Underground coal mine descending drill hole sealing method and device

Abstract

The invention belongs to the field of coal mine underground mining, and relates to a coal mine underground descending drill hole sealing method, equipment and device, and the device achieves accurate control of water pressure in a drill hole by integrating a drill hole upper port sealing section, a drill hole water sealing section, a Marithan short sealing section and other key components and utilizing a PLC controller, a pressure sensor, an electromagnetic valve and other intelligent devices. The method comprises the steps that a descending drill hole is formed in a coal seam, a Marithan short sealing section is arranged for preliminary sealing after cutting off, and then a water pressure control system is constructed through a connecting header pipe, a three-way valve and a water injection and drainage pipeline. The PLC automatically adjusts water injection and water drainage according to feedback of the pressure sensor, it is ensured that the water pressure in the drill hole is maintained within a preset range, and an effective water seal layer is formed. The method is easy and convenient to operate and high in hole sealing efficiency, the gap between the bottom of the drill hole and the cross section of a roadway can be rapidly and evenly filled, a tight sealing layer is formed, gas leakage is effectively prevented, and a powerful guarantee is provided for safe production of a coal mine.

Description

Technical Field

[0001] The invention belongs to the field of underground coal mining, and relates to a method and equipment for sealing a descending borehole in an underground coal mine. Background Art

[0003] With the continuous deepening of mechanized coal mining, pre-extraction of gas by drilling holes in the seam for coal mining working faces in high-gas mines has become a prerequisite for all-round and three-dimensional gas management in the working face. By pre-extracting coal seam gas, the gas content in the coal seam can be greatly reduced, thereby reducing the gas outflow from the mining working face or the tunnel excavation working face, and preventing the gas in the working face or tunnel airflow from exceeding the limit. At present, most of the pre-extraction of coal seam gas by drilling holes in the seam is adopted, especially when the mine is mined from shallow to deep, the downward construction method is mostly adopted. This method usually starts with the construction of a downward drilling hole from the excavated tunnel on one side of the working face to the planned tunnel on the other side for gas pre-extraction. When the area of ​​the planned tunnel of the working face meets the extraction standard, tunnel excavation can be carried out. However, during the construction of the tunnel excavation, it is inevitable that the original downward drilling hole will be cut off, resulting in the bottom of the downward drilling hole being exposed.

[0004] When the extraction of the working face does not meet the standard, the downward borehole still needs to be pre-extracted. However, at this time, the bottom of the downward borehole is affected by the truncation of the tunnel, and it is very easy to leak during extraction, so it is urgent to perform single-side sealing. At present, most of the sealing methods are carried out by two blocking and one injection. This method has a long sealing length, complex material selection, and cumbersome construction process. At the same time, conventional gas extraction drilling hole sealing methods also include cement mortar, polyurethane, etc., but they all have their own defects. The construction of cement mortar sealing is time-consuming and labor-intensive and the length is short; polyurethane has a short foaming time in a confined space, and it is easy to foam and expand, but the sealing tube cannot be delivered to the predetermined position; and the sealing materials used for the "two blocking and one injection" at both ends are not strong enough, and the radial force is insufficient, and effective sealing at both ends cannot be achieved. In addition, the grouting equipment is not perfect, which affects the subsequent grouting effect.

[0005] There is currently no suitable means to seal the borehole after the downward drilling is cut off. If the hole is not sealed tightly, it will seriously affect the gas extraction effect. Therefore, an efficient and convenient hole sealing method and equipment are urgently needed. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a method and equipment for sealing downward drilling holes in coal mines, so as to solve the problem of sealing holes when the lower port is cut off by a newly excavated tunnel during downward drilling holes for pre-extraction of coal seam gas in coal mines and pre-extraction of the working face is still required.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a kind of underground coal mine descending drilling hole sealing equipment, comprising a test borehole arranged in a coal seam, a borehole upper port sealing section arranged above the test borehole for sealing the upper port, and a borehole water seal section and a Marisan short seal section arranged in sequence at the lower port of the test borehole, the borehole water seal section being used to form an aqueous solution seal, the Marisan short seal section being arranged below the borehole water seal section, close to the borehole lower port, for preliminarily sealing the borehole and filling the cracks around the hole; and also comprising a connecting main pipe with one end extending into the interior of the Marisan short seal section, the other end of the connecting main pipe extending out of the borehole and connected to a three-way valve, the other two ends of the three-way valve being respectively connected to a drain pipe and a water injection pipe.

[0008] Optionally, solenoid valves are respectively provided at the connection points between the three-way valve and the drain pipe and the water injection pipe, and a pressure sensor for monitoring the pressure of water or solution in the borehole is provided on the connecting main pipe.

[0009] Optionally, the pressure sensor and the solenoid valve are also connected to a PLC controller, which receives the signal from the pressure sensor and controls the opening and closing of the solenoid valve according to a preset water pressure range, thereby regulating water injection and drainage in the borehole.

[0010] Optionally, a drainage pipeline connected to the inside of the borehole for gas extraction is also provided above the test borehole.

[0011] Optionally, one end of the drain pipe is connected to the three-way valve through a solenoid valve, and the other end is connected to a tunnel pressure water injection pipeline that provides a stable water source for the water injection pipe.

[0012] Optionally, one end of the drain pipe is connected to the three-way valve through a solenoid valve, and the other end extends out of the drilled hole.

[0013] A method for sealing a downward drilling hole in a coal mine, using the above-mentioned downward drilling hole sealing equipment, comprises the following steps:

[0014] S1, opening a downward borehole in a coal seam in a coal mine, and performing a hole sealing step after the lower end of the borehole is cut off by a planned tunnel;

[0015] S2, set a short sealing section of Marisan at the lower end of the truncated borehole for preliminary plugging, and ensure that it fills the cracks around the hole completely;

[0016] S3, a connecting main pipe is arranged above the short sealing section of Marisan, and the end of the connecting main pipe is flush with the short sealing section of Marisan; the tail end of the connecting main pipe is connected to a three-way valve, and the two outlets of the three-way valve are respectively connected to the injection pipe and the drain pipe through the solenoid valve, wherein the injection pipe is further connected to the tunnel pressure injection pipeline;

[0017] S4, a pressure sensor is arranged on the connecting main pipe to monitor the pressure of water or solution in the borehole in real time and transmit the pressure information to the PLC controller;

[0018] S5, the PLC controller adjusts the water injection and drainage in the borehole by controlling the opening and closing of the solenoid valve according to the received pressure information and the preset water pressure range;

[0019] S6, the preset water pressure range is determined according to the minimum length h of water accumulation in the borehole;

[0020] S61, when the water pressure in the borehole is lower than the set range, the PLC controller controls the opening of the water injection pipe solenoid valve to allow the tunnel water pressure pipeline to inject water into the borehole;

[0021] S62, when the water pressure reaches the set range, the PLC controller controls the closing of the water injection pipe solenoid valve;

[0022] S63, when the water pressure in the borehole exceeds the set maximum value, the PLC controller controls the opening of the drain pipe solenoid valve to drain water until the water pressure drops to within the set range and then closes the drain pipe solenoid valve.

[0023] Optionally, the water pressure range preset in the PLC controller is calculated based on the minimum length h of water accumulation in the borehole, and the value range of h is 5 to 10 m.

[0024] The beneficial effects of the present invention are:

[0025] 1) Improve sealing efficiency and quality: The present invention uses an aqueous solution as a sealing material, and through a specific injection device and process, it can quickly and evenly fill the gap between the bottom of the drilled hole and the cross-section of the tunnel to form an effective sealing layer. This sealing method is not only easy to operate, but also can greatly shorten the sealing time and improve the sealing efficiency. At the same time, the aqueous solution sealing material has excellent sealing performance, can effectively prevent gas leakage, and improve the sealing quality.

[0026] 2) Reduced sealing costs: Compared with traditional sealing methods such as two blocking and one injection, cement mortar or polyurethane, the aqueous solution sealing material used in the present invention has lower costs and does not require complicated construction equipment and processes, thereby reducing the overall sealing cost. This has important economic benefits for coal mining companies.

[0027] 3) Strong adaptability: The method and equipment of the present invention are applicable to gas extraction boreholes of different diameters and depths, and coal seams under different geological conditions. No matter how the bottom of the borehole is cut off by the newly excavated roadway, the hole can be effectively sealed by adjusting the ratio and injection volume of the aqueous solution.

[0028] 4) High safety: The aqueous solution sealing material is non-toxic and harmless, and has no impact on the environment and human health. At the same time, in the sealing process, since no flammable and explosive chemicals are needed, the safety of the construction is greatly improved.

[0029] 5) Extending the service life of the borehole: After the borehole is sealed by the method and equipment of the present invention, the sealing performance of the borehole is significantly improved, which can effectively prevent gas, water and other fluids from entering the borehole, thereby extending the service life of the borehole and reducing the maintenance and replacement costs due to borehole damage.

[0030] 6) Promote safe production in coal mines: Effective sealing can ensure the smooth progress of gas extraction, reduce the gas concentration in coal mines, and reduce the risk of gas accidents. This is of great significance to protecting the lives of coal miners and the normal production of coal mines.

[0031] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0034] Figure numerals: coal seam 1, test borehole 2, borehole upper port sealing section 3, extraction pipeline 4, borehole water sealing section 5, Marisan short sealing section 6, pressure sensor 7, connecting main pipe 8, tee 9, solenoid valve 10, drain pipe 11, water injection pipe 12, tunnel pressure injection pipe 13, PLC controller 14. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0037] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] See also Figure 1 , which is a kind of underground coal mine downhole drilling sealing equipment, including a test borehole 2 arranged in a coal seam 1, a borehole upper port sealing section 3 arranged above the test borehole 2 for sealing the upper port, and a borehole water seal section 5 and a Marisan short seal section 6 arranged in sequence at the lower port of the test borehole 2, the borehole water seal section 5 is used to form an aqueous solution seal, the Marisan short seal section 6 is arranged below the borehole water seal section 5, close to the borehole lower port, for preliminarily sealing the borehole and filling the cracks around the hole; it also includes a connecting main pipe 8 with one end extending into the Marisan short seal section 6, the other end of the connecting main pipe 8 extends out of the borehole and is connected to a three-way valve 9, the other two ends of the three-way valve 9 are respectively connected to a drain pipe 11 and a water injection pipe 12, and the three-way valve 9 is connected to the drain pipe 11 and the water injection pipe 12 Solenoid valves 10 are respectively provided at the locations, and a pressure sensor 7 for monitoring the pressure of water or solution in the borehole is provided on the connecting main pipe 8. The pressure sensor 7 and the solenoid valve 10 are also connected to a PLC controller 14. The PLC controller 14 receives the signal of the pressure sensor 7, and controls the opening and closing of the solenoid valve 10 according to a preset water pressure range, thereby adjusting the water injection and drainage in the borehole. A drainage pipeline 4 connected to the inside of the borehole for gas extraction is also provided above the test borehole 2. One end of the drainage pipe 11 is connected to the three-way valve 9 through the solenoid valve 10, and the other end is connected to a tunnel pressure water injection pipeline 13 that provides a stable water source for the water injection pipe 12. One end of the drainage pipe 11 is connected to the three-way valve 9 through the solenoid valve 10, and the other end extends out of the borehole.

[0039] A method for sealing a downward drilling hole in a coal mine, using the above-mentioned downward drilling hole sealing equipment, comprises the following steps:

[0040] S1, a downward borehole (i.e., test borehole 2) is opened in the coal seam 1 in the coal mine. When the lower end of the borehole is cut off due to a newly excavated roadway, the borehole is sealed;

[0041] S2, a short Marisan sealing section 6 is set at the lower end of the truncated borehole for preliminary plugging, and it is ensured to fill the complete cracks around the hole;

[0042] S3, a connecting main pipe 8 is arranged above the Marisan short seal section 6, and the end of the connecting main pipe 8 is flush with the Marisan short seal section 6; the tail end of the connecting main pipe 8 is connected to a three-way valve 9, and the two outlets of the three-way valve 9 are respectively connected to the water injection pipe 12 and the water discharge pipe 11 through the solenoid valve 10, wherein the water injection pipe 12 is further connected to the tunnel pressure water injection pipeline 13;

[0043] S4, a pressure sensor 7 is provided on the connecting main pipe 8 to monitor the pressure of water or solution in the borehole in real time and transmit the pressure information to the PLC controller 14;

[0044] S5, the PLC controller 14 adjusts the water injection and drainage in the borehole by controlling the opening and closing of the solenoid valve 10 according to the received pressure information and the preset water pressure range;

[0045] S6, the preset water pressure range is determined according to the minimum length h of water accumulation in the borehole;

[0046] S61, when the water pressure in the borehole is lower than the set range, the PLC controller 14 controls the opening of the solenoid valve 10 of the water injection pipe 12, so that the tunnel water pressure pipeline 13 injects water into the borehole;

[0047] S62, when the water pressure reaches the set range, the PLC controller 14 controls the solenoid valve 10 of the water injection pipe 12 to close;

[0048] S63, when the water pressure in the borehole exceeds the set maximum value, the PLC controller 14 controls the opening of the solenoid valve 10 of the drain pipe 11 to drain water, and then closes the solenoid valve 10 of the drain pipe 11 after the water pressure drops to within the set range.

[0049] In this embodiment, the water pressure range preset in the PLC controller 14 is calculated based on the minimum length h of water accumulation in the borehole, and the value range of h is 5 to 10 m to ensure the formation of an effective water seal layer. This sealing method based on water pressure control is not only easy to operate, but also can quickly and evenly fill the gap between the bottom of the borehole and the cross-section of the tunnel to form a tight sealing layer, thereby effectively preventing gas leakage.

[0050] In summary, the coal mine underground drilling sealing equipment and method of the present invention, by adopting aqueous solution as sealing material and combining with an intelligent pressure control system, realizes efficient and convenient sealing operation, providing a strong guarantee for the safe production of coal mines.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A coal mine underground drilling and sealing equipment, characterized by: It includes a test borehole set in the coal seam, a borehole upper port sealing section set above the test borehole for sealing the upper port, and a borehole water seal section and a Marisan short seal section sequentially set at the lower port of the test borehole, the borehole water seal section is used to form an aqueous solution seal, and the Marisan short seal section is set below the borehole water seal section, close to the borehole lower port, and is used to preliminarily seal the borehole and fill the cracks around the hole; It also includes a connecting main pipe with one end extending into the interior of the Marisan short sealing section, the other end of the connecting main pipe extending out of the borehole and connected to a three-way valve, and the other two ends of the three-way valve are respectively connected to a drain pipe and a water injection pipe.

2. The underground coal mine drilling and sealing equipment according to claim 1, characterized in that: Solenoid valves are respectively arranged at the connection points between the three-way valve and the drain pipe and the water injection pipe, and a pressure sensor for monitoring the pressure of water or solution in the borehole is arranged on the connecting main pipe.

3. The underground coal mine drilling and sealing equipment according to claim 2, characterized in that: The pressure sensor and the solenoid valve are also connected to a PLC controller, which receives the signal from the pressure sensor and controls the opening and closing of the solenoid valve according to a preset water pressure range, thereby adjusting the water injection and drainage in the borehole.

4. The underground coal mine drilling and sealing equipment according to claim 1, characterized in that: A gas extraction pipeline connected to the inside of the borehole is also provided above the test borehole.

5. The underground coal mine drilling and sealing equipment according to claim 1, characterized in that: One end of the drain pipe is connected to the three-way valve through a solenoid valve, and the other end is connected to a tunnel pressure injection pipeline that provides a stable water source for the injection pipe.

6. The underground coal mine drilling and sealing equipment according to claim 1, characterized in that: One end of the drain pipe is connected to the three-way valve through a solenoid valve, and the other end extends out of the drilled hole.

7. A method for sealing a downward drilling hole in a coal mine, using the downward drilling hole sealing equipment for a coal mine as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1, opening a downward borehole in a coal seam in a coal mine, and performing a hole sealing step after the lower end of the borehole is cut off by a planned tunnel; S2, set a short sealing section of Marisan at the lower end of the truncated borehole for preliminary plugging, and ensure that it fills the cracks around the hole completely; S3, a connecting main pipe is arranged above the short sealing section of Marisan, and the end of the connecting main pipe is flush with the short sealing section of Marisan; the tail end of the connecting main pipe is connected to a three-way valve, and the two outlets of the three-way valve are respectively connected to the injection pipe and the drain pipe through the solenoid valve, wherein the injection pipe is further connected to the tunnel pressure injection pipeline; S4, a pressure sensor is arranged on the connecting main pipe to monitor the pressure of water or solution in the borehole in real time and transmit the pressure information to the PLC controller; S5, the PLC controller adjusts the water injection and drainage in the borehole by controlling the opening and closing of the solenoid valve according to the received pressure information and the preset water pressure range; S6, the preset water pressure range is determined according to the minimum length h of water accumulation in the borehole; S61, when the water pressure in the borehole is lower than the set range, the PLC controller controls the opening of the water injection pipe solenoid valve to allow the tunnel water pressure pipeline to inject water into the borehole; S62, when the water pressure reaches the set range, the PLC controller controls the closing of the water injection pipe solenoid valve; S63, when the water pressure in the borehole exceeds the set maximum value, the PLC controller controls the opening of the drain pipe solenoid valve to drain water until the water pressure drops to within the set range and then closes the drain pipe solenoid valve.

8. A method for sealing a borehole in a coal mine according to claim 7, characterized in that: The water pressure range preset in the PLC controller is calculated based on the minimum length h of water accumulation in the borehole, and the value range of h is 5 to 10 m.

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