Drilling and coal discharging drill rod and drilling and coal discharging construction method

Abstract

The invention provides a drilling and coal discharging drill rod and a drilling and coal discharging construction method.The drilling and coal discharging drill rod comprises a plurality of drill rod bodies which are connected end to end, every two adjacent drill rod bodies are fixedly connected through a connecting piece, the multiple drill rod bodies are each of a hollow structure, and the end of the drill rod body at the foremost end is of a sealing structure; a water spraying hole communicated with the middle of the drill rod body at the foremost end is formed in one side of the drill rod body at the foremost end in the radial direction of the drill rod body, a high-pressure water pipeline connector is connected to the drill rod body at the rearmost end, spiral blades are arranged on the peripheries of the drill rod bodies respectively, and a plurality of prismatic pieces are evenly arranged on the upper side faces of the spiral blades at intervals in the spiral line direction of the spiral blades. A plurality of sawteeth are evenly arranged on the side, away from the drill rod body, of the spiral blade at intervals along a spiral line. And the success rate, the coal breaking efficiency, the coal discharging efficiency and the safety of long drill hole construction in a complex coal seam are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of coal mining technology, specifically relating to a drilling rod for coal drainage and a method for drilling coal drainage construction. Background Technology

[0002] In coal mine production and disaster management, long boreholes, often tens or even hundreds of meters long, are drilled using drill rods. When encountering soft coal or soft rock geological conditions, problems such as increased torque and difficulty in removing slag arise. Drilling in high-gas coal seams can also lead to stuck drill bits, drill bit jacking, and blowouts. Poor slag removal results in dust accumulation and frictional heat within the borehole, which can easily trigger abnormal gas outbursts and injuries, severely impacting drilling efficiency and construction safety.

[0003] While conventional auger drill pipes possess some mechanical slag removal capacity, their primary design purpose is to assist drilling. The depth and slag removal efficiency of the auger blades are limited, and they experience significant resistance and wear under complex borehole conditions. Existing technologies consistently link "coal and rock breaking" and "slag removal" within the same equipment process; failure in either stage directly interrupts the entire "new gas control method." Furthermore, the coal-breaking capacity of the drill pipe is often overlooked, resulting in low efficiency for coal breaking and removal in individual boreholes. For gas control projects involving coal seams, especially soft, high-gas seams, the specific engineering requirement of removing large quantities of coal through boreholes to create pressure relief orifices necessitates a dedicated technology and equipment that can overcome the limitations of traditional processes and fundamentally optimize the slag removal process.

[0004] Therefore, addressing the aforementioned technical bottlenecks, there is an urgent need to invent a novel, specialized drill pipe and its operating method focused solely on coal drainage. This new technology would decouple "efficient borehole formation" from "safe and efficient coal drainage," and couple "drill pipe coal breaking" with "drill pipe coal drainage," thereby significantly improving the success rate, coal breaking efficiency, coal drainage efficiency, and safety of drilling long boreholes in complex coal seams. The implementation of this technology can solve the current problems with drill pipe equipment, providing effective technical equipment for thin coal seam mining and high-gas coal seam disaster management projects, creating significant profit margins for coal enterprises, and possessing significant practical value and broad application prospects. Summary of the Invention

[0005] This invention provides a drilling rod and a drilling method for coal drainage, which significantly improves the success rate, coal breaking efficiency, coal drainage efficiency, and safety of drilling long holes in complex coal seams. The specific solution is as follows: A drilling rod for coal discharge includes multiple drill rod bodies connected end to end. Adjacent drill rod bodies are fixedly connected by connectors. All drill rod bodies are hollow structures, with the end of the foremost drill rod body being sealed. A water spray hole communicating with the middle part is opened radially on one side of the foremost drill rod body. A high-pressure water pipe connector is connected to the last drill rod body. Helical blades are respectively arranged on the outer periphery of the multiple drill rod bodies. Several prismatic plates are evenly spaced on the upper surface of the helical blades along their helical direction. Several serrations are evenly spaced on the side of the helical blades away from the drill rod body along the helical direction.

[0006] Furthermore, the drill rod body has a triangular or polygonal structure.

[0007] Furthermore, the water jets are angled at three different angles to the drill rod shaft: 30°, 60°, and 90°.

[0008] Furthermore, the drill rod body has three lengths: 0.75m, 1m, and 1.5m, and the distance between the water spray hole and the sealing end of the drill rod body is 0.2m-0.5m.

[0009] Furthermore, the drill rod has an outer diameter of 50mm and an inner diameter of 15mm, the spiral blade has an outer diameter of 94mm and an inner diameter of 50mm, and the spiral blade pitch is 0.6-1.2 times the drill rod diameter.

[0010] Furthermore, the tooth spacing of the saw teeth is 3-10mm and the tooth height is 2-6mm.

[0011] Furthermore, the connector includes a plug, a plug groove, a sealing ring, and a positioning bolt. A plug groove is formed in the middle of one end of the drill rod body along its length, and a plug is fixedly connected to the other end. The plug has a connecting hole that communicates with the middle of the drill rod body. A sealing ring is provided on the inner wall of the plug groove. Positioning holes are formed on the plug on both sides of the connecting hole and on both sides of the plug groove. The positioning holes in the plug groove are threaded holes. The plug and the plug groove are fixedly connected by positioning bolts.

[0012] Furthermore, the connector also includes a threaded joint, which is fixedly connected to one end of the drill rod body, and the other end of the drill rod body has an internal thread that is compatible with the threaded joint along its length.

[0013] Furthermore, the spiral blades and saw teeth are made of cemented carbide, and the drill rod body is made of geological alloy steel pipe.

[0014] A method for drilling coal discharge construction includes the following steps: S1: Construction of Rock Roadways: Based on the characteristics of the coal seam, select suitable strata for constructing floor or roof rock roadways. Specifically, floor rock roadways should be prioritized. Floor rock roadways help drain accumulated water or coal slag from the borehole, maximizing the effectiveness of borehole mining. Generally, floor rock roadways should be located in stable rock strata at least 15m away from the coal seam, and the roadway cross-section is typically no less than 10m². S2: Drilling in rock tunnels: Using conventional drilling rigs and drill bits, drilling is carried out according to the designed orientation, inclination and depth until the target coal seam is penetrated or the designed final hole position is reached; S3: Drill rod installation and preparation: Remove all drilling tools from the hole, and then connect the coal discharge drill rods described in this invention in sequence. First, connect the bottom drill rod body with water spray holes, and then slowly feed the drill rods into the formed borehole by connecting them in series through the drilling rig power head or other rotary drive device; S4: Coal Discharge Operation: Start the drilling rig drive unit to allow the coal discharge drill rod to rotate continuously at a certain speed. At this time, in the coal borehole section, the evenly distributed saw teeth will continuously scrape the coal wall or coal particles. The broken coal chunks and powder are forced and continuously transported to the borehole opening under the pushing force of the rotating helical blades, prismatic rod, and prismatic discs, achieving mechanical coal breaking and conveying. In the rock borehole section, the coal discharge drill rod operates with lower resistance to respond to any narrowing of the borehole diameter. S5: Open the high-pressure water hole and carry out coal flushing operation: When it is observed that the coal discharge from the borehole decreases or there is no coal discharge during idling, open the manual water control valve and adjust it to the corresponding pressure according to the coal seam hardness, and carry out coal flushing operation for 1-2 minutes. High-pressure water jets out from the water spray hole at the bottom of the drill rod to hydraulically strip and flush the coal body around the borehole. During the operation, closely observe the coal discharge situation in the borehole. When the slag content of the discharged coal is less than 30%, repeat S4. During this process, operate the drilling rig to make the entire drill rod reciprocate back and forth in the borehole, with the amplitude of movement not less than the thickness of the target coal seam, to ensure that the high-pressure water jet can flush the borehole wall of the entire coal seam thickness. S6: Stop drilling and remove the auger rod: If coal is discharged from the borehole, but the proportion of rock debris is large, exceeding 30%, it indicates that the roof rock has collapsed and mining is considered complete. At this time, drilling can be stopped. If no coal is discharged from the borehole, it is considered that the coal within the borehole control area has been completely mined, which also marks the completion of the borehole coal discharge operation.

[0015] The beneficial effects of this invention are: 1. Innovative Operation Method: The traditional "drilling and slag removal simultaneously" process is innovated into a "first stabilize drilling to form a hole, then perform specialized and efficient coal slag removal and pressure relief" process. High-performance conventional drilling rigs are used to complete the drilling construction, and then specialized coal slag removal drill rods are used for subsequent operations. This allows the single-function drill rod to fully utilize its single function and eliminates the problem of neglecting one aspect while taking into account both slag removal and drilling. 2. Achieving Mechanical Coal Crushing and Efficient Conveying Functions: Coal-crushing saw teeth are evenly distributed on the spiral blades of the drill rod in the coal-bearing section. As the drill rod rotates, it continuously scrapes the coal body from the borehole wall, achieving active coal falling. When the drill rod deforms and necks in the rock-bearing section, the rotation of the drill rod allows the saw teeth to scrape away rock debris from the borehole wall, achieving borehole enlargement and protection. Simultaneously, the optimized spiral blade design ensures that the falling coal slag is efficiently conveyed mechanically.

[0016] 3. Achieve hydraulic coal flushing and efficient conveying functions: By parametrically controlling the water pressure and relating it to the hardness of the coal body, and in conjunction with the reciprocating motion of the drill rod, hydraulic stripping of the coal body around the borehole is achieved. Under the action of the optimized spiral blade rotation, the coal is efficiently conveyed and discharged from the borehole. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the polygonal drill rod of the present invention.

[0019] Figure 3 This is a partial structural diagram of the present invention.

[0020] Figure 4 This is a side sectional view of the present invention.

[0021] Figure 5 for Figure 4 Enlarged view of section A.

[0022] Figure 6 This is a flowchart of the construction method of the present invention.

[0023] Explanation of reference numerals in the attached drawings: 1. Drill rod body; 2. Connector; 201. Insertion joint; 202. Insertion groove; 203. Sealing ring; 204. Positioning bolt; 205. Connecting hole; 3. Water jet hole; 4. Spiral blade; 5. Prism blade; 6. Serration. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0025] See Figure 1-6A drilling rod for coal discharge includes multiple drill rod bodies 1 connected end to end. Adjacent drill rod bodies 1 are fixedly connected by connectors 2. All drill rod bodies 1 are hollow structures. The end of the foremost drill rod body 1 is sealed. A water spray hole 3 communicating with the middle part is opened radially on one side of the foremost drill rod body 1. A high-pressure water pipe connector is connected to the last drill rod body 1. Helical blades 4 are respectively arranged on the outer periphery of the multiple drill rod bodies 1. A number of prismatic pieces 5 are evenly spaced on the upper side of the helical blades 4 along the helical direction. A number of serrations 6 are evenly spaced on the side of the helical blades 4 away from the drill rod body 1 along the helical direction. Specifically, the drill rod body 1 is made of geological alloy steel pipe, while the spiral blades 4 and serrations 6 are made of hard alloy material to improve the overall hardness of the coal discharge drill rod and enhance its wear resistance. Adjacent drill rod bodies 1 are detachably connected by connectors 2. In actual use, the number of connections for the drill rod bodies 1 can be selected according to the length of the borehole. In this case, the connectors 2 can be either threaded or rigid. The design of the water jet holes 3 allows high-pressure water to be sprayed out, thereby hydraulically stripping and scouring the coal on the borehole wall. This mainly serves to wet, assist in crushing, and gently flush the coal, preventing the borehole wall from becoming rapidly unstable due to excessive pressure. The spiral blades 4 are fixed to the drill rod body 1 by welding, while several prismatic blades 5 and several serrations 6 are welded to the outer and upper surfaces of the spiral blades 4. During coal discharge, the drill rod 1 is rotated by the drill rig drive device. Then, with the help of the combination of spiral blades 4, several saw teeth 6, and several prismatic blades 5, the coal blocks and powder are conveyed upwards. Among them, the saw teeth 6 continuously scrape the coal wall or coal particles. The crushed coal blocks and powder are forced and continuously conveyed to the borehole opening by the rotating spiral blades 4 and prismatic blades 5, thereby realizing mechanical coal breaking and conveying. This significantly improves the success rate, coal breaking efficiency, coal discharge efficiency, and safety of drilling long boreholes in complex coal seams.

[0026] The drill rod body 1 has a triangular or multi-faceted structure; specifically, the combination of the axial thrust of the spiral blades 4 and the radial agitation of the rhomboid shape can effectively improve the powder removal capacity.

[0027] The water jet hole 3 is oriented at three different angles to the drill rod body 1: 30°, 60°, and 90°. Specifically, designing the water jet hole 3 with multiple orientations can maximize the water jetting direction along the coal seam layers, producing the best coal breaking effect. In addition, in practical applications, the water jet hole type should be selected according to the existing borehole and the coal seam occurrence.

[0028] The preferred drill rod body 1 has three lengths: 0.75m, 1m, and 1.5m. Depending on the specific application, the distance between the water jet hole 3 and the sealing end of the drill rod body 1 is 0.2m-0.5m.

[0029] The preferred drill rod body 1 has an outer diameter of 50 mm and an inner diameter of 15 mm, the spiral blade 4 has an outer diameter of 94 mm and an inner diameter of 50 mm, and the pitch of the spiral blade 4 is 0.6-1.2 times the diameter of the drill rod body 1.

[0030] The preferred tooth spacing of the saw tooth 6 is 3-10mm and the tooth height is 2-6mm.

[0031] The connector 2 includes a plug 201, a plug groove 202, a sealing ring 203, and a positioning bolt 204. A plug groove 202 is provided in the middle of one end of the drill rod body 1 along its length direction, and a plug 201 is fixedly connected to the other end. The plug 201 has a connecting hole 205 that communicates with the middle of the drill rod body 1. A sealing ring 203 is provided on the inner wall of the plug groove 202. Positioning holes are provided on the plug 201 on both sides of the connecting hole 205 and on both sides of the plug groove 202. The positioning holes in the plug groove 202 are threaded holes. The plug 201 and the plug groove 202 are fixedly connected by the positioning bolt 204. Specifically, both connectors 201 and 202 have a square structure, which makes the connection more secure. Furthermore, connector 201 and the slot 202 have an interference fit, effectively improving rigidity. During installation, simply insert the end of connector 201 into the slot 202 of the next drill rod body 1, then pass the positioning bolt 204 through the positioning hole and tighten it to lock it in the threaded hole within the slot 202. This completes the fixing process, which is convenient and efficient.

[0032] It is worth mentioning that the front end of the drill rod body 1 is a sealed structure, and the rear end is provided with a plug groove 202; one end of the subsequent drill rod body 1 is connected to a plug connector 201, and the other end is provided with a plug groove 202, and the plug connector 201 is connected to the end of the drill rod body 1 on the side opposite to the prism plate 5.

[0033] The connector 2 also includes a threaded joint, which is fixedly connected to one end of the drill rod body 1. The other end of the drill rod body 1 is provided with an internal thread that is compatible with the threaded joint along its length. Specifically, by designing the two ends of the drill rod body 1 as external threaded joints and internal threads respectively, a quick connection can be achieved when connecting the coal discharge drill rod of the present invention.

[0034] A method for drilling coal discharge construction includes the following steps: S1: Construction of Rock Roadways: Based on the characteristics of the coal seam, select suitable strata for constructing floor or roof rock roadways. Specifically, floor rock roadways should be prioritized. Floor rock roadways help drain accumulated water or coal slag from the borehole, maximizing the effectiveness of borehole mining. Generally, floor rock roadways should be located in stable rock strata at least 15m away from the coal seam, and the roadway cross-section is typically no less than 10m². S2: Drilling in rock tunnels: Using conventional drilling rigs and drill bits, drilling is carried out according to the designed orientation, inclination and depth until the target coal seam is penetrated or the designed final hole position is reached; S3: Drill rod installation and preparation: Remove all drilling tools from the hole, and then connect the coal discharge drill rods described in this invention in sequence. First, connect the bottom drill rod body 1 with water spray holes 3, and then slowly feed the drill rods into the formed borehole by connecting them in series through the drill head or other rotary drive device; S4: Coal Discharge Operation: Start the drilling rig drive device to allow the coal discharge drill rod to rotate continuously at a certain speed. At this time, in the coal borehole section, the evenly distributed saw teeth 6 will continuously scrape the coal wall or coal particles. The broken coal blocks and powder are forced and continuously transported to the borehole opening under the push of the rotating spiral blades 4, the prismatic rod and the prismatic blades 5, realizing mechanical coal breaking and conveying. In the rock borehole section, the coal discharge drill rod operates with lower resistance to deal with the narrowing of the borehole at any time. S5: Open the high-pressure water hole and carry out coal flushing operation: When it is observed that the coal discharge from the borehole decreases or there is no coal discharge during idling, open the manual water control valve and adjust the pressure to the corresponding level according to the coal seam hardness, and carry out coal flushing operation for 1-2 minutes. High-pressure water is ejected from the water spray hole 3 of the drill rod at the bottom of the hole to hydraulically strip and flush the coal body on the borehole wall. During the operation, the coal discharge situation in the borehole should be closely observed. When the slag content of the coal discharged from the borehole is less than 30%, repeat S4. During this process, operate the drilling rig to make the entire drill rod string move back and forth in the borehole, with the movement amplitude not less than the thickness of the target coal seam, to ensure that the high-pressure water flow can flush the borehole wall of the entire coal seam thickness section; S6: Stop drilling and remove the auger rod: If coal is discharged from the borehole, but the proportion of rock debris is large, exceeding 30%, it indicates that the roof rock has collapsed and mining is considered complete. At this time, drilling can be stopped. If no coal is discharged from the borehole, it is considered that the coal within the borehole control area has been completely mined, which also marks the completion of the borehole coal discharge operation.

[0035] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0036] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A drilling rod for coal discharge, characterized in that: The system includes multiple drill rod bodies (1) connected end to end. Adjacent drill rod bodies (1) are fixedly connected by connectors (2). All drill rod bodies (1) are hollow structures. The end of the drill rod body (1) at the frontmost end is a sealed structure. A water spray hole (3) connected to the middle part is opened on one side of the drill rod body (1) along its radial direction. A high-pressure water pipe connector is connected to the drill rod body (1) at the rearmost end. Spiral blades (4) are respectively provided on the outer periphery of the drill rod bodies (1). Several prismatic pieces (5) are evenly spaced on the upper side of the spiral blades (4) along its spiral direction. Several serrations (6) are evenly spaced on the side of the spiral blades (4) away from the drill rod body (1) along the spiral line.

2. The drilling rod for coal discharge according to claim 1, characterized in that: The drill rod body (1) has a triangular or polygonal structure.

3. The drilling rod for coal discharge according to claim 1, characterized in that: The water jet (3) is axially aligned with the drill rod body (1) in three types: 30°, 60°, and 90°.

4. A drilling rod for coal discharge according to claim 1, characterized in that: The drill rod body (1) has three lengths: 0.75m, 1m, and 1.5m. The distance between the water jet hole (3) and the sealing end of the drill rod body (1) is 0.2m-0.5m.

5. A drilling rod for coal discharge according to claim 1, characterized in that: The drill rod body (1) has an outer diameter of 50 mm and an inner diameter of 15 mm. The spiral blade (4) has an outer diameter of 94 mm and an inner diameter of 50 mm. The pitch of the spiral blade (4) is 0.6-1.2 times the diameter of the drill rod body (1).

6. A drilling rod for coal discharge according to claim 1, characterized in that: The tooth spacing of the saw teeth (6) is 3-10 mm and the tooth height is 2-6 mm.

7. A drilling rod for coal discharge according to claim 1, characterized in that: The connector (2) includes a plug (201), a plug groove (202), a sealing ring (203), and a positioning bolt (204). The drill rod body (1) has a plug groove (202) in the middle of one end along its length direction and a plug (201) fixedly connected to the other end. The plug (201) has a connecting hole (205) that communicates with the middle of the drill rod body (1). The inner wall of the plug groove (202) is provided with a sealing ring (203). Positioning holes are provided on the plug (201) on both sides of the connecting hole (205) and on both sides of the plug groove (202). The positioning holes in the plug groove (202) are threaded holes. The plug (201) and the plug groove (202) are fixedly connected by the positioning bolt (204).

8. A drilling rod for coal discharge according to claim 1, characterized in that: The connector (2) also includes a threaded joint, which is fixedly connected to one end of the drill rod body (1), and the other end of the drill rod body (1) is provided with an internal thread that is compatible with the threaded joint along its length.

9. A drilling rod for coal discharge according to claim 1, characterized in that: The spiral blades (4) and saw teeth (6) are both made of hard alloy material, and the drill rod body (1) is made of geological alloy steel pipe.

10. A method for drilling coal discharge construction according to any one of claims 1-9, characterized in that, Includes the following steps: S1: Construction of Rock Roadways: Based on the characteristics of the coal seam, select a suitable stratum to construct either a floor rock roadway or a roof rock roadway; specifically, floor rock roadways should be prioritized; floor rock roadways help to drain accumulated water or coal slag from the borehole, enabling the borehole mining to achieve the best results; generally speaking, floor rock roadways should be selected in stable rock strata at least 15m away from the coal seam, and the roadway cross-section is usually not less than 10m². S2: Drilling in rock tunnels: Using conventional drilling rigs and drill bits, drilling is carried out according to the designed orientation, inclination and depth until the target coal seam is penetrated or the designed final hole position is reached; S3: Drill rod installation and preparation: Remove all drilling tools from the hole and then connect the coal discharge drill rods described in this invention in sequence; first connect the bottom drill rod body (1) with water spray hole (3), and slowly send the drill rods into the formed borehole by connecting them in series through the drill power head or other rotary drive device; S4: Coal discharge operation: Start the drilling rig drive device and let the coal discharge drill rod rotate continuously at a certain speed; at this time, in the coal hole section, the evenly distributed saw teeth (6) will continuously scrape the coal wall or coal particles. The broken coal and powder are forced and continuously transported to the hole mouth under the push of the rotating spiral blades (4), prismatic rods and prismatic plates (5), realizing mechanical coal breaking and coal conveying; in the rock hole section, the coal discharge drill rod runs with low resistance and is ready to deal with the narrowing of the borehole at any time; S5: Open the high-pressure water hole and carry out coal flushing operation: When it is observed that the coal discharge of the borehole is reduced or the borehole is idle and no coal is discharged, open the manual water control valve and adjust it to the corresponding pressure according to the coal seam hardness to carry out coal flushing operation for 1-2 minutes; the high-pressure water flow is ejected from the water spray hole (3) of the drill rod at the bottom of the hole to hydraulically peel off and flush the coal body on the borehole wall; during the operation, the coal discharge situation in the borehole should be closely observed. When the slag content of the coal discharged from the borehole is less than 30%, repeat S4; during this process, operate the drilling machine to make the entire drill rod string in the borehole to make "back-to-back reciprocating motion", the motion amplitude is not less than the thickness of the target coal seam, to ensure that the high-pressure water flow can flush the borehole wall of the entire coal seam thickness section; S6: Stop drilling and remove the auger rod: If coal is discharged from the borehole, but the proportion of rock debris is large, exceeding 30%, it indicates that the roof rock has collapsed and can be considered as mining completed. At this time, drilling can be stopped and mining can be stopped. If no coal is discharged from the borehole, it is considered that the coal within the borehole control area has been completely mined, which also marks the completion of the borehole coal discharge operation.

Images