Horizontal well injection-vertical well extraction well pattern arrangement and mining method for in-situ leaching uranium mining

Abstract

The invention discloses a horizontal well injection-vertical well extraction well pattern arrangement and mining method for in-situ leaching uranium mining, and relates to the field of mining engineering. The main method for arranging the well pattern comprises the steps that a horizontal liquid injection well is arranged in the middle of an ore bed in the trend of the ore bed, vertical liquid pumping wells with the same number are arranged on the two sides of the horizontal liquid injection well, the distances between the adjacent vertical liquid pumping wells on the same side of the horizontal liquid injection well are equal, and the vertical distances between the vertical liquid pumping wells and the horizontal liquid injection well are equal and are half of the distances between the adjacent vertical liquid pumping wells; the horizontal distance between the peripheral vertical liquid extraction wells and the end point of the horizontal well is half of the distance between every two adjacent vertical liquid extraction wells, and a similar determinant arrangement is formed. The mining method can overcome the defects of extraction and injection of traditional vertical liquid extraction wells, the leaching range of in-situ leaching uranium mining is expanded, and the leaching efficiency of in-situ leaching uranium mining is improved. Uranium mine mining nonuniformity caused by nonuniform flow distribution of the leaching liquid is reduced, and the uranium mine mining efficiency and the resource utilization rate are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of in-situ leaching of uranium, and more specifically, relates to a well pattern and mining method for in-situ leaching of uranium with "horizontal well injection - vertical well pumping". Background Art

[0002] Entering the new era, natural uranium ore resources are of great strategic significance to the country and are crucial for ensuring national energy security and promoting the optimization of the energy structure. At present, China is intensifying the exploration and development of domestic uranium ore resources, but there is still a huge gap in natural uranium production. Improving China's natural uranium production and intensifying the development efforts still face a series of challenges.

[0003] Sandstone-type uranium ore is the main type of uranium resources in China, accounting for more than 40%. The mining method is the in-situ leaching process (abbreviated as in-situ leaching). In-situ leaching of uranium is a new type of uranium ore mining technology that combines mining and smelting. Under natural burial conditions, uranium in the ore is selectively dissolved through the chemical reaction between the leaching solution and the ore without causing displacement of the ore. At present, the well pattern layout for in-situ leaching of uranium in China mainly adopts the method of vertical pumping wells for injection and extraction. The leaching solution is injected into the ground through vertical pumping wells and contacts the uranium ore underground, and then is pumped out by vertical pumping wells. However, the well pattern of vertical pumping wells for injection and extraction often faces problems such as uneven injection, low ore control area per well, and obvious leaching dead zones, and it is necessary to increase the production capacity by densifying vertical pumping wells, which has become the main bottleneck in the mining of sandstone-type uranium ore. Summary of the Invention

[0004] The purpose of the present invention is to provide a well pattern layout and mining method for in-situ leaching of uranium with "horizontal injection well injection - vertical pumping well pumping", aiming to solve the technical problem of low efficiency caused by in-situ leaching of uranium in the prior art.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: In the first aspect, the present invention provides a well pattern layout method for in-situ leaching of uranium with "horizontal injection well injection - vertical pumping well pumping", including: Arranging a well pattern for each in-situ leaching unit, the well pattern including at least one horizontal injection well and vertical pumping wells; Wherein, the horizontal injection well is located in the middle of the uranium-bearing ore layer, is consistent with the strike direction of the ore layer, and runs through the ore layer horizontally; The vertical pumping wells are arranged in the ore layer and run through the ore layer vertically; a plurality of vertical pumping wells are provided and are distributed on both sides of the horizontal injection well; The horizontal injection well includes an injection section and a full horizontal section; the injection section of the horizontal injection well communicates with the surface and the full horizontal section for injecting the leaching solution into the full horizontal section; The full horizontal section is horizontally arranged in the uranium-bearing deposit, and perforations are evenly distributed on its wellbore for uniformly injecting the leaching solution. The vertical pumping well includes a leading section and a pumping section; the pumping section is located in the uranium-bearing deposit for introducing the leaching solution in the deposit; the leading section connects the pumping section and the ground surface for pumping out the leaching solution in the pumping section.

[0006] Furthermore, the same number of vertical pumping wells are arranged on both sides of the horizontal injection well, and the vertical distances from the vertical pumping wells on both sides to the horizontal injection well are equal. The spacing between adjacent vertical pumping wells on the same side of the horizontal injection well is equal and is twice the vertical distance from the vertical pumping well to the horizontal injection well.

[0007] Furthermore, multiple horizontal injection wells are provided and are evenly arranged horizontally in the ore layer.

[0008] Furthermore, the outermost vertical pumping wells do not extend beyond the two ends of the horizontal injection well, and the distance from the outermost vertical pumping wells to the endpoints of the horizontal injection well in the length direction of the horizontal injection well is half of the spacing between adjacent vertical pumping wells.

[0009] Furthermore, the injection volume of the horizontal injection well is equal to the total pumping volume of the vertical pumping wells, and the total pumping volume is evenly distributed to each vertical pumping well.

[0010] Furthermore, the injection section of the horizontal injection well is connected to the ground surface to form an injection point; When there are multiple groups of horizontal injection wells, the positions of the injection points of the horizontal injection wells can be set on the same side or staggered.

[0011] During the in-situ leaching uranium process, one end of the horizontal injection well is used as an injection point to inject the leaching solution, and the other end is closed.

[0012] The entire 'horizontal injection well injection - vertical pumping well pumping' well pattern maintains the balance of pumping and injection volumes, and the pumping volume of each vertical pumping well is the same.

[0013] In a second aspect, the present invention provides a method for mining uranium by in-situ leaching using a 'horizontal well injection - vertical well pumping' well pattern. Based on the well pattern arrangement method described in the first aspect, the method includes the following steps: In the initial stage of in-situ leaching uranium, the leaching solution is uniformly injected through all the perforations of the full horizontal section, and the leaching solution is pumped out through the vertical pumping wells.

[0014] Furthermore, the method further includes: In the initial mining stage of in-situ leaching uranium, the horizontal injection well injects liquid evenly through all perforations, and the uranium concentration in the leaching solution extracted by the vertical pumping wells is monitored in real time.

[0015] After in-situ leaching of uranium has been carried out for a long time, if the uranium concentration in the leaching solution extracted by the vertical pumping well is lower than the preset plugging threshold (for example, the uranium leaching concentration drops to about 40-50% of the peak concentration), the temporary plugging technology is used to block part of the perforations of all horizontal injection wells facing the vertical pumping well (the perforation range is generally the perforation range of the horizontal injection well extending half of the vertical pumping well spacing on the same side of the vertical pumping well from the vertical intersection point of the vertical pumping well and the horizontal injection well to both sides), and the perforations in other areas of the horizontal injection well continue to inject liquid. The injection volume of the horizontal injection well and the pumping volume of the vertical pumping well remain unchanged until the in-situ leaching of uranium ends.

[0016] Furthermore, when there are multiple groups of horizontal injection wells, the temporary plugging technology is adopted for each horizontal injection well.

[0017] Furthermore, the preset plugging threshold is 40-50% of the peak concentration.

[0018] Furthermore, when the uranium leaching concentration of all vertical pumping wells drops to the preset end threshold, the in-situ leaching of uranium ends.

[0019] Furthermore, the preset end threshold is 10-20% of the peak concentration.

[0020] The beneficial effects of the in-situ leaching uranium well pattern and mining method provided by the present invention are as follows: 1. Compared with the existing well patterns, the present invention uses a method of combining horizontal injection wells and vertical pumping wells to arrange the well pattern for in-situ leaching of uranium. This well pattern can give full play to the advantages of horizontal injection wells, increase the contact area between the injected liquid of the horizontal injection well and the uranium-bearing ore layer, improve the ore control area of the injection well, and at the same time use the vertical pumping well as the pumping well to increase the migration range of the leaching solution in the vertical direction within the uranium-bearing ore layer.

[0021] 2. Compared with the existing in-situ leaching uranium mining methods, the mining method proposed by the present invention can significantly improve the overall mining efficiency of uranium-bearing deposits. When all the perforations in the horizontal section of the horizontal injection well can inject liquid, the main flow of the leaching solution in the 'horizontal injection well injection - vertical pumping well pumping' well pattern is concentrated near the area with the shortest horizontal distance between the horizontal injection well and the vertical pumping well, while the flow in other areas is relatively small. This distribution characteristic leads to a significantly higher mining efficiency of the uranium-bearing deposit in the area with the shortest horizontal distance than in other areas. When the uranium ore resources in this high-efficiency area are exhausted, the remaining areas still contain uranium ore resources with relatively high uranium content. In the later stage of in-situ leaching of uranium, by using the temporary plugging technology to block the perforations of the horizontal injection wells in the area with a higher leaching solution flow rate, the leaching solution flow direction can be guided to the areas with a lower mining efficiency of the uranium-bearing deposit, and this mining method can significantly improve the overall mining efficiency of the uranium-bearing deposit. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0023] Figure 1 Schematic diagram of the three-dimensional distribution of a "horizontal well injection - vertical well pumping" well pattern provided by the present invention; Figure 2 Schematic diagram of the planar distribution of a "horizontal well injection - vertical well pumping" well pattern provided by the present invention; Figure 3 Schematic diagram of the cross-section of a "horizontal well injection - vertical well pumping" well pattern provided by the present invention; Figure 4 Schematic diagram of the temporary plugging position of the horizontal injection well in a "horizontal well injection - vertical well pumping" well pattern provided by the present invention; Figure 5 Planar structure diagram of the model; Figure 6 Schematic diagram of the spatial distribution of the contribution degree of the uniform injection of leaching solution flow in the full horizontal section of a "horizontal well injection - vertical well pumping" well pattern provided by the present invention; Figure 7 Schematic diagram of the spatial distribution of the contribution degree of leaching solution flow after temporary plugging of the horizontal injection well in a "horizontal well injection - vertical well pumping" well pattern provided by the present invention; Figure 8 Structural diagram of the horizontal well plugging; Figure 9 K341 packer.

[0024] In the figure: 1. Uranium-bearing ore layer; 2. Horizontal injection well; 21. Injection section; 22. Full horizontal section; 23. Injection point; 24. Temporary plugging section; 3. Vertical pumping well; 31. Export section; 32. Pumping section. Detailed implementation manners

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] It should be noted that the "leaching solution" in this application refers to the unreacted stock solution, and the "leachate" refers to the solution after the leaching solution reacts with the uranium-containing part in the ore deposit. Embodiment 1

[0027] This embodiment provides a well pattern arrangement method for in-situ leaching of uranium with "horizontal well injection - vertical well pumping". Please refer to Figures 1 to 4 simultaneously, and now the provided in-situ leaching uranium well pattern will be described.

[0028] The method includes: Arranging a well pattern for each in-situ leaching unit, the well pattern including at least one horizontal injection well 2 and a vertical pumping well 3; Among them, the horizontal injection well 2 is located in the middle of the uranium-bearing ore layer 1, is consistent with the ore layer strike direction, and horizontally penetrates the ore layer; The vertical pumping well 3 is arranged in the ore layer and vertically penetrates the ore layer; a plurality of vertical pumping wells 3 are provided and are distributed on both sides of the horizontal injection well 2; The horizontal injection well 2 includes an injection section 21 and a full horizontal section 22; the injection section 21 of the horizontal injection well 2 communicates with the surface and the full horizontal section 22, and is used to inject the leaching solution into the full horizontal section 22; the full horizontal section 22 is horizontally arranged in the uranium-bearing deposit, and its well wall is evenly distributed with perforations for evenly injecting the leaching solution; The vertical pumping well 3 includes a lead-out section 31 and a pumping section 32; the pumping section 32 is located in the uranium-bearing deposit and is used to lead in the leaching solution in the deposit; the lead-out section 31 communicates the pumping section 32 and the surface, and is used to pump out the leaching solution in the pumping section 32.

[0029] The "horizontal injection well injection - vertical pumping well pumping" well group includes a horizontal injection well 2 and a vertical pumping well 3. All horizontal sections of the horizontal injection well 2 are located in the middle of the uranium-bearing injection section 21 and are consistent with the strike of the uranium-bearing deposit. The vertical pumping well 3 (vertical well) penetrates the entire uranium-bearing ore layer 1 from the surface downward. The bottom of the vertical pumping well 3 is located at the bottom of the uranium-bearing ore layer 1. The pumping section 32 of the vertical pumping well 3 is located in the entire uranium-bearing ore layer 1 and can extract the leaching solution from the deposit. There is no hydraulic connection between other areas of the vertical pumping well 3 and the surrounding rock formations.

[0030] The "horizontal injection well injection - vertical pumping well pumping" well pattern includes at least one horizontal injection well 2, and several vertical pumping wells 3 with the same number are distributed on both sides of the horizontal injection well 2. Preferably, in this implementation plan, vertical pumping wells 3 are respectively arranged on each side of the horizontal injection well 2.

[0031] Specifically, the distance between adjacent vertical pumping wells 3 on the same side of the horizontal injection well 2 is equal, the distance from each vertical pumping well 3 to the horizontal injection well 2 is equal, the distance from the vertical pumping well 3 to the horizontal injection well 2 is half of the vertical distance between adjacent horizontal injection wells 2, the outermost vertical pumping well 3 does not exceed the two ends of the horizontal injection well 2, and the horizontal distance from the outermost vertical pumping well 3 to the end point of the horizontal section of the horizontal well is half of the distance between adjacent vertical pumping wells 3.

[0032] Specifically, one end of the horizontal injection well 2 is the injection point 23 of the leaching solution. The entire horizontal section 22 of the horizontal injection well 2 is evenly perforated, and the leaching solution can be evenly injected along the way. The other end of the horizontal injection well 2 is closed, and the vertical pumping well 3 can receive the leaching solution injected from the horizontal injection well 2.

[0033] Preferably, the aperture, distribution range, and hole spacing of the perforations are generally set according to the actual situation and can be set according to the test situation.

[0034] Specifically, the pumping section 326 of the vertical pumping well 3 is located in the uranium-bearing ore layer 1. Only this section of the vertical pumping well 3 has a hydraulic connection with the surrounding uranium-bearing ore layer 1, and there is no hydraulic connection with the surrounding aquifer in other areas, so as to ensure that pumping is carried out only in the ore-bearing section.

[0035] Specifically, the injection volume of the horizontal injection wells 2 in the entire well pattern is equal to the pumping volume of all the vertical pumping wells 3, and the total pumping volume is evenly distributed to each vertical pumping well 3.

[0036] As a specific implementation manner of the "horizontal injection well injection - vertical pumping well pumping" well pattern for in-situ leaching of uranium provided by the present invention, please refer to Figure 2 , multiple horizontal injection wells 2 and vertical pumping wells 3 can be respectively set. The horizontal injection wells 2 and the vertical pumping wells 3 are alternately arranged, and the leaching solution inlets of the horizontal injection wells 2 can be located on the same side or alternately arranged. This implementation manner can set different numbers of horizontal injection wells 22 and corresponding vertical pumping wells 3 according to the geology of different regions. According to the actual thickness of the ore layer and the on-site construction conditions, the length of the horizontal injection section 215 of the horizontal injection well 2 and the number of vertical pumping wells 3 can be adjusted, and the well spacing can also be adjusted, effectively saving the drilling cost and manpower and material resources, and maximizing the return on investment.

[0037] In addition, optionally, the functions of the horizontal injection wells 2 and the vertical pumping wells 3 in the "horizontal injection well injection - vertical pumping well pumping" well pattern can be interchanged, that is, the leaching solution can be injected through the vertical pumping wells 3, and the leaching solution can be extracted by the horizontal injection wells 2, so as to expand the range of the leaching reaction and improve the leaching effect.

[0038] As a specific implementation manner of the embodiment of the present invention, multiple groups of horizontal injection wells 2 are arranged in parallel and aligned at both ends, and multiple groups of vertical pumping wells 3 are arranged in parallel and aligned. Embodiment 2

[0039] The embodiment of the present invention also provides a method for mining uranium by the "horizontal injection well injection - vertical pumping well pumping" well pattern for in-situ leaching of uranium. Based on the well pattern established in Embodiment 1, the mining method includes the following steps: Reasonably construct and arrange the "horizontal injection well injection - vertical pumping well pumping" well pattern according to the position, strike, and hydrogeological conditions of the uranium-bearing ore layer 1; In the initial mining stage, the horizontal injection well 2 first injects liquid throughout the horizontal section 22, and the vertical pumping well 3 pumps the liquid. When the uranium concentration in the vertical pumping well 3 is lower than a certain threshold, the perforations near the position of the horizontal injection well 2 facing the vertical pumping well 3 are blocked using a temporary plugging technique, and the leaching solution is guided to be injected from other perforations until the end of in-situ uranium leaching.

[0040] Specifically, in the initial stage of in-situ uranium leaching, for the "horizontal injection well injection - vertical pumping well pumping" well pattern, the horizontal injection well 2 injects liquid throughout the entire water section, and the vertical pumping well 3 pumps the liquid. The leaching solution is injected from the leaching solution injection point 234, and all the vertical pumping wells 3 extract the leaching solution. At this time, since the horizontal distance between the horizontal injection well 2 and the vertical pumping well 3 is the shortest in a certain area, the migration speed of the leaching solution is the fastest, and the high-flow area of the leaching solution is mainly distributed near the high area. Therefore, the leaching rate of uranium ore in this area is the largest; while the leaching solution flow rate in the middle area between adjacent vertical pumping wells 3 on the same side is the lowest, and the leaching rate of uranium ore is the slowest.

[0041] Real-time monitor the uranium concentration in the leaching solution extracted by the vertical pumping well 3. When the uranium concentration rises and then drops to a certain threshold, it indicates that the uranium ore in the high-flow area of the leaching solution has been basically leached.

[0042] Preferably, according to the conditions of the specific site, the threshold can be set between 40% and 50% of the peak concentration of each vertical pumping well 3; the peak concentration of the vertical pumping well 3 is based on the latest maximum peak among all the vertical pumping wells 3.

[0043] After blocking the corresponding horizontal section, maintain normal pumping and injection of the liquid.

[0044] Use the temporary plugging technique of the horizontal injection well 2 to block the perforations 7 near the high-flow area of the leaching solution in the well pattern, and guide the leaching solution to be injected only from other areas.

[0045] Preferably, according to the conditions of the site, each temporary plugging section 247 of the horizontal injection well 2 is located near the area with the shortest horizontal distance between the horizontal injection well 2 and the vertical pumping well 3, and the length is half of the distance between adjacent vertical pumping wells 3 on the same side. The blocking section is symmetric about the connection lines with the two vertical pumping wells 3 on both sides.

[0046] As an example, the device used for blocking is as Figures 8 - 9 shown. A packer and a sliding sleeve are lowered into the temporary plugging section 24 of the horizontal injection well 2. The specific operation is to lower the composite tail pipe string composed of an external packer and a sliding sleeve into the horizontal open hole section of the horizontal injection well 2. The packer can isolate different layers of the horizontal injection well 2 as Figure 8 . The packer is usually made of a high-pressure-resistant composite material to ensure that it will not be damaged under high-pressure operations. The K341 packer can be used (as Figure 9), the packer is operated hydraulically or mechanically to set it at a predetermined position. The temporary plugging agent is injected through the composite liner string to prevent the injection of the leaching solution in the temporary plugging section 24. The temporary plugging agent can be in the form of solid particles, fibers, gels, foams, etc., and a suitable temporary plugging agent can be selected according to the reservoir characteristics. In actual operation, various types of devices can be used for plugging, Figures 8 to 9 for illustrative purposes only.

[0047] After the temporary plugging of the horizontal injection well 2 is completed, the leaching solution is still injected from the leaching solution injection point 23, and all the vertical pumping wells 3 extract the leaching solution until the in-situ uranium leaching is completed.

[0048] Optionally, the device for plugging can also refer to the plugging technology of horizontal wells in the petroleum field, such as: I. Mechanical plugging technology: 1. Bridge plug sectioning and screen completion: The horizontal well section is divided into multiple small sections by bridge plugs to achieve precise plugging. The "ultra-close cutting + ultra-limited flow rate perforation" process is used to divide the horizontal section like "cutting a sausage", and the weak seepage areas are fracturing and reformed respectively to improve the recovery rate. In addition, screen completion (such as precision micro-hole composite sand control screen pipe) can isolate the water-producing layer.

[0049] 2. Expandable packer: Materials that expand when encountering water or heat are used to plug the water-producing layer section, which is suitable for the well type of screen completion.

[0050] II. Chemical water shutoff technology: Chemicals (such as expansion diagenetic agents, gels) are injected into the water-producing layer section to form a physical barrier through chemical reactions.

[0051] III. Cement slurry plugging technology: Ordinary Portland cement is mixed with additives (such as inorganic expansion agents) to form a solid cement ring to isolate the aquifer. The cement slurry is injected into the annular gap through the flow-blocking ring grouting method or the external pipe grouting method, and the service life can reach 20 years. This technology is applicable to multi-layer water-bearing structures or bedrock formations.

[0052] To further illustrate the implementation effect of the present application, a numerical simulation method is used to show the spatial distribution characteristics of the leaching solution flow rate after uniform injection and temporary plugging in the entire horizontal section 22 of the "horizontal injection well injection - vertical pumping well pumping" well pattern. The entire simulation area is a 500m×500m square ( Figure 5), the thickness of the ore-bearing aquifer is 16 m. The bottom and top elevations of the aquifer are set at 56 m and 30 m respectively. The average permeability coefficient of the aquifer is set at 0.12 m / d. The entire aquifer is simplified as an isotropic medium. The left and right boundaries of the aquifer are impermeable boundaries, and the upper and lower boundaries are set as constant head boundaries with the head set at 80 m. The initial water levels of the model are also set at 80 m. That is, in the absence of any interference (pumping or injection), the groundwater in the aquifer remains basically static, and the water levels of all grid cells are 80 m. The horizontal injection well 2 is located in the middle of the simulation area, with a length of 100 m. There are 8 vertical pumping wells 3 evenly distributed around it. The vertical distance between the pumping wells and the horizontal well is 25 m, and the distance between the vertical pumping wells on the same side is 25 m. The left end of the horizontal well is the injection point 23 of the leaching solution, with an injection volume of 240 m3 / d. The wellbore is assumed to be smooth, and the average roughness coefficient is set at 0.0001 m. The temperature of the leaching solution is set at 20 °C. The upper and lower Reynolds numbers in the horizontal well are set at 2000 and 4000 respectively to judge the flow state in the horizontal well. The exchange coefficient between the horizontal well and the surrounding uranium-bearing reservoir is set at 0.1 m2 / d. The entire model maintains pumping and injection balance, and the total pumping volume is evenly distributed to each vertical pumping well 3, that is, the pumping volume of each vertical pumping well 3 is 30 m3 / d. The entire model is set as a steady flow model, and the MODFLOW-CFP model is used to simulate the flow field of the entire simulation area.

[0053] Based on the MODFLOW-CFP simulation, 500 particles are evenly placed in each grid where the horizontal well is located, with a total of 11,000 particles placed. The simulation period for particle tracking is set at 3 years, and the MODPATH software is used for particle tracking simulation to finally obtain the migration path of the leaching solution injected by the horizontal well. The particle tracking results are statistically analyzed. The traces that do not reach the vertical pumping well 3 during the simulation period are removed, and only the traces that reach the pumping well are retained. The proportional contribution of the leaching solution flow rate of each tracer trace to the total flow rate during the simulation period is calculated.

[0054] Figure 6There are significant differences in the effective tracer line flow contribution degrees between the horizontal well and the vertical pumping well 3. The high-flow contribution areas are concentrated in the area with the shortest horizontal distance between the horizontal well and the vertical pumping well 3. As the distance from this area increases, the flow contribution degree gradually decreases, and the flow contribution degree in the middle area between adjacent vertical pumping wells 3 is relatively low. The outermost areas at both ends of the horizontal well have the longest tracer line lengths and the lowest hydraulic gradients, resulting in the lowest average flow velocity of the leaching solution on the trace lines in this area and the lowest flow contribution degree of the tracer lines. In-situ leaching of uranium mainly relies on the leaching solution to dissolve the uranium-bearing deposit. The larger the flow rate of the leaching solution trace line, the greater the amount of uranium-bearing deposit dissolved by the leaching solution in this area and the higher the uranium ore mining efficiency. For relatively uniform uranium-bearing deposits, this non-uniform spatial distribution of the leaching solution flow rate will lead to non-uniform leaching of the uranium-bearing deposit, thereby seriously affecting the overall mining efficiency of the uranium deposit.

[0055] Figure 7 After the temporary plugging technology is implemented on the horizontal section of the horizontal injection well 2, the leaching solution mainly injects from the non-temporarily plugged section 24 of the horizontal well, and obvious blank areas will appear in the temporarily plugged section 24 area. Comparing Figure 6 and Figure 7 , before temporary plugging, there is no leaching solution flowing through some areas where the leaching solution flow rate is the largest before temporary plugging. In other areas with relatively small leaching solution flow rates, they turn into areas with relatively large leaching solution flow rates after temporary plugging, and the spatial non-uniformity degree of the leaching solution flow rate after temporary plugging is lower than that before temporary plugging. This all indicates that after using the horizontal well temporary plugging technology to plug the high-flow areas of the leaching solution, it can, to a certain extent, make up for the non-uniformity of the spatial distribution of the leaching solution flow rate in the 'horizontal well injection - vertical pumping well 3 pumping' well pattern, guide the leaching solution to flow into the areas with small leaching solution flow rates, and thus improve the leaching efficiency.

[0056] In the description of this embodiment, it should be noted that when terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this embodiment and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to this embodiment.

[0057] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0058] In the present invention, unless otherwise clearly specified or limited, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0060] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0061] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for arranging a well pattern of "horizontal well injection-vertical well extraction" for in-situ leaching of uranium, characterized in that: The following steps are involved: Arranging a well pattern for each in-situ leaching unit, wherein the well pattern includes at least one horizontal injection well and a vertical extraction well; The horizontal injection well is located in the middle of the uranium-bearing ore layer, is consistent with the strike direction of the ore layer, and penetrates the ore layer in the horizontal direction; A vertical pumping well is arranged in the ore layer, and vertically penetrates the ore layer; a plurality of the vertical pumping wells are arranged, and are distributed on both sides of the horizontal injection well; The horizontal injection well comprises an injection section and a full horizontal section; the injection section of the horizontal injection well is connected to the ground surface and the full horizontal section, and is used to inject the leaching liquid into the full horizontal section; the full horizontal section is horizontally arranged in the uranium-containing ore bed, and perforations are evenly distributed on the well wall, and are used to evenly inject the leaching liquid; The vertical pumping well comprises an outlet section and a pumping section; the pumping section is located in a uranium-containing ore bed and is used to introduce leaching liquid from the ore bed; the outlet section connects the pumping section and the surface and is used to extract the leaching liquid from the pumping section.

2. The well pattern arrangement method of "horizontal well injection-vertical well extraction" for in-situ leaching of uranium according to claim 1 is characterized in that: The same number of vertical pumping wells are arranged on both sides of the horizontal injection well, and the vertical pumping wells on both sides are at equal vertical distances from the horizontal injection well. The spacing between adjacent vertical pumping wells on the same side of the horizontal injection well is equal and is twice the vertical distance between the vertical pumping well and the horizontal injection well.

3. The well pattern arrangement method of "horizontal well injection-vertical well extraction" for in-situ leaching of uranium according to claim 1 is characterized in that: There are multiple horizontal injection wells, which are evenly arranged in the ore layer in the horizontal direction.

4. The method for arranging a well pattern of "horizontal well injection-vertical well extraction" for in-situ leaching of uranium according to claim 2, characterized in that: The outermost vertical pumping wells do not exceed the two ends of the horizontal injection wells, and the distance between the outermost vertical pumping wells and the end points of the horizontal injection wells in the length direction of the horizontal injection wells is half of the spacing between adjacent vertical pumping wells.

5. The method for arranging a well pattern of "horizontal well injection-vertical well extraction" for in-situ leaching of uranium according to claim 1, characterized in that: The injection volume of the horizontal injection well is equal to the total pumping volume of the vertical pumping well, and the total pumping volume is evenly distributed to each vertical pumping well.

6. A method for in-situ leaching of uranium by "horizontal well injection-vertical well extraction" well pattern mining, characterized in that: The well pattern arranged according to the well pattern arrangement method according to any one of claims 1 to 5 comprises the following steps: In the early stage of in situ leaching of uranium, the leaching solution is evenly injected through all the perforations in the entire horizontal section, and the leaching solution is extracted through the vertical extraction well.

7. The in-situ uranium leaching "horizontal well injection-vertical well pumping" well pattern mining method according to claim 5 is characterized in that: The method further comprises: The uranium concentration of the leaching solution in each vertical pumping well is monitored. When the uranium content in the leaching solution in any vertical pumping well drops to the preset plugging threshold, it indicates that the uranium mining in the area of ​​the vertical pumping well is basically completed. At this time, the injection of leaching solution is stopped, and the perforations of the horizontal injection well in the area where the vertical pumping well is located are temporarily plugged. After that, the leaching solution is re-injected and guided to be injected from other perforations.

8. The in-situ uranium leaching "horizontal well injection-vertical well pumping" well pattern mining method according to claim 7 is characterized in that: The preset blocking threshold is 40-50% of the peak concentration.

9. The in-situ uranium leaching "horizontal well injection-vertical well pumping" well pattern mining method according to claim 7, characterized in that: The method further comprises: When the uranium leaching concentration of the leaching solution from all vertical pumping wells drops to the preset end threshold, in situ uranium leaching is terminated.

10. The in-situ uranium leaching "horizontal well injection-vertical well pumping" well pattern mining method according to claim 9, characterized in that: The preset end threshold is 10-20% of the peak concentration.

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