CN105507940A - Slotting, plugging and fracturing integrated type intensified marsh gas extraction device and method - Google Patents

Abstract

A cutting, sealing and pressure-integrated enhanced gas drainage device and method, the device includes a grouting cylinder connected with each other by threads, a fracturing tube with a number of small holes at the front end is arranged at the center of the cylinder, and the fracturing tube passes through the cylinder The front end of the cylinder front cover is 3-4m, so that all the small holes go over the cylinder, and the rear end of the fracturing tube is connected to the fracturing pump through the fracturing opening on the lower surface of the cylinder. The fracturing opening is 0.5-1m away from the rear end of the cylinder. The first flexible bladder is welded on the front end, and the second flexible bladder is welded at a position 1.5-3m away from the rear end of the cylinder. Several large holes are opened on the surface of the cylinder in the second flexible bladder and the first flexible bladder. The upper part of the cylinder is welded with a grouting pipe, and the surface of the cylinder is provided with a grouting port and a grouting port. Conventional drilling and slotted drilling are respectively arranged through conventional drilling and hydraulic cutting. The grout outlet on the surface of the cylinder injects grout into the borehole of the coal seam. After the grout solidifies, hydraulic fracturing is carried out to ensure the effective sealing of the borehole for gas drainage integrated with cutting, sealing and pressure, and realize the enhanced gas drainage with integrated cutting, sealing and pressure .

Description

A device and method for enhancing gas drainage integrated with cutting, sealing and pressure

technical field

The invention relates to a cutting, sealing and pressure integrated enhanced gas drainage device and method, which belong to the technical field of gas control in the underground area of coal mines, and are especially suitable for intensifying gas drainage in coal seams with soft, easy-to-collapse and hard-to-seal coal seams. Extraction operations.

Background technique

The occurrence characteristics of high gassy and low permeability coal seams in my country are microporosity, low permeability and high adsorption, which often lead to a large amount of gas gushing out during the mining process, especially with the efficient intensification of coal production and the increase in mining depth. The amount of gas gushing out is increasing, and the threat of gas explosion and gas outburst is becoming more and more serious. Therefore, the national coal mine gas control policy determines that high-gas mines must be drained before mining, and gas drainage is a permanent measure. With the in-depth development of research work on coal seam gas control, many scholars have reached a certain consensus, proposing that hydraulic measures are the development direction of future coal seam gas control, especially deep coal seam gas control. Hydraulic measures such as cracking and hydraulic punching can promote the pressure relief and permeability enhancement of coal seams, improve the permeability of coal seams, and strengthen the pre-pumping of coal seam gas. Among many hydraulic technologies, hydraulic fracturing technology was developed earlier and its application is relatively mature, and it has achieved good results in many mines at home and abroad. However, in the process of various hydraulic measures in the gas drainage boreholes of some soft coal seams that are easy to collapse and difficult to seal, the fracturing fails due to the lax sealing of the holes, which is time-consuming and laborious, and the gas drainage cannot be achieved. Therefore, an enhanced gas drainage measure is urgently needed, which can not only effectively seal the high-pressure borehole, withstand the impact of high pressure in the borehole, but also serve the purpose of enhancing gas drainage through water conservancy measures.

Contents of the invention

Technical problem: The purpose of the present invention is to overcome the problems existing in the prior art, such as lax sealing of high-pressure boreholes and poor gas drainage effects, and to provide a cutting-sealing and pressure-integrated strengthening system with simple operation, low cost and good effect. Gas extraction methods.

Technical solution: The cutting, sealing and pressure integrated enhanced gas drainage device of the present invention includes grouting cylinders connected with each other by threads, and a fracturing tube with a number of small holes at the front end is arranged at the center of the cylinder, and the fracturing tube passes through The front end of the front cover of the cylinder is 3-4m, so that all the small holes go over the cylinder, and the rear end of the fracturing pipe is connected to the fracturing pump through the fracturing port on the lower surface of the cylinder. The front end of the cylinder is welded with a flexible bladder 1, and a flexible bladder 2 is welded at a position 1.5-3m away from the rear end of the cylinder. There are several large holes on the surface of the cylinder in the flexible bladder 2 and the flexible bladder 1. The upper part of the cylinder is welded with a grouting pipe, and the grouting pipe is connected to the grouting pump through the grouting port on the surface of the cylinder, and the grouting pipe injects grout into the coal seam borehole through the grouting port on the surface of the cylinder.

The length of the grouting cylinder is 15-18m, the diameter is 90mm, the diameter of the grouting pipe is 16mm, and the diameter of the fracturing pipe is 25mm.

The grouting port and the fracturing port are arranged on the cylindrical surface outside the second flexible bag, and the grout outlet is arranged on the cylindrical surface between the second flexible bag and the first flexible bag.

The second flexible pouch has a length of 0.5-1m and a diameter of 110mm, and the first flexible pouch has a length of 1-2m and a diameter of 150mm.

The cutting, sealing and pressure-integrated enhanced gas drainage method of the present invention comprises the following steps:

a. Use conventional methods to drill a conventional borehole with a diameter of 100mm perpendicular to the roadway wall to the inside of the rock formation, and the length of the conventional borehole is 15-18m;

b. Using conventional hydraulic slotting technology, continue to drill at the bottom of conventional drilling, and at the same time, through hydraulic rotary slotting, cut a slotted hole with a diameter of 120-140mm, and the length of the slotted hole is 80-100m;

c. Connect the cylinder and the fracturing pipe in sequence, and send the cylinder into the inside of the conventional borehole, so that the flexible bladder just passes through the conventional borehole and is in the slotted borehole;

d. Connect the grout storage tank and the grouting pump, and use the high-pressure hose to connect the grouting pump and the grouting cylinder, the grouting pump and the grouting port, the water tank and the fracturing pump, and the fracturing pump and the fracturing port;

e. Turn on the grouting pump, inject the sealing slurry into the grouting cylinder, the sealing slurry fills the flexible bladder 1 and the flexible bladder 2 through the large hole, and the flexible bladder 1 and the flexible bladder 2 expand to block the conventional drill respectively hole and slot drilling;

f. When the pressure gauge of the grouting pump shows that the grouting pressure stops rising, use the grouting pipe to inject the hole-sealing grout into the conventional drilling space between the first flexible bladder and the second flexible bladder;

g. After the sealing slurry is completely solidified, turn on the fracturing pump for hydraulic fracturing for 30 minutes;

h. After the fracturing is completed, connect the fracturing pipe and the underground gas drainage pipeline of the coal mine for gas drainage, and complete the process of integrated cutting, sealing and pressure-enhanced gas drainage.

Beneficial effects: Due to the adoption of the above-mentioned technical scheme, in the process of carrying out various hydraulic measures in the gas drainage boreholes of some soft and easy-to-collapse coal seams and hard-to-seal coal seams, it can not only effectively seal the high-pressure boreholes, but also be able to withstand drilling The impact of high pressure in the hole can also serve the purpose of strengthening gas drainage through water conservancy measures. It realizes the effective sealing of high-pressure drilling holes in soft coal seams, and meets the needs of coal mines for enhanced gas drainage. Its operation is simple, the cost is low, the effect is good, the workload is small, and it has wide practicability.

Description of drawings

Fig. 1 is a schematic structural view of the present invention.

FIG. 2 is a schematic cross-sectional view of A-A in FIG. 1 .

Fig. 3 is a schematic cross-sectional view along B-B of Fig. 1 .

Figure 4 is a schematic diagram of the connection of the cylindrical structure.

Fig. 5 is a schematic diagram of the structural connection of the fracturing tube.

Fig. 6 is a schematic diagram of an embodiment of the enhanced gas drainage method integrated with cutting, sealing and pressure of the present invention.

In the figure: 1. Grouting port, 2. Grouting pipe, 3. Flexible bladder 2, 4. Grouting outlet, 5. Thread, 6. Flexible bladder 1, 7. Fracture opening, 8. Large hole, 9. Fracturing pipe, 10. Cylinder, 11. Cylinder front cover, 12. Small hole, 13. Rock formation, 14. Coal seam, 15. Slurry storage tank, 16. Grouting pump, 17. Fracturing pump, 18 -1. Valve, 18-2. Valve, 18-3. Valve, 19. Ordinary drilling, 20. Cutting and sealing drilling, 21. High pressure hose, 22. Sealing slurry, 23. Water tank, 24. Pressure gauge.

detailed description

An embodiment of the present invention will be further described below in conjunction with accompanying drawing:

As shown in Fig. 1, the gas drainage device integrated with cutting, sealing and pressing in the present invention includes a grouting cylinder 10 interconnected by threads 5, and a fracturing device with several small holes 12 at the front end is arranged at the center of the cylinder 10. The tube 9 and the fracturing tube 9 pass through the front end of the cylinder front cover 11 for 3-4m, so that all the small holes 12 go over the cylinder 10, and the rear end of the fracturing tube 9 passes through the fracturing port 7 on the lower surface of the cylinder 10 and the fracturing pump Connection, the fracturing port 7 is 0.5-1m away from the rear end of the cylinder 10, the front end of the cylinder 10 is welded with a flexible bladder 1 6, and the position 1.5-3m away from the rear end of the cylinder 10 is welded with a flexible bladder 2 3. The surface of the cylinder 10 in the flexible pouch 2 3 and the flexible pouch 1 6 has a number of large holes 8, and the upper part of the cylinder 10 is welded with a grouting pipe 2, and the grouting pipe 2 passes through the grouting on the surface of the cylinder 10. The port 1 is connected to the grouting pump, and the grouting pipe 2 injects grout into the coal seam borehole through the grouting port 4 on the surface of the cylinder 10 . The grouting cylinder 10 has a length of 15-18m and a diameter of 90mm, the grouting pipe 2 has a diameter of 16mm, and the fracturing pipe 9 has a diameter of 25mm. The grouting port 1 and the fracturing port 7 are arranged on the surface of the outer cylinder 10 of the flexible bag two 3, and the grout outlet 4 is arranged on the surface of the cylinder 10 between the flexible bag two 3 and the flexible bag one 6 superior. The second flexible pouch 3 has a length of 0.5-1 m and a diameter of 110 mm, and the first flexible pouch 6 has a length of 1-2 m and a diameter of 150 mm.

The cutting, sealing and pressure-integrated enhanced gas drainage method of the present invention: firstly, conventional methods are used to drill conventional boreholes 19 with a diameter of 100 mm to the inside of the rock formation 13 perpendicular to the roadway wall, and the length of the conventional boreholes 19 is 15 to 18 m; Slotted technology, continue to drill at the bottom of the conventional borehole 19, and at the same time, cut the slotted hole 20 with a diameter of 120-140 mm through hydraulic rotary slotting, and the length of the slotted hole 20 is 80-100 m; Cylinder 10 and fracturing pipe 9, the cylinder 10 is sent into the interior of the conventional borehole 19, so that the flexible bladder-6 just passes through the conventional borehole 19 and is in the slotted borehole 20; connect the slurry storage tank 15 and the grouting The pump 16 is connected to the grouting pump 16 and the grouting cylinder 10, the grouting pump 16 and the grouting port 1, the water tank 23 and the fracturing pump 17, and the fracturing pump 17 and the fracturing port 7 in turn by using the high-pressure rubber hose 21; The slurry pump 16 injects the sealing slurry 22 into the grouting cylinder 10, the sealing slurry 22 fills the first flexible bladder 6 and the second flexible bladder 3 through the large hole 8, and the first flexible bladder 6 and the second flexible bladder 3 expand Block conventional borehole 19 and slotted borehole 20 respectively; Inject the sealing slurry 22 into the conventional borehole 19 space; after the sealing slurry 22 is completely solidified, turn on the fracturing pump 17 to carry out hydraulic fracturing for 30 minutes; Pipelines are used for gas drainage to complete the gas drainage process integrated with cutting, sealing and pressure enhancement.

Claims (5)

1. A device for enhancing gas drainage integrated with cutting, sealing and pressure, characterized in that: it comprises a grouting cylinder (10) connected to each other by threads (5), and a number of small holes are arranged at the front end of the cylinder (10). The fracturing tube (9) of the hole (12), the fracturing tube (9) passes through the front end of the cylinder front cover (11) for 3-4m, so that all the small holes (12) go over the cylinder (10), and the fracturing tube ( 9) The rear end is connected to the fracturing pump through the fracturing port (7) on the lower surface of the cylinder (10). The fracturing port (7) is 0.5-1m away from the rear end surface of the cylinder (10). The first flexible bladder (6) is installed, and the second flexible bladder (3) is welded at the position 1.5-3m away from the rear end surface of the cylinder (10). The second flexible bladder (3) and the first flexible bladder (6) There are some large holes (8) on the surface of the inner cylinder (10), and a grouting pipe (2) is welded on the upper part of the cylinder (10). The grouting port (1) is connected with the grouting pump, and the grouting pipe (2) grouts into the coal seam borehole through the grouting port (4) on the surface of the cylinder (10). 2. The cutting, sealing and pressure integrated enhanced gas drainage device according to claim 1, characterized in that: the length of the grouting cylinder (10) is 15-18m, the diameter is 90mm, and the grouting pipe (2 ) diameter is 16mm, and the diameter of the fracturing pipe (9) is 25mm. 3. The cutting, sealing and pressure integrated enhanced gas drainage device according to claim 1, characterized in that: the grouting port (1) and the fracturing port (7) are arranged outside the flexible bladder two (3) On the surface of the cylinder (10), the slurry outlet (4) is arranged on the surface of the cylinder (10) between the second flexible bag (3) and the first flexible bag (6). 4. The cutting, sealing and pressure-integrated enhanced gas extraction device according to claim 1, characterized in that: the length of the two flexible bladders (3) is 0.5-1 m, the diameter is 110 mm, and the flexible bladder one (3) 6) The length is 1-2m and the diameter is 150mm. 5. A method for gas drainage integrated with cutting, sealing and pressure integration of the device according to the preceding claim, characterized in that it comprises the following steps: a. Drilling a conventional borehole (19) with a diameter of 100mm perpendicular to the roadway wall to the inside of the rock formation (13) by a conventional method, and the length of the conventional borehole (19) is 15-18m; b. adopt the conventional hydraulic slotting technology, continue to drill at the bottom of the conventional borehole (19), at the same time, cut out the slotted drilling (20) with a diameter of 120 to 140 mm by hydraulic rotary slotting, and slot the drilling ( 20) The length is 80-100m; c. Connect the cylinder (10) and the fracturing pipe (9) in sequence, and send the cylinder (10) into the inside of the conventional borehole (19), so that the flexible bag one (6) just passes through the conventional borehole (19) in the slotted borehole (20); d. Connect the grout storage tank (15) and the grouting pump (16), use the high-pressure rubber hose (21) to connect the grouting pump (16) and the grouting cylinder (10), the grouting pump (16) and the grouting port in sequence (1), water tank (23) and fracturing pump (17), fracturing pump (17) and fracturing port (7); e. Turn on the grouting pump (16), open the valve (18-1), inject the sealing slurry (22) into the grouting cylinder (10), and the sealing slurry (22) fills the flexible bag through the large hole (8) Bag one (6) and flexible pouch two (3), flexible pouch one (6) and flexible pouch two (3) expand and block conventional drilling (19) and slotted drilling (20); f. When the pressure gauge (24) of the grouting pump (16) shows that the grouting pressure stops rising, close the valve (18-1), open the valve (18-2), and use the grouting pipe (2) to fill the flexible bladder Inject the sealing slurry (22) into the space between the conventional drilling (19) between the first (6) and the flexible pouch two (3); g. After the sealing slurry (22) is completely solidified, turn on the fracturing pump (17) and carry out hydraulic fracturing for 30 minutes; h. After the fracturing is completed, connect the fracturing pipe (9) and the underground gas drainage pipeline of the coal mine for gas drainage, and complete the process of cutting, sealing and pressure-integrated enhanced gas drainage.