Method and system for calculating recharge of aquifer in underground reservoir of coal mine

Abstract

The present invention proposes a method and system for calculating the recharge of an aquifer in a coal mine underground reservoir. The method comprises: pumping water from the coal mine underground reservoir to obtain corresponding pumping data, including: water level difference, return water injection volume, water extraction volume, and pumping time; injecting water into the coal mine underground reservoir until the water level returns to the pre-pumping level, obtaining corresponding injection data, including: water level difference, return water injection volume, and injection time; and calculating the stratum seepage recharge volume based on the corresponding pumping data, the corresponding injection data, and a total water storage calculation formula. The present invention solves the technical problem of inaccurate aquifer recharge calculation in the prior art. The present invention combines reservoir pumping tests and water level recovery experiments to directly calculate the aquifer recharge by recording parameters such as water level difference, return water injection volume, water extraction volume, pumping time, return water injection volume, and injection time, bypassing the reservoir water storage coefficient, which has strong spatial variability.

Description

Technical Field

[0001] The present invention relates to the field of coal mines, and in particular to a method and system for calculating the recharge amount of an aquifer in an underground reservoir of a coal mine. Background Art

[0002] Coal mine underground reservoirs not only store large quantities of mine water underground, reducing evaporation losses, but also accurately monitor and control the underground mine water conditions, thereby avoiding mine water disasters and ensuring mine safety. They can also provide water to both the underground and surface areas, addressing water shortages. During the storage process, water replenishment in coal mine underground reservoirs primarily comes from mine water recharge and seepage recharge from the aquifer. Obtaining information on mine water recharge and aquifer recharge is essential for the safe operation of underground reservoirs. Currently, mine water recharge can be measured through flow rate records and can be manually controlled. However, there is no direct and effective method to calculate aquifer recharge in coal mine underground reservoirs, and aquifer recharge cannot be precisely regulated.

[0003] At present, the calculation of aquifer recharge in reservoirs mostly uses the groundwater reservoir storage coefficient R. Since the method of obtaining the groundwater reservoir storage coefficient R is very complicated, the error of the method of calculating aquifer recharge using the storage coefficient R is too large. Summary of the Invention

[0004] To address the above issues, the present invention proposes a method and system for calculating the recharge of aquifers in coal mine underground reservoirs. This method addresses the inaccurate calculation of aquifer recharge in existing technologies. Combining reservoir pumping tests and water level recovery experiments, the present invention records parameters such as water level difference, recharged mine water volume, water extraction volume, pumping time, recharge volume, and injection time. This method bypasses the reservoir water storage coefficient, which has strong spatial variability, and directly calculates the aquifer recharge. This method's simple and reliable testing and calculation processes can address the inability to calculate aquifer recharge in coal mine underground reservoirs, ensuring reservoir regulation and safe operation.

[0005] The present invention proposes a method for calculating the recharge of aquifers in underground reservoirs of coal mines, comprising:

[0006] Pumping water from underground reservoirs in coal mines to obtain corresponding pumping data, including: water level difference, amount of water recharged into the mine, water extraction volume, and pumping time;

[0007] Fill the underground reservoir of the coal mine with water until the water level returns to the level before pumping, and obtain the corresponding water injection data, including water level difference, recharge volume, and water injection time;

[0008] The rock formation seepage water supply is calculated based on the corresponding data of pumping, the corresponding data of water injection and the calculation formula of the total water storage.

[0009] In addition, the calculation of the rock formation seepage water supply based on the corresponding data of pumping, the corresponding data of water injection and the total water storage amount calculation formula includes:

[0010] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (the amount of water recharged into the mine + the amount of rock seepage water supply - the amount of water extracted) x pumping time.

[0011] In addition, the method of calculating the amount of seepage water supply in the rock formation based on the corresponding data of water pumping, the corresponding data of water injection and the total water storage amount calculation formula also includes:

[0012] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time.

[0013] In addition, the rock formation water recharge is obtained by solving the following two equations:

[0014] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time;

[0015] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time;

[0016] The amount of rock seepage water supply = [pumping time / (pumping time + injection time)] / (water extraction volume - mine water reinjection volume - reinjection volume x injection time / pumping time).

[0017] In addition, the average value of the rock formation water seepage recharge calculated multiple times is taken as the final rock formation water seepage recharge.

[0018] The present invention also provides a coal mine underground reservoir aquifer recharge calculation system, comprising:

[0019] Outlet pipes, filling pipes and water level monitors for monitoring water levels;

[0020] Pump water from the underground reservoir of the coal mine through the outlet pipe to obtain the corresponding pumping data, including: water level difference, amount of water recharged into the mine, water extraction volume, and pumping time;

[0021] Inject water into the underground reservoir of the coal mine through the water injection pipe until the water level returns to the level before pumping, and obtain the corresponding water injection data, which includes the water level difference, recharge volume, and water injection time;

[0022] The rock formation seepage water supply is calculated based on the corresponding data of pumping, the corresponding data of water injection and the calculation formula of the total water storage.

[0023] In addition, the calculation of the rock formation seepage water supply based on the corresponding data of pumping, the corresponding data of water injection and the total water storage amount calculation formula includes:

[0024] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (the amount of water recharged into the mine + the amount of rock seepage water supply - the amount of water extracted) x pumping time.

[0025] In addition, the method of calculating the amount of seepage water supply in the rock formation based on the corresponding data of water pumping, the corresponding data of water injection and the total water storage amount calculation formula also includes:

[0026] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time.

[0027] In addition, the rock formation water recharge is obtained by solving the following two equations:

[0028] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time;

[0029] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time;

[0030] The amount of rock seepage water supply = [pumping time / (pumping time + injection time)] / (water extraction volume - mine water reinjection volume - reinjection volume x injection time / pumping time).

[0031] In addition, the average value of the rock formation water seepage recharge calculated multiple times is taken as the final rock formation water seepage recharge.

[0032] The method and system for calculating aquifer recharge in coal mine underground reservoirs, provided by this invention, solves the technical problem of inaccurate aquifer recharge calculations in existing technologies. By combining reservoir pumping tests and water level recovery experiments, the method directly calculates aquifer recharge by recording parameters such as water level difference, mine water recharge volume, water extraction volume, pumping time, recharge volume, and injection time. This bypasses the reservoir's high spatial variability in water storage coefficients and directly calculates aquifer recharge. This method's simple and reliable testing and calculation processes can address the inability to calculate aquifer recharge in coal mine underground reservoirs, ensuring reservoir regulation and safe operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A flow chart of a method for calculating the recharge rate of aquifers in underground reservoirs in coal mines according to one embodiment of the present invention;

[0034] Figure 2 A schematic diagram of a coal mine underground reservoir aquifer recharge calculation system provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to specific embodiments and accompanying drawings, which are intended only to elaborate on the specific embodiments of the present invention and do not impose any limitation on the present invention. The scope of protection of the present invention shall be subject to the claims.

[0036] Reference Figure 1 and Figure 2 The present invention proposes a method for calculating the recharge of aquifers in underground reservoirs of coal mines, comprising:

[0037] Step S001: Pumping water from the underground reservoir of the coal mine to obtain pumping corresponding data, which includes: water level difference, amount of water recharged into the mine, water extraction volume, and pumping time;

[0038] Step S002: inject water into the underground reservoir of the coal mine until the water level returns to the level before pumping, and obtain corresponding water injection data, which includes water level difference, recharge volume, and water injection time;

[0039] Step S003, calculating the amount of rock formation seepage water supply based on the corresponding data of pumping, the corresponding data of water injection and the calculation formula of the total water storage.

[0040] During the impoundment process, coal mine underground reservoirs primarily receive water recharge from mine water recharge and seepage recharge from the aquifer. Obtaining information on both mine water recharge and aquifer recharge is essential for the safe operation of underground reservoirs. Currently, mine water recharge can be measured through flow records and controlled manually. However, there is no direct and effective method for calculating the recharge rate of the reservoir's aquifer, and recharge cannot be precisely controlled.

[0041] Currently, there is no relevant literature that provides a method to accurately calculate the recharge of coal mine underground reservoir aquifers.

[0042] The document "Theoretical Framework and Technical System of Coal Mine Underground Reservoirs" mentions a method for predicting the total recharge of coal mine underground reservoirs (recharge + aquifer recharge). This method establishes a mine water inflow model:

[0043] Q 涌水量 =aS+bH+C

[0044] Q is the water inflow, in cubic meters per hour; S is the mining area, in square meters; H is the working face mining height, in meters; a is the coefficient related to horizontal permeability; b is the coefficient related to vertical permeability; C is an empirical constant. Here Q 总补给量 =Q 涌水量 The recharge volume can be controlled and measured, and the supply volume can be measured by Q 补给 =Q 涌水量 -Q 回灌 The recharge amount obtained by this method is a predicted value and is not accurate.

[0045] Another prior art method is: △V 水 =△hSR (x，y，z，t) =(Q 回灌 +Q 补给 )△t, where R is a function of x, y, z, t, but △V 水 It needs to be calculated from the reservoir water storage coefficient R. The water storage coefficient R is too complex and difficult to obtain. In addition, the water storage coefficient R has strong spatial variability and changes with time and location. 补给 The method has a large error.

[0046] This method combines reservoir pumping tests with water level recovery experiments. By recording parameters such as water level difference, mine water recharge volume, water extraction volume, pumping time, recharge volume, and injection time, it bypasses the high spatial variability of reservoir water storage coefficients and directly calculates aquifer recharge. This method, with its simple and reliable testing and calculation processes, can address the difficulty in calculating aquifer recharge in coal mine underground reservoirs, ensuring reservoir regulation and safe operation.

[0047] In step S001, water is pumped from the underground reservoir of the coal mine to obtain corresponding pumping data, which includes: water level difference, amount of water recharged into the mine, water extraction volume, and pumping time;

[0048] Record the initial water level h1 of the coal mine underground reservoir; determine the reservoir recharge volume Q 回灌矿井水量 , and keep it constant; determine the reservoir extraction volume Q 水开采量 , and keep it constant; start timing;

[0049] When the water level drops to the predetermined level h2, stop reservoir mining, record the cut-off time, and determine the process time t 抽水时间 , determine the reservoir recharge volume Q 回灌量 , remain constant;

[0050] Step S002: inject water into the underground reservoir of the coal mine until the water level returns to the level before pumping, and obtain corresponding water injection data, which includes water level difference, recharge volume, and water injection time;

[0051] In step S002, the water level gradually rises. When the water level returns to the initial water level h1, the cut-off time is recorded and the recovery process time t is determined. 注水时间 ;

[0052] In step S003, the amount of rock formation seepage water supply is calculated based on the corresponding data of water pumping, the corresponding data of water injection and the calculation formula of the total water storage amount.

[0053] Optionally, the total water storage amount is calculated as:

[0054] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time;

[0055] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time;

[0056] Substitute the coefficients into:

[0057] S(h1-h2)R (x，y，z，t) =(Q 回灌矿井水 +Q 补给 -Q 水开采 )t 抽水

[0058] S(h2-h1)R (x，y，z，t) =(Q 回灌 +Q 补给 )t 注水

[0059] Solving the equations according to the two formulas, we get:

[0060] Rock seepage water supply = [pumping time / (pumping time + injection time)] / (water extraction volume - mine water injection volume - injection volume x injection time / pumping time);

[0061] Q 补给 =[t 抽水 / (t 抽水 +t 注水 )] / (Q 水开采 -Q 回罐矿井水 -Q 回罐 t 注水 / t 抽水 ).

[0062] Optionally, repeat the above process three times and take the average value. If the difference in values is greater than 5%, a fourth test is required.

[0063] This method can avoid the reservoir storage coefficient R and obtain more accurate aquifer recharge.

[0064] The present invention only needs to perform a pumping test and a water level recovery test on the reservoir, the process is simple and reliable, and the use of the water storage coefficient R parameter is avoided, and the calculation result is more accurate.

[0065] In one embodiment, the method of calculating the amount of seepage water supply in the rock formation based on the corresponding data of water pumping, the corresponding data of water injection and the total water storage calculation formula includes:

[0066] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (the amount of water recharged into the mine + the amount of rock seepage water supply - the amount of water extracted) x pumping time.

[0067] Substitute the coefficients into:

[0068] S(h1-h2)R (x，y，z，t) =(Q 回灌矿井水 +Q 补给 -Q 水开采 )t 抽水

[0069] This formula is used to express the amount of water seepage supplied to the rock formation, preparing for the next step of calculation.

[0070] In one embodiment, the step of calculating the amount of seepage water supply in the rock formation based on the pumping data, the injection data, and the total water storage calculation formula further includes:

[0071] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time.

[0072] Substitute the coefficients:

[0073] S(h2-h1)R (x，y，z，t) =(Q 回灌 +Q 补给 )t 注水

[0074] This formula is used to express the amount of water seepage supplied to the rock formation, preparing for the next step of calculation.

[0075] In one embodiment, the formation water recharge is obtained by solving the following two equations:

[0076] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time;

[0077] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time;

[0078] The amount of rock seepage water supply = [pumping time / (pumping time + injection time)] / (water extraction volume - mine water reinjection volume - reinjection volume x injection time / pumping time).

[0079] Substitute the coefficients into:

[0080] S(h1-h2)R (x，y，z，t) =(Q 回灌矿井水 +Q 补给 -Q 水开采 )t 抽水

[0081] S(h2-h1)R (x，y，z，t) =(Q 回灌 +Q 补给 )t 注水

[0082] Solving the equations according to the two formulas, we get:

[0083] Q 补给 =[t 抽水 / (t 抽水 +t 注水 )] / (Q 水开采 -Q 回罐矿井水 -Q 回罐 t 注水 / t 抽水 ).

[0084] This embodiment only requires a pumping test and a water level recovery test to be performed on the reservoir. The process is simple and reliable, and the use of the water storage coefficient R parameter is avoided, so the calculation result is more accurate.

[0085] In one embodiment, the average of the multiple calculated formation water recharge rates is used as the final formation water recharge rate. To ensure accurate results and reduce errors, the average of the multiple calculated formation water recharge rates is used as the final formation water recharge rate. Optionally, the above process is repeated three times, and the average value is taken. If the difference in the values is greater than 5%, a fourth test is performed.

[0086] Reference Figure 1 and Figure 2 The present invention proposes a coal mine underground reservoir aquifer recharge calculation system, comprising:

[0087] Outlet pipes, filling pipes and water level monitors for monitoring water levels;

[0088] Pump water from the underground reservoir of the coal mine through the outlet pipe to obtain the corresponding pumping data, including: water level difference, amount of water recharged into the mine, water extraction volume, and pumping time;

[0089] Inject water into the underground reservoir of the coal mine through the water injection pipe until the water level returns to the level before pumping, and obtain the corresponding water injection data, which includes the water level difference, recharge volume, and water injection time;

[0090] The rock formation seepage water supply is calculated based on the corresponding data of pumping, the corresponding data of water injection and the calculation formula of the total water storage.

[0091] In the system, 1 is the surrounding aquifer, 2 is the collapse area, 3 is the overlying aquifer, 4 is the coal pillar, 5 is the injection pipe, 6 is the water level monitor, 7 is the artificial dam, 8 is the coal mine underground reservoir, 9 is the outlet pipe, 10 is the aquifer leakage recharge, 11 is the initial water level before the pumping test and the water level after the water level recovery test, and 12 is the cut-off water level of the pumping test and the initial water level of the water level recovery test.

[0092] In one embodiment, the method of calculating the amount of seepage water supply in the rock formation based on the corresponding data of water pumping, the corresponding data of water injection and the total water storage calculation formula includes:

[0093] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (the amount of water recharged into the mine + the amount of rock seepage water supply - the amount of water extracted) x pumping time.

[0094] Substitute the coefficients into:

[0095] S(h1-h2)R (x，y，z，t) =(Q 回灌矿井水 +Q 补给 -Q 水开采 )t 抽水

[0096] This formula is used to express the amount of water seepage supplied to the rock formation, preparing for the next step of calculation.

[0097] In one embodiment, the step of calculating the amount of seepage water supply in the rock formation based on the pumping data, the injection data, and the total water storage calculation formula further includes:

[0098] The bottom area of the coal mine underground reservoir x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time.

[0099] Substitute the coefficients:

[0100] S(h2-h1)R (x，y，z，t) =(Q 回灌 +Q 补给 )t 注水

[0101] This formula is used to express the amount of water seepage supplied to the rock formation, preparing for the next step of calculation.

[0102] In one embodiment, the formation water recharge is obtained by solving the following two equations:

[0103] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time;

[0104] Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time;

[0105] The amount of rock seepage water supply = [pumping time / (pumping time + injection time)] / (water extraction volume - mine water reinjection volume - reinjection volume x injection time / pumping time).

[0106] Substitute the coefficients into:

[0107] S(h1-h2)R (x，y，z，t) =(Q回灌矿井水 +Q 补给 -Q 水开采 )t 抽水

[0108] S(h2-h1)R (x，y，z，t) =(Q 回灌 +Q 补给 )t 注水

[0109] Solving the equations according to the two formulas, we get:

[0110] Q 补给 =[t 抽水 / (t 抽水 +t 注水 )] / (Q 水开采 -Q 回罐矿井水 -Q 回罐 t 注水 / t 抽水 ).

[0111] This embodiment only requires a pumping test and a water level recovery test to be performed on the reservoir. The process is simple and reliable, and the use of the water storage coefficient R parameter is avoided, so the calculation result is more accurate.

[0112] In one embodiment, the average of the multiple calculated formation water recharge rates is used as the final formation water recharge rate. To ensure accurate results and reduce errors, the average of the multiple calculated formation water recharge rates is used as the final formation water recharge rate. Optionally, the above process is repeated three times, and the average value is taken. If the difference in the values is greater than 5%, a fourth test is performed.

[0113] The above description is only the principle and preferred embodiment of the present invention. It should be noted that for those skilled in the art, several other variations can be made based on the principle of the present invention, which should also be considered as the scope of protection of the present invention.

Claims

1. A method for calculating the recharge of aquifers in underground reservoirs of coal mines, characterized in that: include: Pumping water from underground reservoirs in coal mines to obtain corresponding pumping data, including: water level difference, amount of water recharged into the mine, water extraction volume, and pumping time; Fill the underground reservoir of the coal mine with water until the water level returns to the level before pumping, and obtain the corresponding water injection data, including water level difference, recharge volume, and water injection time; The rock formation seepage recharge volume is calculated based on the corresponding data of pumping, corresponding data of water injection and the total water storage calculation formula; The method of calculating the rock formation seepage water supply amount based on the corresponding data of water pumping, the corresponding data of water injection and the total water storage amount calculation formula includes: Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time; The method of calculating the amount of seepage water supply in the rock formation according to the corresponding data of water pumping, the corresponding data of water injection and the total water storage calculation formula also includes: Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time; The rock formation water recharge is obtained by solving the following two equations: Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time; Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time; The amount of rock seepage water supply = [pumping time / (pumping time + injection time)] / (water extraction volume - mine water reinjection volume - reinjection volume x injection time / pumping time).

2. The method for calculating the recharge of aquifers in underground reservoirs of coal mines according to claim 1, characterized in that: The average value of the rock formation water seepage recharge calculated multiple times is taken as the final rock formation water seepage recharge.

3. A coal mine underground reservoir aquifer recharge calculation system, characterized in that: include: Outlet pipes, filling pipes and water level monitors for monitoring water levels; Pump water from the underground reservoir of the coal mine through the outlet pipe to obtain the corresponding pumping data, including: water level difference, amount of water recharged into the mine, water extraction volume, and pumping time; Inject water into the underground reservoir of the coal mine through the water injection pipe until the water level returns to the level before pumping, and obtain the corresponding water injection data, which includes the water level difference, recharge volume, and water injection time; The rock formation seepage recharge volume is calculated based on the corresponding data of pumping, corresponding data of water injection and the total water storage calculation formula; The method of calculating the rock formation seepage water supply amount based on the corresponding data of water pumping, the corresponding data of water injection and the total water storage amount calculation formula includes: Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time; The method of calculating the amount of seepage water supply in the rock formation according to the corresponding data of water pumping, the corresponding data of water injection and the total water storage calculation formula also includes: Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time; The rock formation water recharge is obtained by solving the following two equations: Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharged mine water volume + rock formation seepage water supply volume - water extraction volume) x pumping time; Coal mine underground reservoir bottom area x water level difference x water storage coefficient = (recharge volume + rock formation seepage supply volume) x injection time; The amount of rock seepage water supply = [pumping time / (pumping time + injection time)] / (water extraction volume - mine water reinjection volume - reinjection volume x injection time / pumping time).

4. The coal mine underground reservoir aquifer recharge calculation system according to claim 3, characterized in that: The average value of the rock formation water seepage recharge calculated multiple times is taken as the final rock formation water seepage recharge.

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