Top cutting and pressure relief system based on ultrahigh pressure hydraulic cutting and pressure integration

Abstract

The utility model belongs to the technical field of safe mining of coal mines, and particularly relates to a roof cutting and pressure relief system based on ultrahigh-pressure hydraulic cutting and pressure integration. Comprising the steps of designing a top-cutting line; a plurality of cutting and fracturing drill holes are uniformly formed along the designed top cutting line; each fracturing guide drill hole is formed between every two adjacent cutting and fracturing drill holes; the hole sealing device is arranged in the cutting drill hole, the fracturing drill hole and the fracturing guide drill hole; and the ultrahigh-pressure water jet device is used for jetting ultrahigh-pressure water into the cutting and fracturing drill holes and the fracturing guide drill holes to form directional hydraulic fracturing cracks. Efficient and safe pressure relief of the top plate of the working face is achieved, the mine ground pressure can be reduced, and the safety and production efficiency of the working face are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coal mine safety mining, and particularly relates to a roof cutting and pressure releasing system based on superhigh pressure hydraulic cutting and pressure releasing integration. BACKGROUND

[0002] In underground production, roof cutting and pressure releasing is a common way to change the structure of rock mass, which aims to damage the roof of the roadway in advance to release the stress. At present, the roof cutting and pressure releasing technology mainly includes three kinds, namely, blasting pre-cracking technology, hydraulic fracturing technology and CO2 gas phase fracturing technology.

[0003] In terms of the blasting pre-cracking roof cutting technology, the technology is widely used in the roadway protection technology, but its high cost, environmental impact and high technical requirements cannot be ignored. In terms of the CO2 gas phase fracturing technology, the technology is not easy to produce a large amount of dust, but the fracturing cost is high and the fracturing range is small. In terms of the hydraulic fracturing technology, the principle is to inject the static pressure water into the rock stratum through the pressure pump to generate cracks and change the structure of the rock stratum to weaken the roof, which is mainly applied to the hard rock stratum roof, and the main influencing factors are the rock mass strength, horizontal stress and angle.

[0004] Therefore, it is particularly important to explore a new, efficient and environmentally friendly roof cutting and pressure releasing technology. The superhigh pressure hydraulic cutting and pressure releasing integrated roof cutting and pressure releasing technology cuts a 100-200mm deep and 3-5mm wide slot along the axial direction on the hole wall by using a superhigh pressure hydraulic cutting device after drilling and before fracturing, and then performs high pressure water fracturing to achieve the effect of directional fracturing. Therefore, compared with the traditional pre-cracking roof control and roof releasing process, the superhigh pressure hydraulic cutting and pressure releasing integrated roof cutting and pressure releasing technology has great advantages and does not violate the relevant policies. With the increase of the depth and intensity of coal mining, the mine pressure problem faced by the working face is increasingly serious. The traditional roof cutting and pressure releasing method often has problems such as complex process and poor safety. SUMMARY

[0005] In order to efficiently and safely release the pressure of the roof of the working face and reduce the mine pressure, the application provides a roof cutting and pressure releasing method based on superhigh pressure hydraulic cutting and pressure releasing integration.

[0006] The application adopts the following technical scheme: a roof cutting and pressure releasing system based on superhigh pressure hydraulic cutting and pressure releasing integration, comprising:

[0007] designing a roof cutting line;

[0008] cutting and fracturing drill holes, a plurality of the cutting and fracturing drill holes are uniformly arranged along the designed roof cutting line;

[0009] fracturing guide drill holes, the fracturing guide drill holes are arranged between two adjacent cutting and fracturing drill holes;

[0010] A sealing device is arranged in the cutting, fracturing drilling and fracturing guide drilling.

[0011] An ultra-high pressure water jet device sprays ultra-high pressure water to form a directional hydraulic fracturing fracture in the cutting, fracturing drilling and fracturing guide drilling.

[0012] In some embodiments, the cutting, fracturing drilling and top hole drilling end hole position is at a position 15 m away from the overburden of the roof, and the error range of the hole depth is ± 100 mm.

[0013] In some embodiments, the fracturing guide drilling has a hole diameter of 94 mm and a hole depth of 20 m, and the error range of the hole depth is ± 100 mm. The hole spacing is 2 m, and the error range of the hole spacing is ± 50 mm.

[0014] In some embodiments, the sealing device comprises:

[0015] A first sealing device is connected at the rear end with a water injection joint, and at the front end with a middle core I. An inflatable rubber tube is arranged in the first sealing device, and the inflatable rubber tube is connected with the water injection joint and the middle core I.

[0016] A second sealing device is connected at the rear end with a middle core II, and at the front end with a dead core.

[0017] A connecting pipe is connected between the middle core I and the middle core II. A water outlet hole is arranged in the middle of the connecting pipe, and a thin iron pipe is sleeved on the water outlet hole.

[0018] In some embodiments, the water injection joint and the first sealing device are fixedly connected through a pipe locking iron sheet; the middle core I and the first sealing device are fixedly connected through a pipe locking iron sheet; the middle core II and the second sealing device are fixedly connected through a pipe locking iron sheet; and the dead core and the second sealing device are fixedly connected through a pipe locking iron sheet.

[0019] In some embodiments, a sealing rubber gasket is arranged between the front end of the connecting pipe and the middle core II.

[0020] In some embodiments, the ultra-high pressure water jet device comprises:

[0021] A fixing seat is installed outside the cutting, fracturing drilling or fracturing guide drilling.

[0022] A high-pressure water inlet mechanism is installed on the fixing seat.

[0023] A gas pressure mechanism provides high-pressure gas for the high-pressure water inlet mechanism.

[0024] The high-pressure water outlet mechanism is connected with the high-pressure water inlet mechanism, and extends into the cutting, fracturing borehole or fracturing guide borehole.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The present application cuts a guide cutting groove of a certain length in the roof rock along a preset top cutting surface direction in the borehole, and then adopts a sectional fracturing method to perform fracturing along the direction of the guide cutting groove, so that the roof is broken along the preset direction, the mining pressure transmission is cut off, and the top cutting pressure relief method is achieved. By combining the ultrahigh-pressure hydraulic cutting technology and the fracturing technology, efficient and safe pressure relief of the working face roof is realized, which helps to reduce the mine pressure and improve the safety and production efficiency of the working face. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Schematic diagram of the principle of the ultrahigh-pressure hydraulic cutting and fracturing integrated top cutting process;

[0028] Figure 2 Schematic diagram of the profile of the combination of directional cutting and directional fracturing;

[0029] Figure 3 Flow chart of the construction process;

[0030] Figure 4 Schematic diagram of the principle of the hole sealing;

[0031] Figure 5 Front view and sectional view of the hydraulic fracturing hole sealing device;

[0032] Figure 6 Front view and sectional view of the ultrahigh-pressure water jet device;

[0033] In the figure, 1 is an ultrahigh-pressure directional water cutting cutting seam; 2 is a cutting and fracturing borehole; 3 is a fracturing guide borehole; 4 is a designed top cutting line; 5 is a directional hydraulic fracturing fracture; 6 is a finally formed top cutting line; 7 is a cutting seam surface; 8 is a fracturing fracture surface; 9 is a fracturing hole sealing; 10 is a water injection joint; 11 is a lock pipe iron sheet; 12 is an expanded rubber pipe; 13.1 is a middle core I; 13.2 is a middle core II; 14 is a water outlet hole; 15 is a thin iron pipe; 16 is a sealing rubber gasket; 17 is a dead plug core; 18 is a protective pad; 19 is a No. 2 hole sealer; 20 is a connecting pipe; 21 is a No. 1 hole sealer; 22 is a gas pressure mechanism; 23 is a high-pressure water inlet mechanism; 24 is a fixing seat; 25 is a high-pressure water outlet mechanism. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below, obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments; based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the protection scope of the utility model.

[0035] As shown in Figure 1 A top cutting and pressure releasing system based on ultra-high pressure hydraulic cutting and pressure integration, comprising:

[0036] Design top cutting line 4;

[0037] Cutting and fracturing borehole 2, a plurality of cutting and fracturing boreholes 2 are evenly arranged along the design top cutting line 4;

[0038] Fracturing guide borehole 3, the fracturing guide borehole 3 is arranged between two adjacent cutting and fracturing boreholes 2;

[0039] Sealing device, the sealing device is arranged in the cutting and fracturing borehole 2 and the fracturing guide borehole 3;

[0040] Ultra-high pressure water jet device, the ultra-high pressure water jet device sprays ultra-high pressure water into the cutting and fracturing borehole 2 and the fracturing guide borehole 3 to form a directional hydraulic fracturing fracture 5.

[0041] The top cutting borehole end position of the cutting and fracturing borehole 2 is at a position 15m away from the top plate overburden, and the error range of the hole depth is ±100mm.

[0042] Fracturing guide borehole 3, the hole diameter of the fracturing guide borehole 3 is 94mm, the hole depth is 20m, and the error range of the hole depth is ±100mm. The hole spacing is 2m, and the error range of the hole spacing is ±50mm.

[0043] As shown in Figure 5 The sealing device comprises:

[0044] No. 1 hole sealer 21, the rear end of the no. 1 hole sealer 21 is connected with a water injection joint 10, the front end is connected with an intermediate core I13.1, an expansion rubber tube 12 is arranged in the no. 1 hole sealer 21, and the expansion rubber tube 12 communicates the water injection joint 10 and the intermediate core I13.1;

[0045] No. 2 hole sealer 19, the rear end of the no. 2 hole sealer 19 is connected with an intermediate core II13.2, and the front end is provided with a dead core 17;

[0046] A connecting pipe 20 is connected between the intermediate core I 13.1 and the intermediate core II 13.2, and a water outlet hole 14 is arranged in the middle of the connecting pipe 20, and a thin iron pipe 15 is sleeved on the water outlet hole 14.

[0047] The water injection joint 10 is fixedly connected with the first hole packer 21 through the lock pipe iron sheet 11; the intermediate core I 13.1 is fixedly connected with the first hole packer 21 through the lock pipe iron sheet 11; the intermediate core II 13.2 is fixedly connected with the second hole packer 19 through the lock pipe iron sheet 11; and the dead core 17 is fixedly connected with the second hole packer 19 through the lock pipe iron sheet 11.

[0048] A sealing rubber gasket 16 is arranged between the front end of the connecting pipe 20 and the intermediate core II 13.2.

[0049] As shown in Figure 6 , the ultrahigh-pressure water jet device comprises:

[0050] A fixed seat 24 is arranged outside the cutting and fracturing borehole 2 or the fracturing guide borehole 3;

[0051] A high-pressure water inlet mechanism 23 is arranged on the fixed seat 24;

[0052] An air pressure mechanism 22 is arranged to provide high-pressure gas for the high-pressure water inlet mechanism 23;

[0053] A high-pressure water outlet mechanism 25 is connected with the high-pressure water inlet mechanism 23, and the high-pressure water outlet mechanism 25 extends into the cutting and fracturing borehole 2 or the fracturing guide borehole 3.

[0054] As shown in Figure 3 , the specific construction process comprises the following steps:

[0055] Firstly, a drilling machine, a matched drill bit and a drill rod are used to construct the cutting and fracturing borehole 2 and the fracturing guide borehole 3 with a certain aperture in the roadway roof; then the hole packer and the ultrahigh-pressure water jet device are connected and sent to the preset position of the borehole.

[0056] Finally, ultrahigh-pressure water is sprayed from the nozzles on both sides of the ultrahigh-pressure water jet device, the drill rod is uniformly retreated at a constant speed, and the cutting and fracturing borehole 2 and the fracturing guide borehole 3 are formed with an initial crack with a certain length and depth on both sides.

[0057] The cutting depth is 200 mm, the cutting length is 1 m, the borehole sealing and fracturing length is 3 m, and the one-time fracturing or segmented fracturing is determined according to the thickness of the key layer. The fracturing and pressure relief effect and efficiency are investigated to determine the final cutting and fracturing parameters. The design of the ultrahigh-pressure hydraulic cutting scheme also needs to consider the spatial size of the working face, the arrangement of equipment and the safety of personnel operation.

[0058] The packers at the upper and lower ends of the fracture are set by injecting high pressure water into the packer. At this time, the high pressure water is continuously injected into the packer section from the water outlet hole at the front end of the jetting device, the initial fracture continuously expands along the fracture tip, and when the pump pressure suddenly drops or the fracturing time reaches the designed time, the high pressure pump is turned off, the pressure of the packer is released, and the fracturing work of this section is completed. The drilling machine is started, the jetting device is moved to the lower fracture position by operating the drill rod, and the next section is constructed according to the above method.

[0059] The method is performed on the basis of the fracture formed by the ultra-high pressure hydraulic cutting, so as to further expand and extend the fracture, make the roof rock mass more broken, and facilitate the caving. Figure 1 As shown in the figure, the cutting is finally performed along the roof cutting line.

[0060] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the utility model, but not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A roof cutting and pressure relief system based on integrated ultra-high pressure hydraulic cutting and pressing, characterized in that, The application relates to a roof cutting and fracturing device. The roof cutting and fracturing device comprises the following parts: a design cutting line (4); cutting and fracturing boreholes (2) which are evenly arranged along the design cutting line (4); fracturing guide boreholes (3) which are arranged between two adjacent cutting and fracturing boreholes (2); hole sealing devices which are arranged in the cutting and fracturing boreholes (2) and the fracturing guide boreholes (3); 2. The integrated top cutting and pressure releasing system based on ultra-high pressure hydraulic cutting pressure according to claim 1, characterized in that, ultra-high pressure water jet devices which spray ultra-high pressure water into the cutting and fracturing boreholes (2) and the fracturing guide boreholes (3) to form directional hydraulic fracturing cracks (5).

3. The integrated hydraulic pressure cutting and pressure-relief system based on ultra-high pressure water, according to claim 1, characterized in that, The cutting and fracturing boreholes (2) are arranged at a position 15 m away from the roof overburden, and the error range of the hole depth is + / - 100 mm.

4. The integrated top cutting and pressure releasing system based on ultra-high pressure hydraulic cutting pressure according to claim 1, characterized in that, The fracturing guide boreholes (3) have a hole diameter of 94 mm, a hole depth of 20 m, and an error range of + / - 100 mm for the hole depth, and the hole spacing is 2 m, and the error range of the hole spacing is + / - 50 mm. The hole sealing device comprises the following parts: a first hole sealing device (21) which is connected with a water injection joint (10) at the rear end and connected with an intermediate core I (13.1) at the front end, and is provided with an inflatable rubber tube (12) in the first hole sealing device (21), wherein the inflatable rubber tube (12) is connected with the water injection joint (10) and the intermediate core I (13.1); a second hole sealing device (19) which is connected with an intermediate core II (13.2) at the rear end and provided with a dead core (17) at the front end; 5. The integrated hydraulic pressure cutting and pressure relief system based on ultra-high pressure water according to claim 4, characterized in that, a connecting pipe (20) which is connected between the intermediate core I (13.1) and the intermediate core II (13.2), and is provided with a water outlet hole (14) in the middle part, and the water outlet hole (14) is sleeved with a thin iron pipe (15).

6. The integrated hydraulic pressure cutting and pressure relief system based on super-high pressure water according to claim 4, characterized in that, The water injection joint (10) and the first hole sealing device (21) are fixedly connected through a pipe locking iron sheet (11); the intermediate core I (13.1) and the first hole sealing device (21) are fixedly connected through the pipe locking iron sheet (11); the intermediate core II (13.2) and the second hole sealing device (19) are fixedly connected through the pipe locking iron sheet (11); and the dead core (17) and the second hole sealing device (19) are fixedly connected through the pipe locking iron sheet (11).

7. The integrated top cutting and pressure releasing system based on ultra-high pressure hydraulic cutting pressure according to claim 1, characterized in that, A sealing rubber gasket (16) is arranged between the front end of the connecting pipe (20) and the intermediate core II (13.2). The ultra-high pressure water jet device comprises the following parts: a fixing seat (24) which is installed outside the cutting and fracturing borehole (2) or the fracturing guide borehole (3); a high-pressure water inlet mechanism (23) which is installed on the fixing seat (24); an air pressure mechanism (22) which provides high-pressure gas for the high-pressure water inlet mechanism (23); a high-pressure water outlet mechanism (25) which is connected with the high-pressure water inlet mechanism (23), and the high-pressure water outlet mechanism (25) extends into the cutting and fracturing borehole (2) or the fracturing guide borehole (3).

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