Method and device for automatically regulating and controlling drilling length of gas extraction directional long drilling hole

Abstract

The invention discloses a method and a device for automatically regulating and controlling the drilling length of a gas extraction directional long drilling hole, and belongs to the technical field of mine gas control. The method comprises the following steps that the position of a directional long drill hole is determined, and drilling construction is conducted; broaching is conducted at some positions of directional long drilling construction, and broaching sections are formed; laying a gas extraction pipe, and arranging a drilling length automatic regulation and control device at the reaming section; and when it is monitored that the gas concentration and the pure amount reach preset starting values, the drill hole is automatically blocked, and automatic regulation and control over the length of the drill hole are achieved. According to the method for automatically regulating and controlling the length of the drill hole, automatic regulation of the length of the drill hole is achieved according to parameters such as gas concentration and purity in the gas extraction pipe in cooperation with the bag capable of being automatically opened in the directional long drill hole, and the site construction burden is relieved; meanwhile, bidirectional plugging can be carried out from the inside and the outside of the extraction pipe, the length of the drill hole is effectively reduced, the gas extraction efficiency is improved, and the service life of the directional long drill hole is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of mine gas control technology, specifically relating to an automatic control method and device for the borehole length of directional long boreholes for gas extraction. Background Technology

[0002] Methane gas is a major hazard in coal mining; therefore, improving gas extraction efficiency and ensuring mine safety have become key focuses of current coal mine technology research. As coal mining depths increase, traditional gas extraction technologies are increasingly unable to meet the demands of safe production. To improve gas extraction efficiency and ensure mine safety, various coal seam gas extraction technologies have been developed. Among them, directional long borehole technology is widely used due to its controllable trajectory, precise control of borehole spatial parameters, and ability to perform functions such as pre-drainage of gas from unmined coal seams and gas extraction from goaf areas.

[0003] Currently, existing directional long borehole technology still faces many problems when applied to gas drainage: First, as the mining face advances, the borehole attenuation becomes obvious, and the gas concentration and purity in the borehole decrease, making it difficult to meet drainage requirements; second, existing construction methods mainly focus on the precise layout of boreholes, such as borehole angle, depth, diameter, orientation, and spatial position parameters, and have failed to effectively solve the problem of excessively rapid attenuation of borehole service life. Summary of the Invention

[0004] Based on the above-mentioned technical problems, the present invention proposes an automatic control method and device for the borehole length of directional long boreholes for gas extraction.

[0005] The technical solution adopted in this invention is: A method for automatically controlling the borehole length of directional long boreholes for gas extraction includes the following steps: (1) Determine the location of the directional long borehole and carry out the drilling construction; (2) Adjust the drilling parameters at certain locations during directional long borehole construction to enlarge the borehole and form an enlarged section; (3) Lay a gas extraction pipe in the directional long borehole. Place a bag on the gas extraction pipe corresponding to the position of the enlarged section formed in step (2). The opening of the bag is connected to the inflation device through a pipeline. The controller is connected to the inflation device and also connected to the gas online real-time monitoring system. When the gas online real-time monitoring system detects that the gas concentration and purity in the gas extraction pipe reach the preset start value, it feeds the signal back to the controller, and the controller controls the inflation device to start. (4) After the gas filling device is turned on, the bag on the gas extraction pipe corresponding to the expansion section will open automatically, and the directional long borehole will be blocked from both inside and outside the gas extraction pipe, so as to realize the automatic control of the borehole length of the directional long borehole. The two-way blocking refers to blocking the directional long borehole from both inside and outside the gas extraction pipe, rather than blocking it from both ends of the borehole.

[0006] Taking multiple reaming sections as an example, the specific steps for gas extraction using the automatic control method for directional long borehole length are as follows: The gas extraction pipe is extended into the fracture zone to extract gas. Initially, the gas concentration and purity values ​​inside the extraction pipe are very high. After extraction for a period of time, the gas concentration and purity decrease. When the online real-time gas monitoring system detects that the gas concentration and purity have decreased to the preset start-up value, it feeds this signal back to the controller. The controller then controls the inflation device to start, simultaneously inflating the bags in the first reaming section (the reaming section farthest from the drilling site and closest to the borehole end position). The directional long borehole is sealed from both inside and outside the gas extraction pipe. After sealing, the gas concentration and purity in the gas extraction pipe rise sharply, and gas extraction continues. After a period of extraction, the gas concentration and purity decrease. When the online real-time gas monitoring system detects that the gas concentration and purity have decreased to the preset start-up value, the above steps are repeated to inflate the gas bag at the second reaming section, achieving the second sealing of the directional long borehole. If there is a third or more reaming sections, the above steps are repeated. The gas bag opening sequence at the reaming section is from far to near the drilling site.

[0007] Preferably, in step (1): the location of the directional long borehole is determined according to the distribution and zoning of the coal seam fracture zone, along the working face and the final borehole location.

[0008] Preferably, in step (2): certain positions refer to starting reaming 30-50m from the end of the borehole to form a reaming section; if there are two or more reaming sections, the distance between each two reaming sections is 20-30m. Specifically: reaming begins 30-50m from the end of the directional long borehole to form the first reaming section; reaming begins 20-30m from the edge of the first reaming section to form the second reaming section; reaming begins 20-30m from the edge of the second reaming section to form the third reaming section; if there are more reaming sections, the reaming positions of the reaming sections are calculated in this manner.

[0009] Preferably, in step (2): the diameter of the reaming section is 2 to 3 times the diameter of the directional long borehole.

[0010] Preferably, in step (2): the length of each hole expansion section is 5~10 m, which is dynamically adjusted according to the specific conditions of the working face.

[0011] Preferably, in step (2): the number of expanded hole sections is at least two.

[0012] Preferably, in step (3): five bags are arranged on the gas extraction pipe corresponding to each expansion section position, of which one bag is located on the inner wall of the gas extraction pipe and four bags are evenly distributed on the outer wall of the gas extraction pipe.

[0013] Preferably, in step (4): the opening sequence of the bags located at the reaming section is from far to near the drilling site. Specifically: the opening sequence of the bags refers to opening the bags at the reaming section furthest from the drilling site first, that is, all bags at the reaming section furthest from the drilling site are opened simultaneously, from far to near the drilling site, and so on.

[0014] An automatic control device for the borehole length of a directional long borehole for gas extraction is provided to implement the aforementioned automatic control method for the borehole length of a directional long borehole for gas extraction. The device includes a bag, a controller, an inflation device, and a real-time online gas monitoring system. The bag is arranged on the gas extraction pipe corresponding to the position of the reaming section, and the opening of the bag is connected to the inflation device through a pipeline. The controller is connected to the inflation device and also to the real-time online gas monitoring system.

[0015] Preferably, five bags are arranged on the gas extraction pipe corresponding to each expansion section position, of which one bag is located on the inner wall of the gas extraction pipe and the other four bags are evenly distributed on the outer wall of the gas extraction pipe.

[0016] The beneficial technical effects of the present invention are as follows: (1) The automatic drilling length control method proposed in this invention can automatically adjust the drilling length based on parameters such as gas concentration and purity in the gas extraction pipe, in conjunction with the automatically opening bag in the directional long borehole, thereby reducing the burden of on-site construction.

[0017] (2) The automatic drilling length control device proposed in this invention automatically opens the bag at the gas extraction pipe, which can block the gas extraction pipe from both inside and outside, effectively reducing the drilling length, improving the gas extraction efficiency, and extending the service life of directional long boreholes. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the location of gas in the goaf extraction area according to the present invention. Figure 2 This is a schematic diagram of the arrangement of the bag and controller in the automatic control device for directional long borehole drilling length of the gas extraction device of the present invention. Figure 3 This is a schematic diagram of the connection method of each component in the automatic control device for the borehole length of directional long boreholes for gas extraction of the present invention. Figure 4This is a flowchart of the automatic control method for the borehole length of directional long boreholes for gas extraction according to the present invention.

[0019] Among them, 1-drilling site, 2-coal seam, 3-coal mining face, 4-goaf, 5-directional long borehole, 6-reaming section, 7-fracture zone, 8-bag on the inner wall of gas extraction pipe, 9-bag on the outer wall of gas extraction pipe, 10-controller, 11-gas extraction pipe, 12-gas filling device, 13-gas online real-time monitoring system. Detailed Implementation

[0020] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Certain embodiments of the invention will be described more fully below with reference to the accompanying drawings, and some, but not all, of these embodiments will be shown. In fact, various embodiments of the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable the invention to meet applicable legal requirements.

[0021] In the description of this invention, it should be noted that the terms "inner", "outer", "upper", "lower", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Example like Figures 1-4 As shown, this embodiment provides a method for automatically adjusting the borehole length of directional long boreholes for gas extraction, including the following steps: (1) During the mining of working face 3, according to the distribution and zoning status of the fracture zone 7 of coal seam 2, the location of the directional long borehole 5 is arranged along the direction of working face 3 and the borehole end position and other parameters are set according to the preset plan and the drilling construction is carried out. (2) The hole is enlarged starting 40m from the end position of the directional long borehole 5 to form the first enlarged section. The hole is enlarged starting 25m from the edge of the first enlarged section to form the second enlarged section. The hole is enlarged starting 25m from the edge of the second enlarged section to form the third enlarged section. The diameter of the hole in the enlarged section 6 is 3 times the diameter of the directional long borehole 5, and the length of each enlarged section 6 is 8m. (3) A gas extraction pipe 11 is laid in the directional long borehole 5 to extract gas from the goaf 4. Five bags are arranged on the gas extraction pipe 11 corresponding to each of the above-mentioned enlarged borehole sections 6. Among them, one bag 8 is located on the inner wall of the gas extraction pipe, and four bags 9 are evenly distributed on the outer wall of the gas extraction pipe. The opening of the bag is connected to the inflation device 12 through a pipeline. The controller 10 is connected to the inflation device 12. The controller 10 is also connected to the gas online real-time monitoring system 13. When the gas online real-time monitoring system 13 detects that the gas concentration and purity in the gas extraction pipe 11 reach the preset start value, it feeds the signal back to the controller 10. The controller 10 controls the inflation device 12 to start. (4) After the gas filling device 12 is started, the five bags on the gas extraction pipe 11 corresponding to the first reaming section (the reaming section farthest from the drilling site 1) automatically open, and the directional long borehole 5 is blocked from the inside and outside of the gas extraction pipe 11, so as to realize the automatic control of the drilling length of the directional long borehole 5. (5) After the first plugging of the directional long borehole 5, the gas concentration and purity values ​​in the gas extraction pipe 11 rise sharply, and gas extraction continues. After a period of extraction, the gas concentration and purity decrease. When the gas online real-time monitoring system 13 detects that the gas concentration and purity have decreased to the preset start value, the above steps are repeated, and the five bags at the second hole expansion section position are automatically opened to plug the directional long borehole 5 for the second time. The automatic plugging steps of the third hole expansion section are similar.

[0023] In addition, such as Figure 2 , Figure 3 As shown, this embodiment also provides an automatic control device for the borehole length of directional long boreholes for gas extraction, used to implement the automatic control method for the borehole length of directional long boreholes for gas extraction described above. The device includes a bag, a controller 10, an inflation device 12, and a real-time online gas monitoring system 13. The bags are arranged on the gas extraction pipe corresponding to the position of the reaming section 6. The number of bags corresponding to each reaming section 6 is 5. One bag 8 is located on the inner wall of the gas extraction pipe 11, and four bags 9 are evenly distributed on the outer wall of the gas extraction pipe 11. The opening of the bag is connected to the inflation device 12 through a pipeline. The controller 10 is connected to the inflation device 12 and is also connected to the real-time online gas monitoring system 13.

[0024] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for automatically regulating the length of a gas extraction directional long borehole, characterized in that, The method comprises the following steps: (1) determining the position of the directional long borehole and performing drilling construction; (2) adjusting the drilling parameters at some positions of the directional long borehole construction to form an expanded section; (3) laying a gas extraction pipe in the directional long borehole, arranging a bag at the position of the expanded section formed in step (2) on the gas extraction pipe, and connecting the open end of the bag to the inflation device through a pipeline; the controller is connected to the inflation device, and the controller is also connected to the online real-time gas monitoring system; when the online real-time gas monitoring system detects that the gas concentration and quantity in the gas extraction pipe reach the preset starting value, the signal is fed back to the controller, and the controller controls the inflation device switch to start; (4) after the inflation device switch starts, the bag at the position of the expanded section on the gas extraction pipe automatically opens, and the directional long borehole is bidirectionally blocked from the inside and outside of the gas extraction pipe, so that the length of the directional long borehole is automatically controlled.

2. The method according to claim 1, wherein the method is characterized in that, In step (1), the position of the directional long borehole is determined according to the distribution and zonal state of the coal seam fracture zone, along the working face strike and the drilling terminal hole position.

3. The method according to claim 1, wherein, In step (2), the positions refer to starting to expand the borehole at 30-50 m from the drilling terminal hole position to form an expanded section; if there are more than two expanded sections, the distance between every two expanded sections is 20-30 m.

4. The method according to claim 1, wherein, In step (2), the diameter of the expanded section is 2-3 times the diameter of the directional long borehole.

5. The method according to claim 1, wherein, In step (2), the length of each expanded section is 5-10 m.

6. The method according to claim 1, wherein, In step (2), the number of expanded sections is at least two.

7. The method according to claim 1, wherein the method is characterized in that, In step (3), five bags are arranged on the gas extraction pipe at each expanded section position, of which one bag is located on the inner wall of the gas extraction pipe, and four bags are evenly distributed on the outer wall of the gas extraction pipe.

8. The method according to claim 1, wherein the method is characterized in that, In step (4), the opening sequence of the bags at the expanded section position is from far to near at the drilling site.

9. A device for automatically regulating the length of a gas extraction directional long borehole, characterized in that, A device for implementing the automatic length control method of the directional long borehole for gas extraction according to any one of claims 1-8, the device comprising a bag, a controller, an inflation device and an online real-time gas monitoring system, the bag being arranged on the gas extraction pipe at the position of the expanded section, and the open end of the bag being connected to the inflation device through a pipeline; the controller is connected to the inflation device, and the controller is also connected to the online real-time gas monitoring system.

10. The automatic length control device for directional long borehole drilling of gas extraction according to claim 9, characterized in that, Five bags are arranged on the gas extraction pipe at each expanded section position, of which one bag is located on the inner wall of the gas extraction pipe, and four bags are evenly distributed on the outer wall of the gas extraction pipe.

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