acting on the sliding block and the first blocking ball, respectively, to bidirectionally push the sliding block and the first blocking ball away from each other. The elastic coefficient of the downstream blocking elastic spacer is greater than that of the elastic spacer. The first blocking ball is configured such that, after being moved by the fluid flow, it pushes the sliding block through the elastic spacer, causing the sliding block to move downstream against the downstream blocking elastic spacer, thereby causing the sliding block to release the blockage of the first communication port.

[0007] As a further technical solution, the sliding block has a downstream conical through-hole at its center for connecting the upstream and downstream of the sliding block. The inner flow pipe has an enlarged diameter section, in which the internal pipe diameter increases. The first sealing ball is configured such that, after being pushed by the liquid flow, it enters the enlarged diameter section. The liquid flow passes through the gap between the outer wall of the first sealing ball and the inner wall of the enlarged diameter section, and then is transported downstream through the sliding downstream conical through-hole. After increasing the liquid flow rate, the first sealing ball leaves the enlarged diameter section and slides again against the inner wall of the inner flow pipe, then abuts against the sliding block and blocks the downstream conical through-hole, thereby pushing the sliding block to slide.

[0008] As a further technical solution, the supporting components include: A retaining ring is fixedly sleeved on the outer wall of the tube extending into the outer tube. A sliding ring is provided, which slides in conjunction with the extended outer tube. The outer abutment strip is a convex arc-shaped elastic strip, and its two ends are respectively disposed on the fixed ring and the sliding ring. The sliding ring is configured such that after sliding to one side of the fixed ring, it compresses the outer abutment strip, causing it to press and push against the inner wall of the extended outer tube to fix the extended outer tube. The outer diameter of the outer abutment strip in its expanded state is larger than the outer diameter of the expansion tube in its naturally contracted state, so that the outer abutment strip maintains sliding contact with the inner wall of the well passage.

[0009] As a further technical solution, the outer wall of the expanded diameter section is fixedly connected to the inner wall of the inserted outer tube, and the sliding ring is located upstream of the fixed ring. The support assembly further includes: A reset elastic element is provided, with one end acting on the outer wall of the expanded diameter section and the other end acting on the sliding ring, for elastically pushing the sliding ring to provide a force for the sliding ring to slide and reset away from the fixed ring.

[0010] As a further technical solution, a set of expansion tubes is located upstream of the support assembly, and the interior of the expansion tubes is connected to the interior of the outer tube through a second communication port, further comprising: A pushed-blocking block is disposed at one end of the sliding ring extending upstream. The pushed-blocking block is used to block the second communication port. The pushed-blocking block is configured to release the blockage of the second communication port after being pushed by the liquid flow, so as to inject liquid into the expansion tube, or to elastically reset under the action of the reset elastic element to block the second communication port.

[0011] As a further technical solution, the pushed-blocking block has an upstream conical through hole in the middle, and the inner flow pipe also has a third connecting port. The inner wall of the sliding ring is used to block the third connecting port, and the inner wall of the pushed-blocking block has a notch. A second sealing ball is located within the upstream conical through-hole. An upstream sealing elastic element is provided between the second sealing ball and the outer end of the inner flow pipe. The upstream sealing elastic element is used to elastically push the second sealing ball so that the second sealing ball remains blocking the upstream conical through-hole. The pushed-blocking block is configured to slide downstream after being pushed by the liquid flow, while the liquid flow pushes the second blocking ball, thereby connecting the extended outer tube and the third connecting port through the notch to provide a path for the liquid flow into the inner flow tube.

[0012] As a further technical solution, both the upstream blocking elastic element and the spacer elastic element are tapered variable diameter springs.

[0013] As a further technical solution, another set of expansion tubes is located downstream of the sliding block. After the liquid flows through the downstream conical through hole, it communicates with the inside of the expansion tube through the fourth connecting port opened on the outer wall of the outer tube.

[0014] The beneficial effects of this invention are as follows: In this invention, the expansion tube expands during the jetting process to form an isolated working space, concentrating the fluid flow from the jet orifice onto the target area, avoiding energy loss due to fluid dispersion, and improving jet fracturing efficiency. The outer abutment strip of the support assembly abuts against the well wall when the outer tube slides, providing support, reducing direct friction between the outer tube and the well wall, minimizing wear, and limiting radial displacement to ensure stability during sliding. When not in use, the expansion tube relaxes and shrinks, with the support assembly replacing it in sliding contact with the well wall. This allows for functional switching between the two components, preventing damage caused by friction between the expansion tube and the well wall during sliding and extending its service life. The stable support of the outer tube by the support assembly ensures precise alignment between the expansion tube and the well wall during expansion, enhancing the sealing of the isolated working space. The isolated space formed by the expansion tube, in turn, ensures that the jet fracturing operation is not affected by the external environment. Together, these two aspects improve the overall operational reliability and efficiency of the equipment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of the present invention and these drawings without any creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of an abrasive waterjet type slotting fracturing device in one embodiment of the present invention; Figure 2 for Figure 1 A structural schematic diagram from another perspective in the embodiment; Figure 3 for Figure 2 Schematic diagram of the internal cross-sectional structure of the DD; Figure 4 for Figure 3 A partially enlarged structural diagram of section A in the middle; Figure 5 for Figure 3 A partially enlarged structural diagram of section B in the middle; Figure 6 for Figure 3 A partially enlarged structural diagram of the C-section.

[0017] In the diagram: Outer tube - 100, jet orifice - 101, jet jacket - 103, second connecting port - 104, fourth connecting port - 105, expansion tube - 200, support assembly - 300, outer abutment strip - 310, fixing ring - 320, sliding ring - 330, reset elastic element - 340, inner flow tube - 400, first connecting port - 401, expansion section - 402, third connecting port - 403, sliding stop - 500, downstream conical through hole - 501, first sealing ball - 600, downstream sealing elastic element - 700, spacer elastic element - 800, pushed sealing block - 900, upstream conical through hole - 901, notch - 902, second sealing ball - 1000, upstream sealing elastic element - 1100. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it.

[0019] To keep the drawings concise, each drawing only schematically shows the parts relevant to the invention; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0020] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, 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 the present invention.

[0023] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] like Figures 1-6 The diagram illustrates an abrasive waterjet fracturing device according to an embodiment of the present invention, used for jet fracturing of a wellbore. It includes an outer tube 100. During operation, the outer tube 100 slides along the extension direction of the wellbore passage. At this time, two sets of expansion tubes 200 are in a relaxed, contracted state. Several outer abutment strips 310 of the support assembly 300 are arranged circumferentially along the outer tube 100, with each outer abutment strip 310 abutting against the wellbore. The outer tube 100 forms a sliding fit with the wellbore through the outer abutment strips 310. When the outer tube 100 moves to a preset operating position, the two sets of expansion tubes 200 deform and expand away from the axis of the outer tube 100 until they abut against the wellbore. At this time, the outer abutment strips 310 of the support assembly 300 disengage from the wellbore. The two sets of expansion tubes 200 and the wellbore together form an isolated operating space, within which the jet holes 101 on the circumferential wall of the outer tube 100 are located. When the fluid is ejected from the jet orifice 101, the fluid acts on the well wall within the isolated working space, completing the jet fracturing operation. After the jet fracturing operation is completed, the two sets of expansion tubes 200 return to their relaxed and contracted state, the outer abutment strip 310 of the support assembly 300 abuts against the well wall again, and the extended outer tube 100 can continue to slide along the well wall passage to adjust the working position.

[0025] The expansion tube 200 expands during the jetting process to create an isolated working space, concentrating the fluid flow from the jet orifice 101 onto the target area. This avoids energy loss due to fluid dispersion and improves jet fracturing efficiency. The outer abutment strip 310 of the support assembly 300 abuts against the well wall when the outer tube 100 slides, providing support for the outer tube 100, reducing direct friction between it and the well wall, decreasing wear, and limiting radial displacement to ensure stability during sliding. When not in use, the expansion tube 200 relaxes and shrinks, with the support assembly 300 replacing it in sliding contact with the well wall. This allows for functional switching between the two components, preventing damage caused by friction between the expansion tube 200 and the well wall during sliding and extending its service life. The support component 300 provides stable support to the outer tube 100, ensuring that the expansion tube 200 is precisely aligned with the well wall during expansion and enhancing the sealing of the isolated working space. The isolated space formed by the expansion tube 200 also ensures that the jet fracturing operation is not affected by the external environment. The combination of the two improves the overall operational reliability and efficiency of the equipment.

[0026] Furthermore, an inner flow pipe 400 is provided inside the outer pipe 100, and a liquid injection jacket 103 is formed between the inner flow pipe 400 and the outer pipe 100. The liquid injection jacket 103 is connected to the outside through the injection hole 101. A first communication port 401 is opened on the pipe wall of the inner flow pipe 400 to connect the inside of the inner flow pipe 400 and the liquid injection jacket 103. A sliding stop 500 is slidably provided inside the inner flow pipe 400. During equipment operation, as the extended outer tube 100 slides along the well wall passage to the preset working position, the sliding block 500 slides to the position of blocking the first connecting port 401, preventing the liquid flow inside the inner flow tube 400 from entering the injection jacket 103. When the extended outer tube 100 reaches the preset working position, after the two sets of expansion tubes 200 expand and abut against the well wall to form an isolated working space, the sliding block 500 slides to the position of unblocking the first connecting port 401. The liquid flow inside the inner flow tube 400 enters the injection jacket 103 through the first connecting port 401, and then is ejected through the injection hole 101 into the isolated working space to perform jet fracturing on the well wall. After the jet fracturing operation is completed, the sliding block 500 slides again to block the first connecting port 401, the two sets of expansion tubes 200 return to the relaxed and reduced state, the outer abutment strip 310 of the support component 300 abuts against the well wall, and the extended outer tube 100 continues to slide along the well wall passage.

[0027] The inner flow pipe 400 provides an independent flow path for the fluid, connecting to the injection interlayer 103 via the first connecting port 401, thus guiding the fluid flow from the inner flow pipe 400 to the injection hole 101. The sliding stop 500 blocks the first connecting port 401 during its sliding insertion into the outer pipe 100, preventing the fluid from entering the injection interlayer 103 and exiting through the injection hole 101 during non-operational periods, reducing ineffective fluid consumption, and preventing unnecessary impact on the wellbore from the injection hole 101 during non-operational periods. After the outer pipe 100 reaches the operating position and the expansion pipe 200 forms an isolated operating space, the sliding stop 500 unblocks the first connecting port 401, ensuring the fluid smoothly enters the injection interlayer 103 and exits through the injection hole 101 for fracturing operations, achieving precise control of the fluid jet. This structural design adds a control link for the flow path between the sliding adjustment position of the extended outer tube 100 and the isolation space formed by the expansion tube 200 for jet fracturing, enabling precise matching of the fluid supply with the operation stage, and further improving the controllability of equipment operation and energy utilization efficiency. Further, in a specific embodiment: Within the inner flow pipe 400, a first sealing ball 600 is located upstream of the sliding stop 500. One end of the downstream sealing elastic element 700 acts on the sliding stop 500, and the other end acts on the inner wall of the inner flow pipe 400 downstream of the sliding stop 500. Two ends of the spacer elastic element 800 act on the sliding stop 500 and the first sealing ball 600, respectively, and the elastic coefficient of the downstream sealing elastic element 700 is greater than that of the spacer elastic element 800. During operation, after the outer pipe 100 slides to a preset position, the liquid flows into the inner flow pipe 400, first pushing the first sealing ball 600 downstream. The first sealing ball 600 pushes against the sliding stop 500 through the spacer elastic element 800, causing the sliding stop 500 to overcome the force of the downstream sealing elastic element 700 and move downstream, thus releasing the blockage of the first connecting port 401. Before the fluid flows into the injection interlayer 103 through the first connecting port 401, it first flows downstream and into the downstream expansion tube 200, causing the downstream expansion tube 200 to deform and expand, and come into contact with the well wall. Then the fluid continues to flow into the upstream expansion tube 200, causing the upstream expansion tube 200 to deform and expand, and come into contact with the well wall. The two sets of expansion tubes 200 together form an isolated working space, and the fluid is ejected from the injection hole 101 for jet fracturing. After the jet fracturing is completed, the fluid pressure decreases, and the downstream sealing elastic element 700 pushes the sliding stop 500 to move upstream. The sliding stop 500 drives the first sealing ball 600 to reset through the spacer elastic element 800, and the sliding stop 500 re-seals the first connecting port 401. The two sets of expansion tubes 200 return to their relaxed and contracted state.

[0028] The cooperation of the first sealing ball 600, the downstream sealing elastic element 700, and the spacer elastic element 800 enables the sliding stop 500 to automatically control the opening and closing of the first connecting port 401. During the process where the fluid flow pushes the first sealing ball 600 to the sliding stop 500 to unblock the first connecting port 401, the fluid first flows into the downstream expansion pipe 200 to expand, and then flows into the upstream expansion pipe 200 to expand subsequently. This sequential expansion allows the downstream expansion pipe 200 to form a preliminary seal with the well wall, providing a stable reference for the expansion of the upstream expansion pipe 200. This reduces the sealing gap caused by uneven force distribution that may occur when the two sets of expansion pipes 200 expand simultaneously, enhancing the sealing performance of the isolated working space. The downstream sealing elastic element 700 has a greater elastic coefficient than the spacer elastic element 800, ensuring that the sliding stop 500 can reliably reset and seal the first connecting port 401 when the fluid pressure decreases, preventing fluid leakage during non-operational periods. This structure, between the sliding stop 500 controlling the opening and closing of the first connecting port 401 and the two sets of expansion tubes 200 forming an isolated working space, increases the sequential expansion process of the expansion tubes 200, further improving the stability and reliability of equipment operation.

[0029] Furthermore, a downstream tapered through-hole 501 is formed through the center of the sliding stop 500, and the inner flow pipe 400 is provided with an enlarged diameter section 402, the internal pipe diameter of which is larger than that of other sections. During operation, the liquid flow enters the inner flow pipe 400 and pushes the first sealing ball 600 downstream. The first sealing ball 600 first enters the enlarged diameter section 402, at which point the liquid flow passes through the gap between the outer wall of the first sealing ball 600 and the inner wall of the enlarged diameter section 402, and then flows downstream through the downstream tapered through-hole 501. As the liquid flow increases, the first sealing ball 600 leaves the enlarged diameter section 402, slides back against the inner wall of the inner flow pipe 400, and then abuts against the sliding stop 500, sealing the downstream tapered through-hole 501. It continues to push the sliding stop 500 downstream against the force of the downstream sealing elastic element 700 until the sliding stop 500 releases the seal on the first connecting port 401. The subsequent fluid flow flows sequentially into the downstream and upstream expansion tubes 200 to complete the expansion sealing and jet fracturing operations. After the operation is completed, the fluid pressure decreases, the downstream sealing elastic element 700 pushes the sliding block 500 to reset, and the sliding block 500 drives the first sealing ball 600 back to the upstream of the expansion section 402, and the downstream conical through hole 501 is restored to the connected state.

[0030] The cooperation between the downstream conical through-hole 501 and the expansion section 402 enables step-wise control of the fluid flow rate. When the first plugging ball 600 enters the expansion section 402, the fluid flow can be delivered downstream through the gap and the downstream conical through-hole 501. At this time, the relatively small fluid flow rate can meet the initial expansion requirements of the downstream expansion tube 200, avoiding uneven deformation of the expansion tube 200 caused by the initial large flow rate impact. When the fluid flow rate increases, causing the first plugging ball 600 to leave the expansion section 402 and block the downstream conical through-hole 501, the fluid flow pushes the sliding stop 500 to fully open the first connecting port 401. At this time, the larger fluid flow rate can quickly meet the expansion requirements of the upstream expansion tube 200 and the fracturing operation requirements of the jet orifice 101. This structure adds a dynamic adjustment link for the liquid flow rate during the sliding process of the first sealing ball 600 pushing the sliding stop 500, so that the expansion process of the expansion tube 200 is precisely matched with the change of liquid flow rate. This not only ensures the stability of the initial expansion of the downstream expansion tube 200, but also improves the efficiency of the subsequent overall operation, and further optimizes the liquid flow distribution and operation rhythm of the equipment.

[0031] Furthermore, the fixing ring 320 of the support assembly 300 is fixedly sleeved on the outer wall of the inserted outer tube 100, the sliding ring 330 slides with the inserted outer tube 100, and the outer abutment strip 310 is a convex arc-shaped elastic strip with its two ends respectively set on the fixing ring 320 and the sliding ring 330. When the inserted outer tube 100 slides along the well wall passage, the outer abutment strip 310 is in an expanded state, and its outer diameter is larger than the outer diameter of the expansion tube 200 in its naturally contracted state, maintaining sliding contact with the inner wall of the well wall passage. When the inserted outer tube 100 moves to the preset working position, and before the first sealing ball 600 is pushed by the fluid flow, the sliding ring 330 slides towards the fixing ring 320, compressing the outer abutment strip 310 so that it is pressed and pushed against the inner wall of the inserted outer tube 100, thereby fixing the inserted outer tube 100. Subsequently, the fluid flow pushes the first sealing ball 600 to move, thereby sequentially causing the sliding stop 500 to unblock the first connecting port 401, and the downstream and upstream expansion pipes 200 to expand in turn to form an isolated working space. The jet orifice 101 ejects fluid to perform jet fracturing. After the jet fracturing is completed, the sliding ring 330 slides away from the fixed ring 320, the outer abutment strip 310 relaxes and resets, and the extended outer tube 100 can continue to slide along the well wall passage.

[0032] The cooperation between the fixed ring 320 and the sliding ring 330 provides the basis for the installation and operation of the outer abutment strip 310. In its expanded state, the outer diameter of the outer abutment strip 310 is larger than the outer diameter of the expansion tube 200 in its naturally contracted state, ensuring that the outer abutment strip 310 remains in contact with the inner wall of the wellbore passage during the sliding process of the outer tube 100, continuously providing support. The sliding ring 330 slides towards the fixed ring 320, compressing the outer abutment strip 310, causing it to press and push against the inner wall of the outer tube 100. This fixes the outer tube 100 in the working position, preventing swaying of the outer tube 100 due to the reaction force of the fluid flow during jet fracturing, and providing a prerequisite for the stable expansion of the expansion tube 200 and the effective formation of an isolated working space. Between the sliding ring 330 sliding and fixing the outer tube 100 and the fluid flow pushing the first sealing ball 600 to move, a fixing process for the outer tube 100 is added. This allows the subsequent expansion of the expansion tube 200 and jet fracturing operations to be carried out in a more stable state, further improving the accuracy and reliability of the equipment operation. At the same time, the arc-shaped elastic structure design of the outer abutment strip 310 allows it to better adapt to the condition of the inner wall of the wellbore passage during compression and expansion, ensuring the stability of the support and fixing effect.

[0033] Furthermore, the outer wall of the enlarged section 402 is fixedly connected to the inner wall of the inserted outer tube 100. The sliding ring 330 is located upstream of the fixed ring 320. One end of the reset elastic element 340 of the support assembly 300 acts on the outer wall of the enlarged section 402, and the other end acts on the sliding ring 330. When the inserted outer tube 100 slides along the well wall passage, the reset elastic element 340 elastically pushes the sliding ring 330, so that the sliding ring 330 is in a position away from the fixed ring 320, and the outer abutment strip 310 remains in a relaxed state and slides against the inner wall of the well wall passage. When the inserted outer tube 100 moves to the preset working position, before the fluid flow pushes the first sealing ball 600 to move, the sliding ring 330 overcomes the force of the reset elastic element 340 and slides towards the fixed ring 320, compressing the outer abutment strip 310 to fix the inserted outer tube 100. Subsequently, the fluid flow pushes the first sealing ball 600 to move, sequentially completing the unblocking of the sliding stop 500 at the first connecting port 401, and the expansion pipes 200 downstream and upstream expanding to form an isolated working space. Fluid is then ejected from the jet orifice 101 for jet fracturing. After jet fracturing is completed, the fluid pressure decreases, and the reset elastic element 340 pushes the sliding ring 330 to slide and reset away from the fixed ring 320. The outer abutment strip 310 expands, extending into the outer tube 100, which can continue to slide along the well wall passage.

[0034] The outer wall of the expansion section 402 is fixedly connected to the inner wall of the outer tube 100, enhancing the connection stability between the expansion section 402 and the outer tube 100 and providing a reliable force support point for the reset elastic element 340. The sliding ring 330 is located upstream of the fixed ring 320. In conjunction with the reset elastic element 340, after the jet fracturing operation is completed, the sliding ring 330 can automatically slide away from the fixed ring 320 under the action of the reset elastic element 340, realizing the relaxation and reset of the outer abutment bar 310. No additional drive mechanism is required, simplifying the equipment operation process. The automatic reset process of the sliding ring 330 between the compression of the outer abutment bar 310 and the completion of the jet fracturing operation ensures that the outer abutment bar 310 can quickly return to its relaxed state, allowing the outer tube 100 to be adjusted again in a timely manner, thus improving the equipment's operating efficiency. Meanwhile, the reset elastic element 340 continuously provides a pushing force to the sliding ring 330, ensuring that the outer abutment strip 310 is always in a stable relaxed state during the sliding process of extending into the outer tube 100, thus ensuring the consistency of the support effect. Furthermore, a set of expansion tubes 200 are located upstream of the support assembly 300. Their interiors are connected to the interior of the outer tube 100 via a second connecting port 104. One end of the sliding ring 330 extending upstream is equipped with a pushed-blocking block 900, which is used to block the second connecting port 104. When the outer tube 100 slides along the well wall passage, the reset elastic element 340 pushes the sliding ring 330 to a position away from the fixed ring 320, and the pushed-blocking block 900 blocks the second connecting port 104. When the outer tube 100 moves to a preset working position, the sliding ring 330 overcomes the force of the reset elastic element 340 and slides towards the fixed ring 320. The pushed-blocking block 900 moves with the sliding ring 330 and releases the blockage of the second connecting port 104. Fluid flows through the second connecting port 104 into the interior of the expansion tube 200 located upstream of the support assembly 300. The expansion tube 200 deforms and expands, abutting against the well wall. Subsequently, the fluid flow pushes the first sealing ball 600 to move, sequentially completing the unblocking of the first connecting port 401 by the sliding stop 500 and the expansion of the downstream expansion tube 200. The two sets of expansion tubes 200 together form an isolated working space, and the jet orifice 101 ejects fluid for jet fracturing. After the jet fracturing is completed, the fluid pressure decreases, and the reset elastic element 340 pushes the sliding ring 330 to slide and reset away from the fixed ring 320. The pushed sealing block 900 resets with the sliding ring 330 and re-seals the second connecting port 104, and the upstream expansion tube 200 returns to its relaxed and contracted state.

[0035] The pushed-blocking block 900 is linked with the sliding ring 330 to control the opening and closing of the second connecting port 104. During the sliding of the sliding ring 330 into the outer tube 100 via the fixed ring 320, the pushed-blocking block 900 simultaneously releases the seal on the second connecting port 104, allowing the fluid flow to enter the upstream expansion tube 200 and expand. This ensures that the expansion of the upstream expansion tube 200 and the fixing of the outer tube 100 are coordinated, reducing independent control links and improving operational continuity. After jet fracturing is completed, the pushed-blocking block 900, along with the sliding ring 330, resets under the action of the reset elastic element 340 and seals the second connecting port 104. This prevents the fluid flow from continuously entering the upstream expansion tube 200 during the sliding of the outer tube 100, ensuring reliable contraction of the expansion tube 200.

[0036] Between the sliding ring 330 sliding and fixing into the outer tube 100 and the liquid flow pushing the first sealing ball 600 to move, the action of the pushed sealing block 900 increases the expansion control process of the upstream expansion tube 200, so that the expansion timing of the upstream expansion tube 200 is precisely matched with the fixed state of the outer tube 100.

[0037] Furthermore, the pushed-to-plug block 900 has an upstream conical through-hole 901 through its center, and the inner flow pipe 400 has a third connecting port 403. The inner wall of the sliding ring 330 blocks the third connecting port 403. The inner wall of the pushed-to-plug block 900 has a notch 902. The second plugging ball 1000 is located inside the upstream conical through-hole 901. An upstream plugging elastic element 1100 is provided between the second plugging ball 1000 and the outer end of the inner flow pipe 400. The upstream plugging elastic element 1100 elastically pushes the second plugging ball 1000 to maintain the blockage of the upstream conical through-hole 901. When the equipment is in operation, during the sliding process along the well wall passage of the inserted outer pipe 100, the pushed-to-plug block 900 blocks the second connecting port 104, and the second plugging ball 1000 blocks the upstream conical through-hole 901. When the outer tube 100 reaches the preset working position, the fluid flow pushes the pushed sealing block 900 to slide downstream. The pushed sealing block 900 releases the seal on the second connecting port 104. At the same time, the fluid flow pushes the second sealing ball 1000 to overcome the force of the upstream sealing elastic element 1100, so that the second sealing ball 1000 no longer seals the upstream conical through hole 901. The notch 902 of the pushed sealing block 900 is opposite to the third connecting port 403, so that the outer tube 100 and the third connecting port 403 are connected through the notch 902. The fluid flows into the inner flow tube 400 through this path. Afterward, the sliding ring 330 slides towards the fixed ring 320 to compress the outer abutment strip 310 to fix the outer tube 100. The fluid flow continues to push the first sealing ball 600 to move, and the subsequent sliding stop 500 action, expansion tube 200 expansion and jet fracturing operation are completed in sequence. After the jet fracturing is completed, under the action of the reset elastic element 340, the sliding ring 330 drives the pushed sealing block 900 to slide and reset upstream. The pushed sealing block 900 re-seals the second connecting port 104. Under the action of the sealing elastic element 1100, the second sealing ball 1000 re-seals the upstream conical through hole 901. The inner wall of the sliding ring 330 re-seals the third connecting port 403.

[0038] The cooperation of the upstream conical through-hole 901, the second sealing ball 1000, and the upstream sealing elastic element 1100 enables automatic sealing and opening of the upstream conical through-hole 901, effectively preventing uncontrolled fluid flow during non-operational phases. The cooperation between the notch 902 on the pushed sealing block 900 and the third connecting port 403 provides a specific passage for fluid to flow into the inner flow pipe 400. This passage only opens when the pushed sealing block 900 is pushed downstream by the fluid flow, ensuring that the timing of fluid entry into the inner flow pipe 400 is synchronized with the movement of the pushed sealing block 900. Between the pushed sealing block 900 being pushed by the fluid flow and the sliding ring 330 sliding and fixing into the outer pipe 100, a control process for fluid entry into the inner flow pipe 400 is added, allowing the fluid supply to more precisely match the equipment's operating steps and avoiding energy waste or operational delays caused by fluid entering the inner flow pipe 400 prematurely or delayed. Meanwhile, the sealing effect of the inner wall of the sliding ring 330 on the third connecting port 403 prevents liquid from accidentally flowing into the inner flow pipe 400 through the third connecting port 403 during non-operational periods, further improving the reliability of the equipment's liquid flow control. The coordinated operation of these structures makes the liquid flow control of the equipment more rigorous, the operation process smoother, and the overall operation efficiency and stability further enhanced. Furthermore, both the upstream sealing elastic element 1100 and the spacer elastic element 800 are tapered variable-diameter springs. During operation, as the outer tube 100 slides along the well wall passage, the upstream sealing elastic element 1100, in the form of a tapered variable-diameter spring, elastically pushes against the second sealing ball 1000, maintaining the seal on the upstream tapered through-hole 901. Similarly, the spacer elastic element 800, also in the form of a tapered variable-diameter spring, acts on the sliding stop block 500 and the first sealing ball 600, providing a force that keeps them apart. When the outer tube 100 reaches the preset operating position, the fluid flow pushes the pushed sealing block 900 downstream, simultaneously pushing the second sealing ball 1000 to overcome the force of the upstream sealing elastic element 1100, causing the second sealing ball 1000 to no longer seal the upstream tapered through-hole 901. The fluid then flows into the inner flow pipe 400 through the connection path between the notch 902 and the third connecting port 403. Subsequently, the fluid flow pushes the first sealing ball 600 to move. The first sealing ball 600 pushes the sliding stop 500 through the spacer elastic element 800, which acts as a tapered variable diameter spring. This causes the sliding stop 500 to move downstream against the force of the downstream sealing elastic element 700, thus canceling the blockage of the first connecting port 401. The expansion of the expansion tube 200 and the jet fracturing operation are then completed sequentially. After the jet fracturing is completed, under the action of the reset elastic element 340, the sliding ring 330 drives the pushed sealing block 900 to slide and reset upstream. The upstream sealing elastic element 1100 restores its deformation and pushes the second sealing ball 1000 to re-seal the upstream tapered through hole 901. The spacer elastic element 800 also restores its deformation, working with the downstream sealing elastic element 700 to reset the sliding stop 500 and the first sealing ball 600.

[0039] The upstream sealing elastic element 1100 uses a tapered variable-diameter spring. Its variable-diameter structure better adapts to the force state of the second sealing ball 1000. When pushing the second sealing ball 1000, it can make the force more concentrated and uniform, ensuring the reliability of sealing the upstream tapered through hole 901. At the same time, when pushed and compressed by the liquid flow, it can deform more smoothly and avoid jamming caused by uneven force. The spacer elastic element 800 also uses a tapered variable-diameter spring. During the process of the first sealing ball 600 pushing the sliding stop 500, its tapered structure can make the force transmission more efficient and reduce energy loss. During reset, it can more accurately drive the first sealing ball 600 and the sliding stop 500 back to the initial position, ensuring the stability of their cooperation. During the process of the second sealing ball 1000 being pushed and the first ball 600 pushing the sliding stop 500, the characteristics of the tapered variable-diameter spring make the deformation and reset of the elastic element smoother, reducing the impact of the equipment during operation transition and extending the service life of the elastic element. Meanwhile, the conical variable diameter spring's structural design enables it to provide more suitable elastic force within a limited space, making it more adaptable to the overall equipment structure and further improving the stability and reliability of the equipment's operation.

[0040] Furthermore, another set of expansion tubes 200 is located downstream of the sliding stop 500, and a fourth connecting port 105 is provided on the outer wall of the outer tube 100. This fourth connecting port 105 is used to connect the inside of the outer tube 100 with the inside of the downstream expansion tube 200. When the equipment is in operation, when the outer tube 100 reaches the preset working position, the liquid flow pushes the first sealing ball 600 into the expansion section 402. The liquid flow passes through the gap between the outer wall of the first sealing ball 600 and the inner wall of the expansion section 402, and then is transported downstream through the downstream conical through hole 501 of the sliding stop 500. As the liquid flow rate increases, the first sealing ball 600 leaves the expansion section 402 and slides again against the inner wall of the inner flow tube 400, and then abuts against the sliding stop 500 and blocks the downstream conical through hole 501, pushing the sliding stop 500 to slide. As the fluid flows through the downstream conical through-hole 501, a portion of the fluid enters the expansion tube 200 located downstream of the sliding stop 500 via the fourth connecting port 105, causing the expansion tube 200 to deform and expand, bringing it into contact with the well wall. Subsequently, the fluid continues to act, causing the upstream expansion tube 200 to also deform and expand. The two sets of expansion tubes 200 together form an isolated working space, from which the jet orifice 101 ejects fluid for jet fracturing. After jet fracturing is completed, the fluid pressure decreases, the sliding stop 500 resets, and the downstream expansion tube 200 returns to its relaxed, contracted state.

[0041] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An abrasive waterjet fracturing equipment for jet fracturing of well walls, characterized in that, include: An outer tube (100) is inserted into and slides along the extension direction within a passageway opened in the well wall; The outer tube (100) has several jet holes (101) that are circumferentially opened on its peripheral wall for jetting fluid to perform jet fracturing on the well wall. Two sets of expansion tubes (200) are also provided on the outer wall of the inserted outer tube (100). The jet hole (101) is located between the two sets of expansion tubes (200). After the two sets of expansion tubes (200) are configured to deform and expand, the two sets of expansion tubes (200) abut against the well wall and together with the well wall form an isolated working space. A support assembly (300) is sleeved on the outer wall of the inserted outer tube (100). The support assembly (300) includes a plurality of circumferentially arranged outer abutment strips (310), each of which is used to abut against the well wall.

2. The abrasive waterjet fracturing equipment according to claim 1, characterized in that, Also includes: An inner flow tube (400) is disposed inside the outer tube (100). The inner flow tube (400) is used to provide a flow path for liquid flow, and a liquid injection jacket (103) is formed between the inner flow tube (400) and the outer tube (100). The liquid injection jacket (103) is connected to the outside through the jet hole (101). A first communication port (401) is provided on the wall of the inner flow tube (400). The first communication port (401) is used to connect the interior of the inner flow tube (400) and the liquid injection jacket (103). A sliding stop (500) is slidably disposed within the inner flow pipe (400). The sliding stop (500) is configured to block or unblock the first communication port (401) after sliding.

3. The abrasive waterjet fracturing equipment according to claim 2, characterized in that, Also includes: The first sealing ball (600) slides within the inner flow pipe (400) and is located upstream of the sliding block (500). Downstream sealing elastic element (700), one end of which acts on the sliding block (500) and the other end of which acts on the inner wall of the inner flow pipe (400) downstream of the sliding block (500). The downstream sealing elastic element (700) is used to provide the sliding block (500) to slide upstream to block the first communication port (401). An elastic spacer (800) is provided, with its two ends acting on the sliding block (500) and the first blocking ball (600) respectively, for bidirectionally pushing the sliding block (500) and the first blocking ball (600) to provide a force that moves them away from each other. The elastic coefficient of the downstream blocking elastic spacer (700) is greater than that of the elastic spacer (800). The first blocking ball (600) is configured such that, after being pushed and moved by the liquid flow, it pushes the sliding block (500) through the elastic spacer (800) so that the sliding block (500) moves downstream against the downstream blocking elastic spacer (700), thereby causing the sliding block (500) to unblock the first communication port (401).

4. The abrasive waterjet fracturing equipment according to claim 3, characterized in that, The sliding stop (500) has a downstream conical through hole (501) through its center for connecting the upstream and downstream of the sliding stop (500). The inner flow pipe (400) has an expansion section (402) with a larger internal pipe diameter. The first sealing ball (600) is configured to enter the expansion section (402) after being pushed by the liquid flow. The liquid flow flows through the gap between the outer wall of the first sealing ball (600) and the inner wall of the expansion section (402), and then is transported downstream through the sliding downstream conical through hole (501). After the liquid flow rate increases, the first sealing ball (600) leaves the expansion section (402) and slides against the inner wall of the inner flow pipe (400) again, and then abuts against the sliding stop (500) and blocks the downstream conical through hole (501) to push the sliding stop (500) to slide.

5. The abrasive waterjet fracturing equipment according to claim 4, characterized in that, The support component (300) includes: A fixing ring (320) is fixedly sleeved on the outer wall of the extension tube (100); A sliding ring (330) is slidably engaged with the extended outer tube (100). The outer abutment strip (310) is a convex arc-shaped elastic strip, and the two ends of the outer abutment strip (310) are respectively disposed on the fixed ring (320) and the sliding ring (330). The sliding ring (330) is configured such that after sliding to one side of the fixed ring (320), it compresses the outer abutment strip (310) so that it presses and pushes against the inner wall of the extended outer tube (100) to fix the extended outer tube (100). The outer diameter of the outer abutment strip (310) in its expanded state is greater than the outer diameter of the expansion tube (200) in its naturally contracted state so that the outer abutment strip (310) maintains sliding contact with the inner wall of the well passage.

6. The abrasive waterjet fracturing equipment according to claim 5, characterized in that, The outer wall of the enlarged section (402) is fixedly connected to the inner wall of the outer tube (100), and the sliding ring (330) is located upstream of the fixed ring (320). The support assembly (300) further includes: The reset elastic element (340) has one end acting on the outer wall of the expanded diameter section (402) and the other end acting on the sliding ring (330), and is used to elastically push the sliding ring (330) to provide the sliding ring (330) to slide and reset in a direction away from the fixed ring (320).

7. The abrasive waterjet fracturing equipment according to claim 6, characterized in that, A set of expansion tubes (200) is located upstream of the support assembly (300), the interior of which is used to connect with the interior of the outer tube (100) via a second communication port (104), and further includes: A push-blocking block (900) is provided at one end of the sliding ring (330) extending upstream. The push-blocking block (900) is used to block the second communication port (104). The push-blocking block (900) is configured to release the blockage of the second communication port (104) after being pushed by the liquid flow, so as to inject liquid into the expansion tube (200), or to be elastically reset by the action of the reset elastic member (340) to block the second communication port (104).

8. The abrasive waterjet fracturing equipment according to claim 7, characterized in that, The pushed-blocking block (900) has an upstream conical through hole (901) through the middle, and the inner flow pipe (400) also has a third connecting port (403). The inner wall of the sliding ring (330) is used to block the third connecting port (403), and the inner wall of the pushed-blocking block (900) has a notch (902). The second sealing ball (1000) is located inside the upstream conical through hole (901). An upstream sealing elastic element (1100) is provided between the second sealing ball (1000) and the outer end of the inner flow pipe (400). The upstream sealing elastic element (1100) is used to elastically push the second sealing ball (1000) so that the second sealing ball (1000) keeps blocking the upstream conical through hole (901). The pushed-blocking block (900) is configured to slide downstream after being pushed by the liquid flow, while the liquid flow pushes the second blocking ball (1000), thereby connecting the outer tube (100) and the third communication port (403) through the notch (902) to provide a path for the liquid flow into the inner flow tube (400).

9. The abrasive waterjet fracturing equipment according to claim 8, characterized in that, Both the upstream blocking elastic element (1100) and the spacer elastic element (800) are tapered variable diameter springs.

10. The abrasive waterjet fracturing equipment according to claim 4, characterized in that, Another set of expansion tubes (200) is located downstream of the sliding stop (500). After the liquid flows through the downstream conical through hole (501), it communicates with the inside of the expansion tube (200) through the fourth connecting port (105) opened on the outer wall of the outer tube (100).

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