WO2012065295A1

WO2012065295A1 - System and method for gas drainage and outburst prevention in coal seam by drill-cut linkage of long drilling hole and high pressure water jet

Info

Publication number: WO2012065295A1
Application number: PCT/CN2010/078749
Authority: WO
Inventors: 陆庭侃; 李健; 高德安; 李一民
Original assignee: 湖南汉寿中煤科技有限公司
Priority date: 2010-11-15
Filing date: 2010-11-15
Publication date: 2012-05-24

Abstract

System and method for gas drainage and outburst prevention in coal seam by a drill-cut linkage of long drilling hole and high pressure water jet are provided. The system comprises a drill bit(9),a pressure induction valve(8),a drill rod(7),a drill machine(5), a high-low pressure water delivery and rotation device(6),a high pressure pump(3) and a water tank(1).The pressure induction valve(8) is mounted on the front end of the drill rod(7).The drill bit(9) is mounted on the front end of the pressure induction valve(8).A nozzle(22) is arranged on the outside of the pressure induction valve(8).The drill machine(5) drives the drill rod(7) to rotate. Water in the water tank(1) is delivered to the high-low pressure water delivery and rotation device(6) by the high pressure pump(3), into the drill rod(7) through the high-low pressure water delivery and rotation device(6), and to the pressure induction valve(8) through the drill rod(7). In the process of withdrawal of drill, coal seam is cut by high pressure water, which achieves the drill-cut linkage, improving work efficiency. The cutting diameter of the system is more than three meters, which increases the gas exposed area to more than six times of a conventional gas exposed area, and increases the range of gas release to more than three times of a conventional range of gas release, solving the problem of gas drainage and outburst prevention in coal seam.

Description

Ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system and method

Technical field

The invention discloses a coal seam gas drainage and anti-burst system and method, in particular to a long bored high pressure water jet drilling and cutting coal seam gas drainage and anti-burst system and method.

Background technique

Coal is an important energy source in people's daily life and plays an invaluable role in people's production and life. The current coal is collected from coal mines. In the process of coal mining, because of the presence of gas in the coal seam, in the process of coal mine drilling, the drainage of gas and the prevention of coal and gas are particularly prominent. Importantly, if the gas drainage cannot be performed well, there is a hidden danger of production accidents, which is likely to cause a production accident. Therefore, gas drainage is a necessary task before coal mining. At present, the gas drainage usually used in coal mines is carried out by perforating technology, that is, a plurality of holes are drilled from the top in the coal mine to allow gas to be emitted from the holes, and the main problem of this practice is That is, the hole diameter of the borehole is too small, usually about 20 cm, so that the effective exposed area is too small, the gas release range in the coal seam is too small, and dense punching, it is necessary to increase the punching time, so that the production efficiency is low, Higher production costs, etc. Although, in the current field of coal drilling research, some other methods of gas drainage have been proposed, such as: first, the hole is cut, and then the water cutting system is inserted into the hole for water cutting. However, due to the complicated underground geological structure, usually When the gas is pumped, the drilled holes are not straight up and down, but are bent and skewed. Thus, the water cutting system is not easy to insert into the hole, and it is usually used at a depth of ten or twenty meters. When the depth of the hole reaches 100-200 meters, even a depth of several hundred meters, it seems to be powerless, so the above practice only stays in the ideal state of the experiment, and can not be applied in actual production; another method is proposed, namely The abrasive is set at the drill bit. When the drill hole reaches the set depth, the coal layer is cut by spraying the abrasive to achieve the purpose of gas drainage. However, in this situation, the abrasive cannot be replenished and is inconvenient to use, so it only stays. In the research phase, it cannot be applied to actual production.

Summary of the invention

In view of the above-mentioned prior art coal mine gas drainage system, the drainage effect is not good, the present invention provides a new gas drainage method and system, which drills the hole to the set position, During the process of retreating, intermittently spraying high-pressure water and rotating the coal seam to expand the gas drainage area.

The technical solution adopted by the present invention to solve the technical problem is: an ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system, the system includes a drill bit, a pressure sensing valve, a drill pipe, a drilling machine, and a high and low pressure transmission. The water rotating device, the high pressure pump and the water tank, the pressure sensing valve is installed at the front end of the drill pipe, the drill bit is installed at the front end of the pressure sensing valve, the nozzle is installed outside the pressure sensing valve, the drilling machine drives the drill pipe to rotate, and the water in the water tank is transmitted to the high through the high pressure pump. The low-pressure water transfer rotating device is input into the drill pipe by the high-low pressure water transfer rotating device, and is transmitted to the pressure sensing valve through the drill pipe.

The method for realizing ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst by using the above-mentioned ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system, the method comprises the following steps :

A. The drilling machine drives the drill rod to rotate, and the drill rod drives the drill bit to rotate, and performs drilling;

B. After drilling to the set depth, the high pressure water is injected into the drill pipe by the high pressure pump to a pressure of 30MPa-70MPa. The high pressure water is sprayed from the side of the pressure sensing valve. At the same time, the drill drives the drill pipe to rotate, and the drill pipe drives the pressure. The induction valve rotates, and the high pressure water sprayed by the pressure sensing valve rotates and cuts the coal seam;

C. When the cutting time is set to 2min-5min or the cutting radius reaches a depth of 0.5m-3.5m, the high-pressure pump stops injecting high-pressure water into the drill pipe, stops the rotary cutting of the coal seam, and the drill drives the drill pipe to rotate, and the drill pipe drives Pressure sensing valve and drill bit retreat;

D, after the drill bit is back set length, repeat step B;

E. Repeat steps C and D until the drill bit retreats to a depth that does not require cutting. The drill drives the drill rod to rotate. The drill rod drives the pressure sensing valve and the drill bit to retreat and exit.

The technical solution adopted by the present invention to solve the technical problem thereof further includes:

The pressure sensing valve comprises a valve body, a coupling head, a valve sleeve, a spring sleeve, a valve core, a ejector rod and a spring. The valve body is hollow, and a partition plate is arranged in the middle of the valve body, and the partition plate has a main body a water hole and a secondary water hole, the first water spray hole is opened on the side of the valve body; the joint head is also hollow, and the joint head is fixedly mounted with the valve body to form a cavity; the valve sleeve is disposed in the joint The cavity formed by the joint and the valve body is a through hole in the middle of the valve sleeve, and a second water spray hole is opened on the side of the valve sleeve, and the second water spray hole is correspondingly arranged with the first water spray hole, and the valve core is disposed in the valve sleeve. And matching with the shape of the through hole in the valve sleeve; the spring sleeve is also disposed in the cavity formed by the coupling head and the valve body, the middle of the spring sleeve is a cavity, the spring is disposed in the spring sleeve, the spring sleeve and the valve sleeve An end cover is provided at one end, an open through hole and a second water passage on the end cover, and the cross hole of the through hole on the end cover is smaller than the cross section of the through hole in the middle of the valve sleeve, and the cross hole of the through hole on the end cover is smaller than the spring cover a cross section of the intermediate cavity; the ram includes a head and a support rod connected together, the head of the ram Placed in the spring sleeve, the support rod of the jack is inserted into the through hole in the end cover of the spring sleeve, and is in contact with the valve core, and the cross-sectional shape of the head of the jack is different from the cross-sectional shape of the cavity in the spring sleeve. The shape of the cross-section of the support rod of the ejector pin coincides with the cross-sectional shape of the through-hole on the end cover of the spring sleeve; the first water storage chamber is formed between the valve core and the end cover of the spring sleeve, and the valve sleeve is opened with the connection pair a water hole and a first water channel of the first water storage chamber, the first water channel can be blocked by the valve core when the spring is squeezed; a second water storage chamber is formed between the head of the ejector pin and the spring cover end cover, The second water channel communicates with the first water storage chamber and the second water storage chamber; a third water storage chamber is formed between the head of the ejector rod and the spring sleeve, and the second water storage chamber is connected to the head of the ejector rod The third water channel of the third water storage chamber; the spring is disposed in the third water storage chamber and pushes the head of the ejector pin.

The inner end of the spring sleeve is provided with a pressure regulating bolt, and a water outlet hole is opened in the middle of the pressure regulating bolt, and one end of the spring abuts against the head of the ejector pin, and the other end abuts against the pressure regulating bolt.

The pressure regulating bolt is internally provided with a first limiting platform, and the spring is set on the first limiting platform.

The side of the coupling head has a positioning hole corresponding to the pressure regulating bolt, and a positioning screw is disposed in the positioning hole.

A nozzle is fixedly mounted in the first water spray hole outside the valve body.

The front end of the ejector pin is provided with a second limit stop, and the spring is set on the second limit stop.

The second limiting platform is provided with a water tank in the middle, and the second water channel is inclined, and connects the water tank and the first water storage chamber.

The first sealing groove is disposed on the outer side of the second sealing hole, and a first sealing ring is disposed in each of the first sealing grooves.

The valve sleeve has a fourth water storage chamber corresponding to one end of the partition.

The outer side of the valve sleeve has a second sealing groove corresponding to one end of the spring sleeve, and a second sealing ring is disposed in the second sealing groove. The drill pipe is connected by a plurality of drill pipes, and the soft seal structure between the adjacent drill pipes includes a male end of the drill pipe and a female end of the drill pipe, and the male end of the drill pipe and the female end of the drill pipe are hollow structures, and the drill pipe The male end is provided with a truncated-shaped connecting head, and the truncated-shaped connecting head is provided with a taper thread, and the female end of the drill rod is provided with a connecting groove matching the shape of the connecting head, and the connecting groove is provided with a tapered thread, and the front end of the connecting head A positioning head with a circular cylinder shape is fixed, and a positioning groove matching the shape of the positioning head is opened at the bottom of the connecting groove, and a sealing ring is set on the positioning head.

The positioning head is provided with two third sealing grooves, and each third sealing groove is provided with a third sealing ring.

The positioning head and the positioning groove are gap-fitted, and the gap width between the positioning head and the positioning groove is between 0.04MM and 0.1MM.

The gap between the positioning head and the positioning groove is 0.06 mm.

The positioning head is provided with a sealing groove, and the sealing ring is disposed in the sealing groove.

The sealing groove has a depth of 1.99-2.025 mm, and the sealing ring body has a cross-sectional diameter of 2.5-2.6 mm.

The sealing groove has a depth of 2 mm, and the sealing ring body has a cross-sectional diameter of 2.6 mm.

The positioning head has a length of 25 mm.

The thread on the connecting head is an external thread, and the thread on the connecting groove is an internal thread.

In the step A, when drilling, the high pressure pump injects a water pressure of 2 MPa-10 MPa into the drill pipe, and the low pressure water flows out from the front end of the pressure sensing valve to cool the drill bit.

In the step D described above, the drill retreat length is 0.2m-3m (depending on the case).

In the step C, the drilling machine drives the drill rod to rotate, and when the drill rod drives the pressure sensing valve and the drill bit retreats, the rotation direction of the drill shaft driven by the drilling machine is consistent with the rotation direction of the drilling rod driven by the drilling machine in step A.

The invention has the advantages that the structure of the invention is simple and the structure is ingenious. The invention cuts the coal seam by high-pressure water during the process of retreating, and realizes the drilling and cutting linkage. By using the invention, the cutting diameter can be more than 3 meters, thereby increasing the gas exposure area by more than 6 times in the conventional one, effectively increasing the gas release range by more than 3 times, and simultaneously releasing the gas pressure and the coal seam stress in the coal seam. Increasing the efficiency of gas drainage in coal seams has effectively alleviated the problems of gas outbursts that have plagued coal mines for many years, the excessively long gas drainage time in this coal seam, and the problem of mine mining imbalance. At the same time, the invention can greatly reduce the number of drill holes, improve production efficiency, and reduce production costs.

DRAWINGS

Figure 1 is a block diagram of the system of the present invention.

2 is a schematic view of a gas drainage punching structure in the prior art.

Fig. 3 is a schematic view showing the structure of gas drainage and punching in the present invention.

4 is a schematic view showing the structure of an exploded state of a soft seal structure between a drill pipe and a drill pipe according to the present invention.

FIG. 5 is a schematic cross-sectional structural view of a soft seal structure between a drill pipe and a drill pipe according to the present invention.

Fig. 6 is a schematic cross-sectional structural view showing the state of the soft seal structure between the drill pipe and the drill pipe in the present invention.

Figure 7 is a schematic cross-sectional view showing the pressure sensing valve of the present invention.

In the picture, 1-water tank, 2-water pipe, 3-high pressure pump, 4-high pressure pipe, 5-drill, 6-high and low pressure water transfer rotating device, 7-drill pipe, 8-pressure induction valve, 9-bit, 10 - hole, 11-ground, 12-drill male end, 13-drilled rod female end, 14-joint, 15-connecting groove, 16-positioning head, 17-positioning groove, 18-third sealing groove, 19- Third sealing ring, 20-valve body, 21-first sealing ring, 22-nozzle, 23-valve, 24-valve, 25-spring sleeve, 26-rod, 27-spring, 28-joint, 29-positioning screw, 30-pressure bolt, 31-fourth water storage chamber, 32-first waterway, 33-second water spray hole, 34-first water storage chamber, 35-second water channel, 36- Second water storage chamber, 37-third water channel, 38-third water storage chamber, 39-water outlet, 40-first limit station, 41-main water hole, 42-pair water hole, 43-first seal groove 44-first spray hole, 45-second seal groove, 46-second seal ring, 47-sink, 48-second limit table, 49-head, 50-support rod, 51-separator.

detailed description

This embodiment is a preferred embodiment of the present invention, and other principles and basic structures are the same as or similar to those of the present embodiment, and are all within the scope of the present invention.

Referring to Figure 1, the system of the present invention mainly comprises a drill bit 9, a pressure sensing valve 8, a drill pipe 7, a drilling machine 5, a high and low pressure water transfer rotating device 6, a high pressure pump 4 and a water tank 1. In this embodiment, a pressure sensing valve 8 is installed at the front end of the drill pipe 7. The pressure sensing valve 8 can automatically adjust the water discharge direction and flow rate according to the water pressure. When the pressure is low, the high pressure water spray hole 22 is blocked, and the water flows out from the low pressure water outlet hole. The main purpose of the water is to cool and slag the drill bit 9 during the drilling process; when the pressure of the water increases to a certain pressure, the pressure sensing valve 8 automatically blocks the low pressure outlet hole, and the water can only pass through the high pressure water injection hole 22 Sprayed out to achieve the purpose of cutting hard materials. Referring to FIG. 7, the embodiment mainly includes a valve body 20, a coupling head 28, a valve sleeve 24, a spring sleeve 25, a valve core 23, a plunger 26 and a spring 27. The valve body 20 and the coupling head 28 are mounted together to form In the main body of this embodiment, in the present embodiment, the valve body 20 and the coupling head 28 are screwed together. In the embodiment, the valve body 20 has a hollow shape, and a partition plate 51 is disposed in the middle of the valve body 20 (the partition plate 51 and the valve body 20 are integrally disposed), and the partition plate 51 has a main water hole 41 and a sub water hole 42 therein, wherein The main water hole 41 is opened at the intermediate position of the partition plate 51. In this embodiment, the rear end of the valve body 20 is internally threaded for connection with the drill pipe. In this embodiment, the first water spray hole 44 is opened in the side of the valve body 20, and the nozzle 22 is fixedly mounted in the first water spray hole 44 for discharging high pressure water to cut the coal seam. In this embodiment, the valve body 20 Two first water spray holes 44 are opened in the side. In this embodiment, the coupling head 28 is also hollow, and the coupling head 28 is fixedly mounted with the valve body 20 to form a cavity, and the valve sleeve 24 and the spring sleeve 25 are disposed in the cavity. In this embodiment, the valve sleeve 24 has a hollow cylindrical shape, a cylindrical through hole is formed in the valve sleeve 24, and the valve core 23 is disposed in the valve sleeve 24. In the embodiment, the valve core 23 is also cylindrical, and the valve core is The cross-sectional diameter of 23 coincides with the diameter of the through hole in the valve sleeve 24, so that the spool 23 can just slide within the valve sleeve 24. In this embodiment, the second water spray hole 33 is opened on the side of the valve sleeve 24, and the second water spray hole 33 is disposed corresponding to the first water spray hole 44 on the valve body 20, so that water can pass through the second side of the valve sleeve 24. The water spray hole 33 and the nozzle 22 provided in the first water spray hole 44 are ejected. In this embodiment, the middle of the spring sleeve 25 is also a hollow structure, the main body of the spring sleeve 25 is cylindrical, and the inner through hole is also cylindrical. One end of the spring sleeve 25 and the valve sleeve 24 is provided with an end cover (the end cover is integrally provided with the spring sleeve 25), and a through hole is formed in the middle of the end cover, and one or more third water channels 37 are opened beside the through hole. The diameter of the through hole at the end cap is smaller than the diameter of the through hole in the valve sleeve 24, and is smaller than the diameter of the through hole in the spring sleeve 25. The jack 26 is disposed in the spring sleeve 25. In the embodiment, the jack 26 includes a head 49 and a support rod 50 connected together. The head 49 of the jack 26 is disposed in the spring sleeve 25, and the support of the jack 26 The rod 50 is inserted into the through hole in the end cover of the spring sleeve 25, and extends into the valve sleeve 24 and is in contact with the valve core 23. The cross-sectional shape of the head 49 of the jack 26 and the through hole in the spring sleeve 25 The cross-sectional shape coincides that the cross-sectional shape of the support rod 50 of the ram 26 coincides with the cross-sectional shape of the through-hole on the end cap of the spring sleeve 25. In this embodiment, the second limit stop 48 is fixedly disposed at the front end of the head 49 of the jack 26 . In this embodiment, the front end of the spring sleeve 25 is internally provided with an internal thread, and the front end of the spring sleeve 25 is screwed with a pressure regulating bolt 30. The coupling head 28 and the spring sleeve 25 are provided with screw holes, screws at positions corresponding to the pressure regulating bolt 30. A positioning screw 29 is provided in the hole, and the position of the spring sleeve 25 and the coupling head 28 can be fixed by the positioning screw 29. In this embodiment, the pressure regulating bolt 30 is provided with a first limiting platform 40, the spring 27 is disposed in the spring sleeve 25, one end of the spring 27 is set on the first limiting platform 40, and the other end of the spring 27 is set in the second limit. On the station 48.

In this embodiment, a first water storage chamber 34 is formed between the valve core 23 and the end cover of the spring sleeve 25. The valve sleeve 24 is provided with a first water passage 32 connecting the auxiliary water hole 42 and the first water storage chamber 34; A second water storage chamber 36 is formed between the head 49 of the rod 26 and the end cover of the spring sleeve 25. The end cover of the spring sleeve 25 is provided with a second water passage 35. The second water passage 35 communicates with the first water storage chamber 34 and the second storage. a water chamber 36; a third water storage chamber 38 is formed between the head 49 of the jack 26 and the spring sleeve 25, and a third water passage 37 is opened on the head 49 of the jack 26. In this embodiment, the head 49 is The second limiting station 48 is provided with a water tank 47. The water tank 47 is in communication with the third water storage chamber 38. The third water channel 37 is disposed obliquely. The third water channel 37 communicates with the water tank 47 and the second water storage chamber 36. In this embodiment, An annular groove is further formed at the rear end of the valve sleeve 24. A fourth water storage chamber 31 is formed between the valve sleeve 24 and the valve body 20. The auxiliary water hole 42 and the first water channel 32 are respectively communicated with the fourth water storage chamber 31. The four water storage chambers 31 facilitate the installation between the valve sleeve 24 and the valve body 20.

The first sealing groove 43 is opened on the outer side of the valve sleeve 24. In the embodiment, the first sealing groove 43 is provided with two sides, which are respectively disposed on two sides of the second water spray hole 33, and each of the first sealing grooves 43 is disposed therein. A first seal ring 21 prevents water from escaping between the valve sleeve 24 and the valve body 20 through the first seal ring 21. In order to further achieve a better waterproof effect, in the embodiment, a second sealing groove 45 is opened at one end of the sleeve 24 corresponding to the spring sleeve 25, and a second sealing ring 46 is disposed in the second sealing groove 45.

In the present embodiment, the drill bit 9 is mounted on the front end of the pressure sensing valve 8 for drilling, and the drilling machine 5 drives the drill rod 7 to rotate, and the drill rod 7 drives the pressure sensing valve 8 and the drill bit 9 to rotate. The water tank 1 is filled with clean water, and the water in the water tank 1 is transferred to the high pressure pump 3 through the water pipe 2, and the high pressure pump 3 pressurizes the water and transmits it to the high and low pressure water transfer rotating device 6 through the high pressure pipe 4, and the high and low pressure water transfer rotating device 6 The water in the high pressure pipe 4 can be changed from a stationary state to a rotating state, and at the same time, the sealing and the pressure can be kept constant. In the present embodiment, the high and low pressure water transfer rotating device 6 adopts the model P8P8 produced by the StoneAge Company of the United States. Low pressure water transfer rotating device. Water is supplied to the drill pipe 7 by the high and low pressure water transfer rotating device 6, and water is transferred to the pressure sensing valve 8 through the drill pipe 7. In the present invention, the drill pipe 7 adopts a hollow drill pipe, and the drill pipe 7 is connected by a plurality of drill pipes. Generally, the length of the drill pipe 7 is about 700 mm-1500 mm, and the drill pipe 7 can be filled with high-pressure water, and In the state of high pressure, there is no leakage or the like at the joint between adjacent drill pipes. In this embodiment, the soft seal structure between the drill pipe and the drill pipe is specially designed. Please refer to FIG. 4 As shown in FIG. 6 , the joint between the drill pipe and the drill pipe of the present invention mainly comprises a drill pipe male end 12 and a drill pipe female end 13 . In specific production, generally one end of one drill pipe 7 is a drill pipe male end 12 . The other end is the drill rod female end 13, which can also be designed as a special drill rod with both ends of the drill rod male end 12 or both ends of the drill rod female end 13. In use, the drill rod male end 12 is inserted into the drill rod female end 13 for use. In this embodiment, the front end of the male end 12 of the drill pipe is a truncated-shaped connector 14 , and the front end of the connector 14 is fixedly provided with a cylindrical positioning head 16 . Since the drill pipe is a hollow rod, the connector 14 is actually hollow. In the shape of a truncated cone, the positioning head 16 has a substantially circular cross section, and the positioning head 16 has a circular cylindrical shape. In this embodiment, the front end of the drill rod female end 13 is a truncated-shaped connecting groove 15, and the shape of the connecting groove 15 is matched with the shape of the connecting head 14. The rear of the connecting groove 15 is a cylindrical positioning groove 17, and the shape of the positioning groove 17 It conforms to the shape of the positioning head 16. In this embodiment, the connecting head 14 is provided with a taper thread on the outside, the external thread of the connecting head 14 is an external thread, and the connecting groove 15 is provided with a taper thread corresponding to the thread on the connecting head 14, and the thread on the connecting groove 15 is The internal thread, in use, can be fixedly mounted between the two drill rods through the joint 14 and the thread at the connecting groove 15. The positioning head 16 of the embodiment is inserted into the positioning slot 17 , and the positioning head 16 and the positioning slot 17 are matched by a gap. The gap width between the positioning head 16 and the positioning slot 6 is between 0.04 MM and 0.1 MM. The length of the positioning head 16 in this embodiment is 25 mm. The invention adopts a special structural design, which can ensure that the breaking phenomenon between the drill pipe and the drill pipe does not occur under a certain degree of curvature, and Ensure the tightness between the drill pipe and the drill pipe. In order to further ensure the tightness between the drill pipe and the drill pipe, a third sealing groove 18 is formed in the positioning head 16. In the embodiment, the positioning head 16 is provided with two third sealing grooves 18, each of which is third. A third sealing ring 19 is disposed in the sealing groove 18. The third sealing groove 18 in the embodiment has a depth of 1.99 MM to 2.025 MM, preferably 2 MM, and the cross-sectional diameter of the ring body of the third sealing ring 19 is Between 2.5MM-2.6MM, preferably 2.6MM, by providing a third sealing ring 19 on the positioning head 16, the sealing between the drill pipe and the drill pipe can be further ensured, so that it can not be under the high pressure of 70MPa. Water leakage, water seepage, etc. may occur. The third sealing ring 19 in this embodiment may adopt various structural forms such as an O-ring, a Y-ring or a drum ring. The drill rod and the drill rod of the invention adopt a truncated cone-shaped connecting structure, and a tapered thread is arranged on the truncated cone-shaped connecting structure, thereby ensuring the firmness of the connection between the drill rod and the drill rod, and the invention is in the joint head The front end is provided with a circular positioning head, and a clearance fit is adopted between the positioning head and the positioning groove, which can ensure that there is no disconnection between the drill pipe and the drill pipe under a certain degree of curvature, and the drill pipe can be ensured. The sealing property with the drill pipe, at the same time, the invention also has a sealing groove on the positioning head, and a sealing ring is arranged in the sealing groove, which can further ensure the sealing between the drill pipe and the drill pipe, and ensure that it is at 70 MPa. There will be no leakage or water seepage under the conditions.

When the invention is used, the following steps are included:

A. The drilling machine drives the drill rod to rotate, and the drill rod drives the drill bit to rotate and drill. In the present embodiment, when drilling, the high pressure pump 3 injects the water pressure into the drill pipe 7 into a low pressure water of 2 MPa-10 MPa, and the low pressure water is pressurized. The front end of the induction valve 8 flows out to cool the drill bit 9;

B. After drilling to a set depth, a high pressure water is injected into the drill pipe 7 through the high pressure pump 3, and the high pressure water is sprayed from the side of the pressure sensing valve 8. At the same time, the drill 5 drives the drill pipe 7 to rotate. The drill pipe 7 drives the pressure sensing valve 8 to rotate, and the high pressure water sprayed by the pressure sensing valve 8 rotates and cuts the coal seam. When cutting, the rotation direction of the drill pipe 7 coincides with the rotation direction when drilling, so that the drill pipe and the drill pipe Will not be disconnected between;

C. When the cutting time is set to 2 min - 5 min or the cutting radius reaches a depth of 0.5 m - 3.5 m (depending on the specific situation), the high pressure pump 5 stops injecting high pressure water into the drill pipe 7 to stop the rotary cutting of the coal seam. The drilling machine 5 drives the drill rod 7 to rotate, and the drill rod 7 drives the pressure sensing valve 8 and the drill bit 9 to retreat. When retracting, the rotation direction of the drill rod 7 is consistent with the rotation direction when drilling, so that the drill rod and the drill rod are not broken. open;

D, after the drill bit retreats the set length, usually, each time the drill retreat length is between 0.2 m and 3 m (depending on the specific circumstances), each time the drill bit 9 is retracted, the step B is repeated;

E. Then repeat steps C and D until the drill bit retreats to a depth that does not require cutting. The drill drives the drill rod to rotate, the drill rod drives the pressure sensing valve and the drill bit retreats, exits, and is completed.

In the present invention, the high pressure pump 3 is used to press water into the pressure sensing valve 8. The present invention is divided into two types of high pressure and low pressure use. When the present invention operates in a low pressure state, the high pressure pump 3 provides low pressure water having a pressure of about 2 MPa to 10 MPa, and the spring 27 is in an extended state. At this time, the spool 23 blocks the second water spray hole 33 to expose the first water passage 32. The low-pressure water flows from the auxiliary water hole 42 into the first water storage chamber 34 through the first water channel 32, flows into the second water storage chamber 36 through the second water channel 35, and then flows into the third water storage chamber 38 through the third water channel 37. And flowing out through the water outlet hole 39 to cool the drill bit; when there is a low pressure to the high pressure state, the high pressure pump 3 supplies high pressure water with a pressure of about 30 MPa to 70 MPa, and the high pressure water is not timely when flowing from the first water channel 32. When the high pressure water pushes the spool 23 forward, the spool 23 pushes the plunger 26, and the plunger 26 presses the spring 27 to compress the spring 27. When the spool 23 moves to a certain extent, the spool 23 blocks the first channel 32, the second water spray hole 33 is exposed, and water is sprayed from the second water spray hole 33 through the nozzle 22 on the side to achieve the purpose of cutting the coal seam. When the invention is used, the pressure of the conversion of the present invention can be adjusted by adjusting the pressure regulating bolt 30. When adjusting, the positioning screw 29 is first loosened, and then the bolt 30 is adjusted by the twisting, when the pressure regulating bolt 30 is rotated forward. The switching pressure of the present invention is lowered; when the pressure regulating bolt 30 is rotated backward, the switching pressure of the present invention is increased.

The invention has simple structure and ingenious structure. With the invention, the cutting diameter can reach more than 3 meters, thereby increasing the gas exposure area by more than 6 times in the conventional one, effectively increasing the gas release range by more than 3 times, and simultaneously releasing effectively. The gas pressure and coal seam stress in the coal seam improve the gas drainage efficiency of the coal seam, which makes the gas outburst problem that has plagued the coal mine for many years, the gas drainage time of the coal seam is too long, and the problem of coal mine mining imbalance is effectively alleviated. At the same time, the invention can greatly reduce the number of drill holes, improve production efficiency, and reduce production costs. At the same time, at the cutting point, due to the self-stress of the coal seam, the coal seam will naturally break, which further increases the gas exposure and drainage area.

Claims

An ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system, characterized in that: the system comprises a drill bit, a pressure sensing valve, a drill pipe, a drilling machine, a high and low pressure water transfer rotating device, a high pressure pump And the water tank, the pressure sensing valve is installed at the front end of the drill rod, the drill bit is installed at the front end of the pressure sensing valve, the nozzle is installed outside the pressure sensing valve, the drilling machine drives the drill rod to rotate, and the water in the water tank is transmitted to the high and low pressure water conveying rotating device through the high pressure pump. The drill pipe is input from the high and low pressure water transfer rotating device and transmitted to the pressure sensing valve through the drill pipe.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 1, wherein the pressure sensing valve comprises a valve body, a coupling head, a valve sleeve, a spring sleeve and a valve. The core body, the ejector rod and the spring, the valve body is hollow, and a partition plate is arranged in the middle of the valve body, the main water hole and the auxiliary water hole are opened in the partition plate, and the first water spray hole is opened on the side of the valve body; The coupling head is also hollow, and the coupling head is fixedly mounted with the valve body to form a cavity; the valve sleeve is disposed in the cavity formed by the coupling head and the valve body, the through hole is in the middle of the valve sleeve, and the side of the valve sleeve a second water spray hole is opened, and the second water spray hole is disposed corresponding to the first water spray hole, and the valve core is disposed in the valve sleeve and conforms to the shape of the through hole in the valve sleeve; the spring sleeve is also disposed at The cavity formed by the coupling head and the valve body is a cavity in the middle of the spring sleeve, the spring is disposed in the spring sleeve, the end cover is provided at one end of the spring sleeve and the valve sleeve, the through hole on the end cover and the second water channel, the end The cross section of the through hole in the cover is smaller than the cross section of the through hole in the middle of the valve sleeve, and the cross section of the through hole on the end cover is also small a cross section of the cavity in the middle of the spring sleeve; the ejector rod includes a head and a support rod connected together, the head of the ejector rod is disposed in the spring sleeve, and the support rod of the ejector rod is inserted into the spring sleeve end cover In the upper through hole and in contact with the valve core, the cross-sectional shape of the head of the ejector pin coincides with the cross-sectional shape of the cavity in the spring sleeve, and the cross-sectional shape of the support rod of the ram and the end of the spring cover end cover The cross-sectional shape of the hole is matched; the first water storage chamber is formed between the valve core and the spring cover end cover, and the valve sleeve is opened with a first water passage connecting the auxiliary water hole and the first water storage chamber, when the spring is squeezed a first water channel can be blocked by the valve core; a second water storage chamber is formed between the head of the ejector pin and the spring cover end cover, and the second water channel communicates with the first water storage chamber and the second water storage chamber; a third water storage chamber is formed between the head of the ejector and the spring sleeve, and a third water passage connecting the second water storage chamber and the third water storage chamber is opened on the head of the ejector; the spring is disposed at the The pressure sensing valve described in the three water storage chamber and pushing the head of the ejector includes a valve body, a coupling head, a valve sleeve, a spring sleeve, and a valve core a ejector rod and a spring, the valve body is hollow, and a diaphragm is arranged in the middle of the valve body, the main water hole and the auxiliary water hole are opened on the partition plate, and the first water spray hole is opened on the side of the valve body; The joint is also hollow, and the joint is fixedly mounted with the valve body to form a cavity; the valve sleeve is disposed in the cavity formed by the joint head and the valve body, the middle of the valve sleeve is a through hole, and the side of the valve sleeve is opened a second water spray hole, the second water spray hole is correspondingly arranged with the first water spray hole, the valve core is disposed in the valve sleeve, and is matched with the shape of the through hole in the valve sleeve; the spring sleeve is also disposed at the joint In the cavity formed by the valve body, the middle of the spring sleeve is a cavity, the spring is disposed in the spring sleeve, and the end cover is provided at one end of the spring sleeve and the valve sleeve, the through hole on the end cover and the second water channel, the end cover The cross-section of the through hole is smaller than the cross section of the through hole in the middle of the valve sleeve, and the cross section of the through hole on the end cover is also smaller than the cross section of the cavity in the middle of the spring sleeve; the ejector includes the head and the support connected together The rod of the ejector rod is disposed in the spring sleeve, and the support rod of the ejector rod is inserted into the through hole of the spring sleeve end cover And in contact with the valve core, the cross-sectional shape of the head of the ram matches the cross-sectional shape of the cavity in the spring sleeve, and the cross-sectional shape of the support rod of the ram and the cross-sectional shape of the through hole on the end cover of the spring sleeve The first water storage chamber is formed between the valve core and the spring sleeve end cover, and the valve sleeve is opened with a first water passage connecting the auxiliary water hole and the first water storage chamber. When the spring is squeezed, the first water channel can Blocked by the valve core; a second water storage chamber is formed between the head of the ejector and the spring cover end cover, and the second water passage communicates with the first water storage chamber and the second water storage chamber; a third water storage chamber is formed between the head and the spring sleeve, and a third water passage connecting the second water storage chamber and the third water storage chamber is opened on the head of the top rod; the spring is disposed in the third water storage chamber, And push the head of the ejector.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 2, wherein: the inner sleeve of the spring sleeve is provided with a pressure regulating bolt, and the pressure regulating bolt has a water outlet in the middle. Hole, one end of the spring against the head of the ejector pin and the other end against the pressure regulating bolt.
The pressure sensing valve according to claim 3, wherein the pressure regulating bolt is internally provided with a first limiting platform, and the spring is sleeved on the first limiting platform.
The pressure sensing valve according to claim 3 or 4, wherein the side of the coupling head has a positioning hole corresponding to the pressure regulating bolt, and the positioning hole is provided with a positioning screw.
The pressure sensing valve according to claim 2, wherein a nozzle is fixedly mounted in the first water spray hole outside the valve body.
The pressure sensing valve according to claim 2, wherein the front end of the ejector pin is provided with a second limit stop, and the spring is sleeved on the second limit stop.
The pressure sensing valve according to claim 7, wherein the second limiting table is provided with a water tank in the middle, and the second water channel is inclined to communicate with the water tank and the first water storage chamber.
The pressure sensing valve according to claim 2, wherein the outer side of the valve sleeve is provided with a first sealing groove, and the first sealing groove is respectively provided on the front and rear sides of the second water spraying hole, and each of the first A first sealing ring is arranged in the sealing groove.
The pressure sensing valve according to claim 2, wherein said valve sleeve has a fourth water storage chamber corresponding to one end of the partition.
The pressure sensing valve according to claim 2, wherein the outer side of the valve sleeve has a second sealing groove corresponding to one end of the spring sleeve, and the second sealing ring is disposed in the second sealing groove.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 1, wherein the drill pipe is connected by a plurality of drill pipes, between adjacent drill pipes. The soft sealing structure comprises a male end of the drill pipe and a female end of the drill pipe, the male end of the drill pipe and the female end of the drill pipe are hollow structures, the male end of the drill pipe is provided with a truncated cone connector, and the truncated cone connector is provided with a taper thread. The female end of the drill rod is provided with a connecting groove matching the shape of the connecting head, the connecting groove is provided with a taper thread, and the front end of the connecting head is fixedly provided with a circular cylindrical positioning head, and the bottom of the connecting groove is formed with a positioning head shape The matching positioning groove is provided with a sealing ring on the positioning head.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 12, wherein the positioning head and the positioning groove are gap-fitted, and between the positioning head and the positioning groove The gap width is between 0.04MM and 0.1MM.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 13, wherein the gap width between the positioning head and the positioning groove is 0.06 mm.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 12, wherein the positioning head is provided with a sealing groove, and the sealing ring is disposed in the sealing groove.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 15, wherein the sealing groove depth is between 1.99MM and 2.025MM, and the sealing ring body is horizontally The cross-sectional diameter is between 2.5MM and 2.6MM.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 16, wherein the sealing groove has a depth of 2 mm, and the sealing ring body has a cross-sectional diameter of 2.6 mm.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to claim 15 or 16 or 17, wherein the positioning head has two sealing grooves, each sealing There is a sealing ring in the groove.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to any one of claims 12 to 17, wherein the positioning head has a length of 25 mm.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst system according to any one of claims 12 to 17, wherein the thread on the connecting head is an external thread, and the connecting groove The upper thread is internal thread.
A gas drainage and anti-burst system for ultra-long borehole high-pressure water jet drilling and cutting coal seams according to any one of claims 1 to 20, realizing gas drainage of ultra-long borehole high-pressure water jet drilling and cutting coal seam A method for preventing protrusion, characterized in that: the method comprises the following steps:

A. The drilling machine drives the drill rod to rotate, and the drill rod drives the drill bit to rotate, and performs drilling;

B. After drilling to the set depth, the high pressure water is injected into the drill pipe by the high pressure pump to a pressure of 30MPa-70MPa. The high pressure water is sprayed from the side of the pressure sensing valve. At the same time, the drill drives the drill pipe to rotate, and the drill pipe drives the pressure. The induction valve rotates, and the high pressure water sprayed by the pressure sensing valve rotates and cuts the coal seam;

C. When the cutting time is set to 2min-5min or the cutting radius reaches a depth of 0.5m-3.5m, the high-pressure pump stops injecting high-pressure water into the drill pipe, stops the rotary cutting of the coal seam, and the drill drives the drill pipe to rotate, and the drill pipe drives Pressure sensing valve and drill bit retreat;

D, after the drill bit is back set length, repeat step B;

E. Repeat steps C and D until the drill bit retreats to a depth that does not require cutting. The drill drives the drill rod to rotate. The drill rod drives the pressure sensing valve and the drill bit to retreat and exit.
The method according to claim 21, wherein the high-pressure pump injects water into the drill pipe during the drilling, when the hole is drilled, the high-pressure pump injects water into the drill pipe. The pressure is 2MPa-10MPa low pressure water, and the low pressure water flows out from the front end of the pressure sensing valve to cool the drill bit.
The ultra-long borehole high-pressure water jet drilling and cutting coal seam gas drainage and anti-burst method according to claim 21, wherein in the step D, the drill retreat length is 0.2m-3m.
The method according to claim 21 or 22 or 23, wherein the rig is driven to rotate the drill pipe and the drill pipe is in the step C. When the pressure sensing valve is driven and the drill bit is retracted, the rotation direction of the drill pipe driven by the drilling machine is the same as the rotation direction of the drill pipe driven by the drilling machine in step A.