High abrasion resistant core barrel and bit construction and method of manufacture

Abstract

The application discloses a high-wear-resistance core tube and drill bit structure and a manufacturing method, and relates to the technical field of drilling equipment, in particular to a high-wear-resistance core tube and drill bit structure and a manufacturing method. The application discloses a core tube for providing drilling support, end heads arranged at two ends of the core tube and welded and fixed on the core tube, drill bits threadedly installed in the end heads, connecting sections arranged between adjacent core tubes and connected with the core tubes through threads, and water grooves formed on outer walls of the core tubes, the drill bits and the connecting sections. The beneficial effects are as follows: the structure design of the thickened end heads can protect the thread connection, can improve the wear resistance under the condition of ensuring the connection strength, and can ensure that water flows smoothly during drilling by the positioning cooperation of the water grooves, so that the core tube is prevented from being damaged due to wear during drilling, and the service life of the core tube is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of geological exploration technology, specifically to a high wear-resistant core tube and drill bit structure and manufacturing method. Background Technology

[0002] During geological exploration, drill bits and core tubes are used to extract core samples from the soil layers. Water flow is used during drilling to facilitate heat dissipation and improve drilling efficiency. Due to the hardness of the rock formations, drill bits often wear out during use and require periodic replacement. Furthermore, as drilling depth increases, core tubes need to be installed. To improve the overall strength and durability of the core tubes, their wall thickness needs to be minimized. However, adjacent core tubes and drill bits are connected by threads; excessively thin walls will affect the connection strength. Additionally, core tubes are consumables. As the usage time increases, the core tube will continuously wear down and thin, making it easy for the drill bit below the core tube to fall off, resulting in drilling accidents. Tests have found that the strength of the threaded connection of the core tube currently on the market cannot be guaranteed, and it is easy to be damaged during subsequent drilling, which will affect the power transmission effect, reduce drilling efficiency, and in severe cases, bend and cause production accidents. Only periodic inspections can be carried out to avoid excessive wear, which is cumbersome. At the same time, the water flow during the drilling process will flow from the drill bit and the outer wall of the core tube, which will also create scouring pressure, further aggravating the wear and tear, causing the service life of the core tube and drill bit to fail to meet the current requirements. Summary of the Invention

[0003] The purpose of this invention is to provide a highly wear-resistant core tube and drill bit structure to solve the aforementioned problems, addressing the issues of insufficient connection strength at the threaded end of existing core tubes, easy wear failure during drilling, and short service life. Among the various technical solutions provided by this invention, the preferred solution employs a thickened end design, which protects the threaded connection and improves wear resistance while ensuring connection strength. Simultaneously, the use of a water groove for positioning ensures smooth water flow during drilling, preventing damage to the core tube due to wear during drilling, thus significantly extending the service life of the core tube. Details are provided below.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] The high wear-resistant core tube and drill bit structure and manufacturing method provided by the present invention include:

[0006] Core tubes are used to provide support during drilling.

[0007] The ends are located at both ends of the core tube and are welded and fixed to the core tube.

[0008] The drill bit is installed inside the end cap via threads;

[0009] The connecting section is located between adjacent core tubes and is connected to the core tubes by threads.

[0010] Water tanks are installed on the outer walls of the core tube, drill bit, and connecting sections.

[0011] Preferably, the outer wall of the core tube is provided with a wear-resistant coating.

[0012] Preferably, the wear-resistant coating consists of two parts, arranged symmetrically in the middle of the core tube.

[0013] Preferably, there are six water tanks, which are arranged in a circular array at equal intervals on the outer wall of the end, drill bit and connecting section.

[0014] Preferably, the water tank is arranged at an angle, and the spiral angle of the water tank when it is set is in the range of 20-45°.

[0015] Preferably, the wall thickness of the drill bit is the same as the wall thickness of the end reinforcement section.

[0016] Preferably, the bottom of the water tank has an arc-shaped structure.

[0017] This invention also provides a method for manufacturing a high-wear-resistant core tube and drill bit structure, comprising:

[0018] S1. Pipe fitting processing: Cut the steel pipe raw material into core tubes according to the production size requirements, and polish the cut surfaces at both ends of the core tubes to ensure smoothness.

[0019] S2. End processing: The end production raw material is cut to size and polished to ensure smoothness. After polishing, it is turned so that the outer diameter of the end corresponds to the outer diameter of the drill bit and the inner diameter of the end corresponds to the outer diameter of the core tube.

[0020] S3, Threading: Threading is performed on the outer wall of the drill bit and the inner wall of the end.

[0021] S4. Water trough opening: Water troughs are opened on the side wall of the end and the drill bit at the corresponding positions.

[0022] S5. End welding: Use a friction welding machine to weld the end to the pipe fitting to ensure coaxiality.

[0023] S6. Heat treatment processing: Quenching heat treatment is performed on the connection between the thread and the end and the core tube to improve the connection strength and wear resistance.

[0024] S7. Turning and grinding: Grind the connection between the end and the core tube, including the inner and outer walls, to ensure that the connection is smooth and flat.

[0025] S8. Spraying treatment: The wear-resistant coating is evenly sprayed onto the outer wall of the core tube to form a wear-resistant coating.

[0026] The beneficial effects are:

[0027] The thickened end design protects the threaded connection, enhancing wear resistance while maintaining connection strength. Combined with the positioning of the water groove, it ensures smooth water flow during drilling, preventing damage to the core tube due to wear and significantly extending its service life. Attached Figure Description

[0028] 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, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is an exploded structural view of the present invention;

[0030] Figure 2 This is a three-dimensional structural view of the present invention in its assembled state;

[0031] Figure 3 This is a three-dimensional structural view of the end of the present invention;

[0032] Figure 4 This is a three-dimensional structural view of the end cap and drill bit of the present invention;

[0033] Figure 5 This is a schematic diagram of the production and processing flow of the present invention.

[0034] The annotations in the attached figures are explained as follows:

[0035] 1. Drill bit; 2. Water tank; 3. Wear-resistant coating; 4. End; 5. Connecting section; 6. Core tube; 7. Thickened section; 8. Threaded section. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0037] See Figures 1-5 As shown, the present invention provides a high wear-resistant core tube and drill bit structure and manufacturing method, including:

[0038] Core tube 6 is used to provide drilling support. Core tube 6 is a hollow round tube used to support the main body so that other components can be installed. The material of core tube 6 is 37Mn5, which can ensure wear resistance and overall strength.

[0039] End 4 is set at both ends of the core tube 6 and welded and fixed to the core tube 6. There are two ends 4, which are used to cooperate with the further installation of the core tube 6.

[0040] Drill bit 1 is threaded into end head 4 and is used to drill into rock formations for crushing.

[0041] The connecting section 5 is set between adjacent core tubes 6 and is connected to the core tube 6 by threads. It is used to splice two adjacent core tubes 6 together by threads. The material of the connecting section 5 is the same as that of the end 4, which is 42GrMo, which can improve wear resistance and extend the service life of the device.

[0042] Water trough 2 is located on the outer wall of core tube 6, drill bit 1 and connecting section 5. The structural design of water trough 2 facilitates the water flow to be discharged through water trough 2 during drilling, improves the efficiency of water circulation, and ensures the cooling effect of drill bit 1.

[0043] In use, the core tube 6 is assembled, and the drill bit 1 is installed into the threaded section 8 of the end 4 according to the usage requirements. Then, the core tube 6, the connecting section 5 and the drill bit 1 are assembled in this way. After the assembly is completed, the water tanks 2 between each component are adjusted to match for easy adjustment.

[0044] In another embodiment, a wear-resistant coating 3 is provided on the outer wall of the core tube 6. The wear-resistant coating 3 is made of tungsten carbide as the main material and is sprayed onto the outer wall of the core tube 6 during use. Since the core tube 6 has a large length-to-diameter ratio, the wear pressure in the middle is too high during use, which can easily cause deviation during drilling, thereby increasing the wear on the outer wall of the core tube 6. At this time, the wear-resistant coating 3 is sprayed onto the outer wall of the core tube 6 to increase the wear resistance of the core tube 6 during rotation and extend the service life of the core tube 6.

[0045] In another embodiment, the wear-resistant coating 3 consists of two parts, arranged symmetrically in the middle of the core tube 6. The distance between the two wear-resistant coatings 3 is 500mm, and the width between each wear-resistant coating 3 is 100mm. The symmetrical arrangement design can increase the wear-resistant area of ​​the core tube 6 and improve its service life.

[0046] In another embodiment, there are six water tanks 22, which are arranged in a circular array at equal intervals on the outer wall of the end 4, the drill bit 1 and the connecting section 5. The water tanks 2 with this structural design can improve the efficiency of water flow during drilling. At the same time, it can facilitate the connection between the core tube 6 and the drill bit 1 or the end 4, so that the positions of the water tanks 2 on the outer wall of each component correspond, thereby facilitating drainage and reducing the difficulty of positioning.

[0047] In another embodiment, the water trough 2 is arranged at an angle, with a spiral angle of 35°. Since water needs to be injected during drilling, and the water supply in the core tube 6 needs to be drained from the gap between the drill bit 1 and the rock mass, water trough 2 is opened at the drill bit 1, end 4, and connecting section 5 to improve drainage efficiency. However, the diameter of the section with the water trough 2 is also relatively large, so the water flow can only be quickly discharged through the water trough 2 to the outer wall of the core tube 6. At this time, a gap is reserved between the core tube 6 and the drilled rock strata, allowing the water to flow within this gap. Experiments have shown that when the water trough... 2. If the thread angle is too small, the water flow will not flow inside the water tank 2 due to centrifugal force, but will overflow at the side wall of the water tank 2, thereby increasing the wear on the water tank 2 and resulting in low drainage efficiency. If the thread angle of the water tank 2 is too large, it is more difficult to open, and the manufacturing cost will increase significantly. In addition, the length of the water tank 2 will also affect the drainage capacity. After multiple tests, it was determined that the water guiding effect is best when the helix angle of the water tank 2 is 35°. Under the working condition of working with the rated speed of the drilling rig, the drainage volume per unit time can reach the peak. Its processing difficulty is moderate, which is the solution with the best overall performance.

[0048] In another embodiment, the wall thickness of drill bit 1 is the same as the wall thickness of the reinforcing section of end 4. It should be noted that the wall thickness of drill bit 1 and the wall thickness of the reinforcing section in this invention are both 2.5 mm thicker than the wall thickness of existing standard pipe fittings, which can increase wear resistance and extend the service life of the device.

[0049] In another embodiment, the bottom of the water tank 2 is an arc-shaped structure, and the depth of the water tank 2 is 2.5mm, the same as the increased wall thickness, so as to facilitate water drainage. At the same time, the arc-shaped structure design can reduce the impact of water flow during drainage and improve the stability of drill bit 1 drilling.

[0050] The present invention also provides a method for manufacturing a high wear-resistant core tube 6 and a drill bit 1 structure, comprising:

[0051] S1. Pipe processing: Cut the steel pipe raw material into core pipe 6 according to the production size requirements, and polish the cut surfaces of both ends of the core pipe 6 to ensure smoothness, so as to facilitate subsequent friction welding.

[0052] S2. End 4 processing: The raw material for end 4 is cut to size and polished to ensure smoothness. After polishing, it is turned. End 4 is provided with a thickened section 7, which is 2.5mm thicker than the wall thickness of the existing standard pipe fittings to improve wear resistance. The outer diameter of end 4 corresponds to the outer diameter of drill bit 11, and the inner diameter of end 4 corresponds to the outer diameter of core tube 6 for easy installation.

[0053] S3, Threading: Threading is performed on the outer wall of drill bit 1 and the inner wall of end 4.

[0054] S4. Water trough 2 is opened. Water trough 2 is opened on the side wall of the end 4 and the drill bit 1 at the corresponding positions. The opening angle between each water trough 2 is the same, which can facilitate the assembly.

[0055] S5. End 4 welding: Use a friction welding machine to weld end 4 onto the pipe fitting to ensure coaxiality. Since steel pipe structure welding is used, full positioning is required to avoid bending of the pipe fitting. However, since the length of end 4 is 200mm, which is relatively short, the impact on installation is not significant. The deflection angle is small and will not affect subsequent use.

[0056] S6. Heat treatment processing: Quenching heat treatment is performed on the threaded section 8 at the connection between the thread and the end 4 and the core tube 6 to improve the connection strength and wear resistance, which can prevent damage to the connection of the threaded section 8 and affect subsequent loading and unloading.

[0057] S7. Turning and grinding: Grind the connection between end 4 and core tube 6, including the inner and outer walls, to ensure that the connection is smooth and flat and to avoid impact when the internal water flows through.

[0058] S8. Spraying treatment: The wear-resistant coating 3 is evenly sprayed onto the outer wall of the core tube 6 to form the wear-resistant coating 3. After the spraying is completed, the wear resistance is improved.

[0059] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing a high wear-resistant core tube and drill bit structure, characterized in that: The structure includes: Core tube (6) is used to provide drilling support; End caps (4) are set at both ends of the core tube (6) and welded and fixed to the core tube (6); The drill bit (1) is installed in the end head (4) by a thread; The connecting section (5) is set between adjacent core tubes (6) and is connected to the core tube (6) by threads; Water tank (2) is located on the outer wall of core tube (6), drill bit (1) and connecting section (5); The outer wall of the core tube (6) is provided with a wear-resistant coating (3); The wear-resistant coating (3) consists of two parts, arranged in a symmetrical structure in the middle of the core tube (6); There are six water tanks (2), and each water tank (2) is arranged in a circular array at equal intervals on the outer wall of the end (4), the drill bit (1) and the connecting section (5); The water tank (2) is arranged in an inclined manner, and the spiral angle of the water tank (2) is in the range of 20-45° when it is opened; the wall thickness of the drill bit (1) is the same as the wall thickness of the end (4); the bottom of the water tank (2) is an arc-shaped structure. The manufacturing method of the high wear-resistant core tube and drill bit structure includes the following specific steps: S1. Pipe processing: Cut the steel pipe raw material into core pipe (6) according to the production size requirements, and polish the cut surfaces of both ends of the core pipe (6) to ensure smoothness. S2. End (4) processing: The end face of the raw material of end (4) is cut according to the size and polished to ensure smoothness. After polishing, it is turned so that the outer diameter of end (4) corresponds to the outer diameter of drill bit (1) and the inner diameter of end (4) corresponds to the outer diameter of core tube (6). S3, threading: threading is performed on the outer wall of the drill bit (1) and the inner wall of the end (4); S4. Water tank (2) is opened, and water tank (2) is opened on the side wall of the end (4) and the drill bit (1) at the corresponding position. S5. End (4) welding: Use a friction welding machine to weld the end (4) onto the pipe fitting to ensure coaxiality; S6. Heat treatment processing: Quenching heat treatment is performed on the connection between the thread and the end (4) and the core tube (6) to improve the connection strength and wear resistance. S7. Turning and grinding: Grind the connection between the end (4) and the core tube (6), including the inner and outer walls, to ensure that the connection is smooth and flat. S8. Spraying treatment: The wear-resistant coating (3) is evenly sprayed onto the outer wall of the core tube (6) to form the wear-resistant coating (3).

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