Downward long borehole pneumatic automatic drainage device and method

Abstract

The application discloses a downhole long drilling air-driven automatic drainage device and method, which comprises a rock breaking structure, a power structure and a pumping structure. The rock breaking structure is used for breaking rocks in a coal seam and placing a filtrate device of the pumping structure into a drilling water accumulation area. The power structure comprises an air motor and an air source and is used for providing power for the pumping structure. The pumping structure comprises a gear pump. A liquid inlet of the gear pump is connected with a liquid inlet pipe. A liquid return pipe is connected with a liquid return port of the gear pump. The liquid return pipe is placed in a roadway drainage groove at the tail end. The liquid inlet pipe is connected with the filtrate device through a one-way valve and is used for draining water in the drilling water accumulation area. The application can reduce the water content in the coal seam for a long time, improve the sealing, grouting and drilling gas extraction effect, avoid high-pressure water from the drainage pipe from hurting people and be more suitable for the complex and changeable roadway conditions in the underground.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of borehole exploration and the field of borehole gas extraction, in particular to a downhole long borehole air-driven automatic drainage device and method. BACKGROUND

[0002] Borehole exploration is a compass for underground tunneling, that is, through drilling means, the occurrence conditions can be known in advance and relevant geological information can be obtained, which plays a huge role in geological exploration. When arranging a downhole gas extraction borehole in a coal seam, due to the difficulty of construction drainage, the accumulated water in the borehole cannot be discharged, thereby affecting the sealing and extraction effect, and the specific problems are as follows: ① it is difficult to drain water upward in a downhole, and water is easy to accumulate at the bottom of the hole; ② the sealing section is washed by water, resulting in poor sealing effect; ③ due to water in the extraction section, the desorption of coal seam gas is inhibited, resulting in poor extraction effect. In view of the above problems, scholars have developed a submersible pump type drainage device to solve the problem of large amount of water in the hole before sealing, but there is a risk during drainage, that is, the nozzle of the submersible pump may have high-pressure water spraying out to injure people, so it is necessary to develop a safer and more efficient downhole drainage device for extraction. SUMMARY

[0003] In view of the above technical deficiencies, the purpose of the present application is to provide a downhole long borehole air-driven automatic drainage device and method.

[0004] To solve the above technical problems, the present application adopts the following technical scheme:

[0005] The present application provides a downhole long borehole air-driven automatic drainage device, which comprises a rock breaking structure, a power structure and a pump extraction structure. The rock breaking structure is used to complete rock breaking in the coal seam and place the filtrate device of the pump extraction structure into the borehole water accumulation area. The power structure comprises an air motor and an air source for providing power to the pump extraction structure. The pump extraction structure comprises a gear pump. The inlet of the gear pump is connected with a liquid inlet pipe. The liquid return port of the gear pump is connected with a liquid return pipe. The end of the liquid return pipe is placed in a roadway drainage tank. The liquid inlet pipe is connected with the filtrate device through a one-way valve for discharging the accumulated water in the borehole water accumulation area.

[0006] Preferably, the rock breaking structure comprises a machine base, a drill rod and a drill bit connected with each other. The machine base is used to provide power to the drill rod, which drives the drill bit to complete rock breaking in the coal seam.

[0007] Preferably, the air motor comprises a motor protection shell. A transmission shaft is arranged in the motor protection shell. The transmission shaft is connected with the gear pump. A negative pressure port corresponding to the transmission shaft is arranged on the motor protection shell. The negative pressure port is connected with the air source. The air source is pressed into the motor from the negative pressure port, so as to convert wind energy into kinetic energy to drive the transmission shaft to rotate, thereby providing power for the pump extraction structure.

[0008] Preferably, the gear pump comprises a pump body shell, a pump cylinder cavity is arranged in the pump body shell, a main gear and a driven gear corresponding to the main gear are arranged in the pump cylinder cavity, the main gear is connected with a transmission shaft, and the liquid inlet and the liquid inlet pipe are arranged on the pump body shell and communicate with the pump cylinder cavity.

[0009] Preferably, the filter has a filter screen inside, and a plurality of water suction holes are arranged on the filter shell.

[0010] Preferably, the filter is fixed to the drill pipe of the rock breaking structure through a slidable buckle.

[0011] Preferably, the liquid inlet pipe and the liquid return pipe are made of an antistatic material.

[0012] The application also provides a use method of the device, comprising the following steps:

[0013] (a) arranging a downward borehole: arranging a downward borehole in a coal seam by using a rock breaking structure; under the influence of excavation stress disturbance, a large number of fissures are generated around the downward borehole, water seeps into the downward borehole through the fissures in the coal seam and accumulates at the bottom to form a water accumulation area at the bottom of the borehole;

[0014] (b) arranging a drainage device: installing the main gear of the gear pump on the transmission shaft of the pneumatic motor, connecting the liquid inlet of the gear pump with the liquid inlet pipe, connecting the filter through the one-way valve and the drainage safety pipe, and connecting the liquid return port of the gear pump with the liquid return pipe, and placing the other end of the liquid return pipe in a roadway drainage tank;

[0015] (c) arranging the filter: after the drill bit of the rock breaking structure is removed, the filter is hung on the drill pipe of the rock breaking structure close to the seat end by using the buckle; the filter is slid along the drill pipe into the water accumulation area at the bottom end of the downward borehole by using the drill pipe parallel to the downward borehole, and the sliding sequence is: the buckle is slid from the initial sliding position to the middle sliding position, and then from the middle sliding position to the end sliding position;

[0016] (d) hole sealing operation: after the filter is arranged at the bottom of the downward borehole, the gas extraction pipe and the drainage safety pipe are placed in the predetermined hole sealing section, and then the hole sealing is completed by using hole sealing materials;

[0017] (e) drainage operation: the air source is pressed into the pneumatic motor through the negative pressure port, the pneumatic motor converts the wind energy into kinetic energy to drive the transmission shaft to rotate, thereby providing power for the main gear in the pump structure, the main gear and the driven gear are engaged to drive, the working volume between the pump cylinder cavity and the engaged gear changes, thereby making the water at the bottom of the downward borehole enter the filter through the water suction hole and the filter screen, and then entering the liquid inlet pipe, the one-way valve, the liquid inlet of the gear pump and the pump cylinder cavity in sequence, and finally flowing into the roadway drainage tank through the liquid return port and the liquid return pipe.

[0018] The application has the following beneficial effects:

[0019] 1、The device of the present application is simple, safe and reliable in operation, and can continuously discharge water accumulated at the bottom of the hole through the cooperation of the filtrate device, the one-way valve, the gear pump and the air motor, thereby reducing the water content in the coal seam for a long time, improving the effect of hole sealing, grouting and gas extraction, and avoiding the high-pressure water from the drainage pipe from spraying and hurting people.

[0020] 2、The power structure of the present application adopts an air motor, which can prevent explosion and static electricity and has a more extensive gas source compared to a common motor, and can adapt to the complex and changeable roadway conditions in the mine.

[0021] 3、The filtrate device of the present application is provided with a plurality of drainage holes and filter screens, which can extend into the water accumulated at the bottom of the hole for omnidirectional drainage, and can also block slag to avoid blockage, thereby realizing efficient drainage and shortening the treatment period.

[0022] 4、The filtrate device of the present application can be matched with a drill rod, and can slide to the water accumulation area along the drill rod by relying on its own gravity, thereby being more convenient to use. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0024] Fig. 1 Fig. 1 is a structural schematic diagram of the device of the present application;

[0025] Fig. 2 Fig. 2 is an installation schematic diagram of the filtrate device of the device of the present application;

[0026] Fig. 3 Fig. 3 is a working schematic diagram of the device of the present application;

[0027] Fig. 4 Fig. 4 is a sectional view of the gear pump of the device of the present application;

[0028] Explanation of reference signs: 1 - base, 2 - drill rod, 3 - drill bit, 4 - negative pressure port, 5 - motor protection shell, 6 - transmission shaft, 7 - pump body shell, 8 - liquid inlet, 9 - liquid inlet pipe, 10 - one-way valve, 11 - liquid return port, 12 - liquid return pipe, 13 - main gear, 14 - driven gear, 15 - gear pump, 16 - pump cylinder inner cavity, 17 - buckle, 18 - filter, 19 - filter screen, 20 - water suction hole, 21 - downward drilling hole, 22 - fracture, 23 - coal seam, 24 - hole bottom water area, 25 - plugging material, 26 - gas extraction pipe, 27 - drainage safety pipe, 28 - roadway drainage groove, 29 - gas, 3001 - sliding initial position, 3002 - sliding intermediate position, 3003 - sliding end position. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0030] As Figs. 1 to 4As shown, the present example provides a downhole long drilling pneumatic automatic drainage device, the device of the present example includes a rock breaking structure I, a power structure II and a pumping structure III which work together; the rock breaking structure I includes a base 1, a drill rod 2 and a drill bit which are connected with each other; the base 1 provides power, and the drill bit 3 is driven by the drill rod 2 to complete rock breaking in the coal seam 23. The rock breaking structure I of the present example adopts the existing product or structure which is well known to those skilled in the art, and will not be described in detail herein. The rock breaking structure I of the present example has two functions: ① arranging a downhole drilling 21 in the coal seam 23 to obtain geological information; ② making the filter 18 slide downward along the inclined drill rod 2 by using the self-weight, and putting the filter 18 of the pumping structure III into the water accumulation area 24 of the drilling, so as to achieve the purpose of drainage. The power structure II includes a pneumatic motor and a wind source, and the pneumatic motor includes a negative pressure port 4, a motor protection shell 5 and a transmission shaft 6. The working mode is as follows: the wind source of the roadway is pressed into the inside of the motor by the negative pressure port 4, and the wind energy is converted into kinetic energy to drive the transmission shaft 6 to rotate, thereby providing power for the pumping structure III. The pumping structure III includes a liquid inlet pipe 9, a one-way valve 10, a liquid return pipe 12, a gear pump 15, a buckle 17 and a filter 18. The core part of the pumping structure III is the gear pump 15, and the gear pump 15 includes a liquid inlet port 8, a liquid return port 11, a main gear 13, a driven gear 14 and a pump cylinder inner cavity 16. The main gear 13 is connected with the pneumatic motor through the transmission shaft 6, and the power is transmitted by the power structure II. The main gear 13 and the driven gear 14 are fixed in the pump cylinder inner cavity 16 and are connected by meshing. The working principle of the gear pump 15 is as follows: the liquid is transported by the change and movement of the working volume between the pump cylinder inner cavity 16 and the meshing gears. The filter 18 is provided with a plurality of water suction holes 20 on the shell, so as to immerse the filter 18 in the water accumulation area 24 at the bottom of the hole, multi-directional drainage and improve the efficiency. The filter 18 is further provided with a filter screen 19, and the main function is to avoid the coal dust and coal block in the downhole drilling 21 from blocking the water suction hole, so as to cause the gear pump 15 to not discharge water. The filter 18 is provided with the buckle 17, which is hung on the drill rod 2 by the buckle 17, and slides to the water accumulation area 24 at the bottom of the drilling along the downward inclined drill rod 2 by using the self-weight. One end of the liquid inlet pipe 9 is connected with the liquid inlet port 8 of the gear pump 15, and the other end is connected with the filter 18 through the one-way valve 10. One end of the liquid return pipe 12 is connected with the liquid return port 11, and the other end is placed in the roadway drainage groove 28. The liquid inlet pipe 9 and the liquid return pipe 12 should be made of materials which are well known to those skilled in the art and have good flexibility and anti-static property, so as to facilitate the placement of the pipes and the filter 18 in the downhole drilling 21, and be applicable to drilling in different azimuth angles.

[0031] The one-way valve 10 of the present example also adopts the existing product or structure which is well known to those skilled in the art, and the connection between the one-way valve 10 and other structures also adopts the existing connection mode which is well known to those skilled in the art.

[0032] The drill pipe 2, the buckle 17 and the filter 18 of the present embodiment adopt existing products or structures known to those skilled in the art, and are connected with each other in a manner known to those skilled in the art.

[0033] The air motor, the air source and the gear pump 15 of the present embodiment adopt existing products or structures known to those skilled in the art, and are connected with each other in a manner known to those skilled in the art.

[0034] The present embodiment also provides a method for using the above device, comprising the following steps:

[0035] a. Arranging a downward borehole: arranging a downward borehole 21 in the coal seam 23 by using the rock breaking structure I; under the influence of excavation stress disturbance, a large number of fissures 22 are generated around the coal rock of the downward borehole 21, water seeps into the downward borehole 21 through the fissures 22 in the coal seam 23 and accumulates at the bottom to form a water accumulation area 24 at the bottom of the borehole;

[0036] b. Arranging a drainage device: installing the main gear 13 of the gear pump 15 on the transmission shaft 6 of the air motor, connecting the liquid inlet 8 of the gear pump 15 with the liquid inlet pipe 9, connecting the filter 18 through the one-way valve 10 and the drainage safety pipe 27, connecting the liquid return pipe 12 of the gear pump 15 with the other end of the liquid return pipe 12 placed in the roadway drainage tank 28;

[0037] c. Placing the filter: after removing the drill bit 3 of the rock breaking structure I, hanging the filter 18 on the drill pipe 2 of the rock breaking structure I near one end of the machine base 1 by using the buckle 17; sliding the filter 15 along the drill pipe 2 into the water accumulation area 24 at the bottom of the downward borehole 21 by using the drill pipe 2 parallel to the downward borehole 21, and the sliding sequence is: sliding the buckle 17 from the initial sliding position 3001 to the intermediate sliding position 3002, and then from the intermediate sliding position 3002 to the final sliding position 3003;

[0038] d. Hole sealing operation: after placing the filter 18 at the bottom of the downward borehole 21, placing the gas extraction pipe 26 and the drainage safety pipe 27 at the predetermined hole sealing section, and then completing the pump pressure hole sealing by using the hole sealing material 25; the drainage safety pipe 27 is used to protect the liquid inlet pipe 9 of the hole sealing section; the gas extraction pipe 26 and the drainage safety pipe 27 adopt existing products or structures known to those skilled in the art, and the connection or installation between them and other structures also adopts a manner known to those skilled in the art, which will not be described in detail here.

[0039] e. Drainage operation: The air source is forced into the pneumatic motor through the negative pressure port 4. The pneumatic motor converts the wind energy into kinetic energy to drive the transmission shaft 6 to rotate, providing power to the main gear 13 in the pumping structure III. The main gear 13 and the driven gear 14 mesh and drive each other. The working volume formed between the pump cylinder cavity 16 and the meshing gear changes, which causes the water accumulated at the bottom of the downward borehole 21 to enter the filter 18 through the suction hole 20 and the filter screen 19. Then it enters the inlet pipe 9, the one-way valve 10, the inlet 8 of the gear pump 15, and the pump cylinder cavity 16 in sequence, and finally flows into the roadway drainage ditch 28 from the return port 11 and the return pipe 12.

[0040] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A down-drilling, long-hole, pneumatically powered automatic drainage device, characterized in that, The system includes a rock-breaking structure (I), a power structure (II), and a pumping structure (III). The rock-breaking structure (I) is used to break rocks in the coal seam (23) and to place the filter (18) of the pumping structure (III) into the water-accumulated area (24) of the borehole. The power structure (II) includes a pneumatic motor and an air source to provide power to the pumping structure (III). The pumping structure (III) includes a gear pump (15), and the inlet (8) of the gear pump (15) is connected to an inlet valve. The return port (11) of the gear pump (15) is connected to a return pipe (12), the end of which is placed in the roadway drainage ditch (28). The inlet pipe (9) is connected to the filter (18) via a one-way valve (10) to drain the water in the borehole water accumulation area (24). The pneumatic motor includes a motor protective housing (5), and a drive shaft (6) is installed inside the motor protective housing (5). The drive shaft (6) is connected to the gear pump (15). The motor protective housing (5) is provided with a negative pressure port (4) corresponding to the drive shaft (6). The negative pressure port (4) is connected to the air source and is used to press the air source of the roadway into the motor through the negative pressure port (4), converting the wind energy into kinetic energy, and driving the drive shaft (6) to rotate, thereby providing power for the pumping structure (III). The gear pump (15) includes a pump body shell (7), and a pump cylinder cavity (16) is provided inside the pump body shell (7). The main gear (1) is provided inside the pump cylinder cavity (16). 3) The driven gear (14) is corresponding to the main gear (13). The main gear (13) is connected to the transmission shaft (6). The liquid inlet (8) and the liquid inlet pipe (9) are set on the pump body shell (7) and communicate with the pump cylinder cavity (16). The filter (18) is provided with a filter screen (19) inside. The filter (18) shell is provided with several water suction holes (20). The filter (18) is fixed to the drill rod (2) of the rock breaking structure (I) by a sliding buckle (17).

2. The down-drilling pneumatic automatic drainage device as described in claim 1, characterized in that, The rock-breaking structure (I) includes a base (1), a drill rod (2), and a drill bit (3) connected to each other. The base (1) provides power to the drill rod (2), and the drill rod (2) drives the drill bit (3) to complete rock breaking in the coal seam (23).

3. The down-drilling pneumatic automatic drainage device as described in claim 1, characterized in that, The inlet pipe (9) and return pipe (12) are made of antistatic material.

4. The method of using the down-drilling pneumatic automatic drainage device as described in any one of claims 1-3, characterized in that, Includes the following steps: (a) Arranging downholes: Using the rock-breaking structure (I), downholes (21) are arranged in the coal seam (23); Affected by the excavation stress disturbance, a large number of cracks (22) are generated in the coal and rock around the downhole (21). Water seeps into the downhole (21) through the cracks (22) in the coal seam (23) and accumulates at the bottom, forming a water accumulation area (24) at the bottom of the hole. (b) Drainage device arrangement: The main gear (13) of the gear pump (15) is installed on the drive shaft (6) of the pneumatic motor. The inlet (8) of the gear pump (15) is connected to the inlet pipe (9), and the filter (18) is connected through the check valve (10) and the drainage safety pipe (27). The return port (11) of the gear pump (15) is connected to the return pipe (12), and the other end of the return pipe (12) is placed in the roadway drainage ditch (28). (c) Installing the filter: After removing the drill bit (3) of the rock-breaking structure (I), use the clip (17) to hang the filter (18) on the drill rod (2) of the rock-breaking structure (I) near the base (1); use the drill rod (2) parallel to the downhole (21) to slide the filter (18) along the drill rod (2) to the water accumulation area (24) at the bottom of the downhole (21). The sliding sequence is as follows: the clip (17) slides from the initial sliding position (3001) to the middle sliding position (3002), and then from the middle sliding position (3002) to the end sliding position (3003). (d) Sealing operation: After placing the filter (18) at the bottom of the downhole (21), place the gas extraction pipe (26) and the drainage safety pipe (27) in the predetermined sealing section, and then use the sealing material (25) to complete the pump pressure sealing. (e) Drainage operation: The air source is forced into the pneumatic motor through the negative pressure port (4). The pneumatic motor converts the wind energy into kinetic energy to drive the drive shaft (6) to rotate, providing power to the main gear (13) in the pump structure (III). The main gear (13) and the driven gear (14) mesh and drive each other. The working volume formed between the pump cylinder cavity (16) and the meshing gear changes, so that the water accumulated at the bottom of the downhole (21) enters the filter (18) through the suction hole (20) and the filter screen (19), and then enters the inlet pipe (9), the one-way valve (10), the inlet (8) of the gear pump (15), and the pump cylinder cavity (16) in sequence. Finally, it flows into the roadway drainage ditch (28) from the return port (11) and the return pipe (12).

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