Deep-hole high-pressure segmented retreating type grouting device and construction technology

Abstract

The invention relates to the field of underground engineering grouting reinforcement, and discloses a deep-hole high-pressure segmented retreating type grouting device and a construction technology. The deep-hole high-pressure segmented retreating type grouting device comprises a packer, the upper end of the packer is provided with a first oil pipe and a second oil pipe, the first oil pipe is arranged outside the second oil pipe in a sleeving mode, and a clear water channel is formed in a gap between the first oil pipe and the second oil pipe; a water injection opening is formed in the middle of the first oil pipe and used for injecting high-pressure water to transmit fluid pressure. A grouting head is arranged at the end of the packer, a grouting channel is formed in the second oil pipe, and an inner channel of the grouting head is matched with the drift diameter of the grouting channel. Fluid pressure is transmitted through the clear water channel of the double-channel oil pipe, and the outer wall of the packer is directly driven to conduct radial expansion hole sealing; the self-sealing hole structure can enable the sealing piece to be tightly attached to the inner wall of the drill hole, the device adapts to the pressure fluctuation environment in deep hole operation, and the fluid channeling path of slurry in the annular space is effectively blocked.

Description

Technical Field

[0001] This invention relates to the field of underground engineering grouting reinforcement, specifically to a deep-hole high-pressure segmented retreating grouting device and its construction process. Background Technology

[0002] In underground engineering construction and resource extraction, deep-hole high-pressure segmented grouting is an important technical means to reinforce fractured surrounding rock, seal fissures, and ensure project safety. However, in current practical operations, existing grouting devices and construction techniques still have certain limitations.

[0003] Traditional packers typically employ simple sealing structures with short effective lengths of the sealing rubber section, usually less than 500mm. In deep-hole high-pressure grouting environments, this structure results in a limited contact area between the packer and the borehole wall, making it difficult to withstand pressure shocks and fluctuations under high pressure. This can easily lead to annular space seal failure, causing grout leakage and affecting the quality of grouting reinforcement.

[0004] Existing grouting devices often employ a single-channel design or lack clear functional zoning, leading to interference between sealing, grouting, and cleaning functions during operation. In particular, the lack of effective isolation between the grouting and cleaning channels makes it difficult to completely remove residual grout after grouting. This residual grout, once solidified, easily causes pipe blockage, preventing tool reuse and increasing construction costs and equipment wear.

[0005] The existing segmented grouting construction process is quite cumbersome. The unsealing and sealing operations of the packer often require multiple adjustments to the tool position, and there is a lack of standardized control methods. During the operation, key actions such as opening the cleaning channel rely heavily on the experience and judgment of the workers, lacking precise stroke control and pressure specifications. This operational uncertainty can easily cause the tools to be subjected to instantaneous high-pressure impacts or mechanical damage due to improper operation, resulting in long operation cycles, low construction efficiency, and accelerated wear and aging of the seals, thus shortening the service life of the device. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a deep-hole high-pressure segmented retreating grouting device and construction process, which solves the problems of sealing failure and leakage caused by insufficient sealing contact area of ​​traditional packers under high-pressure environments, as well as pipeline blockage and tool scrapping caused by confusion of channel functions and incomplete removal of residual grout in existing devices.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: a deep hole high-pressure segmented retreating grouting device and construction process, including a packer, wherein an oil pipe one and an oil pipe two are respectively provided at the upper end of the packer, the oil pipe one is set outside the oil pipe two, the gap between the two forms a clear water channel, the interior of the oil pipe two forms a grouting channel, and a water injection port is provided in the middle of the oil pipe one for injecting high-pressure water to transmit fluid pressure.

[0008] Preferably, the end of the packer is provided with a grouting head, and the internal channel of the grouting head is adapted to the diameter of the grouting channel.

[0009] Preferably, the grouting channel passes through the packer and discharges grout through the grouting head, which is used to prevent grout backflow and protect the bottom interface of the packer.

[0010] Preferably, the packer has a cleaning channel inside, and the cleaning channel is connected to the water inlet.

[0011] Preferably, the ends of the first oil pipe and the second oil pipe are provided with sealing gaskets to ensure sealing performance under high pressure.

[0012] Preferably, the opening of the cleaning channel is controlled by the axial displacement of the packer relative to the second oil pipe; when the packer does not produce axial displacement, the cleaning channel is in a closed state, and the clean water channel is isolated from the grouting channel.

[0013] Preferably, both the first oil pipe and the second oil pipe are splicable structures composed of multiple pipe sections connected in series, and a sealing gasket is provided at each splicing interface of the first oil pipe and the second oil pipe.

[0014] Preferably, the outer wall of the packer is a deformable structure that expands radially under the drive of fluid pressure, and the packer has a pressure-bearing cavity that communicates with the water inlet. The fluid in the clear water channel enters the pressure-bearing cavity through the water inlet and acts on the outer wall of the packer.

[0015] Preferably, the cleaning channel is a fluid passage located inside the packer. When the cleaning channel is opened, the fluid passage connects the water inlet to the grouting channel inside the second oil pipe, allowing fluid from the clean water channel to enter the interior of the grouting channel.

[0016] The deep-hole high-pressure segmented retreat grouting construction process includes the following steps:

[0017] Lower the connected device to the designed depth; Water is supplied through the clear water channel, and the water flows through the water inlet into the packer to expand it and complete the sealing. The grout is injected into the formation through the grouting channel and grouting head until the grouting requirements are met; Release the sealing pressure, raise the device a certain distance, and then press the packer down to a specific stroke to open the cleaning channel; High-pressure water is injected through the clear water channel, and the water flows through the water inlet and the cleaning channel into the grouting channel for reverse flushing. The packer is lifted to reset it, moved to the next grouting section, and the above process is repeated.

[0018] This invention provides a deep-hole high-pressure segmented retreating grouting device and construction process. It has the following beneficial effects: 1. This invention transmits fluid pressure through the clear water channel of the dual-channel oil pipe, directly driving the outer wall of the packer to radially expand and seal the hole; the self-sealing structure enables the sealing element to fit tightly against the inner wall of the borehole, adapting to the pressure fluctuation environment in deep hole operations, effectively blocking the flow path of slurry in the annular space, thereby ensuring the sealing reliability and pressure stabilization effect during high-pressure grouting.

[0019] 2. This invention employs an independent clean water channel and grouting channel design formed by nested oil pipes, combined with a cleaning channel inside the packer controlled by axial displacement, achieving physical isolation and rapid switching between grouting and cleaning functions. After grouting, a reverse flushing circuit is activated by mechanical downward pressure, using high-pressure clean water to thoroughly remove residual grout from the grouting channel, solving the problem of blockage caused by grout solidification in traditional single-channel devices and improving the tool's reusability.

[0020] 3. The construction process of this invention integrates the sealing, grouting and cleaning steps into a single operation process. In particular, it uses a specific downward stroke to trigger the cleaning mode, replacing the cumbersome ground disassembly or experience-based operation. The mechanical control method simplifies the process, reduces the time cost of repeatedly raising and lowering the drill bit, and avoids tool damage caused by misoperation, thereby improving the construction efficiency and operational safety of deep hole segmented grouting. Attached Figure Description

[0021] Figure 1 This is a perspective view of the present invention; Figure 2 This is a cross-sectional view of the grouting channel of the present invention; Figure 3 This is a schematic diagram of the clear water channel structure of the present invention; Figure 4 This is a flow chart of the grouting construction process of the present invention.

[0022] The components are: 1. Packer; 2. Oil pipe one; 3. Sealing gasket; 4. Oil pipe two; 5. Grouting head; 6. Clean water channel; 7. Grouting channel; 8. Water inlet; 9. Cleaning channel. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see the appendix Figure 1 - Appendix Figure 3 This invention provides a deep-hole high-pressure segmented retreating grouting device and construction process, including a packer 1. The upper end of the packer 1 is respectively provided with an oil pipe 2 and an oil pipe 4. The oil pipe 2 is sleeved outside the oil pipe 4, and the gap between them forms a clean water channel 6. The interior of the oil pipe 4 forms a grouting channel 7. A water injection port 8 is provided in the middle of the oil pipe 2 for injecting high-pressure water to transmit fluid pressure. A grouting head 5 is provided at the end of the packer 1, and the internal channel of the grouting head 5 is adapted to the diameter of the grouting channel 7. The grouting channel 7 penetrates the packer 1 and discharges grout through the grouting head 5. The grouting head 5 is used to prevent grout backflow and protect the bottom interface of the packer 1. A cleaning channel 9 is provided inside the packer 1, and the cleaning channel 9 connects to the water injection port 8. Sealing gaskets 3 are provided at the ends of the oil pipe 2 and the oil pipe 4 to ensure sealing performance under high-pressure conditions. The opening of the cleaning channel 9 is controlled by the axial displacement of the packer 1 relative to the second oil pipe 4. When the packer 1 does not undergo axial displacement, the cleaning channel 9 is closed, isolating the clean water channel 6 from the grouting channel 7. Both the first oil pipe 2 and the second oil pipe 4 are connectable structures composed of multiple pipe sections connected in series, and a sealing gasket 3 is provided at each joint of the first oil pipe 2 and the second oil pipe 4. The outer wall of the packer 1 is a deformable structure that expands radially under fluid pressure. The packer 1 has a pressure-bearing chamber connected to the water inlet 8. The fluid in the clean water channel 6 enters the pressure-bearing chamber through the water inlet 8 and acts on the outer wall of the packer 1. The cleaning channel 9 is a fluid passage located inside the packer 1. When the cleaning channel 9 is open, this fluid passage connects the water inlet 8 to the grouting channel 7 inside the second oil pipe 4, allowing the fluid from the clean water channel 6 to enter the interior of the grouting channel 7.

[0025] Packer 1, as the core component for achieving annular space sealing within the borehole, is located at the bottom of the device. The upper end of packer 1 is mechanically connected to tubing 2 and tubing 4, respectively, while the lower end of packer 1 is coaxially connected to grouting head 5. Tubing 2 and tubing 4 extend upwards and form an interface structure that can connect to an external drill pipe system, allowing the entire device to move axially and be positioned with the drill pipe.

[0026] Oil pipe 2 and oil pipe 4 are assembled to form a double-layer coaxial conveying structure. Oil pipe 2 is sleeved on the outside of oil pipe 4, and oil pipe 4 is located inside the cavity of oil pipe 2, with their central axes coinciding. The inner wall surface of oil pipe 2 and the outer wall surface of oil pipe 4 are maintained at a predetermined distance by a radial support structure, and the annular gap space between them is defined as the clear water channel 6. The clear water channel 6 extends along the axial length of oil pipe 2 and is used to transmit high-pressure water fluid medium.

[0027] The internal hollow cavity of tubing 2 4 is defined as grouting channel 7. Grouting channel 7 is installed axially along tubing 2 4 and is physically isolated from water channel 6 by the pipe wall of tubing 2 4, forming two independent fluid transport paths that do not interfere with each other. The lower end of grouting channel 7 passes through the central through hole of packer 1 and extends to grouting head 5, used to transport grout to the target area of ​​the formation.

[0028] Both oil pipe 2 and oil pipe 4 adopt a segmented splicing structure to adapt to the grouting operation requirements of different depths. Sealing gaskets 3 are installed at the joints of each section of oil pipe 2 and oil pipe 4, as well as at the connection interfaces between oil pipe 2, oil pipe 4 and packer 1. The sealing gaskets 3 are configured to be embedded in the interface groove and undergo elastic deformation when the connector is tightened to ensure the airtightness and liquid tightness of the clear water channel 6 and the grouting channel 7 under high pressure, preventing fluid leakage or cross-flow between channels.

[0029] A water inlet 8 is provided in the upper region of the packer 1 or at the connection between the oil pipe 2 and the packer 1. The water inlet 8 is a fluid inlet connecting the clean water channel 6 and the internal functional chamber of the packer 1. The packer 1 uses the fluid pressure input through the clean water channel 6 and the water inlet 8 to achieve radial expansion.

[0030] The packer 1 has an internal cleaning channel 9. The cleaning channel 9 is a controlled fluid passage, one end of which is in fluid communication with the water inlet 8 and the clean water channel 6, and the other end is in fluid communication with the grouting channel 7 under a specific condition. The on / off state of the cleaning channel 9 depends on the mechanical action state of the packer 1, and is used to establish a reverse flushing circuit from the clean water channel 6 to the grouting channel 7 after the grouting operation is completed.

[0031] The grouting head 5 is fixedly installed at the bottom of the packer 1. The grouting head 5 has an axial through-hole whose inner diameter matches the diameter of the grouting channel 7, allowing the grout flowing through the grouting channel 7 to be ejected from the grouting head 5 without obstruction. The outer diameter of the grouting head 5 is less than or equal to the non-expanded outer diameter of the packer 1 to ensure smooth raising and lowering of the device within the borehole.

[0032] In the construction of the dual-channel tubing, tubing 2 serves as the outer pressure-bearing pipe, with an inner diameter larger than that of tubing 4. Tubing 4 is coaxially inserted inside tubing 2, and the two are kept coaxial by a centering bracket or support rib at the joint, thus forming a continuous fluid passage with a circular cross-section, i.e., a clear water channel 6, between the inner wall of tubing 2 and the outer wall of tubing 4. The grouting channel 7, formed by the central cavity of tubing 4, has a smooth inner wall surface, and its diameter is configured to adapt to the flow characteristics of the grouting medium. For example, in one embodiment, the diameter of the grouting channel 7 is set to 16.25 mm to reduce grout flow resistance. The connection interfaces between tubing 2 and tubing 4 both employ trapezoidal threads or special sealing thread structures, and sealing gaskets 3 are provided at the thread root or sealing step. The sealing gasket 3 is made of a corrosion-resistant and high-pressure-resistant elastic material. When the tubing connection is tightened, the sealing gasket 3 is compressed and undergoes elastic deformation to fill the thread gap, ensuring that the water pressure (e.g., 5-10 MPa) in the clear water channel 6 and the grout pressure (e.g., up to 50 MPa) in the grouting channel 7 do not conduct and leak.

[0033] Packer 1 is configured as a fluid pressure-driven expansion sealing mechanism. The main structure of packer 1 includes a central tubing and an elastic sealing assembly covering the central tubing. The central tubing is a downward extension of tubing 4, maintaining the continuity of the grouting channel 7. The outer layer of the elastic sealing assembly is a sealing rubber segment that extends axially for a predetermined length, for example, 880 mm, to form a long-distance sealing contact surface. A pressure-bearing cavity is provided between the central tubing and the sealing rubber segment. A water inlet 8 is located upstream of the central tubing or at the joint on packer 1, connecting the clean water channel 6 to the pressure-bearing cavity. When high-pressure fluid enters the pressure-bearing cavity through the clean water channel 6 and the water inlet 8, the fluid pressure acts on the inner surface of the sealing rubber segment, driving it to expand radially outward against the material's elastic modulus until its outer surface tightly adheres to the borehole wall, thereby sealing the annular space of the borehole.

[0034] The packer 1 integrates a flow path switching mechanism based on axial displacement control to control the opening and closing of the cleaning channel 9. This mechanism includes a relatively slidable inner sleeve and outer sleeve assembly. The cleaning channel 9 includes radial channels formed in the inner sleeve wall and bypass channels disposed within the sealing assembly. During grouting operations, the packer 1 is in a naturally elongated or stretched state, the radial channels are blocked by the seal, and the clean water channel 6 and the grouting channel 7 are physically isolated. When cleaning is required, downward axial pressure is applied to the device through the drill rod, causing the packer 1 to undergo a preset axial compression deformation or displacement stroke (e.g., 230 mm). This axial displacement causes the inner sleeve to shift relative to the outer sleeve, connecting the radial channels to the water inlet 8 or the pressure chamber, thereby opening the cleaning channel 9. At this time, fluid from the clean water channel 6 can pass through the water inlet 8, through the cleaning channel 9, and into the interior of the grouting channel 7, forming a reverse flushing circuit.

[0035] The grouting head 5, as the bottom component of the device, is fixed to the end of the central tubular column of the packer 1 via a threaded connection. The grouting head 5 has an internal one-way flow valve structure or a reduced-diameter nozzle structure, with its internal channel coaxial with and having the same diameter as the grouting channel 7. This structure is configured to allow grout to be ejected at high pressure and high speed, while simultaneously preventing the backflow of external fluids or rock debris into the packer 1 when grouting stops or external pressure backflow occurs, thus protecting the mechanical interface and sealing structure at the bottom of the packer 1 from erosion and wear.

[0036] Please see the appendix Figure 4 The deep-hole high-pressure segmented retreat grouting construction process includes the following steps: Lower the connected device to the designed depth; Water is supplied through the clear water channel 6, and the water flows through the water inlet 8 into the packer 1 to expand it and complete the sealing. The grout is injected into the formation through the grouting channel 7 and the grouting head 5 until the grouting requirements are met; Release the sealing pressure, raise the device a certain distance, and then press the packer 1 down to a specific stroke to open the cleaning channel 9; High-pressure water is injected through the clean water channel 6, and the water flows through the water inlet 8 and the cleaning channel 9 into the grouting channel 7 for reverse flushing. Lift packer 1 to reset it, move it to the next grouting section and repeat the above process.

[0037] During the sealing operation, high-pressure water is injected as the driving medium into the clean water channel 6 between tubing 2 and tubing 4. The fluid is transported axially downwards to the packer 1 and enters the pressure chamber inside the packer 1 through the water inlet 8. At this time, the packer 1 is in a freely extended or uncompressed state, and its internal cleaning channel 9 is in the closed position. The fluid pressure entering the pressure chamber acts on the inner wall of the elastic sealing assembly of the packer 1, forcing the sealing assembly to expand radially outwards. As the injection pressure is maintained (e.g., maintained at 5-10 MPa), the expanded sealing assembly is tightly pressed against the borehole wall, thereby blocking the annular space between the upper and lower parts of the packer 1 and forming a pressure-bearing sealing isolation zone.

[0038] During the grouting operation, after the borehole is sealed, the grout is pumped into the grouting channel 7 inside tubing 2 4. Since the grouting channel 7 is a physically isolated independent pipeline, the grout does not come into contact with the medium in the clear water channel 6 during transmission. The grout flows downwards along the grouting channel 7, passes through the central tubing of the packer 1, and finally exits from the grouting head 5 at the bottom of the device into the formation fracture. Throughout this process, the packer 1 maintains the sealing pressure to prevent the grout from flowing back into the borehole space above the packer 1, ensuring that the grout establishes effective diffusion pressure in the target formation section.

[0039] During the cleaning operation, the device triggers flow path switching through the relative displacement of the mechanical structure. When cleaning is required after a single-stage grouting, the fluid pressure in the clean water channel 6 is first reduced, causing the packer 1 to elastically retract and unseal. Subsequently, axial downward pressure is applied to the device through the drill pipe, causing the packer 1 to generate a set axial compression displacement (e.g., 230 mm) relative to the tubing 4. This axial displacement drives the sliding sleeve assembly inside the packer 1 to move, aligning the originally misaligned fluid channels, thereby opening the cleaning channel 9.

[0040] Once the cleaning channel 9 is opened, high-pressure clean water is injected into the clean water channel 6 again. This time, the water flow is no longer solely used to drive the sealing of the borehole; instead, it is diverted through the water inlet 8 or directly cuts laterally into the interior of the grouting channel 7 through the cleaning channel 9. After entering the grouting channel 7, the high-pressure clean water flushes the pipe wall and pushes the remaining grout downwards, discharging it out of the hole through the grouting head 5 or into the already grouted area. This reverse flushing mechanism utilizes the clean water channel 6 as a high-pressure water source to remove deposits from the grouting channel 7 online without raising the pipe column to the ground, restoring the pipeline's unobstructed flow and preparing for the next grouting cycle.

Claims

1. A deep hole high pressure segmented retreat type grouting device, characterized in that, The packer (1) is provided with a tubing one (2) and a tubing two (4) at its upper end, the tubing one (2) is sleeved outside the tubing two (4), the gap between them forms a clear water channel (6), the inside of the tubing two (4) forms a grouting channel (7), the middle of the tubing one (2) is provided with a water injection port (8) for injecting high-pressure water transmission fluid pressure.

2. The deep hole high pressure segmented retreat type grouting device according to claim 1, characterized in that, The end of the packer (1) is provided with a grouting head (5), the internal channel of the grouting head (5) is matched with the drift diameter of the grouting channel (7).

3. The deep hole high pressure segmented retreat type grouting device according to claim 2, characterized in that, The grouting channel (7) penetrates through the packer (1) and discharges slurry through the grouting head (5), which is used to prevent backflow of slurry and protect the bottom interface of the packer (1).

4. The deep hole high pressure segmented retreat type grouting device according to claim 1, characterized in that, The packer (1) is provided with a cleaning channel (9) inside, which is communicated with the water injection port (8).

5. The deep hole high pressure segmented retreat type grouting device according to claim 1, characterized in that, The end of the tubing one (2) and the tubing two (4) is provided with a sealing washer (3) to ensure the sealing performance in high-pressure environment.

6. The deep hole high pressure segmented retreat type grouting device according to claim 4, characterized in that, The opening of the cleaning channel (9) is controlled by the axial displacement of the packer (1) relative to the tubing two (4); when the packer (1) does not produce axial displacement, the cleaning channel (9) is in a closed state, and the clear water channel (6) is isolated from the grouting channel (7).

7. The deep hole high pressure segmented retreat type grouting device according to claim 5, characterized in that, The tubing one (2) and the tubing two (4) are both splicing structures composed of multiple tube bodies in series, and the sealing washer (3) is arranged at each splicing interface of the tubing one (2) and the tubing two (4).

8. The deep hole high pressure segmented retreat type grouting device according to claim 1, characterized in that, The outer wall of the packer (1) is constructed as a deformation structure that expands radially driven by fluid pressure, and the packer (1) is provided with a pressure-bearing cavity communicated with the water injection port (8) inside, and the fluid in the clear water channel (6) enters the pressure-bearing cavity through the water injection port (8) and acts on the outer wall of the packer (1).

9. The deep hole high pressure segmented retreat type grouting device according to claim 4, characterized in that, The cleaning channel (9) is a fluid passage arranged inside the packer (1), which communicates the water injection port (8) with the grouting channel (7) inside the tubing two (4) when the cleaning channel (9) is opened, so that the fluid from the clear water channel (6) can enter the inside of the grouting channel (7).

10. The construction process of high-pressure segmented retreat grouting in deep hole, characterized in that, The deep-hole high-pressure segmented back-off grouting device of any one of claims 1-9 comprises the following steps: Lower the connected device to the designed depth; Supply water through the clear water channel (6), and the water flows into the packer (1) through the water injection port (8) to make it expand to complete hole sealing; Inject slurry into the formation through the grouting channel (7) and the grouting head (5) until the grouting requirement is reached; Release the hole sealing pressure, lift the device by a distance, and then press the packer (1) to a certain stroke to open the cleaning channel (9); Inject high-pressure water through the clear water channel (6), and the water flows into the grouting channel (7) through the water injection port (8) and the cleaning channel (9) for reverse flushing; Lift the packer (1) to reset it, move it to the next grouting segment and repeat the above process.

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