CN110173216A - A kind of gas drainage pore radius is with boring adjustable type drilling apparatus and its working method - Google Patents

Abstract

The invention relates to a drilling device whose radius can be adjusted while drilling a gas drainage hole and its working method. It comprises a drill bit and a drill pipe connected together. A bracket body is placed, and the expansion body located inside the tubular structure is fixedly connected to the bottom of the bracket body. There are circular and evenly distributed branch pipes, which are connected to the bottom of the bracket groove, and the bracket body is arranged in the bracket groove of the drilling device, and the bracket body can inject gas into the telescopic body in the bracket groove through the gas injection pipe. The brackets protrude, so that the radius of the drill hole can be enlarged. When the gas in the expansion and contraction body is discharged, the brackets can return to the bracket groove under the action of external pressure and the recovery elasticity of the expansion body. The gas in the hole is evenly drained, eliminating the blind area of drainage, and reducing the gas content in the drainage area comprehensively.

Description

A gas drainage hole radius adjustable drilling device and its working method

technical field

The invention relates to the technical field of coal seam gas drainage drilling, in particular to a gas drainage hole radius adjustable drilling device and a working method thereof.

Background technique

With the increase of coal mining depth, the in-situ stress and gas content of coal seams increase, leading to a greater potential risk of coal and gas outbursts, and the control of coal seam gas must be strengthened. Especially as the country's requirements for safe production increase, it becomes more urgent to strengthen gas control.

At present, there are many methods of gas control, which mainly include ground gas drainage and underground gas drainage. Among them, the underground gas drainage method has become the most widely used gas control method due to its advantages of perfect drainage theory, mature drainage technology and good drainage effect. This method is mainly to drill holes in the coal seam. By reducing the pressure of the coal seam, the gas in the coal seam will be desorbed. Then, under the action of the pressure difference, it will migrate and produce through the pores and fissures of the coal seam, and finally be discharged by the drainage pipeline.

Underground gas drainage can fundamentally reduce the gas content of coal seams and reduce the occurrence of gas accidents. However, due to the influence of mining activities and the effect of geological structure, the distribution of permeability in different regions of the coal seam is different. Especially for bedding drilling, due to the influence of the roadway layout, as the distance from the orifice increases, the stress distribution of the coal seam has successively experienced the pressure relief area, the stress concentration area, and the original rock stress area from the outside to the inside, resulting in the original distribution Uneven permeability, becoming more uneven.

For this reason, using the existing conventional gas drilling technology to perform drainage under the same aperture may result in areas with different depths inside the borehole and different drainage efficiencies. Insufficiencies such as long and misjudgment of extraction effect pose a great threat to the safety and high-efficiency production of coal mines. Therefore, there is an urgent need for a device or method that can change the diameter of the borehole with different borehole depths, so that the gas in the drainage borehole can be evenly drained, and the gas content in the drainage area can be reduced comprehensively.

Contents of the invention

In order to solve the above technical problems, the present invention provides a gas drainage hole radius adjustable drilling device and its working method.

The technical scheme of the present invention is: a gas drainage hole radius adjustable drilling device, including a drill bit and a drill rod connected together, one end of the drill bit is provided with annular uniformly distributed drill teeth, and the other end is a threaded connection pipe, the middle part of the drill bit is a cone and the surface is provided with radial teeth, the drill rod is a hollow pipe structure, the center of the drill bit is provided with a water outlet hole communicating with the drill rod, and the drill rod One end of the pipe is provided with an internal thread I, and the other end is provided with a threaded nozzle I. The threaded connecting pipe is matched with the internal thread I of the drill pipe, and the surface of the drill pipe is provided with at least one set of ring-shaped and concave brackets The groove, the diameter-enclosed groove is placed with a diameter-enclosed body, the notch of the diameter-enclosed groove is provided with a notch baffle, the upper end of the diameter-enclosed body is a slope and is provided with a diameter-enclosed tooth, the diameter-enclosed body The lower part is a tubular structure and the end is provided with a bracket baffle, and the bottom of the bracket is fixedly connected with a telescopic body located inside the tubular structure, and the telescopic body is fixed at the bottom of the bracket groove, and the telescopic body The inside of the rod body is provided with an air injection pipe at the center, and the side of the air injection pipe is connected with annular uniform branch pipes, and the branch pipes are connected to the bottom of the bracket groove.

Preferably, there are three groups of bracket grooves on the surface of the drill rod, and the three groups of bracket grooves are arranged in sequence from left to right and are placed with a first bracket body, a second bracket body, and a third bracket body in sequence. body, the baffle under the first baffle is folded outwards and is the first baffle, and the first baffle is matched with its corresponding notch baffle; the second baffle The diameter-enclosing baffle below the diameter body is turned inward and is a second diameter-enclosed baffle. The tubular structure of the second diameter-encloser body is provided with a first-level extension tube located outside the telescopic body. The first-level extension tube There is a first extended baffle turned outwards on the upper side, and a second extended baffle turned outwards on the lower side, the first extended baffle is matched with the second bracket baffle, and the second extended baffle is The two extended baffles cooperate with the corresponding notch baffles; the baffles below the third baffles are also folded inward and are the third baffles, and the tubular structure of the third baffles There is a secondary extension tube located outside the telescopic body inside. The secondary extension tube includes a first extension tube located on the inside and a second extension tube located on the outside. The third extension baffle, the fourth extension baffle that is turned outwards is provided at the bottom, the fifth extension baffle that is turned outwards is arranged above the second extension tube, and the fifth extension baffle that is turned inwards The sixth extension baffle, the fifth extension baffle cooperates with the third diameter baffle, the fourth extension baffle cooperates with its corresponding notch baffle, the third extension baffle cooperates with the The sixth extension baffle fits.

Preferably, a tension spring is provided inside the telescopic body, one end of the tension spring is fixedly connected to the top of the telescopic body, and the other end is fixedly connected to the bottom of the bracket groove.

Preferably, the drill rods are multiple and connected sequentially, and every two adjacent drill rods are connected through the internal thread I and the threaded nozzle I.

Preferably, the gas injection pipe includes a base pipe and an extension pipe, one end of the base pipe is closed, the other end is open and is provided with an internal thread II, both ends of the extension pipe are open and one end is a threaded nozzle II, and the other end One end is an internal thread II, and the internal thread II of the foundation pipe cooperates with the threaded nozzle II.

Preferably, there are multiple extension pipes, and every two adjacent extension pipes are connected through threaded nozzle II and internal thread II.

Preferably, both the base pipe and the extension pipe are provided with a self-sealing gas injection system, the self-sealing gas injection system includes an inflation and deflation valve at the front, and a sealing structure at the rear, and the sealing structure includes a The blocking ball is provided with a slide bar at the rear of the blocking ball, and a guide block is also provided at the rear of the blocking ball, and the guide block is fixed by a support rod protruding to both sides. The center is provided with a guide hole for the slide bar to be inserted into. The slide bar is provided with a fixed bar perpendicular to the slide bar and located behind the guide block. A compression spring is connected between the fixed bar and the guide block. The seal The outer side of the plugging ball is a guide body which is fixedly arranged and has a tapered tube structure. The end of the guide body with a large aperture faces forward, and the end with a small aperture faces rearward.

Preferably, the front end of the extension pipe is threaded nozzle II, and the center of the threaded nozzle II is provided with a blocking disk, and the blocking disk is fixed on the inner wall of the threaded nozzle II through a connecting rod, and the blocking disk One side of the block is a circular groove facing forward, and the circular groove of the blocking plate is matched with the slide bar in front of it.

A working method of the aforementioned gas drainage hole radius-adjustable-while-drilling drilling device, comprising the following steps:

Step 1. Collect coal samples with different coal structures in the study area, conduct permeability test experiments under different stress conditions, and establish a permeability change model based on coal structure and in-situ stress;

Step 2, find out the distribution characteristics of the coal mass structure in the study area;

Step 3, according to the layout of the roadway, analyze the distribution law of ground stress under the condition of mining influence, especially the law of ground stress distribution with the increase of drilling depth;

Step 4, according to the distribution of coal body structure and the distribution characteristics of in-situ stress, find out the distribution law of permeability in the study area;

Step 5, conduct field test of influence radius;

Step 6, according to the test results of the influence radius, combined with the permeability distribution law, design the pore diameter under different pore depth conditions;

Step 7, connect drill bits, drill pipes, drilling rigs and other equipment, check the airtightness and integrity of the equipment, and prepare to start drilling;

Step 8, start drilling according to the designed opening position, and inject water into the continuous drill pipe during drilling;

Step 9, when diameter expansion is required, connect the high-pressure gas pipeline to the inflation and deflation valve for gas injection until the pressure reaches the design value;

Step 10, as the drilling depth increases, when it is necessary to continue connecting the drill pipe, first connect the gas injection pipe, and then continue drilling after connecting the drill pipe;

Step 11, when the diameter needs to be reduced, open the inflation and deflation valve to deflate until the pressure reaches the design value;

Step 12, repeating steps 10 and 11 until the drilling of the entire borehole is completed;

Step 13, open the inflation and deflation valve to deflate, and completely remove the pressure of the gas injection pipe;

In step 14, the drill pipe and the drill bit are taken out to prepare for the drilling of the next borehole.

The beneficial effects of the present invention are:

In the present invention, a bracket body is arranged in the bracket groove of the drill pipe, and the bracket body can inject gas into the telescopic body in the bracket groove through a gas injection pipe to make the bracket body protrude, so that the drilling radius can be enlarged, and the gas in the telescopic body can be discharged , the bracket body can retreat into the bracket groove under the action of the external pressure and the restoring elastic force of the expansion body.

The drill rod of the present invention is provided with three sets of diameter-snipping bodies, and the protruding lengths of the first, second, and third diameter-strutting bodies gradually increase, which can increase the variation of the aperture when drilling in the present invention. scope.

A tension spring is also arranged in the telescopic body, which can improve the recovery elastic force of the telescopic body.

The present invention can use a plurality of drill rods to butt in sequence, and the overall length of the present invention can be increased according to the drilling depth.

The gas injection pipe of the present invention is equipped with a self-sealing gas injection system, which can be sealed by the rear sealing structure when injecting gas into the gas injection pipe through the inflation and deflation valve at the front. As the drilling depth increases, an extension pipe can be connected to the basic pipe. Both the base pipe and the extension pipe are equipped with a self-sealing gas injection system, which can seal the rear during the gas injection process and at the same time disable the front sealing mechanism to ensure the circulation of the injected gas.

A blocking plate is set on the extension tube, and the blocking plate and the sliding rod in front can be forced to move forward by the blocking plate when the extension tube is installed, and the mechanical structure is used to make the front sealing structure invalid, and the effect is stable.

By adopting the working method of the drilling device of the present invention, the gas in the drainage borehole can be evenly drained, the blind area of drainage can be eliminated, and the gas content in the drainage area can be reduced comprehensively.

Description of drawings

Fig. 1 is the front view structure schematic diagram of the present invention;

Fig. 2 is the sectional structure schematic diagram of drill bit;

Fig. 3 is A-A sectional view of Fig. 1;

Figure 4 is a partially enlarged view of Figure 3;

Fig. 5 is the B-B sectional view of Fig. 1;

Figure 6 is a partially enlarged view of Figure 5;

Fig. 7 is the C-C sectional view of Fig. 1;

Fig. 8 is a partially enlarged view of Fig. 7;

Fig. 9 is a D-D sectional view of Fig. 3;

Fig. 10 is a schematic structural view of the base pipe in the gas injection pipe;

Fig. 11 is the schematic structural view of the extension pipe in the gas injection pipe;

In the figure: 1, drill bit; 1-1, drill tooth; 1-2, threaded connecting pipe; 1-3, water outlet; 2, drill pipe; 2-1, bracket groove; 2-2, notch baffle ;2-3, threaded nozzle Ⅰ; 2-4, internal thread Ⅰ; 3, the first diameter body; 3-1, the first diameter baffle; 4, the second diameter body; 4-1, the first Second diameter baffle; 5. Third diameter body; 5-1. Third diameter baffle; 6. Gas injection pipe; 6-1. Branch pipe; 6-2. Foundation pipe; 6-3. Extension pipe ;6-4, plugging ball; 6-4-1, sliding rod; 6-4-2, fixed rod; 6-5, guide block; 6-5-1, support rod; 6-5-2, compression Spring; 6-6, guide body; 6-7, filling and deflation valve; 6-8, internal thread II; 6-9, threaded nozzle II; 6-10, blocking plate; 6-11, connecting rod; 7 , expansion body; 7-1, tension spring; 8, first-level extension tube; 8-1, first extension baffle; 8-2, second extension baffle; 9, second-level extension tube; 9-1, The third extension baffle; 9-2, the fourth extension baffle.

Detailed ways

The specific implementation mode of the present invention refers to Fig. 1-11:

Technical scheme of the present invention is:

Embodiment 1, a gas drainage hole radius adjustable drilling device, as shown in Figure 1-4, includes a drill bit 1 and a drill pipe 2 connected together, and one end of the drill bit 1 is provided with circular uniformly distributed drill teeth 1-1. The other end is a threaded connecting pipe 1-2. The middle part of the drill bit 1 is a conical body and the surface is provided with radial teeth. The drill rod 2 is a hollow tube structure. Hole 1-3, one end of the drill pipe 2 is provided with an internal thread I2-4, and the other end is provided with a threaded nozzle I2-3, the threaded connecting pipe 1-2 cooperates with the internal thread I2-4 of the drill pipe 2, and the drill pipe 2 The surface of the surface is provided with at least one group of ring-shaped and concave bracket grooves 2-1, a bracket body is placed in the bracket groove 2-1, and the notch of the bracket groove 2-1 is provided with a notch baffle plate 2- 2. The upper end of the bracket body is inclined and provided with bracket teeth, the bottom of the bracket body is a tubular structure and the end is provided with a bracket baffle, and the bottom of the bracket body is fixedly connected with the telescopic body 7 inside the tubular structure. The telescopic body 7 is fixed on the bottom of the bracket groove 2-1, and the inside of the rod body of the telescopic body 7 is provided with a gas injection pipe 6 located in the center, and the side of the gas injection pipe 6 is connected with an annular uniform branch pipe 6-1, and the branch pipe 6- 1 is connected to the bottom of the bracket groove 2-1, the inside of the telescopic body 7 is provided with a tension spring 7-1, one end of the tension spring 7-1 is fixedly connected to the top of the telescopic body 7, and the other end is connected to the bracket groove 2 The bottom of -1 is fixed.

The present invention arranges the bracket body in the bracket groove 2-1 of the drill pipe 2, and the bracket body can inject gas into the telescopic body 7 in the bracket groove 2-1 through the gas injection pipe 6 to make the bracket body protrude, thereby being able to Enlarging the drilling radius, when the gas in the expansion body 7 is discharged, the expansion body can return to the expansion groove 2-1 under the action of the external pressure and the recovery elastic force of the expansion body 7, and a tension spring 7-1 is also arranged in the expansion body 7. 1. The recovery elasticity of the telescopic body 7 can be improved.

Embodiment 2 is basically the same as Embodiment 1, except that as shown in Figure 1-9, there are three groups of bracket grooves 2-1 on the surface of the drill pipe 2, and the three groups of bracket grooves 2-1 are from left to right Arranged in sequence and placed in turn are the first bracket body 3, the second bracket body 4, and the third bracket body 5. The bracket baffle plate under the first bracket body 3 is turned outwards and is the first bracket body. Plate 3-1, the first bracket baffle 3-1 cooperates with its corresponding notch baffle 2-2; the bracket baffle below the second bracket body 4 is turned inward and is the second bracket baffle 4-1, inside the tubular structure of the second bracket body 4 is provided a first-level extension tube 8 located outside the telescopic body 7, and above the first-level extension tube 8 is a first extension baffle 8-1 that is turned outwards , The second extended baffle 8-2 that is turned outwards is provided at the bottom, the first extended baffle 8-1 cooperates with the second bracket baffle 4-1, and the second extended baffle 8-2 and its corresponding groove The mouth baffle 2-2 cooperates; the baffle baffle below the third stent 5 is also turned inward and is the third baffle 5-1, and the tubular structure inside the third stent 5 is provided with a The secondary extension tube 9 on the outside of the telescopic body 7, the secondary extension tube 9 includes a first extension tube located on the inside, a second extension tube located on the outside, and a third extension block that is turned outwards is provided above the first extension tube The plate 9-1 is provided with a fourth extension baffle 9-2 which is turned outwards at the bottom, a fifth extension baffle which is turned outwards is arranged above the second extension tube, and a fifth extension baffle which is turned inwards is arranged at the bottom. Six extended baffles, the fifth extended baffle cooperates with the third bracket baffle 5-1, the fourth extended baffle 9-2 cooperates with its corresponding notch baffle 2-2, the third extended baffle 9-1 Cooperating with the sixth extended baffle, there are multiple drill pipes 2 connected in sequence, and every two adjacent drill pipes 2 are connected through the internal thread I2-4 and the threaded nozzle I2-3.

The drill rod 2 of the present invention is provided with three groups of brackets, and the lengths that the first bracket 3, the second bracket 4, and the third bracket 5 can protrude gradually increase, which can increase the amount of drilling in the present invention. When changing the variation range of the hole diameter, the drilling device can use a plurality of drill rods 2 to butt in sequence, and the overall length of the present invention can be increased according to the drilling depth.

Embodiment 3 is basically the same as Embodiment 2, except that as shown in Figures 10 and 11, the gas injection pipe 6 includes a base pipe 6-2 and an extension pipe 6-3, and one end of the base pipe 6-2 is closed and the other end is open And it is provided with internal thread Ⅱ6-8, both ends of the extension pipe 6-3 are open and one end is threaded nozzle Ⅱ6-9, the other end is internal thread Ⅱ6-8, the internal thread Ⅱ6-8 of the base pipe 6-2 is connected with The threaded pipe mouth II 6-9 is matched, and there are multiple extension pipes 6-3, and every two adjacent extension pipes 6-3 are connected through the threaded pipe mouth II 6-9 and the internal thread II 6-8, and the base pipe 6-2 and the extension The pipes 6-3 are equipped with a self-sealing gas injection system. The self-sealing gas injection system includes an inflation and deflation valve 6-7 at the front and a sealing structure at the rear. The sealing structure includes a plugging ball 6-4 at the center. The rear of the blocking ball 6-4 is provided with a slide bar 6-4-1, and the rear of the blocking ball 6-4 is also provided with a guide block 6-5, and the guide block 6-5 passes through the support rod 6-5 stretched out to both sides. 5-1 is fixed, the center of the guide block 6-5 is provided with a guide hole for the insertion of the slide bar 6-4-1, and the slide bar 6-4-1 is provided with a The fixed rod 6-4-2 at the 6-5 rear is connected with a compression spring 6-5-2 between the fixed rod 6-4-2 and the guide block 6-5, and the outside of the plugging ball 6-4 is fixedly arranged and The diversion body 6-6 is a tapered tube structure, the end of the diversion body 6-6 with a larger aperture faces forward, and the end with a smaller aperture faces rearward.

The gas injection pipe 6 of the present invention is provided with a self-sealing gas injection system, which can be sealed by the rear sealing structure when injecting gas into the gas injection pipe 6 through the inflation and deflation valve at the front. As the drilling depth increases, the foundation pipe 6-2 can be sealed. The upper connection extension pipe 6-3, the base pipe 6-2 and the extension pipe 6-3 are equipped with a self-sealing gas injection system, which can seal the rear during the gas injection process and at the same time make the front sealing mechanism invalid, ensuring Circulation of injected gas.

Embodiment 4 is basically the same as Embodiment 3, except that as shown in Figure 11, the front end of the extension tube 6-3 is a threaded nozzle II 6-9, and the center of the threaded nozzle II 6-9 is provided with a blocking disc 6- 10. The blocking plate 6-10 is fixed on the inner wall of the threaded nozzle II 6-9 through the connecting rod 6-11. One side of the blocking plate 6-10 is a circular groove facing forward, and the circular groove of the blocking plate 6-10 and its front The slide bar 6-4-1 cooperates, and the blocking plate 6-10 is set on the extension tube 6-3, and the blocking ball 6-4 and the sliding plate 6-10 in the front can be forced to use the blocking plate 6-10 when the extension tube 6-3 is installed. Rod 6-4-1 moves forward, utilizes mechanical structure to make the sealing structure in front fail, and the effect is stable.

Working method of the present invention is:

Step 1. Collect coal samples with different coal structures in the study area, conduct permeability test experiments under different stress conditions, and establish a permeability change model based on coal structure and in-situ stress;

Step 2, find out the distribution characteristics of the coal mass structure in the study area;

Step 3, according to the layout of the roadway, analyze the distribution law of ground stress under the condition of mining influence, especially the law of ground stress distribution with the increase of drilling depth;

Step 4, according to the distribution of coal body structure and the distribution characteristics of in-situ stress, find out the distribution law of permeability in the study area;

Step 5, conduct field test of influence radius;

Step 6, according to the test results of the influence radius, combined with the permeability distribution law, design the pore diameter under different pore depth conditions;

Step 7, connect drill bit 1, drill pipe 2, drilling rig and other equipment, check the airtightness and integrity of the equipment, and prepare to start drilling;

Step 8, start drilling according to the designed opening position, and inject water into the continuous drill pipe 2 during drilling;

Step 9, when diameter expansion is required, connect the high-pressure gas pipeline to the inflation and deflation valve 6-7 for gas injection until the pressure reaches the design value;

Step 10, as the drilling depth increases, when it is necessary to continue connecting the drill pipe 2, first connect the gas injection pipe 6, and then continue drilling after connecting the drill pipe 2;

Step 11, when the diameter needs to be reduced, open the inflation and deflation valves 6-7 to deflate until the pressure reaches the design value;

Step 12, repeating steps 10 and 11 until the drilling of the entire borehole is completed;

Step 13, open the inflation and deflation valve 6-7 to deflate, and completely remove the pressure of the gas injection pipe 6;

In step 14, the drill pipe 2 and the drill bit 1 are brought out to prepare for the next drilling.

By adopting the working method of the drilling device of the present invention, the gas in the drainage borehole can be evenly drained, the blind area of drainage can be eliminated, and the gas content in the drainage area can be reduced comprehensively.

When the drilling device of the present invention carries out the bracketing, the first bracketing body 3 first reaches the limit position, and the second and third bracketing bodies 5 have the same length as the first bracketing body 3, and then continue to inject gas. The second bracket body 4 also reaches the limit position. At this time, the third bracket body 5 has the same length as the second bracket body 4. If the gas injection is continued, the third bracket body 5 also reaches the limit position; the diameter needs to be reduced. , open the inflation and deflation valve 6-7 to deflate, and the first, second, and third brackets 5 will return to the opposite order of stretching out when they are bracketed.

The working process of the gas injection pipe 6 and the self-sealing gas injection system of the present invention is that the basic pipe 6-2 is used for gas injection, and the gas filling and deflation valve 6-7 on the basic pipe 6-2 is opened during gas injection, and the gas is continuously injected. , the air pressure pushes the sealing ball 6-4 close to the guide body 6-6 to seal the rear of the base pipe 6-2, and the gas is injected from the front to the telescopic body 7 in the bracket groove 2-1, with the increase of the drilling depth , connect the extension pipe 6-3, the inflation and deflation valve 6-7 on the base pipe 6-2 is closed, and the blocking plate 6-10 of the extension pipe 6-3 pushes the slide bar 6-4-1 on the base pipe 6-2 and the plugging ball 6-4 move forward, the plugging ball 6-4 is separated from the guide body 6-6, the inflation and deflation valve 6-7 on the extension tube 6-3 is opened, and the working process with the base tube 6-2 Similarly, continue to inject gas into the telescopic body 7 in the bracket groove 2-1.

Claims (9)

1. a kind of gas drainage pore radius is with adjustable type drilling apparatus is bored, including the drill bit and drilling rod to link together, feature Be: one end of the drill bit is equipped with the uniformly distributed brill tooth of annular, the other end is screw nipple, and the middle part of the drill bit is taper Body and surface, which are equipped with, includes diameter tooth, and the drilling rod is tubular structure, and the center of the drill bit goes out equipped with what is be connected to the drilling rod Water hole, one end of the drilling rod is equipped with internal screw thread I, the other end is equipped with threaded end (TE) I, the interior spiral shell of the screw nipple and drilling rod Line I cooperates, and the surface of the drilling rod is equipped with that at least one set is circular layout and indent includes diameter slot, it is described include to be placed in diameter slot include Diameter body, the notch for including diameter slot be equipped with notch baffle, it is described include diameter body upper end be inclined-plane and be equipped with include diameter tooth, it is described to include diameter body Lower section be that tubular structure and end are equipped with and include diameter baffle, the fixedly connected below of diameter body that include has stretching inside tubular structure Contracting body, the extrusome are fixed on the bottom for including diameter slot, and the inside of the body of rod described in the extrusome is equipped with centrally located Air injection pipe, the side of the air injection pipe are connected with the uniformly distributed branched pipe of annular, and the branched pipe is connected to the bottom for including diameter slot Portion.

2. gas drainage pore radius according to claim 1 is with brill adjustable type drilling apparatus, it is characterised in that: the drilling rod The diameter slot that includes on surface be three groups, diameter slot is included described in three groups be from left to right sequentially arranged and be sequentially placed first and include diameter body, the Two include diameter body, third includes diameter body, and the described first diameter baffle that includes for including below diameter body turns down outward and includes diameter baffle for first, described First includes the corresponding notch baffle fit of diameter baffle；Described second includes including diameter baffle fold inward and being the below diameter body Two include diameter baffle, and described second includes the level-one extension tube for being equipped with and being located on the outside of extrusome inside the tubular structure of diameter body, and described one The top of grade extension tube is equipped with the first extension baffle turned down outward, lower section is equipped with second turned down outward and extends baffle, described First extension baffle includes diameter baffle fit with described second, and described second extends the corresponding notch baffle fit of baffle；Institute It states the diameter baffle that includes that third includes below diameter body and also fold inward and includes diameter baffle for third, the third includes the tubular structure of diameter body Inside is equipped with the second level extension tube being located on the outside of extrusome, and the second level extension tube includes the first extension tube for being located inside, position The second extension tube in outside, the top of first extension tube be equipped with the third turned down outward extend baffle, lower section be equipped with to The 4th of outer fold extends baffle, and the top of second extension tube is equipped with the 5th extension baffle turned down outward, lower section is equipped with The 6th of fold inward extends baffle, and the 5th extension baffle and the third include diameter baffle fit, and the described 4th extends gear The corresponding notch baffle fit of plate, the third extend baffle and the described 6th and extend baffle fit.

3. gas drainage pore radius according to claim 2 is with brill adjustable type drilling apparatus, it is characterised in that: described flexible The inside of body is equipped with extension spring, and the top of one end of the extension spring and the extrusome is connected, the other end and includes diameter slot Bottom be connected.

4. gas drainage pore radius according to claim 3 is with brill adjustable type drilling apparatus, it is characterised in that: the drilling rod Be it is multiple and be sequentially connected, every two adjacent drilling rod is connected by internal screw thread I and threaded end (TE) I.

5. gas drainage pore radius according to claim 4 is with brill adjustable type drilling apparatus, it is characterised in that: the gas injection It manages including base pipe and extension pipe, closed at one end, another end opening of the base pipe and equipped with internal screw thread II, the extension pipe Both ends be open and one end is threaded end (TE) II, the other end is internal screw thread II, the internal screw thread II and the spiral shell of the base pipe Line nozzle II cooperates.

6. gas drainage pore radius according to claim 5 is with brill adjustable type drilling apparatus, it is characterised in that: the lengthening It is multiple for managing, and every two adjacent extension pipe is connected by threaded end (TE) II and internal screw thread II.

7. gas drainage pore radius according to claim 6 is with brill adjustable type drilling apparatus, it is characterised in that: the basis Pipe and the extension pipe are equipped with self-sealing gas injection system, and the self-sealing gas injection system includes the Air filling and discharging valves positioned at front Door, the sealing structure being located behind, the sealing structure include centrally located ball sealer, and the rear of the ball sealer, which is equipped with, to be slided Bar, the rear of the ball sealer are additionally provided with guide pad, and the guide pad is fixed by the support rod stretched out to two sides, the guiding The center of block is equipped with the pilot hole being inserted into for slide bar, and the slide bar is equipped with fixation that is vertical with slide bar and being located at guide pad rear Bar, is connected with compressed spring between the fixed link and the guide pad, the outside of the ball sealer is fixed setting and is cone The baffle of shape pipe structure, the big one end in the aperture of the baffle is towards the small one end in front, aperture towards rear.

8. gas drainage pore radius according to claim 7 is with brill adjustable type drilling apparatus, it is characterised in that: the lengthening Front one end of pipe is threaded end (TE) II, and the center of the threaded end (TE) II is equipped with barrier disc, and the barrier disc passes through connecting rod Be fixed on the inner wall of threaded end (TE) II, the side of the barrier disc is the circular groove towards front, the circular groove of the barrier disc with Slide bar cooperation in front of it.

9. a kind of gas drainage pore radius as claimed in claim 8 is with the working method for boring adjustable type drilling apparatus, feature It is: the following steps are included:

Step 1, acquisition research area's difference Coal Pore Structure coal sample carries out the testing permeability experiment under different stress conditions, establishes Permeability variation model based on Coal Pore Structure, crustal stress；

Step 2, research area's Coal Pore Structure distribution characteristics is found out；

Step 3, it according to roadway layout, analyzes under digging influence condition, the crustal stress regularity of distribution, increases especially with drilling depth Add, the crustal stress regularity of distribution；

Step 4, according to Coal Pore Structure distribution, crustal stress distribution characteristics, research area's permeability regularity of distribution is found out；

Step 5, radius of influence on-the-spot test is carried out；

Step 6, the aperture under the conditions of different hole depths is carried out in conjunction with the permeability regularity of distribution according to radius of influence test result Design；

Step 7, drill bit, drilling rod, the equipment such as drilling machine are connected, preparation, which starts to bore, to be checked to equipment its air-tightness, integrity Into；

Step 8, according to designed openings position, start to be crept into, when drilling fills the water into lasting drilling rod；

Step 9, when needing to carry out expanding, high-pressure gas pipeline is connected to charging and discharging valve and carries out gas injection, until pressure reaches To design value；

Step 10, as drilling depth increases, when needing to continue jointed rod, air injection pipe is first connected, in jointed rod, after It is continuous to be crept into；

Step 11, it when needing undergauge, opens charging and discharging valve and deflates, until pressure reaches design value；

Step 12, step 10, step 11 are repeated, until the drilling for completing entirely to drill；

Step 13, it opens charging and discharging valve to deflate, complete removal gas injection pipe pressure；

Step 14, drilling rod, drill bit are taken out of, prepares for the drilling of next drilling.