Horizontal well injection / vertical well extraction in-situ leaching uranium flow line simulation and visualization method and system

Abstract

The application discloses a kind of horizontal well injection / vertical well pumping in-situ leaching uranium streamline simulation and visualization method, for simulating the law of the dissolution leaching range of uranium deposit under the condition of horizontal well injection / vertical well pumping.The model considers that by solving the groundwater hydrodynamic field in the process of in-situ leaching uranium pumping and injection, then drawing the dissolution leaching streamline, for judging the dissolution leaching range.The characteristics of horizontal well injection / vertical well pumping in-situ leaching uranium streamline simulation and visualization are: (1) simulating the dissolution leaching hydrodynamic process; (2) streamline representation and visualization.The method provided by the application includes: considering the water flow process simulation under the condition of horizontal well injection / vertical well pumping, solving the groundwater hydrodynamic field in the process of pumping and injection, and then carrying out data processing on the dissolution leaching streamline, to simulate and depict the numerical simulation of dissolution leaching range.The simulation technology provided by the application can provide a scientific and reasonable theoretical basis for well pattern layout of mining area.

Description

Technical Field

[0001] This invention relates to a method and system for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping leaching, belonging to the field of Earth Science and Engineering. Background Technology

[0002] Uranium deposits in northern sandstone-type deposits generally have low permeability and exhibit significant spatial heterogeneity, often displaying an interlayered structure of mudstone and sandstone. Uranium-bearing sandstone bodies are frequently confined by mudstone aquitards and are mostly distributed in layers.

[0003] Horizontal well technology has been successfully applied in oil and shale gas extraction in recent years, demonstrating significant advantages, especially in thin-layer and low-permeability reservoirs. In oil extraction, horizontal well technology offers significant advantages such as long penetration of exploitable oil layers and low extraction costs. Sandstone-type uranium deposits, with their thin-layer structure, poor permeability, and strong spatial heterogeneity, share similar characteristics with oil reservoirs where horizontal well technology is used. Therefore, it is proposed to apply horizontal well technology to in-situ leaching uranium extraction. Horizontal well extraction can increase the length of the well site penetrating the uranium layer, increasing the contact area between the well flow and the uranium ore, thereby expanding the effective leaching range and improving the efficiency of in-situ leaching uranium extraction. To better understand the advantages of using horizontal well technology for in-situ leaching uranium extraction and to determine whether it effectively increases the leaching range, it is necessary to conduct research on the in-situ permeability characteristics of horizontal well network technology.

[0004] Accurate simulation of the infiltration flow field under the horizontal / vertical well network operation system is fundamental to proposing a scientific well network mining model, which is the basis for well network optimization, control, and efficient operation. Simulation of the infiltration flow field and quantitative characterization of the leaching range at the horizontal / vertical well site are key indicators for evaluating horizontal well uranium leaching technology. Therefore, a numerical simulation system for simulating and visualizing the streamlines of horizontal well injection / vertical well pumping uranium leaching can visualize the leaching range, providing significant guidance for engineering projects. Summary of the Invention

[0005] Purpose of the invention: In view of the problems of the prior art, the purpose of the present invention is to provide a method and system for simulating and visualizing the streamlines of uranium extraction in horizontal wells / vertical wells. This method can take into account the hydrodynamic field of groundwater during the uranium extraction process and then draw the streamlines of the leaching solution to determine the leaching range.

[0006] Technical Solution: To solve the above-mentioned technical problems, this invention proposes a method for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping leaching. This method includes the following steps:

[0007] Step SS1: Collect geological structure data of the study area, including the spatial distribution of rock strata, lithology, rock strata thickness, groundwater recharge, runoff and discharge conditions, and groundwater level dynamics;

[0008] Step SS2: Based on the geological data collected in Step SS1, the data is modeled and parameterized to establish a geological structure model of the study area and to perform grid subdivision.

[0009] Step SS3: Based on the geological structure model established in Step SS2, determine the initial water level conditions of the model and the permeability coefficient of the study area, and calculate the initial groundwater seepage field of the model;

[0010] Step SS4: Based on the initial groundwater seepage field results obtained in Step SS3, set the basic parameters for horizontal and vertical wells, and construct the groundwater horizontal / vertical well in-situ leaching and injection unit for the study area;

[0011] Step SS5: In the in-situ leaching and injection unit constructed in step SS4, the well-reservoir coupling simulation technology is used. That is, an interaction coefficient is set at the horizontal wellbore-reservoir interface to establish a well-reservoir coupling model. Solute particles are introduced into the horizontal well, and the viscosity and density parameters of the solute are set to simulate the solute transport process in the water flow process of horizontal well injection / vertical well pumping.

[0012] Step SS6: Based on the solute particle transport results obtained in step SS5, export the particle tracing output file, process the output file, calculate the transport path of the solute particles, and plot the leaching range for visualization.

[0013] Furthermore, in step SS3, for a stable groundwater flow field, the groundwater flow field is described by the following formula:

[0014]

[0015] Among them, v x v y and v z denoted as the average groundwater flow velocities in the x, y, and z directions, respectively; n represents the porosity of the aquifer; and W represents the source and sink terms.

[0016] Furthermore, in step SS5, a well-reservoir coupling model is established, wherein the governing equations for establishing the well-reservoir coupling model are:

[0017]

[0018] Where V is the average flow velocity of groundwater in the circular pipe; d is the pipe diameter; g is the acceleration due to gravity; ν is the kinematic viscosity coefficient; J is the hydraulic gradient of the pipe; and k is the average flow velocity of groundwater in the circular pipe. a This represents the average roughness of the circular pipe wall.

[0019] Furthermore, in step SS6, the simulation results of solute particle transport are calculated. The particle transport streamline is discretized into multiple discrete points, and the positions of these discrete points are connected by straight lines to obtain an approximate curve representing the particle transport trajectory. In an infinitesimally small rectangular cell, given the particle's position at the initial time t1, the position of the particle at any time t2 is calculated, thus obtaining the particle's position at each time point. The calculation formula is as follows:

[0020]

[0021]

[0022]

[0023] In the formula, (x p ) t2 , (y p ) t2 , (z p ) t2 Let x, y, z represent the x, y, z coordinates of particle p at time t2, where x1, y1, z1 are the initial position coordinates of the particle, and A x A y A z These represent the velocity increments per unit distance in the x, y, and z directions, respectively (v xp ) t1 , (v yp ) t1 , (v zp ) t1 Let v be the velocity of particle p along the three coordinate axes at time t1. x1 v y1 v z1 The average flow velocity of the grid surface in the three coordinate axes of the cell is Δt = t2 - t1. The unit node coordinates and time data of any particle in the in-situ leaching uranium mining are obtained through equations (3), (4), and (5) to characterize the positional relationship of the particles in the in-situ leaching uranium mining model within the simulation time limit. The simulation calculation results of solute particle transport are output as a file. The Dealunay algorithm is used to process the data of the result file, and the topological relationship of the in-situ leaching uranium mining simulation model is reconstructed. A three-dimensional model with tetrahedrons as the unit type is constructed to obtain the unit structure data of the in-situ leaching uranium mining simulation model, and the data is output as a VTK format file.

[0024] Furthermore, for the VTK file of the model unit structure data of in-situ leaching uranium mining simulation, based on the VTK visualization pipeline method and combined with the in-situ leaching uranium mining flow field simulation calculation results, an in-situ leaching uranium mining streamline simulation visualization pipeline is created. The in-situ leaching uranium mining streamline simulation visualization pipeline is used to achieve the effect of visualizing the in-situ leaching uranium mining flow line simulation calculation results.

[0025] Furthermore, this invention proposes a system for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping leaching, which includes the following modules:

[0026] The model parameter collection module is used to collect geological structure data of the study area, including the spatial distribution of rock strata, lithology, rock strata thickness, groundwater recharge and discharge conditions, and groundwater level dynamics.

[0027] The geological structure model building module is used to model and parameterize the collected geological data to establish a geological structure model of the study area and perform grid subdivision.

[0028] The groundwater seepage field module is used to determine the initial water level conditions and permeability coefficient of the study area based on the established geological structure model, and to calculate the initial groundwater seepage field of the model.

[0029] The injection unit construction module is used to set the basic parameters of horizontal wells and vertical wells based on the initial groundwater seepage field results determined by the groundwater seepage field module, and to construct the groundwater horizontal well / vertical well groundwater immersion injection unit in the study area;

[0030] The migration simulation module is used to simulate the solute migration process during water injection / extraction in horizontal wells and vertical wells based on the constructed in-situ leaching and injection unit. This is achieved by setting an interaction coefficient at the horizontal wellbore-reservoir interface to establish a well-reservoir coupling model, setting the solute particles to be injected into the horizontal well, and setting the viscosity and density parameters of the solute.

[0031] The visualization module is used to export the particle tracing output file based on the obtained solute particle transport results, process the output file, calculate the transport path of the solute particles, and draw the leaching range for visualization.

[0032] Furthermore, in the groundwater seepage field module, for a stable groundwater flow field, the groundwater flow field is described by the following formula:

[0033]

[0034] Among them, v x v y and v z denoted as the average groundwater flow velocities in the x, y, and z directions, respectively; n represents the porosity of the aquifer; and W represents the source and sink terms.

[0035] Furthermore, a well-reservoir coupling model is established in the migration simulation module, wherein the governing equations for establishing the well-reservoir coupling model are:

[0036]

[0037] Where V is the average flow velocity of groundwater in the circular pipe; d is the pipe diameter; g is the acceleration due to gravity; v is the kinematic viscosity coefficient; J is the hydraulic gradient of the pipe; and k is the average flow velocity of groundwater in the circular pipe. a This represents the average roughness of the circular pipe wall.

[0038] Furthermore, in the visualization module, the simulation results of solute particle transport are calculated. The particle transport streamline is discretized into multiple discrete points, and the positions of these discrete points are connected by straight lines to obtain an approximate curve representing the particle transport trajectory. In an infinitesimally small rectangular cell, given the particle's position at the initial time t1, the position of the particle at any time t2 is calculated, thus obtaining the particle's position at each time point. The calculation formula is as follows:

[0039]

[0040]

[0041]

[0042] In the formula, (x p ) t2 , (y p ) t2 , (z p ) t2 Let x, y, z represent the x, y, z coordinates of particle p at time t2, where x1, y1, z1 are the initial position coordinates of the particle, and A x A y A z These represent the velocity increments per unit distance in the x, y, and z directions, respectively (v xp ) t1 , (v yp ) t1 , (v zp ) t1 Let v be the velocity of particle p along the three coordinate axes at time t1. x1 v y1 v z1The average flow velocities of the grid surfaces in the three coordinate axes of the cell are Δt = t2 - t1. The unit node coordinates and time data of any particle in in-situ leaching uranium mining are obtained through equations (3), (4), and (5) to characterize the positional relationship of particles in the in-situ leaching uranium mining model within the simulation time limit. The simulation results of solute particle transport are output as a file. The Dealunay algorithm is used to process the data in the result file, reconstruct the topological relationship of the in-situ leaching uranium mining simulation model, construct a three-dimensional model with tetrahedrons as the unit type to obtain the model unit structure data of the in-situ leaching uranium mining simulation, and output it as a VTK format file.

[0043] Furthermore, for the VTK file of the model unit structure data of in-situ leaching uranium mining simulation, based on the VTK visualization pipeline method and combined with the in-situ leaching uranium mining flow field simulation calculation results, an in-situ leaching uranium mining streamline simulation visualization pipeline is created. The in-situ leaching uranium mining streamline simulation visualization pipeline is used to achieve the effect of visualizing the in-situ leaching uranium mining flow line simulation calculation results.

[0044] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0045] The technical solution of this invention considers the simulation of water flow processes under horizontal well injection / vertical well pumping conditions, solves the groundwater hydrodynamic field during the injection and pumping process, and then processes the data of the leaching fluid streamline to simulate and characterize the leaching range through numerical simulation. The simulation technology provided by this invention can provide a scientific and reasonable theoretical basis for well network layout in mining areas. Attached Figure Description

[0046] Figure 1 This is a flowchart of a numerical simulation method for simulating and visualizing the streamlines of uranium extraction in horizontal wells (injection) and vertical wells (pumping).

[0047] Figure 2 This is a conceptual diagram of a numerical simulation benchmark model for uranium streamline simulation and visualization in horizontal well injection / vertical well pumping leaching.

[0048] Figure 3 This is a schematic diagram illustrating the changes in the underground seepage field within the area after the operation of the horizontal well injection / vertical well pumping leaching unit;

[0049] Figure 4 This is a diagram illustrating the leaching range using a particle tracing model.

[0050] Figure 5 This is a diagram illustrating the effect of a particle tracing model depicting the leaching range under three-dimensional conditions. Detailed Implementation

[0051] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0052] like Figure 1 As shown, this invention proposes a method for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping leaching. This method includes the following steps:

[0053] Step SS1: Collect geological structure data of the study area, including the spatial distribution of rock strata, lithology, rock strata thickness, groundwater recharge, runoff and discharge conditions, and groundwater level dynamics;

[0054] Step SS2: Based on the geological data collected in Step SS1, the data is modeled and parameterized to establish a geological structure model of the study area and to perform grid subdivision.

[0055] Step SS3: Based on the geological structure model established in Step SS2, determine the initial water level conditions of the model and the permeability coefficient of the study area, and calculate the initial groundwater seepage field of the model;

[0056] Step SS4: Based on the initial groundwater seepage field results obtained in Step SS3, set the basic parameters for horizontal and vertical wells, and construct the groundwater horizontal / vertical well in-situ leaching and injection unit for the study area;

[0057] Step SS5: In the in-situ leaching and injection unit constructed in step SS4, the well-reservoir coupling simulation technology is used. That is, an interaction coefficient is set at the horizontal wellbore-reservoir interface to establish a well-reservoir coupling model. Solute particles are introduced into the horizontal well, and the viscosity and density parameters of the solute are set to simulate the solute transport process in the water flow process of horizontal well injection / vertical well pumping.

[0058] Step SS6: Based on the solute particle transport results obtained in step SS5, export the particle tracing output file, process the output file, calculate the transport path of the solute particles, and plot the leaching range for visualization.

[0059] In step SS3, for a stable groundwater flow field, the groundwater flow field is described by the following formula:

[0060]

[0061] Among them, v x v y and v z denoted as the average groundwater flow velocities in the x, y, and z directions, respectively; n represents the porosity of the aquifer; and W represents the source and sink terms.

[0062] Furthermore, in step SS5, a well-reservoir coupling model is established, wherein the governing equations for establishing the well-reservoir coupling model are:

[0063]

[0064] Where V is the average flow velocity of groundwater in the circular pipe; d is the pipe diameter; g is the acceleration due to gravity; v is the kinematic viscosity coefficient; J is the hydraulic gradient of the pipe; and k is the average flow velocity of groundwater in the circular pipe. a This represents the average roughness of the circular pipe wall.

[0065] In step SS6, the simulation results of solute particle transport are calculated. The particle transport streamline is discretized into multiple discrete points, and the positions of these discrete points are connected by straight lines to obtain an approximate curve representing the particle transport trajectory. Given the particle's position at the initial time t1 within an infinitesimally small rectangular cell, the position of the particle at any time t2 is calculated, thus obtaining the particle's position at each time point. The calculation formula is as follows:

[0066]

[0067]

[0068]

[0069] In the formula, (x p ) t2 , (y p ) t2 , (z p ) t2 Let x, y, z represent the x, y, z coordinates of particle p at time t2, where x1, y1, z1 are the initial position coordinates of the particle, and A x A y A z These represent the velocity increments per unit distance in the x, y, and z directions, respectively (v xp ) t1 , (v yp ) t1 , (v zp ) t1 Let v be the velocity of particle p along the three coordinate axes at time t1. x1 v y1 v z1 The average flow velocity of the grid surface in the three coordinate axes of the cell is Δt = t2 - t1. The unit node coordinates and time data of any particle in the in-situ leaching uranium mining are obtained through equations (3), (4), and (5) to characterize the positional relationship of the particles in the in-situ leaching uranium mining model within the simulation time limit. The simulation calculation results of solute particle transport are output as a file. The Dealunay algorithm is used to process the data of the result file, and the topological relationship of the in-situ leaching uranium mining simulation model is reconstructed. A three-dimensional model with tetrahedrons as the unit type is constructed to obtain the unit structure data of the in-situ leaching uranium mining simulation model, and the data is output as a VTK format file.

[0070] For the VTK file of the model unit structure data of in-situ leaching uranium mining simulation, based on the VTK visualization pipeline method and combined with the in-situ leaching uranium mining flow field simulation calculation results, an in-situ leaching uranium mining streamline simulation visualization pipeline is created. The in-situ leaching uranium mining streamline simulation visualization pipeline is used to achieve the effect of visualizing the in-situ leaching uranium mining flow line simulation calculation results.

[0071] Furthermore, this invention proposes a system for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping leaching, which includes the following modules:

[0072] The model parameter collection module is used to collect geological structure data of the study area, including the spatial distribution of rock strata, lithology, rock strata thickness, groundwater recharge and discharge conditions, and groundwater level dynamics.

[0073] The geological structure model building module is used to model and parameterize the collected geological data to establish a geological structure model of the study area and perform grid subdivision.

[0074] The groundwater seepage field module is used to determine the initial water level conditions and permeability coefficient of the study area based on the established geological structure model, and to calculate the initial groundwater seepage field of the model.

[0075] The injection unit construction module is used to set the basic parameters of horizontal wells and vertical wells based on the initial groundwater seepage field results determined by the groundwater seepage field module, and to construct the groundwater horizontal well / vertical well groundwater immersion injection unit in the study area;

[0076] The migration simulation module is used to simulate the solute migration process during water injection / extraction in horizontal wells and vertical wells based on the constructed in-situ leaching and injection unit. This is achieved by setting an interaction coefficient at the horizontal wellbore-reservoir interface to establish a well-reservoir coupling model, setting the solute particles to be injected into the horizontal well, and setting the viscosity and density parameters of the solute.

[0077] The visualization module is used to export the particle tracing output file based on the obtained solute particle transport results, process the output file, calculate the transport path of the solute particles, and draw the leaching range for visualization.

[0078] In the groundwater seepage field module, for a stable groundwater flow field, the groundwater flow field is described by the following formula:

[0079]

[0080] Among them, v x v y and v z denoted as the average groundwater flow velocities in the x, y, and z directions, respectively; n represents the porosity of the aquifer; and W represents the source and sink terms.

[0081] Furthermore, a well-reservoir coupling model is established in the migration simulation module, wherein the governing equations for establishing the well-reservoir coupling model are:

[0082]

[0083] Where V is the average flow velocity of groundwater in the circular pipe; d is the pipe diameter; g is the acceleration due to gravity; v is the kinematic viscosity coefficient; J is the hydraulic gradient of the pipe; and k is the average flow velocity of groundwater in the circular pipe. a This represents the average roughness of the circular pipe wall.

[0084] In the visualization module, the simulation results of solute particle transport are calculated. The particle transport streamline is discretized into multiple discrete points, and the positions of these discrete points are connected by straight lines to obtain an approximate curve representing the particle transport trajectory. In an infinitesimally small rectangular cell, given the particle's position at the initial time t1, the position of the particle at any time t2 is calculated, thus obtaining the particle's position at every time. The calculation formula is as follows:

[0085]

[0086]

[0087]

[0088] In the formula, (x p ) t2 , (y p ) t2 , (z p ) t2 Let x, y, z represent the x, y, z coordinates of particle p at time t2, where x1, y1, z1 are the initial position coordinates of the particle, and A x A y A z These represent the velocity increments per unit distance in the x, y, and z directions, respectively (v xp ) t1 , (v yp ) t1 , (v zp ) t1 Let v be the velocity of particle p along the three coordinate axes at time t1. x1 v y1 v z1The average flow velocities of the grid surfaces in the three coordinate axes of the cell are Δt = t2 - t1. The unit node coordinates and time data of any particle in in-situ leaching uranium mining are obtained through equations (3), (4), and (5) to characterize the positional relationship of particles in the in-situ leaching uranium mining model within the simulation time limit. The simulation results of solute particle transport are output as a file. The Dealunay algorithm is used to process the data in the result file, reconstruct the topological relationship of the in-situ leaching uranium mining simulation model, construct a three-dimensional model with tetrahedrons as the unit type to obtain the model unit structure data of the in-situ leaching uranium mining simulation, and output it as a VTK format file.

[0089] For the VTK file of the model unit structure data of in-situ leaching uranium mining simulation, based on the VTK visualization pipeline method and combined with the in-situ leaching uranium mining flow field simulation calculation results, an in-situ leaching uranium mining streamline simulation visualization pipeline is created. The in-situ leaching uranium mining streamline simulation visualization pipeline is used to achieve the effect of visualizing the in-situ leaching uranium mining flow line simulation calculation results.

[0090] Example 1: This embodiment of the invention takes the established benchmark model as an example.

[0091] 1) Conceptual Model

[0092] The simulation area for this example is rectangular in plan, 500m long and 400m wide, with an aquifer thickness of 90m, divided into 9 layers with a single layer thickness of 10m. The model is divided into 40 rows * 50 columns. Constant head boundaries with a water level of 85m are set on the left and right sides of the simulation area, while impermeable boundaries are set on the top and bottom sides. There is no rainfall recharge in the entire simulation area, meaning the initial water level of the aquifer is 85m. The entire model is set to be isotropic, with a horizontal permeability coefficient of 0.15m / day and an effective porosity of 0.2. The simulation period is set to 7200 days.

[0093] A horizontal well, 220m long and 0.15m in diameter, is placed in the center of this model. The well is located at the 8th layer vertically. The leftmost point of the horizontal well is the injection point, simulating the injection of dissolving solution in uranium leaching, with an injection volume of 150m³. 3 / day. Four vertical pumping wells are installed around the horizontal well, each with a flow rate of 40m³ / day. 3 / day, see horizontal and vertical well locations. Figure 2 On the first day of the model simulation, particles were uniformly released into the grid containing the horizontal well to conduct particle tracking simulation and obtain the runoff range of the injected fluid in the horizontal well. After 6000 days of model operation, the simulation area basically reached a stable state.

[0094] Table 1 Main physical parameters of the conceptual model in the embodiments of the invention

[0095]

[0096] Table 2 Main physical parameters of the well-reservoir coupling model

[0097]

[0098] 2) Determine the governing equations

[0099] A) For a steady groundwater flow field, the groundwater flow field can be described by the following formula:

[0100]

[0101] Where v x v y and v z denoted as the average groundwater flow velocities in the x, y, and z directions, respectively; n represents the porosity of the aquifer; and W represents the source and sink terms.

[0102] B) The governing equations for the well-reservoir coupling model are:

[0103]

[0104] Where V is the average flow velocity of groundwater in the circular pipe; d is the pipe diameter; g is the acceleration due to gravity; v is the kinematic viscosity coefficient; J is the hydraulic gradient of the pipe; and k is the average flow velocity of groundwater in the circular pipe. a This represents the average roughness of the circular pipe wall.

[0105] C) Discretizing streamlines into countless points, to understand the position of a particle at each time, it is necessary to estimate the position of any particle p at a certain moment.

[0106]

[0107]

[0108]

[0109] In the formula, (x p ) t2 , (y p ) t2 , (z p ) t2 Let x, y, z represent the x, y, z coordinates of particle p at time t2, where x1, y1, z1 are the initial position coordinates of the particle, and A x A y A z These represent the velocity increments per unit distance in the x, y, and z directions, respectively (v xp ) t1 , (v yp ) t1 , (v zp ) t1Let v be the velocity of particle p along the three coordinate axes at time t1. x1 v y1 v z1 The average flow velocity of the grid surface in the three coordinate axes of the cell is Δt = t2 - t1. The unit node coordinates and time data of any particle in the in-situ leaching uranium mining are obtained through equations (3), (4), and (5) to characterize the positional relationship of the particles in the in-situ leaching uranium mining model within the simulation time limit. The simulation calculation results of solute particle transport are output as a file. The Dealunay algorithm is used to process the data of the result file, and the topological relationship of the in-situ leaching uranium mining simulation model is reconstructed. A three-dimensional model with tetrahedrons as the unit type is constructed to obtain the unit structure data of the in-situ leaching uranium mining simulation model, and the data is output as a VTK format file.

[0110] 3) Analysis of numerical simulation results of solute particle transport

[0111] Figure 3 To simulate the groundwater isobaric map of the simulated area after 6000 days, the groundwater isobaric map of the entire model is basically symmetrical, and the groundwater level near the well network shows a significant drop.

[0112] Figure 4 To simulate particle tracking results of injected fluid in horizontal wells after 6000 days, the particle tracking trajectories were basically symmetrical throughout the simulation area. Significant infiltration dead zones existed between the two pumping wells in the same direction and above both ends of the horizontal wells, preventing the injected fluid from reaching these areas. Comparing the arrival times of injected fluid at different locations within the horizontal wells, particles directly below the pumping well arrived first, followed by particles at the left and right ends of the horizontal well, with the last particles arriving being those located between the pumping wells. This is mainly related to the groundwater hydraulic gradient. Figure 3 It can be seen that the area directly below the pumping well has the shortest runoff path and the largest hydraulic gradient. Although the runoff paths are similar in the middle region of the horizontal well compared to the left and right ends, the head difference between the middle region of the horizontal well and the pumping well is lower than that at the left and right ends, resulting in a smaller hydraulic gradient and the longest time for particles to reach the pumping well.

[0113] Figure 5 To simulate the particle tracking results of the injection fluid in a horizontal well under three-dimensional conditions after 6000 days, the particle tracking trajectory was basically symmetrical throughout the simulation area. The particles were released from the horizontal well and moved to the vertical well, and the leaching range around the vertical well was larger in the vertical direction.

[0114] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping leaching, characterized in that, The method includes the following steps: Step SS1: Collect geological structure data of the study area, including the spatial distribution of rock strata, lithology, rock strata thickness, groundwater recharge, runoff and discharge conditions, and groundwater level dynamics; Step SS2: Based on the geological data collected in Step SS1, the data is modeled and parameterized to establish a geological structure model of the study area and to perform grid subdivision. Step SS3: Based on the geological structure model established in Step SS2, determine the initial water level conditions of the model and the permeability coefficient of the study area, and calculate the initial groundwater seepage field of the model; Step SS4: Based on the initial groundwater seepage field results obtained in Step SS3, set the basic parameters for horizontal and vertical wells, and construct the groundwater horizontal / vertical well in-situ leaching and injection unit for the study area; Step SS5: In the in-situ leaching and injection unit constructed in step SS4, the well-reservoir coupling simulation technology is used. That is, an interaction coefficient is set at the horizontal wellbore-reservoir interface to establish a well-reservoir coupling model. Solute particles are introduced into the horizontal well, and the viscosity and density parameters of the solute are set to simulate the solute transport process in the water flow process of horizontal well injection / vertical well pumping. Step SS6: Based on the solute particle transport results obtained in step SS5, export the particle tracing output file, process the output file, calculate the transport path of the solute particles, and plot the leaching range for visualization. In step SS6, the simulation results of solute particle transport are calculated. The particle transport streamline is discretized into multiple discrete points. The positions of these discrete points are connected by straight lines to obtain an approximate curve representing the particle transport trajectory. In an infinitesimally small rectangular cell, given the position of the particle at the initial time t1, the position of the particle at any time t2 is calculated, thus obtaining the position of the particle at each time. The calculation formula is as follows: （3） （4） （5） In the formula, This represents the x, y, z coordinates of particle p at time t2. Let be the initial position coordinates of the particle. These represent the velocity increments per unit distance in the x, y, and z directions, respectively. These represent the flow velocities of particle p along the three coordinate axes at time t1. These represent the average flow velocities of the grid surface in the three coordinate axes of the cell. The unit node coordinates and time data of any particle in in-situ leaching uranium mining are obtained through equations (3), (4), and (5) to characterize the positional relationship of particles in the in-situ leaching uranium mining model within the simulation time limit. The simulation calculation results of solute particle transport are output as a result file. The result file is processed by the Dealunay algorithm to reconstruct the topological relationship of the in-situ leaching uranium mining simulation model. A three-dimensional model with tetrahedrons as the unit type is constructed to obtain the unit structure data of the in-situ leaching uranium mining simulation model, and the result file is output as a VTK format file.

2. The method for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping as described in claim 1, characterized in that, In step SS3, for a stable groundwater flow field, the groundwater flow field is described by the following formula: （1） Among them, v x v y and v z denoted as the average groundwater flow velocities in the x, y, and z directions, respectively; n represents the porosity of the aquifer; and W represents the source and sink terms.

3. The method for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping as described in claim 1, characterized in that, In step SS5, a well-reservoir coupling model is established, wherein the governing equations for establishing the well-reservoir coupling model are: （2） Where V is the average flow velocity of groundwater in the circular pipe; d is the pipe diameter. It is the acceleration due to gravity. Let be the coefficient of kinematic viscosity. For the hydraulic gradient of the pipeline, This represents the average roughness of the circular pipe wall.

4. The method for simulating and visualizing the streamlines of uranium production in horizontal well injection / vertical well pumping as described in claim 1, characterized in that, For the VTK file of the model unit structure data of in-situ leaching uranium mining simulation, based on the VTK visualization pipeline method and combined with the in-situ leaching uranium mining flow field simulation calculation results, an in-situ leaching uranium mining streamline simulation visualization pipeline is created. The in-situ leaching uranium mining streamline simulation visualization pipeline is used to achieve the effect of visualizing the in-situ leaching uranium mining flow line simulation calculation results.

5. A system for simulating and visualizing the streamlines of uranium production via horizontal well injection / vertical well pumping, characterized in that, The system includes the following modules: The model parameter collection module is used to collect geological structure data of the study area, including the spatial distribution of rock strata, lithology, rock strata thickness, groundwater recharge and discharge conditions, and groundwater level dynamics. The geological structure model building module is used to model and parameterize the collected geological data to establish a geological structure model of the study area and perform grid subdivision. The groundwater seepage field module is used to determine the initial water level conditions and permeability coefficient of the study area based on the established geological structure model, and to calculate the initial groundwater seepage field of the model. The injection unit construction module is used to set the basic parameters of horizontal wells and vertical wells based on the initial groundwater seepage field results determined by the groundwater seepage field module, and to construct the groundwater horizontal well / vertical well groundwater immersion injection unit in the study area; The migration simulation module is used to simulate the solute migration process during water injection / extraction in horizontal wells and vertical wells based on the constructed in-situ leaching and injection unit. This is achieved by setting an interaction coefficient at the horizontal wellbore-reservoir interface to establish a well-reservoir coupling model, setting the solute particles to be injected into the horizontal well, and setting the viscosity and density parameters of the solute. The visualization module is used to export the particle tracing output file based on the obtained solute particle transport results, process the output file, calculate the transport path of the solute particles, and draw the leaching range for visualization. In the visualization module, the simulation results of solute particle transport are calculated. The particle transport streamline is discretized into multiple discrete points, and the positions of these discrete points are connected by straight lines to obtain an approximate curve representing the particle transport trajectory. In an infinitesimally small rectangular cell, given the position of the particle at the initial time t1, the position of the particle at any time t2 is calculated, thus obtaining the position of the particle at each time. The calculation formula is as follows: （3） （4） （5） In the formula, This represents the x, y, z coordinates of particle p at time t2. Let be the initial position coordinates of the particle. These represent the velocity increments per unit distance in the x, y, and z directions, respectively. These represent the flow velocities of particle p along the three coordinate axes at time t1. These represent the average flow velocities of the grid surface in the three coordinate axes of the cell. The unit node coordinates and time data of any particle in in-situ leaching uranium mining are obtained through equations (3), (4), and (5) to characterize the positional relationship of particles in the in-situ leaching uranium mining model within the simulation time limit. The simulation calculation results of solute particle transport are output as a result file. The result file is processed by the Dealunay algorithm to reconstruct the topological relationship of the in-situ leaching uranium mining simulation model. A three-dimensional model with tetrahedrons as the unit type is constructed to obtain the unit structure data of the in-situ leaching uranium mining simulation model, and the result file is output as a VTK format file.

6. The system for simulating and visualizing uranium streamlines in horizontal well injection / vertical well pumping leaching as described in claim 5, characterized in that, In the groundwater seepage field module, for a stable groundwater flow field, the groundwater flow field is described by the following formula: （1） Among them, v x v y and v z denoted as the average groundwater flow velocities in the x, y, and z directions, respectively; n represents the porosity of the aquifer; and W represents the source and sink terms.

7. The system for simulating and visualizing uranium streamlines in horizontal well injection / vertical well pumping leaching as described in claim 5, characterized in that, The migration simulation module establishes a well-reservoir coupling model, wherein the governing equations for establishing the well-reservoir coupling model are: （2） Where V is the average flow velocity of groundwater in the circular pipe; d is the pipe diameter. It is the acceleration due to gravity. Let be the coefficient of kinematic viscosity. For the hydraulic gradient of the pipeline, This represents the average roughness of the circular pipe wall.

8. The system for simulating and visualizing uranium streamlines in horizontal well injection / vertical well pumping leaching as described in claim 5, characterized in that, For the VTK file of the model unit structure data of in-situ leaching uranium mining simulation, based on the VTK visualization pipeline method and combined with the in-situ leaching uranium mining flow field simulation calculation results, an in-situ leaching uranium mining streamline simulation visualization pipeline is created. The in-situ leaching uranium mining streamline simulation visualization pipeline is used to achieve the effect of visualizing the in-situ leaching uranium mining flow line simulation calculation results.

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