Full-mechanized shaft construction method based on raise boring technology

Abstract

The invention discloses a full-mechanized shaft construction method based on a raise boring technology, which comprises the following steps of: arranging a raise boring machine on the ground, mounting a guide hole drill bit on the end part of a drill rod of the raise boring machine, drilling downwards from the ground to form a primary directional guide hole, detaching the guide hole drill bit, replacing the guide hole drill bit with a reaming drill bit, and performing primary reaming operation to form a shaft. Concrete is filled in the shaft, after the setting strength of the concrete reaches the specified strength, secondary directional guide hole drilling is carried out in the concrete through a raise boring machine on the ground until the concrete is drilled through, then a guide hole drill bit is detached and replaced with a secondary raise boring machine with a small diameter, and secondary reaming operation is carried out. According to the full-mechanical shaft construction method, shaft wall supporting and shaft one-time forming are achieved, the shaft wall supporting construction does not need manual well descending for construction operation, the problem that potential safety hazards exist in underground supporting construction is avoided, the purpose that well digging does not descend is achieved, the construction safety is improved, and meanwhile the shaft wall supporting quality can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of vertical shaft excavation, and more particularly to a fully mechanized shaft construction method based on reverse well drilling technology. Background Art

[0002] Raise boring machine method is a well drilling method that uses a raise boring machine as the main equipment to form a wellbore through processes such as pilot hole drilling, reaming drilling and well support. The general construction method is to first drill a pilot hole from top to bottom, extend the drill rod to the bottom of the borehole, penetrate the lower roadway or tunnel, and then connect a large-diameter reaming drill bit at the bottom to achieve reaming drilling from bottom to top. After the reaming is completed and supported, a wellbore is formed.

[0003] However, the current problem is that during the support process, concrete needs to be poured to support the well wall. At this time, construction workers need to go down into the well to carry out construction. This is inconsistent with our original intention of "digging wells without going down into the well", and it also greatly increases the safety hazards of underground operations. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a fully mechanized wellbore construction method based on reverse well drilling technology, which avoids manual downhole construction work and improves construction safety.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a fully mechanized wellbore construction method based on reverse drilling technology, comprising the following steps:

[0006] Step A: Drilling a primary directional guide hole: a raise boring machine is set on the ground, a guide hole drill bit is installed on the end of the drill rod of the raise boring machine, and a primary directional guide hole is drilled downward from the ground until the primary directional guide hole is connected with the roadway;

[0007] Step B: primary well bore expansion: after the pilot drill penetrates the formation and enters the tunnel, the pilot drill is removed and then the well expansion drill is installed, the well drilling machine is started, and well bore expansion construction is performed, and a wellbore is formed after the well bore expansion construction;

[0008] Step C: Well bottom sealing: After the well construction is completed and the reaming drill bit leaves the ground, a well bottom support plate is installed at the well bottom position of the well, and the well bottom support plate is supported by support columns to seal the well bottom;

[0009] Step D: Shaft filling: concrete is filled into the shaft in sections by a concrete pouring tank truck. While filling the concrete, a guide positioning ring is coaxially installed in the shaft until the shaft is filled with concrete. By filling the shaft with concrete, the pressure provided by the concrete to the outside can counteract the pressure of the surrounding soil layer. After the concrete solidifies, the concrete and the surrounding soil layer can be tightly combined, and there is a certain prestressed force supporting the outside after the concrete solidifies, which can improve the strength and quality of the final shaft wall. The concrete is filled in sections to avoid excessive concrete filling at a single time, which causes leakage due to excessive pressure, and can ensure that the pressure of the concrete at different depths of the shaft wall is relatively uniform, thereby improving the uniformity of the final shaft wall after forming.

[0010] Step E: Secondary directional pilot hole drilling: When the concrete is cured to the specified strength, the bottom support plate and support column are removed, and a secondary directional pilot hole drilling is performed using a raise borer on the ground until the pilot hole drill penetrates the concrete and enters the tunnel, completing the secondary directional pilot hole drilling and forming a secondary directional pilot hole in the concrete;

[0011] Step F: Secondary well reaming: Remove the pilot drill bit in the tunnel and replace it with a reaming drill bit that is smaller than the shaft diameter, start the well reaming machine, and perform secondary well reaming in the concrete on the basis of the secondary directional pilot hole. The concrete that is not cut by the reaming drill bit forms the well wall until the reaming drill bit drills out of the ground surface to complete the construction. The traditional well wall construction only sprays or uses a mold to construct a layer of support layer of corresponding thickness, which cannot form a prestressed support effect, and the overall support strength and support effect are relatively poor. The well wall formed by the present invention is an integrated structure, and the inner wall has higher flatness and roundness, which can provide a higher support effect.

[0012] In the above-mentioned fully mechanized wellbore construction method based on reverse drilling technology, in step E, during the secondary directional guide hole drilling, a rotating magnetic beacon is first installed between the drill rod and the guide hole drill bit of the reverse drilling rig, and the drill rod drives the rotating magnetic beacon to rotate synchronously. When the rotating magnetic beacon moves, the guide positioning ring detects the coordinate position of the rotating magnetic beacon.

[0013] In the above-mentioned fully mechanized wellbore construction method based on reverse drilling technology, in step F, when the guide drill bit is removed for secondary reverse well expansion, the rotating magnetic beacon is retained on the drill pipe, and then the expansion drill bit is installed and connected to the rotating magnetic beacon.

[0014] In the above-mentioned fully mechanized wellbore construction method based on reverse drilling technology, the outer wall of the guide positioning ring is in contact with the inner wall of the wellbore, and in the depth direction of the wellbore: more than two guide positioning rings are installed in the wellbore; and magnetic sensors are installed in the guide positioning ring along its circumferential direction.

[0015] In the above-mentioned fully mechanized shaft construction method based on reverse drilling technology, in step A, while performing a directional hole drilling, the required hole expansion drill bit is transported to a specified position in the tunnel.

[0016] In the above-mentioned fully mechanized wellbore construction method based on reverse drilling technology, in step B, when the reaming drill drills to 2 to 5 meters before the concrete foundation on the surface, the drilling pressure and rotation speed are reduced, and the deformation and displacement of the surface are observed to ensure that the reaming drill drill safely drills out of the wellbore.

[0017] In the above-mentioned fully mechanized shaft construction method based on reverse drilling technology, in step D, the height of each section of concrete filling is 3 to 5 meters.

[0018] The above-mentioned fully mechanized shaft construction method based on reverse drilling technology, when filling concrete, during the initial filling, the concrete pouring tank truck enters the tunnel, and the delivery pipe of the concrete pouring tank truck penetrates into the shaft from the bottom of the shaft bottom support plate, and fills the concrete section by section from bottom to top.

[0019] The above-mentioned fully mechanized shaft construction method based on reverse drilling technology, when filling concrete, when the concrete height is close to the ground, the concrete filling from the concrete pouring tank truck in the tunnel into the shaft is stopped, and concrete is directly filled into the shaft by the concrete pouring tank truck on the ground until the shaft is full of concrete.

[0020] In the above-mentioned fully mechanized shaft construction method based on reverse drilling technology, in step D, low-grade C30 concrete is used as concrete.

[0021] The technical solution of the present invention achieves the following beneficial technical effects:

[0022] The fully mechanized wellbore construction method of the present invention realizes well wall support and wellbore forming in one step. Well wall support construction does not require manual work in the well, thus avoiding potential safety hazards in well support construction, achieving "drilling without going down the well", improving construction safety, and at the same time being able to improve the quality of well wall support. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the construction of one-step directional guide hole drilling of the present invention;

[0024] Figure 2 A schematic diagram of the construction of a single reverse well expansion of the present invention;

[0025] Figure 3 A schematic diagram of the present invention after the completion of a reverse well expansion construction;

[0026] Figure 4 A schematic diagram of the present invention of filling concrete into a shaft from below;

[0027] Figure 5 A schematic diagram of the present invention of filling concrete into a wellbore from the ground;

[0028] Figure 6 A schematic diagram of the construction of secondary directional hole drilling of the present invention;

[0029] Figure 7 A schematic diagram of the construction of the secondary well expansion of the present invention;

[0030] Figure 8 A schematic diagram of the secondary well expansion construction after completion of the present invention.

[0031] The reference numerals in the figure are as follows: 1-pilot drill bit; 2-drill rod; 3-pilot hole side; 4-circulation pool; 5-raised well drilling rig; 6-crushed rock debris; 7-rock loader; 8-hole expansion drill bit; 9-tunnel; 10-bottom well support plate; 11-support column; 12-wellbore; 13-concrete; 14-concrete pouring tank truck; 15-guide positioning ring; 16-well wall; 17-rotating magnetic beacon. DETAILED DESCRIPTION

[0032] In the fully mechanized wellbore construction method based on the reverse drilling technology in this embodiment, when implemented, for a drilling project with a net diameter of 3m, the specific construction process is as follows:

[0033] Step A: primary directional guide hole drilling: a raise boring machine 5 is set on the ground, a guide hole drill bit 1 is installed on the end of the drill rod 2 of the raise boring machine 5, the guide hole drill bit 1 uses a three-cone drill bit to break the rock, the drill rod 2 has a diameter of 328 mm, and a primary directional guide hole is drilled downward from the ground to form a primary directional guide hole, the diameter of the primary directional guide hole is 350-370 mm, until the primary directional guide hole is connected with the roadway 9;

[0034] Step B: one-time well expansion: after the pilot drill 1 penetrates the formation and enters the tunnel 9, a well expansion operation with a diameter of 4 m is carried out. Through the mutual communication and cooperation between the well and the underground, the pilot drill 1 is first disassembled in the tunnel 9, and then the expansion drill 8 is installed, and then the well drilling machine 5 is started to carry out well expansion construction. After the well expansion construction, a wellbore 12 with a diameter of 4 m is formed. When the expansion drill 8 drills to 2 to 5 m before the concrete foundation on the surface, the drilling pressure and rotation speed are reduced, and the deformation and displacement of the surface are observed to ensure that the expansion drill 8 safely drills out of the wellbore 12;

[0035] Step C: Well bottom sealing: After the wellbore 12 is constructed and the reaming drill bit 8 leaves the ground, a well bottom support plate 10 is installed at the well bottom position of the wellbore 12, and the well bottom support plate 10 is supported by a support column 11 to seal the well bottom of the wellbore 12;

[0036] Step D: Shaft filling: concrete 13 is filled into the shaft 12 in sections by a concrete pouring tanker 14. The concrete 13 adopts low-grade C30 concrete. The filling height of each section is 3 to 5 meters. While the concrete 13 is filled in sections, a guide positioning ring 15 is coaxially installed in the shaft 12, and a guide positioning ring 15 is installed in each section of concrete 13. The outer diameter of the guide positioning ring 15 is 3950 mm, until the shaft 12 is filled with concrete 13;

[0037] Step E: Secondary directional guide hole drilling: When the concrete 13 is cured to a specified strength, the bottom support plate 10 and the support column 11 are removed, and a secondary directional guide hole drilling is performed using a raise borer 5 on the ground until the guide drill bit 1 drills through the concrete 13 and enters the tunnel 9, completing the secondary directional guide hole drilling and forming a secondary directional guide hole in the concrete 13;

[0038] Step F: Secondary wellbore expansion: The diameter of the secondary wellbore expansion is 3m. The pilot drill bit 1 is removed in the tunnel 9 and replaced with a reaming drill bit 8 with a diameter of 3m. The diameter of the secondary reaming drill bit 8 is smaller than the diameter of the shaft. The wellbore drill 5 is started. On the basis of the secondary directional pilot hole, a secondary wellbore expansion operation is performed in the concrete 13. The concrete 13 not removed by the reaming drill bit 8 forms the shaft wall 16 until the reaming drill bit 8 is drilled out from the surface and the construction is completed.

[0039] The construction process requires that the first counter-well expansion and the second counter-well expansion be coaxial. The guide positioning ring 15 can make the two expansions concentric, so the following requirements are required:

[0040]

[0041] In the formula It is expressed as the net diameter of the wellbore, d is expressed as the thickness of the wellbore support, δ is expressed as the wellbore deflection rate, and h is the wellbore depth.

[0042] The outer wall of the guide positioning ring 15 is fitted with the inner wall of the wellbore 12. In the depth direction of the wellbore 12, more than two guide positioning rings 15 are installed in the wellbore 12. A plurality of magnetic sensors are installed at equal intervals along the circumferential direction of the guide positioning ring 15, and the magnetic sensors are connected to the ground computer. During the secondary directional hole drilling, a rotating magnetic beacon 17 is first installed between the drill rod 2 of the well raising rig 5 and the guide hole drill bit 1. The drill rod 2 drives the rotating magnetic beacon 17 to rotate synchronously. When the rotating magnetic beacon 17 moves, a dynamic rotating magnetic field is generated. The magnetic sensors at various positions in the guide positioning ring 15 continuously detect the coordinate position of the rotating magnetic beacon 17, and the position of the guide hole drill bit 1 is obtained by computer calculation. The correction and adjustment of the ground well raising rig 5 ensure that the secondary directional hole drilling is concentric with the primary directional hole drilling.

[0043] When the guide drill bit 1 is disassembled for the secondary well reaming, the rotating magnetic beacon 17 is retained on the drill pipe 2, and then the reaming drill bit 8 is installed and connected to the rotating magnetic beacon 17. Similarly, during the secondary well reaming, the position of the secondary well reaming drill bit 8 is detected by the rotating magnetic beacon 17 and the magnetic sensor, and the correction adjustment of the ground well reaming rig 5 is used to ensure that the secondary well reaming is concentric with the first well reaming, thereby ensuring the forming quality of the well wall 16.

[0044] In step A, while a directional hole drilling is being carried out, the required reaming drill bit 8 is transported to a designated position in the tunnel 9 to improve the construction efficiency.

[0045] When filling concrete 13, at the initial filling, the concrete pouring tank truck 14 enters the tunnel 9, and the delivery pipe of the concrete pouring tank truck 14 penetrates into the shaft 12 from the bottom of the shaft bottom support plate 10, and the concrete 13 is filled from bottom to top. When filling concrete into the shaft 12 in the tunnel 9, after each filling, the delivery pipe inserted into the shaft 12 is moved upward for a distance to carry out the next filling work. When the lower half of the shaft 12 is filled, the delivery pipe inserted into the shaft 12 is pulled out, and the shaft bottom support plate is sealed. 10; when the height of the concrete 13 is close to the ground, the concrete 13 is stopped from being filled into the shaft 12 from the concrete pouring tanker 14 in the tunnel 9, and the concrete is directly filled into the shaft 12 by the concrete pouring tanker 14 on the ground until the shaft 12 is full of the concrete 13; due to the use of segmented filling from bottom to top, the lower layer of concrete 13 has a longer solidification time than the upper layer of concrete 13 in the same period of time, and has a higher strength than the upper layer of concrete 13, and can play a role of auxiliary support.

[0046] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A fully mechanized wellbore construction method based on reverse drilling technology, characterized in that: The following steps are involved: Step A: primary directional guide hole drilling: a raise boring machine (5) is arranged on the ground, a guide hole drill bit (1) is installed on the end of a drill rod (2) of the raise boring machine (5), and a primary directional guide hole is drilled downward from the ground until the primary directional guide hole is connected to the tunnel (9); Step B: primary wellbore expansion: after the pilot drill bit (1) penetrates the stratum and enters the tunnel (9), the pilot drill bit (1) is removed and then the expansion drill bit (8) is installed, the wellbore drilling machine (5) is started, and wellbore expansion construction is performed, and after the wellbore expansion construction, a wellbore (12) is formed; Step C: Well bottom sealing: After the wellbore (12) is constructed and the reaming drill bit (8) leaves the ground, a well bottom support plate (10) is installed at the well bottom of the wellbore (12), and the well bottom support plate (10) is supported by a support column (11) to seal the well bottom of the wellbore (12); Step D: Shaft filling: concrete (13) is filled into the shaft (12) in sections by a concrete pouring tanker (14). While the concrete (13) is being filled, a guide positioning ring (15) is coaxially installed in the shaft (12) until the shaft (12) is filled with concrete (13); Step E: secondary directional guide hole drilling: when the concrete (13) is cured to a specified strength, the bottom support plate (10) and the support column (11) are removed, and a secondary directional guide hole drilling is performed using a raised well drilling machine (5) on the ground until the guide hole drill bit (1) drills through the concrete (13) and enters the tunnel (9), completing the secondary directional guide hole drilling and forming a secondary directional guide hole in the concrete (13); Step F: Secondary backhole expansion: Remove the pilot drill bit (1) in the tunnel (9) and replace it with a reaming drill bit (8) with a smaller diameter than the shaft (12). Start the backhole drilling machine (5). On the basis of the secondary directional pilot hole, perform secondary backhole expansion in the concrete (13). The concrete (13) not cut off by the reaming drill bit (8) forms the shaft wall (16) until the reaming drill bit (8) is drilled out from the ground surface, and the construction is completed.

2. A fully mechanized wellbore construction method based on reverse drilling technology according to claim 1, characterized in that: In step E, during the secondary directional drilling, a rotating magnetic beacon (17) is first installed between the drill rod (2) of the raise boring machine (5) and the guide drill bit (1), and the drill rod (2) drives the rotating magnetic beacon (17) to rotate synchronously. When the rotating magnetic beacon (17) moves, the guide positioning ring (15) detects the coordinate position of the rotating magnetic beacon (17).

3. A fully mechanized wellbore construction method based on reverse drilling technology according to claim 2, characterized in that: In step F, when the pilot drill bit (1) is disassembled for secondary back-reaming, the rotating magnetic beacon (17) is retained on the drill pipe (2), and then the reaming drill bit (8) is installed and connected to the rotating magnetic beacon (17).

4. A fully mechanized wellbore construction method based on reverse drilling technology according to claim 3, characterized in that: The outer wall of the guide positioning ring (15) fits the inner wall of the wellbore (12), and in the depth direction of the wellbore (12): more than two guide positioning rings (15) are installed in the wellbore (12); and magnetic sensors are installed in the guide positioning ring (15) along its circumferential direction.

5. A fully mechanized wellbore construction method based on raise drilling technology according to claim 1, characterized in that: In step A, while a directional hole drilling is being carried out, the required reaming drill bit (8) is transported to a designated position in the tunnel (9).

6. A fully mechanized wellbore construction method based on raise drilling technology according to claim 1, characterized in that: In step B, when the reaming drill bit (8) drills to 2 to 5 m before the concrete foundation on the ground surface, the drilling pressure and rotation speed are reduced, and the deformation and displacement of the ground surface are observed to ensure that the reaming drill bit (8) drills out of the wellbore (12) safely.

7. A fully mechanized wellbore construction method based on raise drilling technology according to claim 1, characterized in that: In step D, the height of each section of concrete (13) filling is 3 to 5 meters.

8. A fully mechanized wellbore construction method based on raise drilling technology according to claim 7, characterized in that: When filling the concrete (13), at the initial filling, the concrete pouring tank truck (14) enters the tunnel (9), and the delivery pipe of the concrete pouring tank truck (14) penetrates into the shaft (12) from the bottom of the shaft bottom support plate (10), and the concrete (13) is filled section by section from bottom to top.

9. A fully mechanized wellbore construction method based on raise drilling technology according to claim 8, characterized in that: When filling the concrete (13), when the height of the concrete (13) approaches the ground, the concrete (13) is stopped from being filled into the shaft (12) from the concrete pouring tank truck (14) in the tunnel (9), and the concrete (13) is directly filled into the shaft (12) by the concrete pouring tank truck (14) on the ground until the shaft (12) is filled with concrete (13).

10. A fully mechanized wellbore construction method based on raise drilling technology according to claim 9, characterized in that: In step D, the concrete (13) uses low-grade C30 concrete.

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