A method for designing a drilling arrangement parameter of a side leakage uphole drilling

Abstract

The application discloses a kind of borehole layout parameter design method of uphole side leakage method, which is based on engineering geology condition, overburden movement parameter, stope mine pressure appearance law, uses engineering experience analogy, numerical simulation, the method of combining theory calculation, obtains the minimum distance of working face after mining and working face cut eye, maximum caving zone height, maximum water flowing fractured zone height when overburden is stable, further according to the relative position relationship of borehole and caving zone, fracture zone, design working face uphole side leakage method observed borehole layout position, borehole angle and borehole length.It utilizes existing data multi-angle comprehensive borehole layout parameter design, and combines clinometer to carry out field measurement feedback adjustment, realizes the reasonable arrangement of uphole side leakage method borehole, and provides basis for accurately predicting water flowing fractured zone development height.

Description

Technical Field

[0001] This invention relates to the field of borehole layout parameter design method for the overhead borehole side leakage method, and specifically to a borehole layout parameter design method for the overhead borehole side leakage method. Background Technology

[0002] During the advancement of the longwall face, the disturbance caused by coal mining leads to various movements of the roof overburden, such as collapse, fracture, and delamination. This results in the formation of three zones above the working face: a collapse zone, a fracture zone, and a flexural subsidence zone. These three zones with different deformation characteristics are collectively referred to as the "three zones." The collapse zone and the fracture zone are collectively called the water-conducting fracture zone. The height and size of the water-conducting fracture zone are crucial to the safety of the mining operation and determine the thickness or presence of the roof overburden safety protection layer. During gas drainage, it is also necessary to understand the development pattern of the fracture zone to determine the appropriate location for the drainage boreholes.

[0003] The overhead borehole side-leakage method is a new technology for detecting the height of water-conducting fracture zones, developed in recent years. This method offers advantages such as reliable data, accurate information, high speed, and cost-effectiveness. Furthermore, the test results are less affected by external interference, significantly reducing engineering costs and improving detection accuracy. Currently, there is no accurate and comprehensive design method for borehole layout parameters in the overhead borehole side-leakage method. However, the borehole location, borehole angle, and borehole length are key factors affecting the accuracy of water-conducting fracture zone height measurements. Therefore, designing a borehole layout parameter design method for the overhead borehole side-leakage method is of great significance for achieving accurate detection of water-conducting fracture zone height. Summary of the Invention

[0004] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a method for designing borehole layout parameters for the overhead borehole side-leakage method. This method utilizes existing data to comprehensively design borehole layout parameters from multiple angles, and combines this with on-site measurement feedback and adjustments using an inclinometer. This achieves a reasonable layout for the overhead borehole side-leakage method, providing a foundation for accurately predicting the development height of water-conducting fracture zones.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention provides a method for designing borehole layout parameters for the overhead borehole side-leakage method, comprising the following steps:

[0007] S1. Data collection; including information on engineering geological conditions of the coal mining face, overburden movement parameters, and data on the manifestation patterns of mining pressure in the mining area;

[0008] S2. Data Processing: The maximum collapse zone height H is obtained through a combination of engineering experience analogy, numerical simulation, and theoretical calculation. k Maximum water-conducting fracture zone height H s The minimum distance L between the overlying rock and the working face cut-off point when the overlying rock is stable after mining.w ;

[0009] S3. Parameter Design: Design the borehole layout; design the borehole angles; determine the minimum borehole angle φ. min And the initial drilling angle φ0; design the drilling length and determine the minimum drilling angle φ. min Minimum borehole length S min and the initial borehole length S0;

[0010] S4. Parameter Optimization and Correction: Initially select a set of parameters for construction. The initial drilling angle φ0 needs to be greater than the minimum drilling angle φ0. min For borehole angles greater than 2° to 5°, the initial borehole length S0 must be longer than the minimum borehole length S. min 5-15m in length; measure the borehole offset angle q to determine the vertical height Q of the final borehole height from the coal seam. h Is it greater than the maximum water-conducting fracture zone height H? s ;

[0011] If so, a reasonable set of drilling layout parameters is obtained; if not, the drilling angle φ and the drilling length S are increased.

[0012] Preferably, in step S1:

[0013] Information on the engineering geological conditions of the coal mining face includes mining engineering plan, mining footage planning table, borehole stratigraphic column, physical and mechanical parameters of coal and rock mass, empirical formulas for caving zone and water-conducting fracture zone.

[0014] Overburden movement parameters include surface subsidence data as the working face advances and the height H of the caving zone in the surrounding coalfield. k3 Height H of the water-conducting fracture zone s3 ;

[0015] Data on the manifestation patterns of mining pressure include the initial pressure step distance and the periodic pressure step distance in the same coalfield mining area.

[0016] Preferably, step S2 specifically includes:

[0017] S21. Based on engineering geological information, a numerical model of surface subsidence during mining is established through numerical simulation to obtain the height H of the collapse zone. k1 Height H of the water-conducting fracture zone s1 Numerical simulation results;

[0018] S22. Obtain the caving zone height H using empirical formulas for coal mines. k2 Height H of the water-conducting fracture zone s2 Theoretical calculation results;

[0019] S23. Compare the numerical simulation results, theoretical calculation results, and empirical data from surrounding coalfields, and take the maximum caving zone height H.k Maximum water-conducting fracture zone height H s This was determined as the basis for the design of borehole layout parameters for the overhead borehole side leakage method.

[0020] S24. Based on surface subsidence data, mining advance planning tables, and data on the manifestation of mining pressure in the mining area, determine the minimum distance L between the working face and the cut-off point when the overlying strata are stable after mining. w .

[0021] Preferably, the specific steps of step S3 are as follows:

[0022] S31. Drill hole layout design: Pre-mining comparison holes are arranged in two roadways or two roadway chambers. To ensure stable and accurate measurement data, the distance L from the leading working face is [not specified]. q It needs to be greater than L w Post-mining comparison boreholes are arranged in two roadways or two roadway chambers, with a lag distance L from the working face. h It needs to be greater than L w ;

[0023] S32. Drilling angle design, based on the maximum caving zone height H. k Maximum coal seam height H at the working face m Coal seam dip angle α, width of roadway protection coal pillar P w and tunnel height H h The vertical height H when drilling to create a protective coal pillar z It must be greater than the maximum caving zone height H k To determine the minimum drilling angle φ as a standard. min Specifically, as shown in equation (1);

[0024] (1)

[0025] S33, Drilling length design, with minimum drilling angle φ min Drilling continues until the final hole reaches a vertical coal seam height Q. h It must be greater than or equal to the height H of the water-conducting fracture zone. s The minimum borehole length S is obtained. min Specifically, as shown in equation (2);

[0026] (2)

[0027] Preferably, in step S1, the physical and mechanical parameters of the coal and rock mass include bulk modulus / GPa, shear modulus / GPa, cohesion / MPa, tensile strength / MPa, internal friction angle / °, and density / kg·m³. -3 .

[0028] Preferably, in step S1, the stability of the overlying rock after the working face is mined means that the mining pressure is not obvious after the working face is mined, the overlying rock does not move significantly, and the surface subsidence reaches a stable value.

[0029] Preferably, in step S2, the numerical model for surface subsidence during working face mining refers to the FLAC3D numerical model established based on the Mohr-Coulomb criterion.

[0030] The beneficial effects of this invention are as follows: The method of this invention fully utilizes existing data to comprehensively design borehole layout parameters from multiple angles, and combines this with on-site measurement feedback and adjustment using an inclinometer. This method achieves a reasonable layout for boreholes using the overhead borehole side-leakage method, providing a foundation for accurately predicting the development height of water-conducting fracture zones, and is of great significance for achieving precise detection of water-conducting fracture zone height. This prediction method is simple, easy to implement, low in cost, and has wide applicability. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0032] Figure 1 A flowchart of a borehole layout parameter design method for the overhead borehole side leakage method provided in an embodiment of the present invention;

[0033] Figure 2 Numerical model of surface subsidence in working face mining provided for embodiments of the present invention;

[0034] Figure 3 A plan view of the borehole layout for observing side leakage in the working face according to an embodiment of the present invention;

[0035] Figure 4 This is a borehole profile layout diagram for the working face upward hole side leakage observation method provided in an embodiment of the present invention. Detailed Implementation

[0036] 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.

[0037] like Figures 1 to 4As shown, a method for designing borehole layout parameters for the overhead borehole side-leakage method, taking a coal mine as an example, is implemented as follows:

[0038] (1) Conduct on-site investigation at a coal mine working face where water-conducting fracture zone observation is required by borehole side leakage method:

[0039] ① Collect information on the engineering geological conditions of the coal mining face under study, including mining engineering plan, mining footage planning table, borehole stratigraphic column, physical and mechanical parameters of coal and rock mass (see Table 1), empirical formulas for caving zone and water-conducting fracture zone;

[0040] ② Overburden movement parameters, including surface subsidence data as the working face advances, and the height H of the caving zone in the surrounding coalfield. k3 The water-conducting fracture zone is 15.6m high and has a height of H. s3 It is 78.9m;

[0041] ③ Data on the manifestation pattern of mining pressure in the mining area (see Table 2) shows that the initial pressure step distance in the mining area of ​​the same coalfield is 33.5m and the average periodic pressure step distance is 25.8m.

[0042] Table 1

[0043] 1 coarse sandstone 34.08 2490 2679 1764 1.49 43.15 2 sandstone 1.80 2540 2886 1901 1.72 39.6 3 fine sandstone 7.40 2630 2643 1820 1.46 40.23 4 coarse sandstone 11.68 2490 2679 1764 1.49 43.15 5 sandstone 1.70 2540 2886 1901 1.72 39.6 6 coal 0.60 1350 2139 1204 0.78 48.23 7 fine sandstone 13.8 2630 2643 1820 1.46 40.23 8 siltstone 19.17 2660 3550 2345 1.38 39.6 9 fine sandstone 2.28 2630 2643 1820 1.46 40.23 10 coal 0.80 1350 2139 1204 0.78 48.23 11 siltstone 14.06 2660 3550 2345 1.38 39.6 12 siltstone 5 2660 3550 2345 1.38 39.6 13 <![CDATA[Lower 5th Coal Seam]]> 8.6 1350 2139 1204 0.78 48.23 14 fine sandstone 7.99 2630 2643 1820 1.46 40.23 15 sandstone 1.50 2540 2886 1901 1.72 39.6 16 fine sandstone 17.70 2630 2643 1820 1.46 40.23

[0044] Table 2

[0045] Pressure size / MPa 29.5 30.95 30.03 31.52 30.8 Dynamic load factor 1.08 1.13 1.13 1.10 1.11 Step distance / m 33.5 26.3 25 26 25.8

[0046] (2) Data processing stage:

[0047] ① Based on engineering geological information, the average dip length M of the 110501 fully mechanized longwall face is 155m, and the average strike length is 1282.5m. Based on the Mohr-Coulomb criterion, a model with a length × width × height of 500m × 265m × 147m was established. The horizontal displacement of the model was fixed around its perimeter, and the vertical displacement of the bottom surface was fixed. A gravitational acceleration of 9.8m / s² was applied to the entire model. 2 Establish a numerical model for surface subsidence during mining operations, such as... Figure 2 As shown. The height H of the landslide zone is obtained. k1 The height of the water-conducting fracture zone is 16m and H. s1 It is 79.5m.

[0048] ② Calculation using empirical formulas for coal mines: Based on relevant geological surveys of the working face of this coal mine, the overlying strata are mainly medium sandstone and siltstone, with a uniaxial compressive strength of 28.4–61.0 MPa, belonging to medium-hard to hard rock strata. Calculated based on the maximum coal seam height of 8.6 m at the working face, the caving zone height H is predicted using formula (1). k2 The height H of the water-conducting fracture zone is approximately 17.28m, as predicted by formula (2). s2 It is 82.74m;

[0049] H k2 = +2.2 (1)

[0050] Medium-hard to hard type:

[0051] H s2 = +5.6 (2)

[0052] Where: H k2 —The height of the landslide zone development; H s2 —Development height of water-conducting fracture zones; —Cumulative thickness.

[0053] ③ Compare the numerical simulation results, theoretical calculation results, and empirical data from surrounding coalfields, and take the maximum caving zone height H. k The maximum water-conducting fracture zone height is 17.28m, H. s The value is 82.74m, which is determined as the design basis for the borehole layout parameters of the overhead borehole side leakage method.

[0054] ④ Based on surface subsidence data, mining advance planning tables, and the pattern of mine pressure manifestation in the stope (as shown in Table 2), when the working face advanced to 33.5m from April to June, the support experienced a pressure increase to 29.5MPa, indicating the initial pressure from the roof, with an initial pressure step of 33.5m. Subsequently, between advancing to 110.8m, the support experienced three cyclical pressure events at 59.8m, 84.8m, and 110.8m, with pressure magnitudes of 30.95MPa, 30.03MPa, and 31.52MPa respectively, an average cyclical pressure magnitude of 30.8MPa, and a cyclical pressure step between 25m and 26.3m, with an average cyclical pressure step of 25.8m. The minimum distance L between the working face cut-off point and the overlying strata when the overlying strata stabilize after mining is determined. w It is 33.5m.

[0055] (3) Parameter design stage:

[0056] ① Drill hole layout design: Pre-mining comparison holes are arranged in two roadways or two roadway chambers. To ensure stable and accurate measurement data, the distance L from the leading working face is [not specified]. q The depth must be greater than 33.5m. Post-mining comparison boreholes should be arranged in two roadways or two roadway chambers, with a lag distance L from the working face. h It needs to be greater than 33.5m;

[0057] ② Drilling angle design, based on the maximum caving zone height H k The maximum water-conducting fracture zone height is 17.28m, H. s The depth is 82.74m, the coal seam dip angle α is 10°, and the width P of the protective coal pillar in the roadway is...w For 12m and tunnel height H h The minimum borehole angle φ is 3.24m. The standard is that the vertical height of the borehole exiting the protective coal pillar must be greater than the maximum caving zone height. As calculated using equation (3), the minimum borehole angle φ is... min It is approximately 74°.

[0058] (3)

[0059] ③ Drilling length design, with minimum drilling angle φ min Drilling continues until the final hole reaches a vertical coal seam height Q. h It must be greater than or equal to the height H of the water-conducting fracture zone. s Substituting the specific values ​​into equation (4), we can obtain the minimum borehole length S. min It is 104.3m;

[0060] (4)

[0061] (4) Parameter optimization and calibration stage:

[0062] ① Based on the above design, from an economic perspective, it is generally better to have a smaller drilling angle and drilling length. To increase the safety factor, the drilling should not pass through the caving zone, and the final hole height should be Q perpendicular to the coal seam. h Greater than the height H of the water-conducting fracture zone s The initial drilling angle φ0 needs to be greater than the minimum drilling angle φ min For borehole angles greater than 2° to 5°, the initial borehole length S0 must be longer than the minimum borehole length S. min The boreholes are 5-15m long. Based on the existing ZDY1900S drilling rig capacity in the coal mine, the preliminary borehole layout parameters within the above range are as follows:

[0063] (a) Pre-mining comparison hole: In order to eliminate the influence of the original fractures in the overlying rock on the observation results, a pre-mining comparison hole (drill hole number S1) was set up. In order to avoid the influence of the pre-stress, the S1 borehole was constructed in the 110503 return air roadway, which is 400m away from the old cut of the 110501 working face, i.e. 100m ahead of the working face, as a pre-mining comparison hole. The total length of the designed construction borehole is 110m and the drilling angle is 77°.

[0064] (b) Post-mining observation boreholes: Considering that the roof overburden collapse was relatively sufficient when the 110501 working face advanced to the "square" position, a set of post-mining water-conducting fracture zone observation boreholes were arranged at 160m away from the 110501 modified roadway (borehole number S2) and 260m away from the 110501 modified roadway (borehole number S3). The total length of the designed and constructed boreholes was 110m and the borehole angle was 77°.

[0065] ② The drilling offset angle q of the pre-mining comparison hole was measured to be 4° using an inclinometer, and the vertical height Q of the final borehole from the coal seam was [missing information]. h The value of 91.42m is greater than the maximum water-conducting fracture zone height H. s That is, 87.24m, indicating that the parameters are still reasonable and applicable under the influence of the drilling offset angle q, thus obtaining a reasonable set of borehole layout parameters. See the borehole layout plan. Figure 3 See the borehole layout profile. Figure 4 .

[0066] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for designing borehole layout parameters for the overhead borehole side-leakage method, characterized in that, Includes the following steps: S1. Data collection; including information on engineering geological conditions of the coal mining face, overburden movement parameters, and data on the manifestation patterns of mining pressure in the mining area; S2. Data Processing: The maximum collapse zone height H is obtained through a combination of engineering experience analogy, numerical simulation, and theoretical calculation. k Maximum water-conducting fracture zone height H s The minimum distance L between the overlying rock and the working face cut-off point when the overlying rock is stable after mining. w ; S3. Parameter Design: Design the drilling layout; design the drilling angles; determine the minimum drilling angle. and initial drilling angle ; Design the borehole length and determine the minimum borehole angle. Minimum borehole length S min and the initial borehole length S0; The specific steps of step S3 are as follows: S31. Drill hole layout design: Pre-mining comparison holes are arranged in two roadways or two roadway chambers. To ensure stable and accurate measurement data, the distance L from the leading working face is [not specified]. q It needs to be greater than L w Post-mining comparison boreholes are arranged in two roadways or two roadway chambers, with a lag distance L from the working face. h It needs to be greater than L w ; S32. Drilling angle design, based on the maximum caving zone height H. k Maximum coal seam height H at the working face m Coal seam dip angle α, width of roadway protection coal pillar P w and tunnel height H h The vertical height H when drilling to create a protective coal pillar z It must be greater than the maximum caving zone height H k To determine the minimum drilling angle as a standard. Specifically, as shown in equation (1); ； S33, Drilling length design, with minimum drilling angle Drilling continues until the final hole reaches a vertical coal seam height Q. h It must be greater than or equal to the height H of the water-conducting fracture zone. s The minimum borehole length S is obtained. min Specifically, as shown in equation (2); ； S4. Parameter Optimization and Correction: Initially select a set of parameters for construction, initial drilling angle. Minimum drilling angle required For boreholes with an angle greater than 2° to 5°, the initial borehole length S0 must be greater than the minimum borehole length S. min 5-15m in length; measure the borehole offset angle q to determine the vertical height Q of the final borehole height from the coal seam. h Is it greater than the maximum water-conducting fracture zone height H? s ; If so, a reasonable set of drilling layout parameters is obtained; if not, the drilling angle is increased. Increase the borehole length S.

2. The method for designing borehole layout parameters for the overhead borehole side-leakage method according to claim 1, characterized in that, In step S1: Information on the engineering geological conditions of the coal mining face includes mining engineering plan, mining footage planning table, borehole stratigraphic column, physical and mechanical parameters of coal and rock mass, empirical formulas for caving zone and water-conducting fracture zone. Overburden movement parameters include surface subsidence data as the working face advances and the height H of the caving zone in the surrounding coalfield. k3 Height H of the water-conducting fracture zone s3 ; Data on the manifestation patterns of mining pressure include the initial pressure step distance and the periodic pressure step distance in the same coalfield mining area.

3. The method for designing borehole layout parameters for the overhead borehole side-leakage method according to claim 2, characterized in that, Step S2 specifically includes: S21. Based on engineering geological information, a numerical model of surface subsidence during mining is established through numerical simulation to obtain the height H of the collapse zone. k1 Height H of the water-conducting fracture zone s1 Numerical simulation results; S22. Obtain the caving zone height H using empirical formulas for coal mines. k2 Height H of the water-conducting fracture zone s2 Theoretical calculation results; S23. Compare the numerical simulation results, theoretical calculation results, and empirical data from surrounding coalfields, and take the maximum caving zone height H. k Maximum water-conducting fracture zone height H s This was determined as the basis for designing the borehole layout parameters for the side-leaking borehole method. S24. Based on surface subsidence data, mining advance planning tables, and data on the manifestation patterns of mining pressure in the stope, determine the minimum distance L between the working face and the cut-off point when the overlying strata are stable after mining. w .

4. The method for designing borehole layout parameters for the overhead borehole side-leakage method according to claim 2, characterized in that, In step S1, the physical and mechanical parameters of the coal and rock mass include bulk modulus / GPa, shear modulus / GPa, cohesion / MPa, tensile strength / MPa, internal friction angle / °, and density / .

5. The method for designing borehole layout parameters for the side-leaking borehole method according to claim 1, characterized in that, In step S1, the stability of the overlying rock after the working face is mined means that the mining pressure is not obvious after the working face is mined, the overlying rock does not move significantly, and the surface subsidence reaches a stable value.

6. The method for designing borehole layout parameters for the overhead borehole side-leakage method according to claim 3, characterized in that, In step S2, the numerical model for surface subsidence during working face mining refers to the FLAC3D numerical model established based on the Mohr-Coulomb criterion.

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