A method and device for reverse hole reaming intensive construction

Abstract

This invention discloses an intensive reverse borehole reaming construction method and equipment, relating to the field of underground engineering construction technology. The core of this method lies in innovating the traditional full-face rock breaking into a two-step process of "peripheral annular cutting + central hydraulic crushing": first, the roller cutter on the reaming drill bit cuts an annular groove in the rock strata, retaining a cylindrical central rock core; then, the hydraulic crushing device integrated into the reaming drill bit directly squeezes or impacts the central rock core, causing it to break and fall off entirely. This invention significantly reduces the rock breaking area and the number of roller cutters, significantly improving drilling efficiency and reducing energy consumption and tool wear. The corresponding equipment includes a drilling rig, drill rod, reaming drill bit, hydraulic power unit system, and an optional clamping and pressing device.

Description

Technical Field

[0001] This invention belongs to the field of mining engineering and underground engineering construction technology, and in particular relates to a reverse shaft enlargement intensive construction method and equipment, which is especially suitable for the new reverse shaft enlargement intensive process in the construction of pumped storage power stations, mine vertical shafts and inclined shafts. Background Technology

[0002] Raising shaft drilling is a commonly used technique in the construction of vertical and inclined shafts in pumped storage power stations and mines. The traditional process is as follows: first, a pilot hole is drilled in the rock strata; then, a reaming bit connected to the raising rig via a drill pipe is placed at the bottom of the pilot hole; subsequently, driven by the raising rig, the reaming bit's cutting edge is used to enlarge the entire cross-section of the pilot hole from bottom to top to the designed diameter, such as 2 meters, 4 meters, or even larger, in one go or in stages.

[0003] However, this existing raised hole drilling technology has the following drawbacks: regardless of whether a single-stage or multi-stage reaming method is used, the rock breaking method involves using a cutting roller to break the rock across the entire working face. Obviously, this method involves a large amount of rock breaking work, severe tool wear, and insufficient downward pressure from the reaming bit, resulting in low drilling efficiency, high energy consumption, and the need for a large number of cutting rollers, leading to high construction costs and long construction periods.

[0004] Therefore, exploring methods for reverse shaft enlargement is also an important issue that urgently needs to be addressed in the field of mine vertical and inclined shaft design. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a method and equipment for intensive reverse well enlargement construction that minimizes rock breaking workload, increases efficiency, and reduces tool wear.

[0006] To achieve the above objectives, the reverse well enlargement intensive construction method provided by the present invention includes the following steps performed in sequence:

[0007] S1. Construct a pilot hole in the rock strata that runs through the upper and lower tunnels;

[0008] S2. A reaming drill bit is placed at the bottom of the guide hole and connected to a riser drill located in the upper tunnel via a drill rod. The reaming drill bit includes a circular cutterhead and a hydraulic crushing device installed inside the cutterhead. A slag leakage area is formed in the middle of the cutterhead, and a roller cutter is provided on the circumference.

[0009] S3. Drive the reaming drill bit to rotate and apply axial drilling pressure to it, and perform annular cutting on the rock strata through the roller cutter on the cutter head to form an annular groove in the rock strata and an isolated central rock core located inside the annular groove; wherein, the annular cutting is carried out by either an upward reaming method from bottom to top or a downward reaming method from top to bottom;

[0010] S4. When the annular cutting advance reaches the predetermined height H, stop cutting, start the hydraulic crushing device, and extend its piston rod to apply mechanical force to the central rock core, causing the central rock core to break.

[0011] S5. The broken rock core falls to the bottom of the well through the slag leakage zone on the reaming drill bit or the guide hole.

[0012] In step S3, the axial drilling pressure is an upward pulling force, which is provided by the raise boring machine through the drill pipe and provides rotational power to the reaming drill bit to achieve bottom-up reaming.

[0013] In step S3, the axial drilling pressure is a downward pressure, which is provided by the raise boring machine to the reaming drill bit and a separate clamping and pressing device applies downward pressure to the drill pipe to achieve reaming from top to bottom.

[0014] In step S4, the hydraulic crushing device is connected to the hydraulic power unit located in the upper tunnel through a hydraulic pipeline installed inside the drill pipe, and the hydraulic power unit supplies hydraulic oil to the hydraulic crushing device through the hydraulic pipeline.

[0015] The cutter head uses toothed cutters, and the end of the piston rod on the hydraulic crusher is also toothed.

[0016] The cutterhead has various diameters to accommodate wellbore construction of different diameters.

[0017] The hobs arranged symmetrically around the circumference of the cutter head.

[0018] The reverse well reaming equipment provided by the present invention for implementing the above-mentioned intensive reverse well reaming construction method includes a reverse well drilling rig, drill pipe, reaming drill bit and hydraulic power unit; the reaming drill bit includes a circular cutterhead and a hydraulic crushing device; the drill pipe has integrated hydraulic pipelines for connecting the hydraulic power unit located in the upper tunnel and the hydraulic crushing device.

[0019] The raise boring machine also includes a clamping and pressing device, which includes a base frame, a clamping plate, a hydraulic clamping system, and a pressing actuator. The base frame is fixed to the bottom of the upper tunnel. The lower end of the hydraulic clamping system is fixed to the outer side of the base frame, and the upper end is connected to the clamping plate to clamp the clamping plate to the top of the upper tunnel. The upper end of the pressing actuator is fixed to the middle of the clamping plate, and the lower end is connected to the top of the drill pipe connected to the power head of the raise boring machine to apply continuous downward axial pressure to the drill pipe.

[0020] The hydraulic clamping system includes at least two symmetrically arranged clamping hydraulic cylinders. The cylinder body of the clamping hydraulic cylinder is fixed to the outer part of the base frame, and its piston rod extends upward and is connected to the clamping plate to clamp the entire device between the top and bottom of the upper tunnel. The downward pressing actuator adopts a downward pressing hydraulic cylinder.

[0021] The reverse well enlargement and intensive construction method and equipment provided by this invention have the following beneficial effects:

[0022] High efficiency: By changing full-section crushing to local annular cutting, the rock-breaking area is greatly reduced, which significantly improves the pure drilling speed and shortens the construction period.

[0023] Low wear: The number of hobbing cutters is reduced, and they mainly act on the intact surrounding rock wall, avoiding repeated friction with the broken rock in the center, which greatly reduces tool wear and energy consumption.

[0024] High-quality well completion: The hydraulic method for breaking the core rock results in less disturbance to the surrounding rock of the wellbore, and a smoother and more regular well wall.

[0025] Wide adaptability: By using variable diameter drill bits, it can flexibly adapt to the construction needs of wells with different diameters, and has strong versatility. After the pilot hole is completed, a ring-shaped cutter bit is used to perform peripheral circumferential cutting to cut out the annular groove. After that, hydraulic blasting is performed, and the broken rock core falls to the bottom of the well by itself. This realizes the transformation from full-section cutting to peripheral circumferential partial cutting, which can significantly reduce the amount of cutting work, improve efficiency, reduce the number of cutters, and save resources and energy. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the reverse well enlargement equipment structure used in the intensive construction method of the upward-lift reverse well enlargement provided in Embodiment 1 of the present invention.

[0027] Figure 2 This is a schematic diagram of the upward-lifting reaming drill bit structure used in Embodiment 1 of the present invention.

[0028] Figure 3 yes Figure 2 Top view.

[0029] Figure 4 This is a schematic diagram of the downward-pressing reaming drill bit structure used in Embodiment 2 of the present invention.

[0030] Figure 5 This is a schematic diagram of the reverse well enlargement equipment used in the intensive construction method of reverse well enlargement provided in Embodiment 2 of the present invention.

[0031] Figure 6 A schematic diagram of the overall structure of the top clamping and pressing device used in conjunction with a reverse drilling rig in Embodiment 2 of the present invention. Detailed Implementation

[0032] The technical solutions of 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.

[0033] Example 1:

[0034] like Figures 1 to 3 As shown, the intensive reverse well enlargement construction method provided in this embodiment adopts a lifting construction method and includes the following steps performed in sequence:

[0035] S1: This reverse well reaming equipment is set up, which includes a reverse well drilling rig 1, a drill pipe 2, a reaming drill bit 3, and a hydraulic power unit 4; wherein the reverse well drilling rig 1 and the hydraulic power unit 4 are installed at the designed position on the upper tunnel; a roller cone drill bit or a tri-cone drill bit is used as the guide hole drill bit, and a guide hole penetrating the upper and lower tunnels is constructed from top to bottom in the rock strata by extending the drill pipe 2;

[0036] S2: After the pilot hole is completed, in the lower tunnel, remove the pilot hole drill bit and replace it with the upper drill bit. Figure 2 The upward-lifting reaming drill bit 3 is lowered to the bottom of the guide hole. The drill bit is screwed to the female connector at the lower end of the drill rod 2 via the male connector on its central rod 5.

[0037] S3: Drive the raise boring machine 1, which provides rotational power and upward drilling pressure. The drill rod 2 drives the reaming bit 3 to rotate. The hobbing cutter 6 at the circumference of the reaming bit 3 performs upward annular cutting, cutting an annular groove with a width of about 200-300mm and a cylindrical central rock core located inside the annular groove in the rock formation. During the cutting process, the mud water cooling the hobbing cutter 6 and some rock cuttings will be discharged through the slag leakage zone 7 in the middle of the reaming bit 3. The rock breaking efficiency can be improved by using a toothed hobbing cutter.

[0038] S4: When the cutting height H of the annular cutting reaches 1.5 meters, shut down the raise drill rig 1 and stop cutting, start the hydraulic power unit 4, the hydraulic power unit 4 provides hydraulic oil to the hydraulic crushing device 8 set in the cutter head through the hydraulic pipeline 9 set inside the center rod of the drill rod 2 and the reaming drill bit 3, so that the piston rod on the hydraulic crushing device 8 extends outward and violently squeezes the side or lower end face of the central rock core. Under the huge concentrated load, the central rock core will undergo brittle fracture and be broken into several large rock core pieces;

[0039] S5: The large rock core fragments, after being broken up, fall to the bottom of the well under the action of gravity through the slag leakage zone 7 on the reaming drill bit 3 or the guide hole, and are then transported out by equipment such as loaders located in the lower tunnel. Then, the piston rod on the hydraulic crushing device 8 retracts, and the raise drill rig 1 restarts its rotation and lifting to carry out the next cycle of annular cutting and hydraulic crushing operations. This process is repeated until the entire well shaft is enlarged.

[0040] Example 2:

[0041] like Figures 4 to 6 As shown, the intensive reverse well enlargement construction method provided in this embodiment adopts a downward pressure construction method, including the following steps performed in sequence:

[0042] S1: This reverse well reaming equipment is installed, which includes a reverse well drilling rig 1, a drill pipe 2, a reaming drill bit 3, a hydraulic power unit 4, and a top clamping and pressing device 10; wherein the reverse well drilling rig 1, the hydraulic power unit 4, and the top clamping and pressing device 10 are all installed at the designed positions on the upper tunnel; a roller cone drill bit or a tri-roller drill bit is used as the guide hole drill bit, and a guide hole penetrating the upper and lower tunnels is constructed from top to bottom in the rock strata by extending the drill pipe 2;

[0043] S2: After the pilot hole is completed, in the lower tunnel, remove the pilot hole drill bit and replace it with the upper drill bit. Figure 4 The downward-pressing reaming drill bit 3 shown is lowered to the bottom of the guide hole. The drill bit is screwed to the female connector at the lower end of the drill rod 2 via the male connector on its central rod 5.

[0044] S3: The downward hydraulic cylinder on the downward actuator 11 of the clamping and downward pressing device 10 applies a constant downward drilling pressure to the drill pipe 2; at the same time, the raise boring machine 1 is driven, and the raise boring machine 1 provides rotational power, which drives the reaming drill bit 3 to rotate through the drill pipe 2. The roller cutter 6 at the circumference of the reaming drill bit 3 performs downward annular cutting. Under the combined action of rotation and downward drilling pressure, an annular groove with a width of about 200-300mm and a cylindrical central rock core located inside the annular groove are cut out in the rock formation; during the cutting process, the mud water cooling the roller cutter 6 and some rock cuttings will be discharged through the slag leakage zone 7 in the middle of the reaming drill bit 3. The rock breaking efficiency can be improved by using a toothed roller cutter.

[0045] S4: When the cutting height H of the annular cutting reaches 1.5 meters, shut down the raise drill rig 1 and the top clamping and pressing device 10 to stop cutting, start the hydraulic power unit 4, and the hydraulic power unit 4 provides hydraulic oil to the hydraulic crushing device 8 set in the cutter head through the hydraulic pipeline 9 set inside the center rod of the drill rod 2 and the reaming drill bit 3. This causes the piston rod on the hydraulic crushing device 8 to extend outward and violently squeeze the side or lower end face of the central rock core. Under the huge concentrated load, the central rock core will undergo brittle fracture and be broken into several large rock core pieces.

[0046] S5: The large rock core fragments, after being broken up, fall to the bottom of the well through the guide hole under the action of gravity, and are then transported out by equipment such as loaders located in the lower tunnel. Then, the piston rod on the hydraulic breaking device 8 retracts, the raise boring machine 1 restarts its rotation, and at the same time, the pressing device 10 continues to apply downward drilling pressure to carry out the next cycle of annular cutting and hydraulic breaking operation. This process is repeated until the entire well shaft is enlarged.

[0047] Example 3:

[0048] This embodiment provides a reverse well enlargement device for an intensive construction method of pull-up reverse well enlargement, such as... Figures 1 to 3 As shown, the hoisting and reaming equipment includes a hoisting drill 1, a drill pipe 2, a reaming drill bit 3, and a hydraulic power unit 4; wherein the hoisting drill 1 and the hydraulic power unit 4 are installed at the designed positions on the upper tunnel; the reaming drill bit 3 includes a circular cutterhead 12 and a hydraulic crushing device 8 disposed within the cutterhead 12; the drill pipe 3 has an integrated hydraulic pipeline 9 for connecting the hydraulic power unit 4 located in the upper tunnel and the hydraulic crushing device 8.

[0049] Example 4:

[0050] This embodiment provides a reverse well enlargement device for a downforced reverse well enlargement intensive construction method, such as... Figures 4 to 6 As shown, the raise boring machine includes a raise drilling rig 1, a drill pipe 2, a reaming drill bit 3, a hydraulic power unit 4, and a clamping and pressing device 10. The clamping and pressing device 10 includes a base frame 13, a clamping plate 14, a hydraulic clamping system 15, and a pressing actuator 11. The base frame 13 is fixed to the bottom of the upper tunnel. The lower end of the hydraulic clamping system 15 is fixed to the outer side of the base frame 13, and the upper end is connected to the clamping plate 14 to clamp the clamping plate 14 to the top of the upper tunnel. The upper end of the pressing actuator 11 is fixed to the middle of the clamping plate 14, and the lower end is connected to the top of the drill pipe 2 connected to the power head of the raise drilling rig 1, to apply continuous downward axial pressure to the drill pipe 2.

[0051] The embodiments of this invention alter the rock-breaking mechanism, and its efficiency improvement can be illustrated by simple calculations: Assuming a well shaft with a diameter of 5 meters is being excavated, the total rock-breaking area is 19.63 m². However, using the method and equipment of this invention, if the annular groove width is 0.25 meters, the rock-breaking area is only 3.80 m², reducing the rock-breaking workload by approximately 80%. This is the fundamental reason for the significant efficiency improvement.

Claims

1. A method for intensive construction of reverse well enlargement, characterized in that: The intensive construction method for re-well enlargement includes the following steps performed in sequence: S1. Construct a pilot hole in the rock strata that runs through the upper and lower tunnels; S2. A reaming drill bit is placed at the bottom of the guide hole and connected to a riser drill located in the upper tunnel via a drill rod. The reaming drill bit includes a circular cutterhead and a hydraulic crushing device installed inside the cutterhead. A slag leakage area is formed in the middle of the cutterhead, and a roller cutter is provided on the circumference. S3. Drive the reaming drill bit to rotate and apply axial drilling pressure to it, and perform annular cutting on the rock strata through the roller cutter on the cutter head to form an annular groove in the rock strata and an isolated central rock core located inside the annular groove; wherein, the annular cutting is carried out by either an upward reaming method from bottom to top or a downward reaming method from top to bottom; S4. When the annular cutting advance reaches the predetermined height H, stop cutting, start the hydraulic crushing device, and extend its piston rod to apply mechanical force to the central rock core, causing the central rock core to break. S5. The broken rock core falls to the bottom of the well through the slag leakage zone on the reaming drill bit or the guide hole.

2. The intensive construction method for reverse well enlargement according to claim 1, characterized in that: In step S3, the axial drilling pressure is an upward pulling force, which is provided by the raise boring machine through the drill pipe and provides rotational power to the reaming drill bit to achieve bottom-up reaming.

3. The intensive construction method for reverse well enlargement according to claim 1, characterized in that: In step S3, the axial drilling pressure is a downward pressure, which is provided by the raise boring machine through the drill pipe to the reaming drill bit, and a separate clamping and pressing device applies downward pressure to the drill pipe to achieve reaming from top to bottom.

4. The intensive construction method for reverse well enlargement according to claim 1, characterized in that: In step S4, the hydraulic crushing device is connected to the hydraulic power unit located in the upper tunnel through a hydraulic pipeline installed inside the drill pipe, and the hydraulic power unit supplies hydraulic oil to the hydraulic crushing device through the hydraulic pipeline.

5. The intensive construction method for reverse well enlargement according to claim 1, characterized in that: The cutter head uses toothed cutters, and the end of the piston rod on the hydraulic crusher is also toothed.

6. The intensive construction method for reverse well enlargement according to claim 1, characterized in that: The cutterhead has various diameters to accommodate wellbore construction of different diameters.

7. The intensive construction method for reverse well enlargement according to claim 1, characterized in that: The hobs arranged symmetrically around the circumference of the cutter head.

8. A reverse well drilling apparatus for implementing the method according to any one of claims 1-7, characterized in that: The wellbore reaming equipment includes a wellbore drilling rig, drill pipe, reaming bit, and hydraulic power unit; the reaming bit includes a circular cutterhead and a hydraulic crushing device disposed within the cutterhead; the drill pipe has integrated hydraulic pipelines for connecting the hydraulic power unit located in the upper tunnel and the hydraulic crushing device.

9. The wellbore enlargement equipment according to claim 8, characterized in that: The raise boring machine also includes a clamping and pressing device, which includes a base frame, a clamping plate, a hydraulic clamping system, and a pressing actuator. The base frame is fixed to the bottom of the upper tunnel. The lower end of the hydraulic clamping system is fixed to the outer side of the base frame, and the upper end is connected to the clamping plate to clamp the clamping plate to the top of the upper tunnel. The upper end of the pressing actuator is fixed to the middle of the clamping plate, and the lower end is connected to the top of the drill pipe connected to the power head of the raise boring machine to apply continuous downward axial pressure to the drill pipe.

10. The wellbore enlargement equipment according to claim 9, characterized in that: The hydraulic clamping system includes at least two symmetrically arranged clamping hydraulic cylinders. The cylinder body of the clamping hydraulic cylinder is fixed to the outer part of the base frame, and its piston rod extends upward and is connected to the clamping plate to clamp the entire device between the top and bottom of the upper tunnel. The downward pressing actuator adopts a downward pressing hydraulic cylinder.

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