Variable-frequency electrically-driven top-drive core drill for geological coring exploration

Abstract

The invention discloses a variable-frequency electrically-driven top drive type core drill for geological coring exploration, and relates to the technical field of drilling tools, the variable-frequency electrically-driven top drive type core drill comprises a fixed support, a mud tank is mounted on the fixed support, and a liquid outlet of the mud tank is communicated with a hollow flowing channel in a drill rod through a conveying hose; the lifting supporting frame is connected with a variable-frequency driving motor, the variable-frequency driving motor can move up and down along the lifting supporting frame, an output shaft of the variable-frequency driving motor is connected with a rotating rod, and the end, away from the variable-frequency driving motor, of the rotating rod is connected with a drill rod; the downward pressing device is fixed to the lifting supporting frame, and the telescopic end of the downward pressing device can push the rotating rod downwards; a mixture inlet of the slurry treatment equipment is communicated with the drill hole through an overflow pipe, a conveyor is arranged below a solid outlet of the slurry treatment equipment, and a liquid outlet of the slurry treatment equipment is communicated with a liquid inlet of the slurry tank through a return pipe. According to the invention, the injection and recovery system of the drilling fluid is optimized.

Description

Technical Field

[0001] The invention relates to the technical field of drilling tools, in particular to a variable frequency electric drive top drive core drilling rig used for geological coring exploration. Background Art

[0002] The variable frequency electric drive top drive core drill is an advanced geological exploration equipment, specially designed for coring and drilling in deep formations. This kind of drilling rig integrates modern power electronics technology, mechanical manufacturing technology, hydraulic control technology, electronic information technology and modular design concept. Its core feature is the use of AC variable frequency electric drive technology to control the key operating components of the drilling rig.

[0003] The variable frequency electric drive can achieve precise speed and torque control, allowing the drill rig to maintain an efficient drilling speed under different geological conditions, while adapting to the different process requirements of high-speed top drive coring and high-torque rotary table drilling.

[0004] Compared with traditional diesel-driven drilling rigs, electric drive systems can use energy more efficiently, reduce energy consumption and operating costs, and also reduce noise and environmental pollution. It is suitable for deep hole coring drilling within 4,500 meters, especially suitable for mineral resource exploration, geothermal well drilling, coalbed methane and shale gas exploration and other fields.

[0005] The Chinese patent application No. 201310732037.9 is a variable frequency electric drive top drive core drilling rig for geological coring exploration, which includes a platform and a vertical derrick on the platform, an electric drive winch and a salvage winch for retracting and releasing ropes are arranged on the platform, and an electric drive turntable is also arranged on the platform at the lower end of the derrick; a guide rail parallel to the derrick is arranged on the derrick, and the guide rail is connected to the top drive through a bracket pulley; the top drive adopts a top drive variable frequency motor to be directly connected to the drill pipe through a connecting shaft; the motors of the top drive, electric drive winch, salvage winch and electric drive turntable are driven by a frequency converter in the electric control room, and the motor is controlled in the driller's room; the drilling rig is also provided with an engineer room for monitoring the operation of the drilling rig; and a rope tension and rope speed detection device is also arranged at the top of the derrick. The drilling rig adopts an AC variable frequency motor drive to realize the operations of rotation, lifting, feeding, salvage, etc., and has a long-stroke guide rail and rope speed and tension detection function, and is controlled by a frequency converter to realize high-efficiency and low-energy drilling operations.

[0006] It is difficult for existing core drilling rigs to effectively inject and recover drilling fluid during use, which may have the following adverse effects:

[0007] Reduced drilling efficiency: Insufficient injection of drilling fluid will lead to poor cooling of the drill bit, making it difficult to effectively remove drill cuttings, thereby increasing drilling resistance and reducing drilling speed.

[0008] Increased wear of drilling tools: Lack of sufficient drilling fluid circulation will reduce the lubrication of drilling tools, increase the friction between the drilling tools and the well wall, cause premature wear of the drill bit and other drilling tool components, and shorten their service life.

[0009] Wellbore stability is affected: One of the important functions of drilling fluid is to stabilize the wellbore and prevent collapse. If the drilling fluid is not injected smoothly, it cannot form an effective pressure balance on the wellbore, which may cause the wellbore to collapse or the wellbore diameter to expand, affecting the drilling quality and safety.

[0010] Damaged core quality: Poor drilling fluid circulation will prevent cuttings from being carried out of the well in time, which may cause core blockage or contamination, affecting subsequent core analysis and geological judgment.

[0011] Increased safety hazards: Poor circulation of drilling fluid may cause pressure imbalance in the well, increase the risk of well kick and blowout, and even threaten the safety of operators in serious cases.

[0012] Environmental issues: Failure to effectively recover drilling fluid may cause ground environmental pollution, especially leakage of drilling fluid containing harmful chemicals, which poses a threat to the surrounding environment and ecosystem.

[0013] Rising costs: Frequent replacement of drill bits damaged by accelerated wear, handling of ground contamination, and possible accident response and aftermath can significantly increase operating costs.

[0014] From the above shortcomings, it can be seen that optimizing the injection and recovery system of drilling fluid and ensuring its smooth and efficient operation are crucial to ensuring the smooth progress of core drilling work, improving drilling efficiency, protecting the environment and reducing costs.

[0015] Therefore, there is an urgent need in the art for a new type of variable frequency electric drive top drive core drill for geological coring exploration to solve the above problems. Summary of the invention

[0016] The purpose of the present invention is to provide a variable frequency electric drive top drive core drilling rig for geological coring exploration, so as to solve the problems existing in the above-mentioned prior art, optimize the injection and recovery system of drilling fluid, and its operation is smooth and efficient, and has the advantages of ensuring the smooth progress of core drilling work, improving drilling efficiency, protecting the environment and reducing costs.

[0017] To achieve the above object, the present invention provides the following solutions:

[0018] The invention discloses a variable frequency electric drive top drive core drilling rig for geological coring exploration, comprising:

[0019] A fixed bracket, on which a mud tank is installed, and a liquid outlet of the mud tank can be connected to a hollow flow channel in the drill pipe through a delivery hose;

[0020] A lifting support frame, the lifting support frame is connected to a variable frequency drive motor, the variable frequency drive motor can move up and down along the lifting support frame, the output shaft of the variable frequency drive motor is connected to a rotating rod, and the end of the rotating rod away from the variable frequency drive motor is used to connect the drill rod;

[0021] A pressing device, the pressing device is fixed on the lifting support frame, and the telescopic end of the pressing device can push the rotating rod downward;

[0022] The mud processing equipment has a mixture inlet connected to the borehole through an overflow pipe, a conveyor is provided below the solid outlet of the mud processing equipment, and a liquid outlet of the mud processing equipment is connected to the liquid inlet of the mud tank through a reflux pipe.

[0023] Preferably, it further comprises a winch, wherein one end of a steel wire rope of the winch away from the winch is connected to the variable frequency drive motor.

[0024] Preferably, the steel wire rope of the hoist is connected to a motor sliding bracket, the motor sliding bracket is slidably connected to the lifting support frame, and the variable frequency drive motor is fixed on the motor sliding bracket.

[0025] Preferably, a plurality of guide wheels are provided at the upper end of the lifting support frame, and the wire rope of the winch passes around each of the guide wheels in sequence.

[0026] Preferably, the pressing device comprises a pressing hydraulic cylinder, the fixed end of the pressing hydraulic cylinder is fixed on the lifting support frame, and the telescopic end of the pressing hydraulic cylinder is fixed with a sliding pressing seat;

[0027] The outer side of the rotating rod is provided with a clamping sleeve, the outer side wall of the clamping sleeve is provided with an annular clamping groove, and one end of the sliding pressing seat away from the pressing hydraulic cylinder is clamped in the clamping groove.

[0028] Preferably, a liquid outlet ring is provided on the outer side of the drill pipe, and one end of the delivery hose away from the mud tank is connected to the liquid outlet ring. A mud injection hole is provided on the side wall of the drill pipe, and an annular chamber is provided in the liquid outlet casing. A movable piston is slidably connected in the annular chamber, and a nozzle is provided on the movable piston. A return spring is connected between the movable piston and the outer side wall of the annular chamber, and a one-way structure is provided on the inner side of the mud injection hole, and the one-way structure is located in the hollow flow channel.

[0029] Preferably, the one-way structure comprises a one-way ring body, a one-way valve is arranged in the one-way ring body, and the one-way ring body and the one-way valve are connected by an elastic sheet.

[0030] Preferably, the one-way flap is made of rubber.

[0031] Preferably, the return pipe is provided with a first mud pump, the overflow pipe is provided with a second mud pump, and the delivery hose is provided with a third mud pump.

[0032] Preferably, the mud processing equipment includes a vibrating screen, a desilter and a centrifuge which are arranged in sequence, the liquid inlet end of the vibrating screen is connected to the liquid outlet end of the overflow pipe, the liquid outlet end of the vibrating screen is connected to the liquid inlet end of the desilter, the liquid outlet end of the desilter is connected to the liquid inlet end of the centrifuge, and the solid impurities separated from the vibrating screen, the desilter and the centrifuge all flow out from the solid outlet.

[0033] Compared with the prior art, the present invention has achieved the following technical effects:

[0034] During use, the present invention can transport the drilling fluid in the mud tank to the drill pipe, and the mud at the overflow port at the upper end of the borehole can flow back to the mud treatment equipment through the overflow pipe. After being processed by the mud treatment equipment, the separated liquid is the drilling fluid and is transported to the mud tank again, while the solid waste is transported to the solid waste collection site by the conveyor. In this way, a circulation system for effectively injecting and recycling drilling fluid is formed, and this circulation system will bring many benefits, as follows:

[0035] Improve drilling efficiency: Good drilling fluid circulation can ensure that the drill bit is effectively cooled, reduce heat accumulation, carry and discharge drill cuttings, keep the borehole clean, and thus improve drilling speed and efficiency;

[0036] Extend the life of drilling tools: The lubricating effect of drilling fluid can significantly reduce the friction between drilling tools and rocks, reduce wear, extend the service life of drilling tools such as drill bits and drill pipes, reduce replacement frequency, and save costs;

[0037] Enhance wellbore stability: Continuously injected drilling fluid can form a liquid column pressure to support the wellbore wall and prevent collapse, which is particularly important when drilling in soft or unstable formations;

[0038] Improve core quality: The rational use of drilling fluid can prevent core contamination by drilling fluid, reduce core breakage and blockage, ensure the core is intact and pure, and improve the accuracy of geological analysis;

[0039] Environmentally friendly: By recycling drilling fluid, the preparation of new drilling fluid and the discharge of waste drilling fluid are reduced, which reduces the impact on the environment and conforms to the concept of green drilling;

[0040] Cost control: The recycling of drilling fluid reduces drilling fluid consumption and treatment costs, and also reduces maintenance costs caused by equipment wear and failure, which is generally beneficial to improving the economic efficiency of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a structural schematic diagram of a variable frequency electric drive top drive core drilling rig used for geological coring exploration according to an embodiment of the present invention;

[0043] Figure 2 This is a diagram showing the internal structure of a liquid outlet collar in a variable frequency electric drive top drive core drill for geological coring exploration according to an embodiment of the present invention;

[0044] Figure 3 It is a structural schematic diagram of a unidirectional structure in a variable frequency electric drive top drive core drilling rig for geological coring exploration according to an embodiment of the present invention;

[0045] Figure 4 It is a front view of a liquid outlet collar in a variable frequency electric drive top drive core drilling rig used for geological coring exploration according to an embodiment of the present invention;

[0046] Figure 5 This is a schematic diagram of the internal structure of a mud processing device in a variable frequency electric drive top drive core drilling rig for geological coring exploration according to an embodiment of the present invention;

[0047] In the figure: 1-fixed bracket; 2-lifting support frame; 3-frequency drive motor; 4-mud processing equipment; 5-conveyor; 6-first mud pump; 7-second mud pump; 8-third mud pump; 9-rotating rod; 10-drill pipe; 11-down-pressure hydraulic cylinder; 12-sliding down-pressure seat; 13-clamping sleeve; 14-winch; 15-guide wheel; 16-medicament adding tank; 17-conveyance hose; 18-liquid outlet ring; 19-moving piston; 20-reset spring; 21-mud injection hole; 22-hollow flow channel; 23-one-way structure; 24-one-way ring body; 25-one-way flap; 26-elastic sheet; 27-vibrating screen; 28-desilter; 29-centrifuge; 30-mud tank; 31-nozzle. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The purpose of the present invention is to provide a variable frequency electric drive top drive core drilling rig for geological coring exploration, so as to solve the problems existing in the above-mentioned prior art, optimize the injection and recovery system of drilling fluid, and its operation is smooth and efficient, and has the advantages of ensuring the smooth progress of core drilling work, improving drilling efficiency, protecting the environment and reducing costs.

[0050] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] like Figure 1-Figure 5 As shown, this embodiment provides a variable frequency electric drive top drive core drilling rig for geological coring exploration, including the following structure:

[0052] The fixed support 1 is a vertical frame structure, on which a mud tank 30 is installed. The liquid outlet of the mud tank 30 can be connected to the hollow flow channel 22 in the drill pipe 10 through a delivery hose 17, so that the drilling fluid in the mud tank 30 can be delivered to the hollow flow channel 22 located at the center of the drill pipe 10.

[0053] The lifting support frame 2 is a vertical rod-shaped structure. The lifting support frame 2 is connected with a variable frequency drive motor 3. The variable frequency drive motor 3 can move up and down along the vertical direction of the lifting support frame 2. The output shaft of the variable frequency drive motor 3 is connected with a rotating rod 9. Since the output shaft of the variable frequency drive motor 3 is vertically arranged downward, the output shaft of the variable frequency drive motor 3 is connected to the upper end of the rotating rod 9 through a connecting flange, and the end of the rotating rod 9 away from the variable frequency drive motor 3 (i.e., the lower end of the rotating rod 9) is used to connect the upper end of the drill rod 10, and the rotating rod 9 and the drill rod 10 are also flange-connected. The flange connection means that the adjacent ends of the two are provided with corresponding flanges, and the two adjacent flanges can be connected by bolts. The lower end of the drill rod 10 is used to connect the drill bit, and different drill bits can be selected according to different needs.

[0054] The pressing device is fixed on the lifting support frame 2. The telescopic end of the pressing device can push the rotating rod 9 downward, so that the drill rod 10 can also move downward during the rotation process, thereby achieving the technical purpose of downward drilling.

[0055] The mud treatment equipment 4, the mixture inlet of the mud treatment equipment 4 is connected to the overflow port (i.e., the orifice) of the borehole through an overflow pipe, so that the overflowed mud can flow back to the mud treatment equipment 4 through the overflow pipe, and then the mud treatment equipment 4 performs solid-liquid separation on the mud. A conveyor 5 is provided below the solid outlet of the mud treatment equipment 4, wherein the conveyor 5 includes but is not limited to the existing belt conveyor 5, and can also be other conveying devices that can be used to transport solid waste. The solid waste after solid-liquid separation will be transported to a predetermined place by the conveyor 5, and the liquid outlet of the mud treatment equipment 4 is connected to the liquid inlet of the mud tank 30 through a reflux pipe. The liquid after solid-liquid separation is drilling fluid, and the liquid after solid-liquid separation flows back to the mud tank 30 through the reflux pipe as drilling fluid for standby use.

[0056] In actual use, the drilling fluid in the mud tank 30 is transported to the drill pipe 10, and the mud at the overflow port at the upper end of the borehole can flow back to the mud treatment equipment 4 through the overflow pipe. After being processed by the mud treatment equipment 4, the separated liquid is the drilling fluid and is transported to the mud tank 30 again, and the solid waste will be transported to the solid waste collection site by the conveyor 5, thereby forming a circulation system for effective injection and recycling of the drilling fluid.

[0057] In this embodiment, in order to realize the up and down movement of the variable frequency drive motor 3, a winch 14 is further included, and the winch 14 can be installed on one side of the lifting support frame 2. The end of the steel wire rope extending from the winch 14 away from the winch 14 is connected to the variable frequency drive motor 3. In actual use, the up and down movement of the variable frequency drive motor 3 is controlled by controlling the retraction and release of the steel wire rope. Specifically, when the steel wire rope is extended, the variable frequency drive motor 3 moves downward; when the steel wire rope is retracted, the variable frequency drive motor 3 moves upward.

[0058] In this embodiment, the steel wire rope of the hoist 14 is connected to the motor sliding bracket, and the motor sliding bracket is slidably connected to the lifting support frame 2. In order to reduce the sliding friction between the motor sliding bracket and the lifting support frame 2, a pulley can be set on the motor sliding bracket, and a corresponding slide groove can be set on the lifting support frame 2, so that the pulley rolls up and down in the slide groove, which can not only reduce the friction between the motor sliding bracket and the lifting support frame 2, but also limit the position of the motor sliding bracket so that it can only move vertically up and down. The variable frequency drive motor 3 is fixed to the motor sliding bracket by screws, and finally the variable frequency drive motor 3 moves vertically up and down along the lifting support frame 2 as the motor sliding bracket is driven by the steel wire rope of the hoist 14.

[0059] In this embodiment, a plurality of guide wheels 15 are provided at the upper end of the lifting support frame 2, specifically two guide wheels 15, and the wire rope of the winch 14 passes around each guide wheel 15 in turn, thereby guiding the wire rope.

[0060] In this embodiment, the pressing device includes a pressing hydraulic cylinder 11, which is vertically arranged, and the fixed end located above the pressing hydraulic cylinder 11 is fixed to the lifting support frame 2, and the telescopic end located below the pressing hydraulic cylinder 11 is fixedly connected to a sliding pressing seat 12, which is also slidably connected to the lifting support frame 2. Further, in order to avoid excessive friction between the sliding pressing seat 12 and the lifting support frame 2, a pulley can be arranged on the sliding pressing seat 12, and a corresponding slide groove can be arranged on the lifting support frame 2, so that the friction between the two is converted into rolling friction.

[0061] The outer side of the rotating rod 9 is provided with a clamping sleeve 13, and the clamping sleeve 13 and the rotating rod 9 are connected by a bearing, so as to realize the relative rotation of the two. An annular clamping groove is provided on the middle part of the outer side wall of the clamping sleeve 13, and the end of the sliding lower pressing seat 12 away from the pressing hydraulic cylinder 11 can be an arc-shaped clamping part, and two clamping parts can be provided, and the two clamping parts are respectively clamped on both sides of the clamping groove, so that the end of the sliding lower pressing seat 12 away from the pressing hydraulic cylinder 11 can be clamped in the clamping groove.

[0062] When the pressing hydraulic cylinder 11 is extended, the telescopic end of the pressing hydraulic cylinder 11 will drive the clamping sleeve 13 and the rotating rod 9 to move downward through the sliding pressing seat 12; when the pressing hydraulic cylinder 11 is shortened, the telescopic end of the pressing hydraulic cylinder 11 will drive the clamping sleeve 13 and the rotating rod 9 to move upward through the sliding pressing seat 12.

[0063] In this embodiment, if Figure 2 As shown, the outer side of the drill pipe 10 is provided with a liquid outlet collar 18, and the end of the delivery hose 17 away from the mud tank 30 is connected to the liquid outlet collar 18. A plurality of mud injection holes 21 are provided on the side wall of the drill pipe 10, and an annular chamber is provided in the middle interlayer of the liquid outlet sleeve. A movable piston 19 is slidably connected in the annular chamber, and a nozzle 31 is provided on the movable piston 19. The movable piston 19 is in contact with the outer side wall of the annular chamber (the outer side wall here is Figure 2 A plurality of return springs 20 are connected between the left side wall of the middle annular chamber. A one-way structure 23 is provided on the inner side of the mud injection hole 21. The one-way structure 23 is located in the hollow flow channel 22. The one-way structure 23 allows the drilling fluid in the annular chamber to flow only into the hollow flow channel 22, thereby preventing the drilling fluid in the hollow flow channel 22 from flowing back.

[0064] In actual use, the drilling fluid from the delivery hose 17 will first enter the annular chamber. As the drilling fluid in the annular chamber continues to increase, the drilling fluid will push the movable piston 19 to move inward until the nozzle of the nozzle 31 coincides with the mud injection hole 21. At this time, the drilling fluid in the annular chamber is injected into the hollow flow channel 22 through the nozzle 31, the mud injection hole 21 and the one-way structure 23, and finally flows into the drill pipe 10 and the drill bit.

[0065] In this embodiment, for the specific structure of the one-way structure 23, those skilled in the art can fully adopt existing one-way valves and other structures. Figure 3 As shown, the one-way structure 23 includes a circular one-way ring body 24, in which a one-way petal 25 is provided. The one-way petal 25 is umbrella-shaped (can also be regarded as cone-shaped), and the one-way ring body 24 and the one-way petal 25 are connected by an elastic sheet 26.

[0066] When the drilling fluid is blown toward the one-way flap 25, the one-way flap 25 is blown open, the elastic sheet 26 is compressed, and the drilling fluid flows into the hollow flow channel 22 through the gap between the deformed one-way flap 25 and the one-way ring body 24. When there is no drilling fluid passing through, the elastic sheet 26 is reset and supports the one-way flap 25 to prevent the liquid in the hollow flow channel 22 from flowing back.

[0067] In this embodiment, the one-way flap 25 is made of a deformable material, specifically a rubber material, and the elastic sheet 26 can be made of an existing elastic metal, including but not limited to spring steel.

[0068] In this embodiment, a first mud pump 6 is provided on the return pipe, a second mud pump 7 is provided on the overflow pipe, and a third mud pump 8 is provided on the delivery hose 17. The first mud pump 6, the second mud pump 7 and the third mud pump 8 can provide delivery power for the return pipe, the overflow pipe and the delivery hose 17.

[0069] Furthermore, a controller may be added, and the controller may be an existing PLC controller or a single chip microcomputer controller, etc. The above-mentioned hoist 14 (electric model), variable frequency drive motor 3, first mud pump 6, second mud pump 7 and third mud pump 8 and other electronic control devices may be electrically connected to the controller, so as to realize remote control by the staff.

[0070] In this embodiment, the mud processing equipment 4 includes a vibrating screen 27, a desilter 28 and a centrifuge 29 which are arranged in sequence. Specifically, the liquid inlet end of the vibrating screen 27 is connected to the liquid outlet end of the overflow pipe, and the mixed mud flowing into the mud processing equipment 4 first passes through the vibrating screen 27, wherein the large particles of solid impurities are retained on the vibrating screen 27 and transported to the solid outlet, and the liquid passes through the vibrating screen 27 and flows to the desilter 28. The liquid outlet end of the vibrating screen 27 is connected to the liquid inlet end of the desilter 28, and the desilter 28 can use an existing desilter cyclone to perform further solid-liquid separation, wherein the small particles of solid are transported to the solid outlet, and the liquid is transported to the centrifuge 29. The liquid outlet of the desilter 28 is connected to the liquid inlet of the centrifuge 29. The centrifuge 29 can be any centrifuge model capable of solid-liquid separation. The solids after centrifugal separation are finally transported to the solid outlet, and the liquid flows back to the mud tank 30 through the reflux pipe. The solid impurities separated by the vibrating screen 27, the desilter 28 and the centrifuge 29 finally flow out from the solid outlet and fall onto the conveyor 5. Of course, the mud processing equipment 4 can also use other existing types of solid-liquid separation equipment, not just limited to this one.

[0071] In addition, the liquid outlet or return pipe of the centrifuge 29 is connected to a reagent adding tank 16 to add reagents to the liquid to modify it into a suitable drilling fluid to meet the use requirements of different environments.

[0072] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A variable frequency electric drive top drive core drilling rig for geological coring exploration, characterized in that: include: A fixed bracket, on which a mud tank is installed, and a liquid outlet of the mud tank can be connected to a hollow flow channel in the drill pipe through a delivery hose; A lifting support frame, the lifting support frame is connected to a variable frequency drive motor, the variable frequency drive motor can move up and down along the lifting support frame, the output shaft of the variable frequency drive motor is connected to a rotating rod, and the end of the rotating rod away from the variable frequency drive motor is used to connect the drill rod; A pressing device, the pressing device is fixed on the lifting support frame, and the telescopic end of the pressing device can push the rotating rod downward; The mud processing equipment has a mixture inlet connected to the borehole through an overflow pipe, a conveyor is provided below the solid outlet of the mud processing equipment, and a liquid outlet of the mud processing equipment is connected to the liquid inlet of the mud tank through a reflux pipe.

2. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 1, characterized in that: It also includes a winch, and one end of the steel wire rope of the winch away from the winch is connected to the variable frequency drive motor.

3. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 2, characterized in that: The steel wire rope of the hoist is connected with a motor sliding bracket, the motor sliding bracket is slidably connected to the lifting support frame, and the variable frequency drive motor is fixed on the motor sliding bracket.

4. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 2, characterized in that: A plurality of guide wheels are arranged at the upper end of the lifting support frame, and the steel wire rope of the hoist passes around each of the guide wheels in sequence.

5. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 1, characterized in that: The pressing device comprises a pressing hydraulic cylinder, the fixed end of which is fixed to the lifting support frame, and the telescopic end of which is fixed with a sliding pressing seat; The outer side of the rotating rod is provided with a clamping sleeve, the outer side wall of the clamping sleeve is provided with an annular clamping groove, and one end of the sliding pressing seat away from the pressing hydraulic cylinder is clamped in the clamping groove.

6. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 1, characterized in that: A liquid outlet ring is provided on the outer side of the drill pipe, and one end of the delivery hose away from the mud tank is connected to the liquid outlet ring. A mud injection hole is provided on the side wall of the drill pipe, and an annular chamber is provided in the liquid outlet casing. A movable piston is slidably connected in the annular chamber, and a nozzle is provided on the movable piston. A return spring is connected between the movable piston and the outer side wall of the annular chamber, and a one-way structure is provided on the inner side of the mud injection hole, and the one-way structure is located in the hollow flow channel.

7. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 6, characterized in that: The one-way structure comprises a one-way ring body, a one-way valve is arranged in the one-way ring body, and the one-way ring body and the one-way valve are connected by an elastic sheet.

8. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 7, characterized in that: The one-way flap is made of rubber.

9. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 1, characterized in that: The return pipe is provided with a first mud pump, the overflow pipe is provided with a second mud pump, and the delivery hose is provided with a third mud pump.

10. The variable frequency electric drive top drive core drilling rig for geological coring exploration according to claim 1, characterized in that: The mud processing equipment includes a vibrating screen, a desilter and a centrifugal separator which are arranged in sequence. The liquid inlet end of the vibrating screen is connected to the liquid outlet end of the overflow pipe, the liquid outlet end of the vibrating screen is connected to the liquid inlet end of the desilter, the liquid outlet end of the desilter is connected to the liquid inlet end of the centrifugal separator, and the solid impurities separated by the vibrating screen, the desilter and the centrifugal separator all flow out from the solid outlet.

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