Gas extraction drilling arrangement structure, arrangement method and arrangement system

Abstract

The application discloses a gas extraction drilling hole arrangement structure, which comprises multiple rows of gas extraction drilling holes arranged at equal intervals along a roadway driving direction, and the number of gas extraction drilling holes in any row of gas extraction drilling holes is the same; any gas extraction drilling hole intersects with a coal seam to be extracted to form a final hole, odd rows of final holes and even rows of final holes are arranged alternately along the roadway driving direction, so that the odd rows of final holes and the even rows of final holes form a row of final hole projections on the same roadway section plane, wherein the final hole projection of the odd rows of final holes and the final hole projection of the even rows of final holes are cross-spaced and arranged at equal intervals. The application uniformly arranges strip gas extraction drilling holes in an array mode in the roadway, reduces the roadway construction amount and improves the roadway driving speed, reduces the drilling hole abandonment rate and the roadway driving investment, and improves the gas extraction effect. The application further provides a gas extraction drilling hole arrangement method and a gas extraction drilling hole arrangement system.

Description

Technical Field

[0001] This invention belongs to the field of coal mining and relates to coal mine gas control technology, particularly to a gas drainage borehole layout structure, layout method and layout system. Background Technology

[0002] The coal industry occupies an important position, and coal resources play a leading role in economic development. However, as coal mining progresses to deeper levels and high-gas mines, the difficulty of coal mine gas control continues to increase. During mine construction and mining, excessive or accumulated gas can lead to safety accidents, even coal and gas outbursts and gas explosions, seriously threatening the lives of underground coal miners.

[0003] The mainstream method for gas control is gas drainage. During the excavation of the working face roadway, boreholes are drilled along the roadway to pre-drain the gas from the working face. This method not only controls the gas but also enhances gas emission reduction and utilization, achieving co-mining of coal and gas. If there is a risk of gas outburst or exceeding limits during roadway excavation, gas drainage roadways need to be arranged in the roof or floor, and cross-layer boreholes are drilled to pre-drain the gas in the area where the recovery roadway is located.

[0004] Currently, the arrangement method for gas drainage boreholes is the drilling field layout, which means that drilling fields are constructed at certain intervals in the gas drainage roadway, and dense drainage boreholes are constructed in the drilling fields to ensure that the effective gas drainage area fully covers the area where gas needs to be drained. The boreholes extract gas from the coal body through negative pressure, thereby reducing the gas concentration in the coal body and achieving the purpose of gas control.

[0005] However, existing drilling site layout technology has the following drawbacks:

[0006] 1) Drilling sites need to be constructed at regular intervals along the tunnel excavation direction, which greatly increases the investment in tunnel excavation;

[0007] 2) The dense arrangement of gas drainage boreholes in the drilling site has a significant impact on the integrity of the surrounding rock on the roadway surface, which can easily lead to air leakage and reduce the extraction efficiency and the concentration of extracted gas.

[0008] 3) The inclination and azimuth of each gas drainage borehole are different. The drilling rig needs to be adjusted in multiple directions when operating in the drilling site. The positioning of the drilling rig and the orientation of the borehole are difficult, which leads to the difficulty of construction. In addition, the geological conditions of the surrounding rock change during construction, and adjacent boreholes are prone to cross-holes. The two boreholes intersect, resulting in poor gas drainage effect and high borehole scrap rate.

[0009] 4) The extraction boreholes are arranged in a fan shape, with a large borehole length (depth). The negative pressure of extraction decreases significantly along the length (depth) of the borehole, making it difficult to seal the boreholes and resulting in low gas extraction efficiency.

[0010] Therefore, it is necessary to propose a new gas drainage borehole layout scheme to solve the above problems. Summary of the Invention

[0011] The purpose of this invention is to provide a gas drainage borehole layout structure, layout method and layout system, which solves the problems of large drilling volume, high roadway excavation investment, high borehole scrap rate and low gas drainage efficiency in the prior art by eliminating the centralized layout of roadway drilling site type drainage boreholes.

[0012] To achieve the above objectives, the present invention provides the following solution:

[0013] The present invention provides a gas drainage borehole layout structure, comprising multiple rows of gas drainage boreholes arranged at equal intervals along the roadway excavation direction, wherein the number of gas drainage boreholes in any row of the gas drainage boreholes is the same.

[0014] Each of the gas drainage boreholes intersects with the coal seam to be drained to form a final borehole. Odd-numbered and even-numbered rows of final boreholes are arranged alternately along the roadway excavation direction so that the odd-numbered and even-numbered rows of final boreholes form a row of final borehole projections on the same roadway cross-section. The final borehole projections of the odd-numbered and even-numbered rows of final boreholes are arranged alternately at equal intervals.

[0015] Optionally, the interval between any two adjacent rows of gas drainage boreholes is less than twice the effective drainage radius of the gas drainage borehole.

[0016] Optionally, the interval between adjacent final hole projections is less than twice the effective extraction radius of the gas extraction borehole.

[0017] Optionally, the opening height of any column of gas extraction boreholes is the same, and the inclination angles of odd-numbered rows of boreholes and even-numbered rows of boreholes are different.

[0018] This invention also proposes a method for laying out gas drainage boreholes, used to lay out the gas drainage borehole layout structure as described above, including the following steps:

[0019] S1. Determine the effective drainage radius of the gas drainage borehole to provide a basis for setting the parameters of the gas drainage borehole, so as to ensure that the effective drainage range of the gas drainage borehole covers the coal body around the roadway; wherein, the setting parameters include the number of gas drainage boreholes in each row, the position of the final borehole, and the interval between any two adjacent rows of gas drainage boreholes.

[0020] S2. Determine the setting parameters of the gas extraction borehole;

[0021] S3. Construct the gas drainage borehole at the designated location in the roadway, and ensure that any one of the gas drainage boreholes intersects with the coal seam to be drained to form the final borehole.

[0022] S4. After depressurizing the gas extraction borehole, seal the gas extraction borehole.

[0023] Optionally, step S1 includes:

[0024] S11. Select a structurally stable area in the bottom drainage tunnel and mark the construction location of the gas drainage borehole.

[0025] S12. Construct multiple pressure testing holes on both sides of the construction point, and arrange the pressure testing holes at intervals in the direction away from the construction point.

[0026] S13. Seal at any of the pressure measuring holes where the hole depth is 0m to 8m;

[0027] S14. After the pressure of any of the pressure measuring holes has stabilized, the gas extraction borehole is constructed at the construction point, and the gas extraction borehole is sealed before a gas extraction test is conducted.

[0028] S15. After the gas extraction is completed, measure the gas pressure and gas content of the pressure measuring hole. When it is found that the gas pressure of a certain pressure measuring hole and the pressure measuring hole further away from the construction point are both less than 0.74 MPa and the gas content decreases by more than 30%, the distance between the certain pressure measuring hole and the construction point is determined as the effective extraction radius of the gas extraction borehole.

[0029] Optionally, in step S12, the construction point and the pressure measuring holes on both sides thereon are arranged on the same straight line, the distance between different pressure measuring holes and the construction point is different, and the distance between different pressure measuring holes and the construction point is arranged in an increasing arithmetic sequence; wherein, the pressure measuring hole corresponding to the odd-numbered value in the arithmetic sequence is located on one side of the construction point, and the pressure measuring hole corresponding to the even-numbered value in the arithmetic sequence is located on the other side of the construction point.

[0030] Optionally, the first value in the arithmetic sequence is 2m, and the common difference is 0.5m.

[0031] Optionally, in step S3, the depth of the gas extraction borehole is checked and confirmed during the construction of the gas extraction borehole, and mapping analysis is performed to promptly fill in any areas where the construction is inadequate.

[0032] Optional steps may also be included:

[0033] S5. Record the construction parameters and measure the extraction parameters for any one of the gas extraction boreholes; the negative pressure at the borehole opening of any one of the gas extraction boreholes shall not be less than 13 kPa.

[0034] Furthermore, this invention proposes a gas drainage borehole layout system for laying out the gas drainage borehole layout structure as described above, including a gas pipeline and a hydraulic drilling rig for constructing the gas drainage borehole, wherein the gas pipeline is connected to the gas drainage borehole for gas extraction.

[0035] The present invention achieves the following technical effects compared to the prior art:

[0036] The gas drainage borehole layout structure proposed in this invention eliminates the centralized arrangement of roadway drilling site-style drainage boreholes. Instead, it uses an array to evenly arrange strip-type gas drainage boreholes in the roadway, that is, multiple rows of gas drainage boreholes are arranged at equal intervals along the roadway's excavation direction, with each row of boreholes positioned identically on the roadway cross-section. This invention, by arranging bottom drainage roadways and gas drainage boreholes below the coal seam in the working face, pre-drains gas around the coal body in the working face roadway, thereby eliminating the danger of excessive gas levels during roadway excavation. Moreover, the strip-type gas drainage borehole layout can reduce roadway construction work, increase roadway excavation speed, reduce borehole scrap rate and roadway excavation investment, and improve gas drainage efficiency, making it highly practical.

[0037] This invention proposes a method for laying out gas drainage boreholes, which can solve the problems of large drilling volume, high investment in roadway excavation, high borehole scrap rate and low gas drainage efficiency in the existing technology.

[0038] This invention proposes a gas drainage borehole layout system, including a gas pipeline and a hydraulic drilling rig for constructing gas drainage boreholes. The gas pipeline is connected to the gas drainage boreholes for gas extraction. This gas drainage borehole layout system can reduce roadway construction work, increase roadway excavation speed, reduce borehole scrap rate and roadway excavation investment, and improve gas drainage efficiency. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a cross-sectional view of the coal seam dip direction disclosed in the embodiments of the present invention;

[0041] Figure 2 This is a cross-sectional view of the coal seam strike direction disclosed in the embodiments of the present invention;

[0042] Figure 3 This is a top view perpendicular to the coal seam plane as disclosed in the embodiments of the present invention;

[0043] Figure 4 This is a schematic diagram of the cross-sectional structure of a gas extraction roadway disclosed in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the pressure measuring hole layout disclosed in an embodiment of the present invention.

[0045] The attached diagram is labeled as follows: 1. Coal seam to be extracted; 2. Location of the working face transport roadway; 3. Location of the working face return air roadway; 4. Gas extraction roadway; 5. Gas extraction borehole; 6. Gas pipeline; 7. Hydraulic drilling rig; 8. Belt conveyor; 9. Air duct; 10. Anchor bolt; 11. Final borehole; L1. Lower side profile line; L2. Upper side profile line; L3. Spacing between final boreholes; L4. Spacing of boreholes along the direction of the roadway. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] One of the objectives of this invention is to provide a gas drainage borehole layout structure that eliminates the centralized arrangement of roadway drilling site-type drainage boreholes, thereby solving the problems of large drilling site construction volume, high roadway excavation investment, high borehole scrap rate, and low gas drainage efficiency in the existing technology.

[0048] Another objective of this invention is to provide a method for laying out gas drainage boreholes, which can solve the problems of large drilling volume, high investment in roadway excavation, high borehole scrap rate and low gas drainage efficiency in the prior art.

[0049] Another object of the present invention is to provide a gas extraction borehole layout system.

[0050] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] Example 1

[0052] like Figures 1-4As shown, this embodiment provides a gas drainage borehole layout structure, including multiple rows of gas drainage boreholes arranged at equal intervals along the tunneling direction. The number of gas drainage boreholes 5 in any row is the same. Each gas drainage borehole 5 intersects with the coal seam 1 to be drained (i.e., the coal body from which gas is to be drained) to form a terminal borehole 11. Odd-numbered and even-numbered rows of terminal boreholes 11 are staggered along the tunneling direction, so that the odd-numbered and even-numbered rows of terminal boreholes 11 form a row of terminal borehole projections on the same tunnel cross-sectional plane. In this row of terminal borehole projections, the terminal borehole projections corresponding to the odd-numbered and even-numbered rows of terminal boreholes 11 are intersected and equally spaced. This spacing is... Figure 1 and Figure 3 L3 is shown in the diagram. The spacing between the multiple rows of gas extraction boreholes arranged along the tunnel's excavation direction is... Figure 2 and Figure 3 L4 is shown in the diagram.

[0053] In this embodiment, the interval between any two adjacent rows of gas drainage boreholes, that is, the distance L4 between the gas drainage boreholes 5 along the roadway direction, is less than twice the effective drainage radius of the gas drainage boreholes.

[0054] In this embodiment, the interval L3 between adjacent final hole projections is preferably less than twice the effective extraction radius of the gas extraction borehole.

[0055] In this embodiment, the opening height of any row of gas extraction boreholes is the same, and the inclination angles of odd-numbered rows of boreholes are different from those of even-numbered rows. The "opening height" of the borehole refers to the height of the borehole opening from the roadway floor. Ensuring that the opening height of each row of boreholes is the same ensures that the opening position of each row of boreholes is the same on the roadway cross-section, which facilitates construction. Since the final positions of odd-numbered and even-numbered rows of boreholes intersect, they are drilled at different inclination angles.

[0056] This embodiment also proposes a method for laying out gas drainage boreholes, used to lay out the above-mentioned gas drainage borehole layout structure, mainly including the following steps:

[0057] S1. Determine the effective drainage radius of the gas drainage borehole to provide a basis for setting parameters of the gas drainage borehole, so as to ensure that the effective drainage range of the gas drainage borehole covers the coal body around the roadway; wherein, the setting parameters include the number of gas drainage boreholes in each row, the position of the final borehole, and the interval between any two adjacent rows of gas drainage boreholes.

[0058] S2. Determine the setting parameters for the gas drainage borehole;

[0059] S3. Construct gas drainage boreholes at designated locations in the roadway, and ensure that any gas drainage borehole intersects with the coal seam to be drained to form a final borehole.

[0060] S4. After depressurizing the gas extraction borehole, seal the gas extraction borehole.

[0061] In this embodiment, step S1 is mainly performed according to the following steps:

[0062] S11. In the bottom drainage roadway, select areas with stable geological conditions and mark the construction points of gas drainage boreholes.

[0063] S12. Construct multiple pressure testing holes on both sides of the construction point, and arrange the pressure testing holes at intervals in the direction away from the construction point.

[0064] S13. Seal at any pressure testing hole with a depth of 0m to 8m.

[0065] S14. After the pressure of any pressure test hole has stabilized, construct a gas extraction borehole at the construction point, seal the gas extraction borehole, and then conduct a gas extraction test.

[0066] S15. After the allowable time for gas extraction is reached, gas extraction ends. Then, the gas pressure and gas content of the pressure measuring holes are measured. When the gas reduction in the pressure measuring holes meets the requirements, in order to ensure the effectiveness of gas extraction, it is necessary to ensure that the pressure measuring holes further away from the gas extraction hole (i.e., the construction point) also meet the requirements for gas extraction. Therefore, when it is found that the gas pressure of a certain pressure measuring hole and the pressure measuring hole further away from the construction point are both less than 0.74 MPa and the gas content reduction is greater than 30%, the distance between the aforementioned pressure measuring hole and the construction point is determined as the effective extraction radius of the gas extraction borehole.

[0067] In this embodiment, the construction points and the pressure measuring holes on both sides of them in step S12 are arranged on the same straight line. The distances between different pressure measuring holes and the construction points are different, and the distances between different pressure measuring holes and the construction points are arranged in an arithmetic progression. Specifically, the pressure measuring hole corresponding to the odd-numbered value in the arithmetic progression is located on one side of the construction point, and the pressure measuring hole corresponding to the even-numbered value in the arithmetic progression is located on the other side of the construction point. Preferably, the first value (i.e., the minimum value) of the arithmetic progression is 2, and the tolerance is 0.5, meaning the first pressure measuring hole is 2m away from the gas drainage borehole 5, and the distances between subsequent pressure measuring holes and the gas drainage borehole 5 increase by 0.5m. Figure 5 As shown, the first value in the arithmetic sequence is 2m, and the first pressure measuring hole 1 corresponds to this first value. # Located to the left of gas drainage borehole 5, the second value in the arithmetic sequence is 2.5m. The second pressure measurement borehole 2 corresponds to this second value. # Located to the right of gas drainage borehole 5, the third value in the arithmetic sequence is 3m, and the third pressure measuring borehole 3 corresponds to this third value.# Located to the left of gas drainage borehole 5... and so on, the pressure measuring borehole corresponding to the odd-numbered value in the arithmetic sequence is located to the left of gas drainage borehole 5, while the pressure measuring borehole corresponding to the even-numbered value in the arithmetic sequence is located to the right of gas drainage borehole 5. Based on the above arrangement of pressure measuring boreholes, if the second pressure measuring borehole 2 is determined... # The distance between the drilling point and the construction site is the effective drainage radius of the gas drainage borehole. Therefore, the second pressure testing borehole is required to be 2... # And the third pressure measuring port 3 # The gas pressure was less than 0.74 MPa and the gas content decreased by more than 30%.

[0068] In this embodiment, step S3 involves checking and confirming the depth of the gas drainage borehole during the construction process, and simultaneously performing mapping analysis to promptly fill in any areas where construction was inadequate.

[0069] In this embodiment, step S5 is also included: recording the construction parameters and measuring the extraction parameters of any gas extraction borehole; the negative pressure at the borehole opening of any gas extraction borehole is not less than 13 kPa.

[0070] The following is a description of this embodiment:

[0071] S1. Determination of the effective drainage radius of gas drainage boreholes

[0072] According to the "Coal Mine Safety Regulations" and the "Basic Indicators for Coal Mine Gas Drainage," the pre-drainage rate of coal seam gas must be greater than 30% and the residual gas pressure must be less than 0.74 MPa. Since the occurrence conditions of different coal seams vary, the drainage capacity of the gas drainage borehole 5 also differs. Therefore, the effective drainage radius of the borehole is first tested to provide a basis for setting the parameters of the gas drainage borehole 5, ensuring that the effective drainage range of the gas drainage borehole 5 covers the coal body surrounding the roadway.

[0073] The testing steps are as follows: First, select a structurally stable area in the bottom drainage roadway and mark the construction point (construction location) of gas drainage borehole 5. Then, construct multiple pressure testing holes on both sides of the construction point of gas drainage borehole 5, numbered sequentially as 1. # 2 # 3 # ...n # The first pressure test port 1 #The construction point of gas drainage borehole 5 is 2m away from the construction point of subsequent pressure testing boreholes, with the distance between each borehole and the same construction point of gas drainage borehole 5 increasing by 0.5m. Each pressure testing borehole is sealed at a drilling depth of 0m to 8m. After the pressure in the pressure testing boreholes stabilizes, gas drainage borehole 5 is constructed at the originally marked construction point, and the borehole is sealed for gas drainage testing. After the permissible gas drainage time has elapsed, the gas pressure and gas content of the pressure testing boreholes are observed. If the gas pressure of pressure testing borehole n and the next pressure testing borehole after it (i.e., pressure testing borehole n+1) are all less than 0.74MPa and the gas content decreases by more than 30%, then the effective drainage radius of the borehole is the distance between pressure testing borehole n and the construction point of gas drainage borehole 5.

[0074] Determination of setting parameters for S2 and gas drainage borehole 5

[0075] The parameters for setting up the gas drainage borehole 5 include the borehole diameter, the number of boreholes in each row, the final borehole position, and the spacing L4 of the boreholes along the direction of the roadway.

[0076] The diameter of the gas drainage borehole 5 is determined based on the drill rod diameter of the drilling rig in the actual mine, and is consistent with the diameter of the drainage borehole during the effective drainage radius test.

[0077] The principle for determining the number and final position of each row of gas drainage boreholes 5 is to ensure that the gas drainage boreholes 5 are controlled to extend at least 15m from the contour lines L2 and L1 of the upper and lower face of the coal roadway (distance along the bedding plane), with the same final borehole spacing L3. The final borehole spacing L3 and the spacing L4 of each row of boreholes along the roadway direction must be less than twice the effective drainage radius of the boreholes. Ultimately, the effective drainage range of the boreholes is guaranteed to cover 15m on each side of the working face roadway.

[0078] Construction of S3, Gas Drainage Borehole 5

[0079] A hydraulic drilling rig is used to construct gas drainage boreholes 5 at designated locations within the roadway. A positioning and guiding device guides the gas drainage boreholes 5 along a designated trajectory. The "designated location within the roadway" is determined by the measured effective drainage radius of the gas drainage boreholes and the layout parameters (borehole diameter, borehole spacing, etc.) of the gas drainage boreholes 5 determined by this effective drainage radius. Generally, it is preferable to have four gas drainage boreholes 5 spaced at intervals in each row. Figure 1 and Figure 3 As shown.

[0080] In addition, during the construction of gas drainage borehole 5, video monitoring and other means should be used to check and confirm the borehole depth. For gas drainage borehole 5 with an actual coal exposure length error of more than one-third compared to the designed coal exposure length, the borehole trajectory should be measured.

[0081] S4, sealing of gas extraction borehole 5

[0082] During the construction of gas extraction borehole 5, mapping analysis should be carried out, and boreholes should be added in a timely manner for areas where construction is not in place. After the construction of gas extraction borehole 5 is completed, pressure relief measures should be taken by flushing, and the borehole should be sealed by the "two plugs and one injection" pressurized sealing process. The length of the sealed section should not be less than 16m.

[0083] S5, Verification and extraction of gas extraction borehole 5

[0084] After the construction of gas drainage borehole 5, the construction parameters of each borehole and the extraction parameters should be recorded and measured. The negative pressure at the borehole opening of all gas drainage boreholes 5 should not be less than 13 kPa. If the gas concentration in gas drainage borehole 5 is found to be too low, additional boreholes need to be drilled. Gas drainage should be carried out after the verification and construction of gas drainage borehole 5 are completed.

[0085] In this embodiment, the gas drainage roadway eliminates the drilling site and adopts a strip-shaped arrangement of gas drainage boreholes 5. The gas drainage boreholes 5 are evenly arrayed along the roadway excavation direction, and the gas drainage boreholes 5 in the roadway are arranged in an alternating manner to reduce the number of boreholes in the roadway cross section and increase the number of rows of drainage boreholes. The odd-numbered rows and even-numbered rows of gas drainage boreholes 5 adopt different inclination angles, so that the gas drainage boreholes 5 are evenly distributed in the coal seam from which gas is extracted, and at the same time, the effective drainage radius of the boreholes is maximized.

[0086] In conventional drilling site layouts, the inclination and azimuth of gas drainage boreholes 5 change, requiring the drilling rig to adjust multiple directions during operation, increasing construction difficulty. Furthermore, changes in surrounding rock geological conditions during construction can easily lead to cross-cutting between adjacent boreholes, resulting in poor gas drainage and potential borehole failure, posing safety hazards. In this embodiment, the strip-style layout of the gas drainage boreholes 5, with their uniform array arrangement in the roadway, ensures that the direction of each borehole 5 lies in a plane perpendicular to the roadway. The drilling rig does not need to adjust multiple drilling directions within the roadway; only the inclination angle of the drill rod needs adjustment. This simplifies borehole orientation, reduces construction difficulty, and minimizes the impact of dense drilling on the integrity of the surrounding rock surface, ensuring effective gas drainage.

[0087] The aforementioned strip-shaped borehole arrangement method eliminates the need for a drilling site, reducing the amount of tunnel excavation work. Furthermore, after eliminating the drilling site, the azimuth angle of the cross-layer extraction boreholes remains unchanged, all perpendicular to the tunnel surface; only the borehole inclination angle changes. This significantly reduces the length of the extraction boreholes for gas control, lowering the investment cost of the extraction project. The reduced borehole length also lowers gas flow resistance and the negative pressure required for gas extraction, thus improving gas extraction efficiency.

[0088] The above-mentioned strip-type gas drainage boreholes 5 are arranged in an alternating manner, so that the effective drainage radius of the gas drainage boreholes 5 can fully cover the area where the gas to be drained, thereby maximizing the utilization of the gas drainage boreholes 5. Furthermore, due to the alternating arrangement of the strip-type drainage boreholes, the number of boreholes on the roadway cross-section is reduced, thereby reducing the impact of dense openings on the integrity of the surrounding rock on the roadway surface.

[0089] Example 2

[0090] This embodiment proposes a gas drainage borehole layout system, including a gas pipeline 6 and a hydraulic drilling rig 7 for constructing gas drainage boreholes 5. The gas pipeline 6 is connected to the gas drainage boreholes 5 for gas extraction. The aforementioned gas drainage borehole layout system is actually a comprehensive operating system that combines borehole layout and gas extraction.

[0091] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0092] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A gas extraction borehole layout method for laying out a gas extraction borehole layout structure, characterized by, The structure includes multiple rows of gas extraction boreholes arranged at equal intervals along the tunnel excavation direction, and the number of gas extraction boreholes in any row of the gas extraction boreholes is the same. Any of the gas drainage boreholes intersects with the coal seam to be drained to form a final hole. Odd-numbered and even-numbered rows of final holes are arranged alternately along the roadway excavation direction so that the odd-numbered and even-numbered rows of final holes form a row of final hole projections on the same roadway cross section. The final hole projections of the odd-numbered and even-numbered rows of final holes are arranged alternately at equal intervals. The deployment method includes the following steps: S1. Determine the effective drainage radius of the gas drainage borehole to provide a basis for setting the parameters of the gas drainage borehole, so as to ensure that the effective drainage range of the gas drainage borehole covers the coal body around the roadway; wherein, the setting parameters include the number of gas drainage boreholes in each row, the position of the final borehole, and the interval between any two adjacent rows of gas drainage boreholes. S2. Determine the setting parameters of the gas extraction borehole; S3. Construct the gas drainage borehole at the designated location in the roadway, and ensure that any one of the gas drainage boreholes intersects with the coal seam to be drained to form the final borehole. S4. After depressurizing the gas extraction borehole, seal the gas extraction borehole.

2. The gas extraction borehole layout method according to claim 1, characterized in that, The interval between any two adjacent rows of gas drainage boreholes is less than twice the effective drainage radius of the gas drainage borehole.

3. The gas extraction borehole layout method according to claim 2, characterized in that, The interval between adjacent final hole projections is less than twice the effective extraction radius of the gas extraction borehole.

4. The gas extraction borehole layout method according to claim 1, characterized in that, The opening heights of any row of gas extraction boreholes are the same, and the inclination angles of odd-numbered rows of boreholes are different from those of even-numbered rows of boreholes.

5. The gas extraction borehole layout method according to claim 1, characterized in that, Step S1 includes: S11. Select a structurally stable area in the bottom drainage tunnel and mark the construction location of the gas drainage borehole. S12. Construct multiple pressure testing holes on both sides of the construction point, and arrange the pressure testing holes at intervals in the direction away from the construction point. S13. Seal at any of the pressure measuring holes where the hole depth is 0m to 8m; S14. After the pressure of any of the pressure measuring holes has stabilized, the gas extraction borehole is constructed at the construction point, and the gas extraction borehole is sealed before a gas extraction test is conducted. S15. After the gas drainage is completed, measure the gas pressure and gas content of the pressure measuring hole. When it is found that the gas pressure of a certain pressure measuring hole and the pressure measuring hole further away from the construction point are both less than 0.74 MPa and the gas content decreases by more than 30%, the distance between the certain pressure measuring hole and the construction point is determined as the effective drainage radius of the gas drainage borehole.

6. The gas extraction borehole layout method according to claim 5, characterized in that, In step S12, the construction point and the pressure measuring holes on both sides thereon are arranged on the same straight line. The distance between different pressure measuring holes and the construction point is different, and the distance between different pressure measuring holes and the construction point is arranged in an increasing arithmetic sequence. The pressure measuring hole corresponding to the odd-numbered value in the arithmetic sequence is located on one side of the construction point, and the pressure measuring hole corresponding to the even-numbered value in the arithmetic sequence is located on the other side of the construction point.

7. The gas extraction borehole layout method according to claim 1, characterized in that, In the step S3, the depth of the gas extraction borehole is checked and confirmed during the construction of the gas extraction borehole, and a mapping analysis is performed, and a hole is timely supplemented in a region where the construction is not in place.

8. The gas extraction borehole layout method according to claim 1, characterized in that, Further comprising steps: S5, recording the construction parameters and measuring the extraction parameters of any gas extraction borehole; the orifice extraction negative pressure of any gas extraction borehole is not less than 13KPa.

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