Method for deep pipe cutting of a filling borehole casing using a drilling rig

Abstract

The present application relates to non-coal mine underground mining, geological disaster control technical field, specifically relates to a kind of filling drilling casing deep pipe cutting method using drilling machine.The present application includes the following steps: S1, construction drilling, S2, making filling scheme, S3, empty area filling construction and filling height control, S4, drill pipe cutter production, S5, pipe cutting operation, S6, new found empty area filling operation and hole sealing.The present application designs a kind of drill pipe cutter structure, carries out three times cutting, and the casing is broken into two sections, to ensure that casing is smoothly separated;Filling casing deep pipe cutting is carried out using drilling machine, and filling casing is successfully cut in the middle, without needing to construct new drilling hole, to realize that one filling drilling hole fills upper and lower two empty areas;Reduce construction engineering quantity and engineering investment, shorten construction period, improve construction efficiency, while also reducing production cost.

Description

Technical Field

[0001] This invention relates to the fields of underground mining in non-coal mines and geological disaster management, specifically to a method for deep cutting of borehole casing using a drilling rig. Background Technology

[0002] To ensure the safety of underground voids, the government is carrying out filling and remediation work on unfilled goaf areas within its jurisdiction. A survey revealed that some goaf areas in the area had not been filled, the operating entities were no longer in operation, and data on the goaf areas was incomplete. During the filling drilling process to complete the goaf remediation project, a new goaf area was discovered above the original goaf area, outside the designed area. To prevent geological disasters, this newly discovered goaf area needs to be filled and remediated. Summary of the Invention

[0003] The technical problem to be solved by this invention is: how to use a drilling rig to cut the casing at a depth of 102 meters underground without the need for additional filling boreholes, so as to fill the upper and lower empty areas with the same filling borehole, thereby reducing the amount of drilling work, saving construction costs, and shortening the construction period.

[0004] The technical solution of this invention is as follows:

[0005] A method for deep casing cutting in a filling borehole using a drilling rig includes the following steps:

[0006] S1. Construction drilling: Drilling is carried out from the surface using rotary drilling technology, with bentonite slurry for wall protection, then casing is installed and cement is used to fix the casing; continue drilling using down-the-hole hammer drilling technology, then casing is installed; if a new void is discovered, continue drilling to the designed void position of the final hole.

[0007] S2. Formulate a filling plan: First, fill the lower designed void area and control the filling height. Then, cut the pipe at the height of the newly discovered void area in the upper part, and then carry out filling construction on the newly discovered void.

[0008] S3. Void filling construction and filling height control: Accurate control is carried out based on the designed filling volume and the actual filling volume. The filling height is continuously measured during the filling process to accurately control the filling height. It is necessary to ensure that the filling reaches the top and that the slurry level of the lower designed void filling material is not higher than the bottom of the casing.

[0009] S4. Drill rod cutting tool manufacturing: The drill rod is made of alloy material, which is not easy to bend. The bottom section of the drill rod is made of arc chord rod. After the arc chord rod is baked at high temperature with an oxy-acetylene flame, it is bent into a certain arc by a road bending machine. An alloy cutting tool is welded along the end of the arc chord rod.

[0010] S5. Pipe Cutting Operation: Utilize the drilling rig to continuously rotate the drill rod cutter, allowing the alloy cutter to continuously cut the inner wall of the casing until it is completely severed. This includes the following steps:

[0011] S51: Perform the first cut with the alloy cutter along the lowest part of the sleeve, and mark it as the first cutting position;

[0012] S52: Move 20cm upward along the sleeve to perform the second cut with the alloy cutter, and mark it as the second cutting position;

[0013] S53: Continue moving upwards along the sleeve by 20cm to perform the third cut with the alloy cutter, marking it as the third cutting position;

[0014] S6. Filling and sealing of newly discovered voids: After the pipe is cut, the newly discovered voids in the upper part are filled until they reach the ground surface, and then the voids are sealed.

[0015] Optionally, in the construction drilling of S1, a ￠325mm hole is drilled from the ground surface to 15.3m, and then a ￠219mm casing is installed; below 15.3m, a ￠180mm hole is drilled to 85~102m, and then a ￠108mm casing is installed; from 102m of the newly discovered void, drilling continues to 132m of the designed void location.

[0016] Optionally, in the filling scheme of S2, the height of the newly discovered void is 5m, the newly discovered void is located above the designed void, and the distance between the newly discovered void and the designed void is 30m.

[0017] Optionally, in the formulation of the filling scheme in S2, the newly discovered void and the designed void need to meet the filling connection requirements. After technical and economic analysis, it is decided to use the same casing to fill the two voids at the same time.

[0018] Optionally, in the pipe cutting operation of S5, since the pipe cutting gap is small, although two cuts can cut the sleeve, the broken pipe cannot be removed from the sleeve. Therefore, it is necessary to cut three times at different positions to break the sleeve into two sections before the broken pipe can be removed.

[0019] Optionally, in the fabrication of the drill pipe cutter in S4, the drill pipe cutter includes a drill pipe, an arc chord extending downward along the drill pipe, an alloy cutter welded to the end of the arc chord, and a pad installed at the bend of the arc chord; wherein:

[0020] The drill rod is made of alloy material and rotates continuously under the drive of the drilling rig;

[0021] The arc chord bar, bent into a certain arc, with the arc chord height not exceeding 90mm, is used to bring the alloy cutter into contact with the sleeve;

[0022] An alloy cutting tool is welded to the end of the arc chord bar. The welding position is opposite to the bending direction of the arc chord bar, and the end of the arc chord bar extends outward by a certain length.

[0023] The pad is made of elastic, high-temperature resistant material. The pad is welded at the highest point of the drill rod's curvature, and the pad and the alloy cutter are located on the same vertical plane.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] By using a drilling rig to perform deep casing cutting, the casing was successfully cut in the middle without the need to drill a new hole. This allows for the filling of two empty areas with a single filling borehole, reducing the amount of construction work and investment, shortening the construction period, improving construction efficiency, and also reducing production costs. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 This is a schematic diagram of the filling borehole structure of the present invention.

[0029] Figure 3 This is a schematic diagram of the drill pipe cutter structure of the present invention.

[0030] Figure 4 yes Figure 3 A magnified view of a portion of the image.

[0031] In the diagram: 1. Casing; 2. Newly discovered void; 3. Design void; 5. Drill pipe; 6. Arc chord rod; 7. Alloy cutter; 8. Spacer block; 9. First cutting position; 10. Second cutting position; 11. Third cutting position. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0033] Example 1

[0034] like Figure 1 As shown, the present invention provides a method for deep casing cutting in a filling borehole using a drilling rig, comprising the following steps:

[0035] S1. Construction Drilling: Drill a 325mm borehole from the surface to 15.3m. Since this section belongs to Quaternary strata with weathered rock interbedded, rotary drilling (coring) was used. Bentonite was used for wall slurry preparation, followed by the installation of a 219mm casing (1), which was then cemented in place. Below 15.3m, the bedrock is relatively intact, so down-the-hole hammer drilling was used to construct a 180mm borehole and install a 108mm casing (1). A new void was discovered between 85.1 and 102.8m, so drilling continued to 132.2m (the final hole design location for filling the void). Figure 2 As shown;

[0036] S2. Formulate a filling plan: The newly discovered goaf is located above the designed filling goaf. To ensure that the filling of the upper and lower goafs is connected to the roof, it was decided, based on technical and economic analysis, to use the same casing 1 to fill both goafs simultaneously. The construction plan is as follows: first fill the lower goaf, control the filling height, then cut the casing at the height of the newly discovered goaf 2, and then fill the new goaf.

[0037] S3. Void filling construction and filling height control: Accurately control the filling volume according to the design and actual filling volume. Continuously measure the filling height during the filling process to accurately control the filling height. Ensure that the filling reaches the top and that the slurry level of the filling material in the lower void does not exceed the lower end of the casing 1.

[0038] S4. Drill rod 5 cutting tool manufacturing: Drill rod 5 is made of alloy material, which is not easy to bend. The bottom section of drill rod 5 is made of thinner drill rod 5. Then, it is baked at high temperature with an oxy-acetylene flame. The drill rod 5 is bent to a certain degree of curvature using a road bending machine. The arc chord height should not exceed 90mm. Finally, the alloy cutting tool 7 is welded to the end of the drill rod 5.

[0039] S5. Pipe Cutting Operation: The drilling rig rotates continuously, driving the drill rod 5 to rotate continuously, allowing the alloy cutter 7 to continuously cut the inner wall of the casing 1 until it is severed. Due to the small cutting gap, although two cuts can sever the casing 1, the severed pipe cannot detach from the filling main pipeline. Therefore, it is necessary to cut three times at different locations to break the casing 1 into two sections before the severed pipe can be detached. Each section of pipe is approximately 20cm high. The cutting begins at the bottom, proceeding upwards, and finally at the top.

[0040] S6. Filling and sealing of the upper void: After the pipe is cut, the upper void is filled until it reaches the ground surface, and then the hole is sealed.

[0041] Working Principle: The purpose of this invention is to fill newly discovered goaf areas using existing filling boreholes. The deep-cutting method for the filling borehole casing 1 specifically includes: when the filling borehole reaches 102 meters, a new goaf area is discovered, with a height of approximately 5 meters. A designed goaf area 3 is located at a borehole depth of 132 meters, and the distance between the designed goaf area 3 and the newly discovered goaf area is 30 meters. During filling, casing 1 needs to be cut at the 102-meter position to fill the newly discovered goaf area. A self-made cutter is used, cutting the casing 1 three times at the 102-meter mark to sever it. This cutting method allows one casing 1 to fill two goaf areas (upper and lower). The cutter is simple to manufacture and operate. This achieves the goals of saving production costs, shortening the construction period, and improving production efficiency.

[0042] Example 2

[0043] Based on Example 1, such as Figure 1 and Figure 3 As shown, the principle of pipe cutting is as follows: When the bent drill rod 5 rotates within the confined space of the casing 1, the end of the drill rod 5 experiences relative friction with the inside of the casing 1, causing scratches on the pipe wall. A cutting tool is welded to the end of the drill rod 5 that causes the scratches on the pipe wall, allowing the cutting tool to have a relative cutting effect on the casing 1, thus achieving the purpose of pipe cutting.

[0044] Pipe cutting solution: Due to the small gap in the pipe cutting slit, although two cuts can cut through the sleeve 1, the broken pipe cannot be removed from the filling main pipeline. Therefore, three cuts are needed on the sleeve 1 to break it into two sections before the broken pipe can be removed.

[0045] Pipe cutting operation: The drilling rig rotates continuously, causing the drill rod 5 to rotate continuously, allowing the alloy cutting blade 7 to continuously cut the inner wall of the casing 1 until it is completely cut. Then, the next section of pipe is cut. The bottom section is cut first, then upwards, and finally the top section is cut. Figure 4 As shown, the pipe cutting operation specifically includes the following steps:

[0046] S51: Perform the first cut with the alloy cutter 7 along the lowest position of the sleeve 1, and mark it as the first cutting position 9;

[0047] S52: Move 20cm upward along sleeve 1 to perform the second cut of alloy cutter 7, marked as the second cutting position 10;

[0048] S53: Continue moving upwards along sleeve 1 for 20cm to perform the third cut of alloy cutter 7, marked as the third cut position 11.

[0049] Example 3

[0050] Based on Example 2, such as Figure 3As shown, the drill rod 5 is made of alloy material, which is not easy to bend. The bottom section of the drill rod 5 is made of thinner drill rod 5. Then, it is baked at high temperature with an oxy-acetylene flame. The drill rod 5 is bent to a certain degree of curvature using a bending machine. The pad block 8 is welded at the highest point of the curvature of the drill rod 5. Finally, the alloy cutter 7 is welded to the end of the drill rod 5.

[0051] In the fabrication of the drill rod 5 cutter, the drill rod 5 cutter includes a drill rod 5, an arc chord rod 6 extending downward along the drill rod 5, an alloy cutter 7 welded to the end of the arc chord rod 6, and a pad block 8 installed at the bend of the arc chord rod 6; wherein:

[0052] Drill rod 5, made of alloy material, rotates continuously under the drive of the drilling rig;

[0053] The arc chord 6 is bent into a certain arc, and the arc chord height cannot exceed 90mm. It is used to bring the alloy cutter 7 into contact with the sleeve 1.

[0054] The alloy cutter 7 is welded to the end of the arc chord 6. The welding position is opposite to the bending direction of the arc chord 6, and the end of the arc chord 6 extends outward by a certain length.

[0055] The pad 8 is made of elastic high-temperature resistant material. The pad 8 is welded at the high point of the arc of the drill rod 5, and the pad and the alloy cutter 7 are located on the same vertical plane.

[0056] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A method for deep casing cutting in a filling borehole using a drilling rig, characterized in that, Includes the following steps: S1. Construction drilling: Drilling is carried out from the surface using rotary drilling technology, with bentonite slurry for wall protection, and then casing (1) is installed and cement is used to fix the casing; continue drilling using down-the-hole hammer technology, and then casing (1) is installed; when a new void (2) is discovered, continue drilling to the designed void (3) position of the final hole. S2. Formulate a filling plan: First fill the lower designed void (3) and control the filling height. Then cut the pipe at the height of the newly discovered void (2) in the upper part and then carry out filling construction on the newly discovered void. S3. Construction and control of filling height of void area: Accurate control is carried out according to the design filling volume and the actual filling volume. The filling height is continuously measured during the filling process to accurately control the filling height. It is necessary to ensure that the filling reaches the top and that the slurry surface of the filling material in the lower void area (3) is not higher than the bottom of the casing (1). S4. Drill rod cutter manufacturing: The drill rod (5) is made of alloy material and is not easy to bend. The bottom section of the drill rod (5) adopts an arc chord rod (6). After the arc chord rod (6) is baked at high temperature with an oxy-acetylene flame, it is bent into a certain arc by a road bending machine. An alloy cutter (7) is welded along the end of the arc chord rod (6). S5. Pipe cutting operation: Use the drilling rig to drive the drill rod cutter to rotate continuously, so that the alloy cutter (7) continuously rotates and cuts the inner wall of the casing (1) until it is cut off, including the following steps: S51: Make the first cut with the alloy cutter (7) along the lowest position of the sleeve (1), and mark it as the first cutting position (9); S52: Move 20cm upward along the sleeve (1) and make the second cut with the alloy cutter (7), marking it as the second cutting position (10); S53: Continue moving upwards for 20cm along the sleeve (1) to make the third cut with the alloy cutter (7), and mark it as the third cut position (11); S6. Filling and sealing of newly discovered void (2): After the pipe is cut, the newly discovered void (2) in the upper part is filled until it reaches the ground surface, and then the hole is sealed.

2. The method for deep casing cutting using a drilling rig for filling boreholes as described in claim 1, characterized in that, In the construction drilling of S1, a ￠325mm hole is drilled from the ground surface to 15.3m, and then a ￠219mm casing (1) is installed; below 15.3m, a ￠180mm hole is drilled to 85~102m, and then a ￠108mm casing (1) is installed; from 102m of the newly discovered void (2), drilling continues to 132m of the designed void (3).

3. The method for deep casing cutting using a drilling rig as described in claim 2, characterized in that, In the filling scheme of S2, the height of the newly discovered void (2) is 5m, the newly discovered void (2) is located above the designed void (3), and the distance between the newly discovered void (2) and the designed void (3) is 30m.

4. The method for deep casing cutting using a drilling rig as described in claim 1, characterized in that, In the filling scheme of S2, the newly discovered void (2) and the designed void (3) need to meet the filling connection requirements. After technical and economic analysis, it was decided to use the same casing (1) to fill the two voids at the same time.

5. The method for deep casing cutting using a drilling rig for filling boreholes as described in claim 1, characterized in that, In the pipe cutting operation of S5, since the pipe cutting gap is small, although two cuts can cut the sleeve (1), the broken pipe cannot be removed from the sleeve (1). Therefore, it is necessary to cut three times at different positions to break the sleeve (1) into two sections before the broken pipe can be removed.

6. The method for deep casing cutting using a drilling rig for filling boreholes as described in claim 1, characterized in that, In the fabrication of the drill pipe cutter in S4, the drill pipe cutter includes a drill pipe (5), an arc chord rod (6) extending downward along the drill pipe (5), an alloy cutter (7) welded to the end of the arc chord rod (6), and a pad (8) installed at the bend of the arc chord rod (6); wherein: The drill rod (5) is made of alloy material and rotates continuously under the drive of the drilling machine; The arc chord bar (6) is bent into a certain arc, and the arc chord height cannot be greater than 90mm. It is used to bring the alloy cutter (7) into contact with the sleeve (1). The alloy cutter (7) is welded to the end of the arc chord (6), with the welding position opposite to the bending direction of the arc chord (6), and the end of the arc chord (6) extends outward by a certain length. The pad (8) is made of elastic high-temperature resistant material. The pad (8) is welded at the high point of the arc of the drill rod (5), and the pad (8) and the alloy cutter (7) are located on the same vertical plane.

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