CN111859751B - Method for predicting water inflow of underground coal mine inclined drainage drilling - Google Patents
Method for predicting water inflow of underground coal mine inclined drainage drilling Download PDFInfo
- Publication number
- CN111859751B CN111859751B CN202010692059.7A CN202010692059A CN111859751B CN 111859751 B CN111859751 B CN 111859751B CN 202010692059 A CN202010692059 A CN 202010692059A CN 111859751 B CN111859751 B CN 111859751B
- Authority
- CN
- China
- Prior art keywords
- hydrophobic
- aquifer
- borehole
- water
- water inflow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 123
- 238000000034 method Methods 0.000 title claims abstract description 67
- 239000003245 coal Substances 0.000 title claims abstract description 50
- 238000005553 drilling Methods 0.000 title claims abstract description 42
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 99
- 239000003673 groundwater Substances 0.000 claims abstract description 19
- 238000004088 simulation Methods 0.000 claims abstract description 17
- 238000013178 mathematical model Methods 0.000 claims abstract description 11
- 238000004364 calculation method Methods 0.000 claims abstract description 10
- 239000002131 composite material Substances 0.000 claims abstract description 7
- 230000035699 permeability Effects 0.000 claims description 8
- 230000001133 acceleration Effects 0.000 claims description 7
- 230000002093 peripheral effect Effects 0.000 claims description 7
- 238000005094 computer simulation Methods 0.000 claims description 5
- 238000013461 design Methods 0.000 claims description 4
- 230000004907 flux Effects 0.000 claims description 4
- 230000005484 gravity Effects 0.000 claims description 4
- 230000001052 transient effect Effects 0.000 claims description 4
- 230000010354 integration Effects 0.000 claims description 3
- 238000012545 processing Methods 0.000 claims description 3
- 238000004458 analytical method Methods 0.000 description 5
- 230000007547 defect Effects 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 238000012512 characterization method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 239000002349 well water Substances 0.000 description 2
- 235000020681 well water Nutrition 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/28—Design optimisation, verification or simulation using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/10—Numerical modelling
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2113/00—Details relating to the application field
- G06F2113/08—Fluids
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- Algebra (AREA)
- Computing Systems (AREA)
- Fluid Mechanics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Mathematical Physics (AREA)
- Pure & Applied Mathematics (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
A method for predicting water inflow of a downward-tilting drainage borehole of a coal mine comprises the following steps: step one: determining a mathematical model of the upward inclined drilling movement of the groundwater in the aquifer; step two: determining the simulation range and simulation boundary of the numerical model; step three: constructing a hydrophobic aquifer and inclined drilling composite numerical model and discretizing; step four: the wall of the inclined drilling hole is generalized into a seepage overflow boundary, and the simulation of the definition method is closer to a real seepage field based on a definite solution condition of the seepage overflow condition; step five: according to the field measured data, inputting a hydrophobic aquifer into a numerical model; step six: integrating the Darcy flow rate of the wall of the hydrophobic borehole in real time, and dynamically calculating the dynamic water inflow of the inclined hydrophobic borehole; therefore, the application adopts a finite element model method based on an unsteady seepage motion model of underground water to dynamically predict the numerical value of the water inflow process of the inclined hydrophobic drilling hole of the coal mine, thereby realizing the dynamic calculation of the water inflow amount of the inclined hydrophobic drilling hole of the coal mine.
Description
Technical Field
The application relates to the technical field of mine water control and underground water resource protection, in particular to a method for predicting water inflow of a downward-tilting drainage borehole of a coal mine.
Background
The underground coal mine coal face is subjected to drainage drilling construction in a centralized manner in the underground to the roof aquifer by taking safety as a target before stoping, and underground water in the (dry) aquifer is dredged in advance so as to reduce the roof water burst intensity in the coal mine mining process, so that the method is a main means for controlling roof water damage. As shown in fig. 1A and 1B, the underground drainage borehole of the coal mine is inclined from the tunnel opening to enter the roof aquifer through the coal seam (referred to as an inclined borehole for short), the water inflow of the inclined drainage borehole has an obvious attenuation rule, the water inflow of the borehole in the early stage of drainage is generally composed of the aquifer static reserve Qs and the dynamic supply quantity Qd, the attenuation rate of the water level and the water level is smaller and smaller along with the extension of the drainage period, and the underground water flow field reaches a dynamic balance state, and the water level is mainly supplied to the aquifer in the stage. Therefore, the spatial structure of the inclined drainage borehole, the borehole water inflow form and the ground vertical well water pumping difference are obvious, the underground inclined borehole water drainage process is generalized to be the ground well water pumping process, and the Qiu Buyi steady flow theory is adopted to predict that the underground drainage borehole water inflow process has larger errors. The experimental formula of the single-hole water inflow of the underground sounding and discharging hollow water body is given in the manual of the total coal mine engineering, and is derived based on Bernoulli equation in fluid mechanics, and is suitable for the water inflow prediction of the sounding and discharging hole under the conditions that the water filling source is surface water and the hollow water, and obviously not suitable for the water inflow prediction of the sounding and discharging water source in the inclined hole in the form of aquifer seepage under the condition that the water level is unchanged and the orifice flow is constant.
Therefore, how to scientifically predict the water inflow change process of the inclined drainage drilling in the coal mine is a technical problem which is difficult to solve in the field for a long time.
Therefore, the designer of the application has the defects that the experience and the achievement of relevant industries are integrated for a long time through intensive research and design, and a coal mine underground inclined drainage drilling water inflow prediction method is researched and designed to overcome the defects.
Disclosure of Invention
The application aims to provide a coal mine underground inclined drainage drilling water inflow prediction method, which can overcome the defects of the prior art, is based on an unsteady seepage motion model of underground water, and adopts a finite element model method to dynamically predict the numerical value of the coal mine inclined drainage drilling water inflow process. A computer model of complex characterization of a hydrophobic aquifer and a drilling hole on the scale of a discretized coal face is utilized by a finite element triangle tetrahedron unit subdivision method; numerical value depicting the peripheral boundary of the hydrophobic aquifer by using an infinity definition method; numerical characterization of the wall of the hydrophobic borehole by using a Darcy seepage overflow boundary definition method; and the dynamic calculation of the water inflow of the inclined drainage borehole in the coal mine is realized by integrating the Darcy flow velocity u of the wall of the drainage borehole in real time.
In order to achieve the purpose, the application discloses a method for predicting water inflow of a downward-tilting drainage borehole of a coal mine, which is characterized by comprising the following steps:
step one: the mathematical model of the movement of the groundwater of the aquifer to the borehole is selected, and is described by using a Darcy non-stable seepage mathematical model, such as the following formula (1) and formula (2):
wherein: epsilon p Is the porosity of the aquifer; ρ is the density of water, kg/m 3 ；Is a Laplacian operator; u is the flow rate of groundwater, m/s; kappa is the permeability of the aquifer, m 2 The method comprises the steps of carrying out a first treatment on the surface of the Mu is the dynamic viscosity of water and Pa.s; p is water pressure, pa; t is time, s; g is gravity acceleration, m/s 2 ；Q m Is a water flow source;
step two: determining the simulation range of the hydrophobic aquifer and processing the range boundary;
step three: constructing a composite numerical model of a hydrophobic aquifer and a upward-inclined hydrophobic borehole, and discretizing;
step four: the boundary treatment of overflow between the hydrophobic aquifer and the borehole wall is defined as the following formula (3) according to the principle of groundwater dynamics:
H＝z+p/r+u 2 /2g (3)
wherein: h is a water head value (m) at a certain point; z is position head (m); p is water pressure (MPa), r is groundwater volume weight (1000N/m 3 ) P/r is called pressure head; u is the velocity of groundwater flow (m/s), g is the gravitational acceleration (m/s) 2 )，u 2 2g is the velocity head;
step five: inputting parameters of a hydrophobic aquifer, and defining two hydrogeological parameters of a permeability coefficient and a water supply degree of the hydrophobic aquifer in a model;
step six: calculating the water inflow of the hydrophobic borehole, setting a solver as a transient process, setting a solving step length and a solving time according to the actual demand of numerical calculation, finally performing unstable flow simulation calculation, and integrating the Darcy flow velocity U in the wall of the hydrophobic borehole in real time, namely Q Gushing up ＝∫∫UdΩ Hole wall area The Darcy seepage flow obtained by dynamic integration is the water inflow of the drilling hole.
Wherein: and in the second step, only establishing a composite numerical model of the hydrophobic aquifer and the hydrophobic borehole in the coverage range of the coal face according to the spatial structure of the coal face and the roof aquifer by using the finite element model.
Wherein: using the infinity definition method, the hydrophobic aquifer peripheral values were processed into "large-scale" infinitely spread water-filled aquifers, with the values processed into "zero" flux boundaries at the top and bottom of the hydrophobic aquifer.
Wherein: and thirdly, constructing a hydrophobic borehole according to the structural design parameters of the cylindrical hydrophobic borehole space, and constructing a hydrophobic aquifer by taking the coverage of the coal face as a boundary according to the dimension of the coal face.
Wherein: and establishing a computer model for compositely describing the aquifer and the drill hole on the dimension of the coal face by utilizing a triangular tetrahedron unit subdivision method of the finite element model, and carrying out local fine subdivision on the wall of the hydrophobic drill hole by taking 1/3 of the aperture size of the hydrophobic drill hole as a minimum unit subdivision standard.
According to the above, the method for predicting the water inflow of the underground inclined hydrophobic drilling of the coal mine has the following effects:
1) The Darcy stable seepage mathematical model is used for describing the movement process of the underground water of the hydrophobic aquifer to the hydrophobic borehole, and the bottleneck that the water inflow of the borehole is difficult to dynamically predict in the underground inclined borehole drainage process of the underground water of the aquifer of the coal mine is broken through.
2) The finite element subdivision unit infinity definition method is utilized to process the peripheral numerical value of the water-filled aquifer into a water-filled aquifer which is infinitely spread in a large range, so that the influence of a small-range artificial water head boundary and a flow boundary on the prediction precision is reduced, the subdivision of a model unit is also reduced, the mesh subdivision quality is improved, and the numerical value at the top and the bottom of the hydrophobic aquifer is processed into a zero-flow boundary.
3) In a finite element analysis platform, the wall of a hydrophobic borehole is generalized into a seepage and overflow boundary of an aquifer, and the adopted definition method of the model solution condition based on the seepage and overflow boundary piece has the simulation result closer to a real seepage field, so that the problem that the borehole flow state is difficult to numerically describe is reasonably solved.
The details of the present application can be found in the following description and the accompanying drawings.
Drawings
Fig. 1A and 1B show schematic diagrams of the water flushing process of the inclined drainage borehole of the present application.
Figure 2 shows a schematic representation of the discretization of the hydrophobic aquifer and hydrophobic borehole of the present application.
FIG. 3 shows a schematic representation of the boundary between a hydrophobic aquifer and a hydrophobic borehole wall seepage overflow of the present application.
FIG. 4 shows a schematic diagram of a calculated water inflow and measured water inflow fitting curve of a working surface drainage borehole according to the present application.
Detailed Description
It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular forms also are intended to include the plural forms unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, and/or combinations thereof.
The method for predicting the water inflow of the underground inclined drainage drilling of the coal mine comprises the following steps:
step one: the mathematical model of the movement of the underground water of the aquifer to the drilling is selected, and in order to describe the movement process of the underground water of the aquifer to the hydrophobic drilling, the Darcy unsteady seepage mathematical model is adopted for description, such as the following formula (1) and formula (2):
wherein: epsilon p Is the porosity of the aquifer; ρ is the density of water, kg/m 3 ；Is a Laplacian operator; u is the flow rate of groundwater, m/s; kappa is the permeability of the aquifer, m 2 The method comprises the steps of carrying out a first treatment on the surface of the Mu is the dynamic viscosity of water and Pa.s; p is water pressure, pa; t is time, s; g is gravity acceleration, m/s 2 ；Q m Is the source of the water flow.
Step two: the hydrophobic aquifer simulation range is determined and the range boundary is processed, the artificial given boundary conditions on the coal face and the drilling small-scale model have great influence on drilling water burst analysis, the model of the working face and the drilling scale is extremely small in scale compared with the traditional groundwater system numerical simulation range (the traditional groundwater numerical simulation takes a regional hydrogeological unit as a simulation range), and the influence range on the aquifer under the drilling hydrophobic influence is limited, so that the finite element model is utilized, and only the hydrophobic aquifer and hydrophobic drilling composite numerical model in the coverage range of the coal face is established according to the spatial structure of the coal face and the roof aquifer, as shown in fig. 2. The peripheral numerical value of the hydrophobic aquifer is processed into a large-range infinitely-spread water-filled aquifer by using an infinite definition method, so that the influence of a small-range artificial water head boundary and a flow boundary is reduced, and the subdivision of a model unit is also reduced. Values were processed to "zero" flux boundaries at the top and bottom of the hydrophobic aquifer.
Step three: constructing and discretizing a composite numerical model of the hydrophobic aquifer and the inclined hydrophobic borehole, constructing the hydrophobic borehole according to the design parameters (length, elevation angle, azimuth angle and aperture) of the cylindrical hydrophobic borehole space structure, and constructing the hydrophobic aquifer according to the dimension of the coal face by taking the coverage of the coal face as a boundary; since the diameter of the hydrophobic borehole is generally smaller (in centimeter level) on the dimension of the coal face, and the difference between the diameter of the hydrophobic borehole and the dimension of the working face (in hundred meters level) is too large, the subdivision of the quadrangular hexahedral model is difficult to carry out, as shown in fig. 2, a computer model for compositely describing the aquifer and the borehole on the dimension of the coal face is established by utilizing a triangular tetrahedron subdivision method of a finite element model, and 1/3 of the diameter of the hydrophobic borehole is the minimum unit subdivision standard, the wall of the hydrophobic borehole is locally finely subdivided, wherein in the setting of the size of a grid unit, the size of a network unit is calibrated to be hydrodynamic, and the quality of the network subdivision unit of the whole model is improved.
Step four: and when the drainage of the underground drilling hole is completely opened, as the underground water of the drainage aquifer seeps to the wall of the drainage drilling hole and then is discharged out of the hole in a free flow form, the seeper is difficult to form a pressure water head in the drilling hole. The total head at any point of the aquifer according to the principles of groundwater dynamics is defined as the following equation (3):
H＝z+p/r+u 2 /2g (3)
wherein: h is a water head value (m) at a certain point; z is position head (m); p is water pressure (MPa), r is groundwater volume weight (1000N/m 3 ) P/r is called pressure head; u is the velocity of groundwater flow (m/s), g is the gravitational acceleration (m/s) 2 )，u 2 And/2 g is the velocity head.
The wall of the hydrophobic borehole can be used as an overflow boundary of water-filled aquifer seepage, and according to the above formula, the groundwater seepage speed is slow according to the flow speed continuous principle on the overflow boundary of the aquifer seepage, so that in the above formula, the total water head on the overflow boundary of the seepage can be calculated by neglecting u 2 2g velocity head term; in addition, since the hydrophobic bore is in communication with the atmosphere, the pore water pressure at the interface is approximately equal to the atmospheric pressure (0.1 MPa), and the p/r pressure head is at a minimum value (10 -4 m). Therefore, the height H of the underground water head on the wall of the hole reaching the western seepage overflow boundary is approximately equal to the value of the fixed pressure water head of the position elevation z and p/r of each split node of the hole wall (10 - 4 m), i.e. h=z+10 -4 . As shown in figure 3, in the finite element analysis platform, the wall of the hydrophobic borehole can be generalized into the seepage and overflow boundary of the aquifer, and the definition method of the definite solution condition based on the seepage and overflow condition is adopted, and the simulation is closer to the real seepage field, so that the reasonable solution of the borehole is achievedThe flow state is difficult to be numerically depicted.
Step five: and (3) inputting parameters of the hydrophobic aquifer, and defining two hydrogeological parameters of the permeability coefficient and the water supply degree of the hydrophobic aquifer in a model according to actual measurement data on site.
Step six: calculating the water inflow of the hydrophobic drilling, setting a solver as a transient process, setting a solving step length and a solving time according to the actual demand of numerical calculation, and finally performing unstable flow simulation calculation, as shown in fig. 3. By integrating the Darcy flow velocity U in real time, i.e. Q, in the area of the wall of the hydrophobic borehole Gushing up ＝∫∫UdΩ Hole wall area The Darcy seepage flow obtained by dynamic integration is the water inflow of the drilling hole.
The application will now be further described with reference to the drawings and examples using a first-aid working surface of a bingham mine as an example.
Step one: the mathematical model of the movement of the underground water of the aquifer to the drilling is selected, and in order to describe the movement process of the underground water of the aquifer to the hydrophobic drilling, the Darcy unsteady seepage mathematical model is adopted for description:
wherein: epsilon p Is the porosity of the aquifer; ρ is the density of water, kg/m 3 ；Is a Laplacian operator; u is the flow rate of groundwater, m/s; kappa is the permeability of the aquifer, m 2 The method comprises the steps of carrying out a first treatment on the surface of the Mu is the dynamic viscosity of water and Pa.s; p is water pressure, pa; t is time, s; g is gravity acceleration, m/s 2 ；Q m Is the source of the water flow.
Step two: simulation range determination and range boundary processing, the coal face size of the embodiment is 500m inclined length and 150m face width, the hydrophobic aquifer consists of fine sandstone (thickness 13 m), sandy mudstone (thickness 23 m) and medium coarse sandstone layer (thickness 36 m), an aquifer hydrophobic borehole prediction model in the range of 150×500m of the coal face is built, as shown in fig. 2, the water-filled aquifer peripheral numerical value is processed into a water-filled aquifer which is infinitely spread in a large range by using an infinity definition method, and the hydrophobic aquifer top and bottom plate numerical values are processed into a zero flux boundary.
Step three: constructing and discretizing a numerical model of a hydrophobic aquifer and a hydrophobic drilling hole, wherein in the embodiment, the azimuth angle of the hydrophobic drilling hole is 228 degrees, the inclination angle is 55 degrees, the aperture is 94mm, the inclined length is 85m (the hydrophobic aquifer is not penetrated), constructing the hydrophobic drilling hole, and constructing the hydrophobic aquifer by taking the coverage of a coal face of 150 multiplied by 500m as a boundary according to the dimension of the coal face; and establishing a computer model for compositely describing the hydrophobic aquifer and the hydrophobic drilling hole by adopting a finite element triangular tetrahedral unit subdivision method, taking the minimum dimension of 31.3mm as a subdivision standard for 1/3 of the aperture of the hydrophobic drilling hole, and carrying out local fine subdivision on the wall of the hydrophobic drilling hole, wherein in the mesh unit size setting, the network unit size is calibrated into fluid dynamics, so that the quality of the network subdivision unit of the whole model is improved.
Step four: the overflow boundary treatment of the water-bearing layer and the borehole wall, the hydrophobic borehole wall is defined as the overflow boundary of the seepage of the water-bearing layer, the height H of the underground water head on the wall darcy seepage overflow boundary is equal to the position elevation z and the p/r constant pressure water head value (10 -4 m), i.e. h=z+10 -4 。
Step five: and (3) inputting parameters of the hydrophobic aquifer, and defining two hydrogeological parameters of the permeability coefficient and the water supply degree of the hydrophobic aquifer in a model according to the data actually measured on site, wherein the two hydrogeological parameters are shown in the following table 1.
TABLE 1 model parameters
Step six: calculating the water inflow of the hydrophobic borehole, setting a solver as a transient process, setting a solving step length and a solving time according to the actual demand of numerical calculation, finally performing non-steady flow simulation calculation, taking 0.1h as a time step length by a model, and calculating the Darcy seepage flow as the water inflow of the borehole by integrating the Darcy flow velocity U in the wall of the hydrophobic borehole in real time. The change process of the drilling water inflow and the measured water inflow are calculated as shown in fig. 4, the embodiment uses fitting analysis for 0-30d to simulate the calculated drilling water inflow, and the attenuation rule of the drilling water inflow accords with a single-order exponential decay process, as shown in the following formula (4):
Q＝42.82+14.02*exp(-2.03*t) (4)
wherein the fitted stable water quantity Q e ＝42.82m 3 And/h, the stabilizing period is about 41h, the drilling water inflow attenuation coefficient a=2.03, and the fitting determination coefficient reaches R 2 ＝0.93。
Through the embodiment, the method for predicting the water inflow change process of the underground inclined hydrophobic drilling of the coal mine is scientific and practical.
Therefore, the application has the beneficial effects that:
1) The Darcy stable seepage mathematical model is used for describing the movement process of the underground water of the hydrophobic aquifer to the hydrophobic borehole, and the bottleneck that the water inflow of the borehole is difficult to dynamically predict in the underground inclined borehole drainage process of the underground water of the aquifer of the coal mine is broken through.
2) The finite element subdivision unit infinity definition method is utilized to process the peripheral numerical value of the water-filled aquifer into a water-filled aquifer which is infinitely spread in a large range, so that the influence of a small-range artificial water head boundary and a flow boundary on the prediction precision is reduced, the subdivision of a model unit is also reduced, the mesh subdivision quality is improved, and the numerical value at the top and the bottom of the hydrophobic aquifer is processed into a zero-flow boundary.
3) In a finite element analysis platform, the wall of a hydrophobic borehole is generalized into a seepage and overflow boundary of an aquifer, and the adopted definition method of the model solution condition based on the seepage and overflow boundary piece has the simulation result closer to a real seepage field, so that the problem that the borehole flow state is difficult to numerically describe is reasonably solved.
It is to be clearly understood that the above description and illustration is made only by way of example and not as a limitation on the disclosure, application or use of the application. Although embodiments have been described in the embodiments and illustrated in the accompanying drawings, the application is not limited to the specific examples illustrated by the drawings and described in the embodiments as the best mode presently contemplated for carrying out the teachings of the application, and the scope of the application will include any embodiments falling within the foregoing specification and the appended claims.
Claims (5)
1. The method for predicting the water inflow of the underground inclined drainage borehole of the coal mine is characterized by comprising the following steps of:
step one: the mathematical model of the movement of the groundwater of the aquifer to the borehole is selected, and is described by using a Darcy non-stable seepage mathematical model, such as the following formula (1) and formula (2):
wherein: epsilon p Is the porosity of the aquifer; ρ is the density of water, kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the Let be the laplace operator; u is the flow rate of groundwater, m/s; kappa is the permeability of the aquifer, m 2 The method comprises the steps of carrying out a first treatment on the surface of the Mu is the dynamic viscosity of water and Pa.s; p is water pressure, pa; t is time, s; g is gravity acceleration, m/s 2 ；Q m Is a water flow source;
step two: determining the simulation range of the hydrophobic aquifer and processing the range boundary;
step three: constructing a composite numerical model of a hydrophobic aquifer and a upward-inclined hydrophobic borehole, and discretizing;
step four: the boundary treatment of overflow between the hydrophobic aquifer and the borehole wall is defined as the following formula (3) according to the principle of groundwater dynamics:
H＝z+p/r+u 2 /2g(3)
wherein: h is a water head value (m) at a certain point; z is the positionA water placing head (m); p is water pressure (MPa), r is groundwater volume weight (1000N/m 3 ) P/r is called pressure head; u is the velocity of groundwater flow (m/s), g is the gravitational acceleration (m/s) 2 )，u 2 2g is the velocity head;
step five: inputting parameters of a hydrophobic aquifer, and defining two hydrogeological parameters of a permeability coefficient and a water supply degree of the hydrophobic aquifer in a model;
step six: calculating the water inflow of the hydrophobic borehole, setting a solver as a transient process, setting a solving step length and a solving time according to the actual demand of numerical calculation, finally performing unstable flow simulation calculation, and integrating the Darcy flow velocity U in the wall of the hydrophobic borehole in real time, namely Q Gushing up ＝∫∫UdΩ Hole wall area The Darcy seepage flow obtained by dynamic integration is the water inflow of the drilling hole.
2. The method for predicting the water inflow of a coal mine underground inclined drainage borehole of claim 1, wherein the method comprises the following steps: and in the second step, only establishing a composite numerical model of the hydrophobic aquifer and the hydrophobic borehole in the coverage range of the coal face according to the spatial structure of the coal face and the roof aquifer by using the finite element model.
3. The method for predicting the water inflow of a coal mine underground inclined drainage borehole of claim 2, wherein the method comprises the following steps: using the infinity definition method, the hydrophobic aquifer peripheral values were processed into "large-scale" infinitely spread water-filled aquifers, with the values processed into "zero" flux boundaries at the top and bottom of the hydrophobic aquifer.
4. The method for predicting the water inflow of a coal mine underground inclined drainage borehole of claim 1, wherein the method comprises the following steps: and thirdly, constructing a hydrophobic borehole according to the structural design parameters of the cylindrical hydrophobic borehole space, and constructing a hydrophobic aquifer by taking the coverage of the coal face as a boundary according to the dimension of the coal face.
5. The method for predicting the water inflow of a coal mine underground inclined drainage borehole of claim 4, wherein the method comprises the following steps: and establishing a computer model for compositely describing the aquifer and the drill hole on the dimension of the coal face by utilizing a triangular tetrahedron unit subdivision method of the finite element model, and carrying out local fine subdivision on the wall of the hydrophobic drill hole by taking 1/3 of the aperture size of the hydrophobic drill hole as a minimum unit subdivision standard.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010692059.7A CN111859751B (en) | 2020-07-17 | 2020-07-17 | Method for predicting water inflow of underground coal mine inclined drainage drilling |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010692059.7A CN111859751B (en) | 2020-07-17 | 2020-07-17 | Method for predicting water inflow of underground coal mine inclined drainage drilling |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111859751A CN111859751A (en) | 2020-10-30 |
| CN111859751B true CN111859751B (en) | 2023-10-24 |
Family
ID=73000534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010692059.7A Active CN111859751B (en) | 2020-07-17 | 2020-07-17 | Method for predicting water inflow of underground coal mine inclined drainage drilling |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111859751B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112502775B (en) * | 2020-11-06 | 2023-04-28 | 扎赉诺尔煤业有限责任公司 | Semi-solid sandstone aquifer drainage depressurization method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103226732A (en) * | 2013-03-21 | 2013-07-31 | 中南大学 | GMS (groundwater modeling system)-based forecast method for ground water seepage fields at different mining levels of mining area |
| JP2018154969A (en) * | 2017-03-15 | 2018-10-04 | 大成建設株式会社 | Method for estimating spring water pressure of natural ground |
| CN109723424A (en) * | 2018-12-11 | 2019-05-07 | 中煤科工集团西安研究院有限公司 | A kind of down-hole drilling waterdrainage amount prediction technique |
-
2020
- 2020-07-17 CN CN202010692059.7A patent/CN111859751B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103226732A (en) * | 2013-03-21 | 2013-07-31 | 中南大学 | GMS (groundwater modeling system)-based forecast method for ground water seepage fields at different mining levels of mining area |
| JP2018154969A (en) * | 2017-03-15 | 2018-10-04 | 大成建設株式会社 | Method for estimating spring water pressure of natural ground |
| CN109723424A (en) * | 2018-12-11 | 2019-05-07 | 中煤科工集团西安研究院有限公司 | A kind of down-hole drilling waterdrainage amount prediction technique |
Non-Patent Citations (6)
| Title |
|---|
| 基于Visual Modflow的台格庙勘查区矿井涌水量预测;张保建;;煤炭科学技术(S1);全文 * |
| 基于Visual Modflow的岩溶水疏降流场模拟和涌水量预测;刘永良;潘国营;;河南理工大学学报(自然科学版)(01);全文 * |
| 基于排水沟数值模型的工作面涌水量预测;郭小铭;;煤矿安全(01);全文 * |
| 基于渗流井理论的放水试验数值模拟及水文地质参数不确定性分析;孙启明;柯贤敏;田国林;王玮;;水土保持通报(03);全文 * |
| 导水裂缝带部分波及顶板含水层条件下涌水量预测;刘英锋;郭小铭;;煤田地质与勘探(05);全文 * |
| 王河煤矿矿井涌水量数值模拟及预测;李平;郭会荣;吴孔军;靳孟贵;李学问;;地球科学(中国地质大学学报)(04);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111859751A (en) | 2020-10-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Clemens et al. | A combined continuum and discrete network reactive transport model for the simulation of karst development | |
| Bruthans et al. | Fast evolving conduits in clay-bonded sandstone: Characterization, erosion processes and significance for the origin of sandstone landforms | |
| CN114372352B (en) | Method for predicting peak regulation capacity of gas storage of complex fault block oil reservoir through seepage-temperature double-field coupling numerical simulation | |
| CN112597673B (en) | Method for determining effect of servo support system on foundation pit deformation control under rainfall condition | |
| CN111859751B (en) | Method for predicting water inflow of underground coal mine inclined drainage drilling | |
| CN109036065A (en) | Single layer waterproofing type cap rock is collapsed to because of experimental provision | |
| CN104952326A (en) | Water-air two-phase flow simulation experiment device for two-layer medium and using method of water-air two-phase flow simulation experiment device | |
| CN108572401A (en) | The construction method of fracture hole built-up pattern and the method for detection reservoir fracture hole deformation | |
| Borash et al. | OPTIMIZATION OF TECHNOLOGICAL PARAMETERS OF AIRLIFT OPERATION WHEN DRILLING WATER WELLS. | |
| Dai et al. | Modeling of two‐phase flow in rough‐walled fracture using level set method | |
| Reilly et al. | Analysis of steady‐state salt‐water upconing with application at Truro well field, Cape Cod, Massachusetts | |
| CN111767670B (en) | Aquifer geological parameter inversion method based on underground inclined single-hole water discharge test | |
| Shi et al. | Optimal design and dynamic control of construction dewatering with the consideration of dewatering process | |
| CN103161499A (en) | Division method for underground coal bed outburst and dangerous zones | |
| Lavrov | Newtonian fluid flow from an arbitrarily-oriented fracture into a single sink | |
| Wu et al. | Numerical simulation of inrush water spreading through a mine: A case study of the Beixinyao mine, Shanxi province, china | |
| CN112539063A (en) | Three-dimensional simulation device for dynamic evolution of underground water under coastal coal mining condition | |
| Xu et al. | Sensitivity analysis and prediction method for water inflow of underground oil storage caverns in fractured porous media | |
| CN116401816A (en) | Horizontal well injection/vertical well in-situ leaching uranium extraction streamline simulation and visualization method and system | |
| CN116467958A (en) | Salt lake brine numerical model construction and water supplementing and mineral dissolving efficiency calculation method | |
| CN109899037A (en) | A kind of gas pumping method during mining steeply dipping coal seam and after exploitation | |
| Xiao et al. | Effects of declining water levels on water-air interactions in cover collapse sinkhole | |
| Liu et al. | Analysis of external water pressure for a tunnel in fractured rocks | |
| Snee et al. | Prediction of compressed air leakage from tunnels | |
| CN114491989A (en) | Earth pressure balance shield gushing judgment method and system under action of cutterhead tunneling vibration load |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |