A fully mechanized wellbore construction method based on raise drilling technology

Abstract

The present invention discloses a fully mechanized wellbore construction method based on raise drilling technology. First, a raise drilling rig is set up on the ground, and a pilot drill bit is installed on the end of the drill pipe of the raise drilling rig. A directional guide hole is drilled downward from the ground to form a primary directional guide hole. Then, the pilot drill bit is removed and replaced with a reaming drill bit to perform a primary reaming operation to form a wellbore. Concrete is then filled into the wellbore. When the concrete setting strength reaches a specified strength, a secondary directional guide hole is drilled into the concrete by the raise drilling rig on the ground until the concrete is drilled through. The pilot drill bit is then removed and replaced with a secondary raise drilling bit with a smaller diameter to perform a secondary reaming operation. The fully mechanized wellbore construction method of the present invention realizes the one-time formation of the wellbore support and the wellbore. The wellbore support construction does not require manual work in the wellbore, thus avoiding the problem of safety hazards in the wellbore support construction. It achieves "drilling without going down the well", improves construction safety, and can also improve the quality of the wellbore support.

Description

Technical Field

[0001] The present invention relates to the technical field of vertical shaft excavation, in particular to a fully mechanized shaft construction method based on raise well drilling technology. Background Art

[0002] The raise boring method uses a raise boring rig as the primary equipment, and forms a wellbore through processes such as pilot hole drilling, reaming drilling, and side support. The typical construction method involves first drilling a pilot hole from top to bottom, extending the drill rod to the bottom of the borehole, connecting it to the underlying roadway or tunnel. A large-diameter reaming drill bit is then attached to the lower portion, allowing for upward reaming. After reaming is complete and support is provided, the 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 current original intention of "drilling 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 drilling technology, which avoids manual downhole construction work and improves construction safety.

[0005] To solve the above technical problems, the present invention provides the following technical solution: a fully mechanized wellbore construction method based on raise drilling technology, comprising the following steps:

[0006] Step A: Primary directional guide hole drilling: a raise boring machine is set up on the ground, a pilot hole drill bit is installed on the end of the drill pipe 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 to the roadway;

[0007] Step B: Primary raise hole reaming: After the pilot drill bit penetrates the stratum and enters the tunnel, the pilot drill bit is removed and the reaming drill bit is installed. The raise drilling machine is started to carry out raise hole reaming construction. After the raise hole reaming construction, a wellbore is formed;

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

[0009] Step D: Shaft Filling: Concrete is filled into the shaft in sections using a concrete pouring tanker. While filling the concrete, a guide positioning ring is coaxially installed in the shaft until the shaft is full of concrete. By filling the shaft with concrete, the outward pressure provided by the concrete can counteract the pressure of the surrounding soil layer. After the concrete solidifies, the concrete and the surrounding soil layer can be tightly bonded. After the concrete solidifies, there is a certain amount of outward supporting prestress, 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 may cause 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: After the concrete has been cured to the specified strength, the bottom support plate and support columns are removed, and a raise borer on the ground is used to perform secondary directional pilot hole drilling until the pilot drill bit penetrates the concrete and enters the roadway. This completes the secondary directional pilot hole drilling and forms a secondary directional pilot hole in the concrete.

[0011] Step F: Secondary Raise-Bore Reaming: Remove the pilot drill bit in the tunnel and replace it with a reaming drill bit smaller than the shaft diameter. The raise-boring rig is then activated. Based on the secondary directional guide hole, a secondary raise-boring operation is performed within the concrete. The concrete not removed by the reaming drill bit forms the shaft wall until the reaming drill bit emerges from the surface, completing the construction. Traditional shaft wall construction involves spraying or applying a single layer of support layer using a mold. This layer lacks prestressed support and results in relatively poor overall support strength and effectiveness. The shaft wall formed by the present invention is a single-piece structure with improved inner wall flatness and roundness, providing a higher support effectiveness.

[0012] In the above-mentioned fully mechanized wellbore construction method based on raise drilling technology, in step E, during the secondary directional guide drilling, a rotating magnetic beacon is first installed between the drill rod and the guide drill bit of the raise drilling rig. 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 pilot drill bit is removed during the secondary reverse drilling, the rotating magnetic beacon is retained on the drill pipe, and then the reaming 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 wellbore construction method based on raise drilling technology, in step A, the required reaming drill bit is transported to a specified position in the tunnel while performing a directional guide drilling.

[0016] In the above-mentioned fully mechanized wellbore construction method based on reverse drilling technology, in step B, when the reaming drill bit drills 2 to 5 meters in front of 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 bit safely drills out of the wellbore.

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

[0018] The above-mentioned fully mechanized wellbore 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 passes through the bottom of the well bottom support plate into the wellbore, and concrete is filled section by section from bottom to top.

[0019] The above-mentioned fully mechanized wellbore construction method based on reverse drilling technology, when filling concrete, when the concrete height is close to the ground, stops filling concrete into the wellbore from the concrete pouring tanker in the tunnel, and directly fills concrete into the wellbore through the concrete pouring tanker on the ground until the wellbore is full of concrete.

[0020] In the above-mentioned fully mechanized shaft construction method based on the raise 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 the one-time formation of well wall support and wellbore. Well wall support construction does not require manual work in the well, thus avoiding the problem of safety hazards in well support construction, realizing "drilling a well without going down the well", improving construction safety, and at the same time improving the quality of well wall support. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0025] Figure 3 Schematic diagram of the present invention after the one-step well enlargement construction is completed;

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

[0027] Figure 5 A schematic diagram of the method of filling a wellbore with concrete from the ground according to the present invention;

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

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

[0030] Figure 8 Schematic diagram of the secondary well enlargement 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 tank; 5-raised well drilling rig; 6-crushed rock debris; 7-rock loader; 8-reaming drill bit; 9-tunnel; 10-bottom well support plate; 11-support column; 12-wellbore; 13-concrete; 14-concrete pouring tanker; 15-guide positioning ring; 16-well wall; 17-rotating magnetic beacon. DETAILED DESCRIPTION

[0032] In the fully mechanized wellbore construction method based on the raise 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 pilot hole drill bit 1 is installed on the end of the drill rod 2 of the raise boring machine 5. The pilot hole drill bit 1 uses a three-cone drill bit to break the rock. The drill rod 2 has a diameter of 328 mm. A primary directional guide hole is drilled downward from the ground to form a primary directional guide hole with a diameter of 350-370 mm until the primary directional guide hole is connected to the roadway 9.

[0034] Step B: Primary Raise-Well Reaming: After the pilot drill bit 1 penetrates the stratum and enters the tunnel 9, a raise-well reaming operation with a diameter of 4 m is carried out. Through mutual communication and cooperation between the surface and underground wells, the pilot drill bit 1 is first removed from the tunnel 9, and then the reaming drill bit 8 is installed. Subsequently, the raise-well drilling rig 5 is started to carry out the raise-well reaming construction. After the raise-well reaming construction, a wellbore 12 with a diameter of 4 m is formed. When the reaming drill bit 8 reaches 2 to 5 m in front of 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 bit 8 safely drills out of the wellbore 12;

[0035] Step C: Bottom Sealing: After the wellbore 12 is constructed and the reaming drill bit 8 leaves the ground, a bottom support plate 10 is installed at the bottom of the wellbore 12 and supported by support columns 11 to seal the bottom of the wellbore 12.

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

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

[0038] Step F: Secondary Raising: The diameter of the secondary raising hole is 3 m. The pilot drill bit 1 is removed from the tunnel 9 and replaced with a reaming drill bit 8 with a diameter of 3 m. The diameter of the secondary reaming drill bit 8 is smaller than the diameter of the wellbore. The raise drilling rig 5 is started. Based on the secondary directional guidance, the secondary raising hole is expanded in the concrete 13. The concrete 13 not removed by the reaming drill bit 8 forms the well wall 16 until the reaming drill bit 8 emerges from the surface, completing the construction.

[0039] The construction process requires that the first and second rounds of well reaming be coaxial. The guide positioning ring 15 can make the two rounds of well reaming 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 wellbore support thickness, δ is expressed as the wellbore deflection rate, and h is the wellbore depth.

[0042] The outer wall of the guide positioning ring 15 fits 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 guide drilling, a rotating magnetic beacon 17 is first installed between the drill rod 2 and the pilot drill bit 1 of the raise boring rig 5. 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 pilot drill bit 1 is obtained by computer calculation. The correction and adjustment of the ground raise boring rig 5 are then performed to ensure that the secondary directional guide drilling is concentric with the primary directional guide drilling.

[0043] When the pilot drill bit 1 is removed during the secondary raise-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 raise-well reaming, the position of the secondary raise-well reaming drill bit 8 is detected by the rotating magnetic beacon 17 and the magnetic sensor, and the surface raise-well drilling rig 5 is corrected and adjusted to ensure that the secondary raise-well reaming is concentric with the primary raise-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 construction efficiency.

[0045] When filling concrete 13, during the initial filling, the concrete pouring tanker 14 enters the tunnel 9, and the delivery pipe of the concrete pouring tanker 14 penetrates into the shaft 12 from the bottom of the well bottom support plate 10, and fills the concrete 13 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 well bottom support plate is sealed. 10; when the height of the concrete 13 is close to the ground, stop filling the concrete 13 into the shaft 12 from the concrete pouring tanker 14 in the tunnel 9, and directly fill the concrete into the shaft 12 through the concrete pouring tanker 14 on the ground until the shaft 12 is full of concrete 13; due to the adoption of segmented filling from bottom to top, the lower layer of concrete 13 takes longer to solidify than the upper layer of concrete 13 in the same period of time, has 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 clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the claims of this patent application.

Claims

1. A fully mechanized wellbore construction method based on raise drilling technology, characterized in that: The following steps are involved: Step A: Drilling a primary directional guide hole: a raise drilling rig (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 drilling rig (5), and a primary directional guide hole is drilled downward from the ground until the primary directional guide hole is connected to the roadway (9); Step B: One-time back-well reaming: After the pilot drill bit (1) penetrates the ground and enters the tunnel (9), the pilot drill bit (1) is removed and the reaming drill bit (8) is installed. The back-well drilling machine (5) is started to carry out back-well reaming construction. After the back-well reaming construction, a wellbore (12) is formed. Step C: Sealing the bottom of the well: After the wellbore (12) is constructed and the reaming drill bit (8) leaves the ground, a bottom support plate (10) is installed at the bottom of the wellbore (12), and the bottom support plate (10) is supported by support columns (11) to seal the bottom of the wellbore (12); Step D: Wellbore filling: concrete (13) is filled into the wellbore (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 wellbore (12) until the wellbore (12) is filled with concrete (13); Step E: Secondary directional guide hole drilling: After 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 ground raise boring machine (5) until the guide hole drill bit (1) penetrates 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 back-well reaming: 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 back-well drilling machine (5). On the basis of the secondary directional pilot hole, perform a secondary back-well reaming operation 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, completing the construction. In step E, during secondary directional drilling, a rotating magnetic beacon (17) is first installed between the drill rod (2) and the pilot drill bit (1) of the raise drilling rig (5), 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); 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); 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); and magnetic sensors are installed in the guide positioning ring (15) along its circumferential direction.

2. 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).

3. 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) reaches 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) is safely drilled out of the wellbore (12).

4. 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.

5. A fully mechanized wellbore construction method based on raise drilling technology according to claim 4, characterized in that: When filling the concrete (13), at the initial filling time, the concrete pouring tank truck (14) enters the tunnel (9), and the delivery pipe of the concrete pouring tank truck (14) penetrates the shaft (12) from the bottom of the shaft bottom support plate (10), and the concrete (13) is filled from bottom to top in sections.

6. A fully mechanized wellbore construction method based on raise drilling technology according to claim 5, 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 tanker (14) in the tunnel (9), and the concrete is directly poured into the shaft (12) by the concrete pouring tanker (14) on the ground until the shaft (12) is filled with the concrete (13).

7. A fully mechanized wellbore construction method based on raise drilling technology according to claim 6, characterized in that: In step D, the concrete (13) is low-grade C30 concrete.

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