A high pressure tracer test device and method for in-situ leaching of uranium low permeability multilayer ore

Abstract

The present invention provides a high-pressure tracer test device and method for in-situ leaching of uranium in low-permeability multi-layer mines, and relates to the technical field of in-situ leaching of uranium. It includes a storage tank group, in which a variety of tracers are stored; an injection well, the injection well sequentially passes through a plurality of mineral-bearing layers underground, and a first filter is provided in each layer section where the mineral-bearing layer is located; an injection pipeline, one end of the injection pipeline is connected to the storage tank group, and the other end extends downward into the injection well, and a liquid distribution device is installed in each layer section where the mineral-bearing layer is located; a plurality of extraction wells arranged around the injection well, the extraction wells sequentially pass through a plurality of mineral-bearing layers underground, and a second filter is provided in each layer section where the mineral-bearing layer is located; a water storage tank, one port of the water storage tank is connected to a plurality of extraction wells, and one port is connected to the injection pipeline to form a passage. The present invention can grasp the migration process of groundwater in different mineral-bearing layers in multiple directions, and there are fewer types of tracers, and the detection is simple.

Description

Technical Field

[0001] The invention relates to the technical field of in-situ leaching uranium mining, and in particular to a high-pressure tracer test device and method for in-situ leaching uranium low-permeability multi-layer ore. Background Art

[0002] In-situ uranium leaching tracer test is a test method in which tracers are injected into underground mineral-bearing layers through drilling. Groundwater carrying tracers continuously migrates in the mineral-bearing layers and is lifted to the surface after reaching the extraction well. The concentration of tracers in the extracted liquid is detected to understand the changes in the concentration of tracers in the extracted liquid, thereby understanding the migration law of groundwater in the mineral-bearing layers. At present, the tracer test method used in in-situ leaching of uranium is generally the method of injecting tracers at normal pressure, which is suitable for a single mineral-bearing layer. Even if the mineral layer is composed of multiple mineral-bearing layers, the tracer test is only carried out on a certain layer, which cannot meet the needs of conducting tracer tests on multiple ore bodies in strata with multiple mineral-bearing layers at the same time.

[0003] At the same time, for low-permeability, difficult-to-inject and difficult-to-mine ore-bearing layers, the low-permeability sandstone uranium deposits are difficult to inject tracers using the normal pressure tracer test method due to the dense rock, poor permeability and slow groundwater migration, making it impossible to effectively carry out tracer tests. Summary of the invention

[0004] The purpose of the present invention is to provide a high pressure tracer test device and method for in-situ leaching of uranium low permeability multilayer ore to improve the above problems. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A high-pressure tracer test device for in-situ leaching of uranium low-permeability multilayer ore, the device comprising:

[0006] A storage tank group, wherein a plurality of tracers are stored in the storage tank group;

[0007] An injection well, wherein the injection well sequentially passes through a plurality of mineral-bearing layers underground, and a first filter is arranged in a layer section where each mineral-bearing layer is located;

[0008] A liquid injection pipeline, one end of which is connected to the storage tank group, and the other end of which extends downward into the injection well, and a liquid distribution device is installed for each ore-bearing layer section;

[0009] Arrange a plurality of extraction wells around the injection well, wherein the extraction wells sequentially pass through a plurality of mineral-bearing layers underground, and a second filter is arranged in the layer section where each mineral-bearing layer is located;

[0010] A water storage tank, one port of which is connected to a plurality of extraction wells, and another port of which is connected to an injection pipeline through a high-pressure injection pump to form a passage.

[0011] Furthermore, one port of the high-pressure liquid injection pump is connected to a plurality of storage tanks in the storage tank group through a plurality of injection pipelines, and another port is connected to a water storage tank through a water injection pipeline.

[0012] Furthermore, a plug is provided at the end of the injection pipeline, and a plurality of groups of liquid distribution devices and hydraulic anchors are sequentially installed above the plug, each group of liquid distribution devices includes a water distributor and a packer, and the packer is located above the water distributor.

[0013] Furthermore, it also includes a control room, one port of which is connected to multiple extraction wells through multiple extraction pipelines, and one port is connected to a water storage tank through a liquid collecting pipeline, and a sampling port is arranged on the extraction pipeline.

[0014] Furthermore, a submersible pump is provided in the extraction well, and the submersible pump is located above the second filter at the uppermost layer and below the dynamic water level.

[0015] Furthermore, a high-pressure wellhead device is provided at the wellhead of the injection well, and a valve for controlling the opening or closing of the injection pipeline is provided on the high-pressure wellhead device.

[0016] On the other hand, the present invention provides a high pressure tracer test method for in-situ leaching of uranium low permeability multilayer ore, the method comprising:

[0017] A first liquid distribution device is installed on the upper part of the upper ore-bearing layer, and a second liquid distribution device is installed between the upper ore-bearing layer and the lower ore-bearing layer;

[0018] The first tracer and the second tracer are respectively injected into different storage tanks, and the first tracer and the second tracer are respectively introduced into the high-pressure injection pump through corresponding injection pipelines;

[0019] Start the submersible pumps of multiple extraction wells, and the groundwater enters the control room through the extraction pipeline. After the extraction flow rate stabilizes, start the high-pressure injection pump;

[0020] The second liquid dispensing device is closed, the first liquid dispensing device is opened, and the high-pressure liquid injection pump injects the first tracer into the upper ore-bearing layer; after the first tracer is injected, the first liquid dispensing device is closed, the second liquid dispensing device is opened, and the high-pressure liquid injection pump injects the second tracer into the lower ore-bearing layer;

[0021] The first tracer and the second tracer are transported to a plurality of extraction wells along with the groundwater, the groundwater is extracted by a submersible pump and pumped into the corresponding extraction pipeline, and the extracted liquid is taken at the sampling port to analyze the tracer content to determine the time and concentration of the tracer appearance;

[0022] The extracted liquids from multiple extraction wells are collected into the liquid collecting pipeline in the control room to form a mixed liquid. The mixed liquid flows into the water storage tank through the liquid collecting pipeline and is injected into the injection pipeline by a high-pressure injection pump to form a pumping and injection cycle.

[0023] The beneficial effects of the present invention are:

[0024] The present invention uses a packer and a water distributor to realize the same-well pumping and same-well injection method. Different tracers can be injected into different mineral-bearing layers through one injection well, and groundwater from different mineral-bearing layers can be simultaneously extracted through other extraction wells. The above-mentioned layered tracer injection method can distinguish the migration of tracers in different mineral-bearing layers, and the mixed extraction method of the extraction well can accurately determine the source and flow direction of the tracer, and can save the material investment of packers, pumping equipment, etc., thereby achieving the purpose of conducting effective tracer tests on multi-layer mines.

[0025] At the same time, for low-permeability, difficult-to-inject and difficult-to-mine multi-layer mineral-bearing layers, the present invention can quickly increase the formation pressure by injecting tracers in a high-pressure manner, greatly improve the groundwater migration rate of low-permeability sandstone uranium deposits, drive the tracer to quickly migrate from the injection well to the extraction well, shorten the test cycle, and effectively improve the tracer test effect.

[0026] Other features and advantages of the present invention will be described in the following description, and some will become apparent from the description, or will be understood by implementing the embodiments of the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 This is a schematic diagram of a high-pressure tracer test device for in-situ leaching of uranium in a low-permeability multi-layer ore;

[0029] Figure 2 It is a schematic diagram of the position relationship between the injection well and the pumping well;

[0030] Figure 3 This is a flow chart of the high-pressure tracer test method for in-situ leaching of uranium in low-permeability multi-layer mines. Labels in the figure:

[0031] 1. Storage tank; 2. Injection well; 21. First filter; 22. High-pressure wellhead device; 3. Liquid injection pipeline; 31. Plug; 32. First water distributor; 33. First packer; 34. Second water distributor; 35. Second packer; 4. Pumping well; 41. Second filter; 42. Submersible pump; 5. Water storage tank; 6. High-pressure liquid injection pump; 7. Injection pipeline; 8. Water injection pipeline; 9. Control room; 10. Liquid extraction pipeline; 11. Liquid collection pipeline; 12. Upper ore-bearing layer; 13. Lower ore-bearing layer.

[0032] 800. High-pressure tracer test equipment for in-situ leaching of uranium in low-permeability multilayer mines; 801. Processor; 802. Memory; 803. Multimedia component; 804. I / O interface; 805. Communication component. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0035] Embodiment 1:

[0036] like Figure 1 As shown, a high pressure tracer test device for in-situ leaching of uranium low permeability multilayer ore comprises:

[0037] A storage tank group, wherein a plurality of tracers are stored in the storage tank group, and the storage tank group comprises a plurality of storage tanks 1;

[0038] Specifically, the selection of tracers must meet the following conditions:

[0039] 1) Easily soluble in water and can form a true solution in a homogeneous state in groundwater.

[0040] 2) It is conducive to both the placement and the rapid diffusion of alcohol (salt) along with groundwater, so that the data obtained from the test can more truly reflect the law of groundwater movement;

[0041] 3) When two or more tracers are used in combination, the physical and chemical properties of different tracers should be as close as possible to reduce the impact of different tracers on the test results.

[0042] 4) The chemical properties are relatively stable, there are few interfering factors, and the tracing effect is significant;

[0043] 5) The detection is convenient and the determination method has high sensitivity.

[0044] Preferably, the tracer selected in this embodiment can be alcohols such as methanol, ethanol, isopropanol, etc., and soluble salts such as ammonium molybdate, zinc chloride, etc.

[0045] An injection well 2, wherein the injection well 2 sequentially passes through a plurality of mineral-bearing layers in the underground layer, and a first filter 21 is provided in each layer section where the mineral-bearing layer is located, wherein the first filter 21 is used to connect the injection well and the mineral-bearing layer. Preferably, the position of the first filter 21 is aligned with the position of the mineral layer, and the thickness is consistent with the thickness of the mineral layer; when the thickness of the mineral layer is less than 5m, the length of the filter is 5m, and the center is aligned with the center of the mineral layer;

[0046] In this embodiment, an example is given in which an underground layer sequentially passes through two mineral-bearing layers. Two tracers are used in combination and injected into different mineral-bearing layers in the injection well. The tracer source is injected once, and different types of tracers are successively injected into the center hole.

[0047] A liquid injection pipeline 3, one end of which is connected to the storage tank group, and the other end of which extends downward into the injection well 2, and a liquid distribution device is installed for each ore-bearing layer section;

[0048] A plurality of extraction wells 4 are arranged around the injection well 2. The extraction wells 4 sequentially pass through a plurality of mineral-bearing layers in the underground layer, and a second filter 41 is arranged in the layer section where each mineral-bearing layer is located. The second filter 41 is used to connect the mineral-bearing layer and the extraction well, and its installation position and method are consistent with the first filter 21;

[0049] In this embodiment, the multi-layer mine high pressure tracer test adopts the same well pumping and injection method, and the well pattern layout method is injection in the center hole and pumping in the surrounding holes. Preferably, the well pattern layout can be a two-hole type, a five-point type, a seven-point type, a nine-point type, etc. Figure 2 In the figure, point B and point A are the extraction well and injection well respectively. The distance between the extraction well and the injection well is calculated according to the formation permeability. The calculation formula is:

[0050]

[0051] Where a represents half of the distance between the extraction well and the injection well; P is the formation pressure at any point in the formation; P w is the bottom flow pressure of the extraction well; Q is the flow rate of the pumping and injection well during the tracer test; K is the formation permeability; h is the thickness of the mineral-bearing aquifer; μ is the viscosity of the leaching solution; α is the well diameter coefficient; r w is the wellbore radius, optionally, the wellbore radius is 139.7mm, 152mm and 190mm.

[0052] A water storage tank 5, one port of which is connected to a plurality of extraction wells 4, and another port of which is connected to an injection pipeline 3 via a high-pressure injection pump 6 to form a passage.

[0053] The present invention adopts a well network layout method of injecting into a central hole and extracting from multiple surrounding holes. It only needs to inject corresponding tracers into different mineral-bearing layers in the central hole, and then extract groundwater containing different tracers in multiple surrounding extraction wells 4. According to the changes in the concentrations of different tracers in the extraction wells 4 in multiple directions, the migration of groundwater in different mineral-bearing layers can be grasped in multiple directions, thereby reducing the types of tracers used and reducing the difficulty of detection.

[0054] Based on the above embodiments, one port of the high-pressure injection pump 6 is connected to multiple storage tanks 1 in the storage tank group through multiple injection pipelines 7, and one port is connected to the water storage tank 5 through the water injection pipeline 8. The high-pressure injection pump 6 pressurizes the tracer or water and then enters the injection well 2 through the injection pipeline 3.

[0055] Specifically, a valve is provided on the injection pipeline 7 to control the injection or shutoff of the tracer. The injection pipeline 7 is also provided with a flow meter and a pressure gauge to record the flow rate and pressure during the tracer injection;

[0056] Specifically, the high-pressure injection pump 6 is provided with a frequency converter for adjusting the working frequency to control the injection pressure of the injection pump, thereby adjusting the injection flow rate, and the working frequency range is 0-50Hz. The high-pressure injection pump 6 is also provided with a pressure gauge and a flow meter for recording the pressure and flow rate of the injection.

[0057] Preferably, the injection pressure of the high-pressure injection pump 6 is selected according to the pressure head pressure of the groundwater in the mineral-bearing layer. Normally, the maximum injection pressure does not exceed 2-2.5 times the pressure head pressure of the groundwater in the mineral-bearing layer.

[0058] Preferably, the injection flow rate of the high-pressure injection pump 6 is equivalent to the pumping flow rate of the water pumping test.

[0059] Preferably, the injection pipeline 3 is made of high-strength anti-corrosion pipe, and optionally, it can be a stainless steel pipe, a high-pressure polyethylene-lined steel pipe, a high-pressure fiberglass pipe, etc.

[0060] Based on the above embodiment, a plug 31 is provided at the end of the injection pipeline 3 for plugging the injection pipeline 3, and a hydraulic anchor and multiple groups of liquid distribution devices are provided above the plug 31, each group of liquid distribution devices includes a water distributor and a packer, and the packer is located above the water distributor. Preferably, the water distributor is a bridge-type concentric water distributor, and the packer is a Y341 type packer.

[0061] Based on the above embodiment, it also includes a control room 9, one port of the control room 9 is connected to multiple extraction wells 4 through multiple extraction pipelines 10, and one port is connected to the water storage tank 5 through a liquid collection pipeline 11. The extraction pipeline 10 is provided with a sampling port, and the sampling port is used to collect extraction liquids from different extraction wells and at different times, and the tracer content of different extraction liquids is analyzed to determine the time and concentration of the tracer appearance.

[0062] Based on the above embodiments, a submersible pump 42 is provided in the extraction well 4. The submersible pump 42 is located above the second filter 41 of the top mineral-bearing layer and below the dynamic water level. Specifically, the placement depth of the submersible pump 42 is determined according to the pumping flow rate and the head of the submersible pump. The lowering position of the submersible pump 42 is generally 20m above the maximum head. When the pump is lowered to the deepest position, the bottom of the pump is not lower than the top of the filter. The pumping flow rate of the submersible pump 42 is usually equivalent to or slightly higher than the injection flow rate of the high-pressure injection pump 6. The groundwater in the extraction well is pumped to the surface by the submersible pump 42 and enters the control room 9 through the pumping pipeline 10. The extracted liquids from different extraction wells 4 are merged into the collecting pipeline 11 in the control room 9, and then uniformly flow into the water storage tank 5 to supply the high-pressure injection pump 6, and are injected into the injection well 2 again, forming a pumping and injection cycle until the high-pressure tracer test is completed.

[0063] Preferably, a submersible pump frequency converter and a flow meter are provided in the control room 9. The submersible pump frequency converter is used to control the operating frequency of the submersible pump, thereby adjusting the pumping flow rate of the submersible pump 42, and the flow meter is used to record the pumping flow rate.

[0064] Based on the above embodiment, a high-pressure wellhead device 22 is provided at the wellhead of the injection well 2, which is used to seal the wellhead during high-pressure injection. A valve for controlling the opening or closing of the injection pipeline 3 is provided on the high-pressure wellhead device 22. The high-pressure wellhead device 2 is also provided with a pressure gauge for recording the wellhead pressure. The function of recording the wellhead pressure is:

[0065] 1) After the fluid is injected into the formation, when the stable flow is not achieved in the initial stage of injection, the pressure field and seepage field of the original formation change. When the permeability of the formation is poor, the formation around the injection well may be pressurized, resulting in an increase in the formation pressure around it. The increase in formation pressure may cause the opening of fractures. Therefore, it is necessary to adjust the injection volume by observing the changes in the wellhead pressure in real time to ensure that the bottom flow pressure of the injection well is lower than the formation fracture pressure.

[0066] Assume the formation fracture pressure is P r During the test, the bottom flow pressure of the injection well is P f , wellhead pressure is P o , the pressure of the liquid column in the injection well is P h , then during the test the following should be met:

[0067] P f ≤P r , P f =P o +P h ;

[0068] 2) Under the premise of ensuring the above pressure, by adjusting the wellhead injection pressure P o The migration and concentration changes of the tracer under different injection pressure conditions can be obtained from the wellhead pressure recorded by the wellhead pressure gauge. The tracing results of the different injection pressure and tracer concentration change curves can provide a basis for the subsequent pumping and injection operation design.

[0069] This embodiment adopts central hole injection and surrounding hole extraction, and injects the tracer into different mineral-bearing layers through the central injection well at high pressure, so that no matter in which direction the solution of the central injection hole diffuses, there is a corresponding extraction hole that can detect the tracer, and can accurately determine the mineral-bearing layer from which the tracer comes, and more accurately determine the migration direction of groundwater in different mineral-bearing layers, and depict the flow field changes and migration laws of groundwater in different mineral-bearing layers.

[0070] Embodiment 2:

[0071] like Figure 3 As shown, this embodiment also provides a high-pressure tracer test method for in-situ leaching of uranium low-permeability multi-layer ore, wherein the underground layer comprises multiple ore-bearing layers. This embodiment is described by taking the underground layer comprising two ore-bearing layers as an example, wherein the two ore-bearing layers are an upper ore-bearing layer 12 and a lower ore-bearing layer 13, respectively, and include:

[0072] S1. Install a first liquid distribution device on the upper part of the upper ore-bearing layer 12, and install a second liquid distribution device between the upper ore-bearing layer 12 and the lower ore-bearing layer 13, wherein the first liquid distribution device includes a first water distributor 32 and a first packer 33, and the second liquid distribution device includes a second water distributor 34 and a second packer 35;

[0073] Specifically, the step S1 includes:

[0074] S11. Install the wire plug 31 at the end of the injection pipeline 3;

[0075] S12. A second packer 35 and a second water distributor 34 are sequentially provided on the injection pipeline 3, wherein the second packer 35 is located between the lower ore-bearing layer 13 and the upper ore-bearing layer 12, and the second water distributor 34 is located below the second packer 35;

[0076] Specifically, the second packer 35 is used to separate the lower ore-bearing layer 13 from the upper ore-bearing layer 12 , and the second water distributor 34 is used to inject solution into the lower ore-bearing layer 13 .

[0077] S13. A first packer 33 and a first water distributor 32 are sequentially arranged on the injection pipeline 3, wherein the first packer 33 is located above the upper mineral-bearing layer 12, and the distance between the first packer 33 and the upper mineral-bearing layer 12 is a first preset value, which is 2m-5m; the first water distributor 32 is located below the second packer 35;

[0078] S14. Install a hydraulic anchor on the injection pipeline 3 , wherein the hydraulic anchor is located above the first packer 33 .

[0079] Based on the above embodiments, the method further includes:

[0080] S2. Inject the first tracer and the second tracer into different storage tanks 1, respectively, and the first tracer and the second tracer enter the high-pressure injection pump 6 through the corresponding injection pipelines 7;

[0081] S3. Open multiple submersible pumps 42 of the extraction wells 4, and groundwater enters the control room 9 through the pumping pipeline 10. After the pumping flow rate stabilizes, start the high-pressure injection pump 6;

[0082] In this embodiment, the surrounding extraction wells 4 are started first, which is conducive to forming a depth reduction funnel in the central area, first reducing the formation pressure in the central area, and then injecting the tracer at high pressure to quickly replenish the lost formation pressure, greatly improving the groundwater migration rate, driving the tracer to migrate quickly from the injection well 2 to the extraction well 4, and at the same time helping to reduce the peak injection pressure, reduce energy consumption, shorten the test period, and improve the test effect.

[0083] S4. The second liquid dispensing device is closed, the first liquid dispensing device is opened, and the high-pressure liquid injection pump 6 injects the first tracer into the upper mineral-bearing layer 12; after the first tracer is injected, the first liquid dispensing device is closed, the second liquid dispensing device is opened, and the high-pressure liquid injection pump 6 injects the second tracer into the lower mineral-bearing layer 13;

[0084] Specifically, step S4 includes:

[0085] S41. Open the first water distributor 32, close the second water distributor 34, and the first tracer enters the injection well 2 through the injection pipeline 3;

[0086] S42. The first tracer enters the upper mineral-bearing layer 12 from the first filter 21 of the upper mineral-bearing layer 12 and diffuses toward the underground layer;

[0087] S43. After the injection of the first tracer is completed, clean water with the same volume as that of the injection well 2 is injected to flush the first tracer in the injection pipeline 3, and the first water distributor 32 is closed to stop injecting water into the upper ore-bearing layer 12.

[0088] Based on the above embodiments, the method further includes:

[0089] S5. The first tracer and the second tracer follow the groundwater to migrate to a plurality of extraction wells 4, and the groundwater in the extraction well 4 is pumped into the corresponding extraction pipeline 10 by the submersible pump 42. The extraction liquid is taken at the sampling port and the content of the first tracer and the second tracer is analyzed to determine the time and concentration of the tracer appearance. Specifically, taking alcohol tracers as an example, the tracer alcohol content analysis can be analyzed by gas chromatograph, and the detection method is hydrogen flame detection. The detector will give a signal according to the physicochemical properties of the test sample, and the quantitative information of the alcohol tracer is obtained by analyzing the maximum value and time of the chromatographic peak. The detection parameter is mainly the alcohol concentration.

[0090] In this embodiment, the general rule for detecting tracers from the extract is that no tracer is detected at the beginning of the test, then one or more tracers appear, and the tracer concentration gradually increases from low to high, reaches a peak concentration, and then gradually decreases until the end of the test.

[0091] Specifically, the diffusion velocity of the tracer is a reflection of the migration velocity of the tracer with groundwater in the formation and the diffusion velocity of the tracer in the formation water. Its value is determined by the time of agent appearance and the distance from the injection hole to the monitoring hole. The migration velocity of the tracer is equal to the migration velocity of the formation water during dynamic pumping of the test unit, which is calculated by the peak time and migration distance of the tracer concentration. According to the calculated migration velocity and diffusion velocity of the tracer in each pumping hole, the heterogeneity of the formation in different directions, the difference in permeability in different directions and the connectivity between different pumping holes are judged. Generally speaking, the permeability and connectivity in the direction with a large tracer migration velocity are better than those in the direction with a small migration velocity. When there is a large difference in the pumping flow rate in the test area, when the tracer concentration time of the pumping well 4 is short and the peak concentration is high, there should be large pores or cracks; when the tracer concentration of the pumping well 4 is not seen until the end of the test, it indicates that the hydraulic connection between some boreholes is poor.

[0092] Specifically, step S5 includes:

[0093] S51. Open the second water distributor 34, and the second tracer enters the injection well 2 through the injection pipeline 3;

[0094] S52. The second tracer enters the lower mineral-bearing layer 13 from the first filter 21 of the lower mineral-bearing layer 13 and diffuses into the underground layer;

[0095] S53. After the second tracer is injected, the same volume of water as the injection well 2 is injected to flush the second tracer in the injection pipeline 3, and the second water distributor 34 is closed to stop injecting water into the ore-bearing layer 13 downward;

[0096] S54. The water in the water storage tank 5 is injected into the high-pressure injection pump 6 through the injection pipe 8;

[0097] S55. Open the first water distributor 32 and the second water distributor 34, and the high-pressure injection pump 6 injects water into the upper mineral-bearing layer 12 and the lower mineral-bearing layer 13. During the process of the high-pressure injection pump 6 injecting water into the well, the head pressure of the injection well 2 is increased, further pushing the tracer to migrate to the depth of the mineral-bearing stratum and finally reaching the extraction well 4.

[0098] In this embodiment, since the second filters 41 are provided in both the upper ore-bearing layer 12 and the lower ore-bearing layer 13 of the extraction well 4 , when the groundwater carrying the tracer migrates to the extraction well 4 , it can pass through the second filters 41 and enter the extraction well 4 .

[0099] S6. The extracted liquids from multiple extraction wells 4 are collected in the liquid collecting pipeline 11 in the centralized control room 9 to form a mixed liquid. The mixed liquid flows into the water storage tank 5 through the liquid collecting pipeline 11 and is injected into the liquid injection pipeline 3 by the high-pressure injection pump 6 to form a pumping and injection cycle.

[0100] In this embodiment, the duration of the tracer test can ensure that the leaching liquid can reach the extraction well faster only when the following conditions are met:

[0101] P 中心 >S(P f +P wmin );

[0102] Where P 中心 It represents the formation pressure at the midpoint of the main flow line of the extraction well and the injection well, P wmin Indicates the minimum allowable bottom hole pressure of the extraction well, p f represents the bottom hole flowing pressure of the injection well, and S represents the tracing time coefficient.

[0103] Among them, P wmin =P pump -0.2, P pump Indicates the pressure corresponding to the liquid column from the lowering position of the pump to the bottom of the well.

[0104] In summary, the present invention adopts the same-well extraction and injection method, and the well network layout method of central hole injection and surrounding hole extraction, so that the tracer is injected into different mineral-bearing layers at high pressure through the central injection well, and then the groundwater containing the tracer is pumped to the surface through the surrounding extraction wells, so as to achieve the purpose of monitoring the migration law of groundwater, reduce the types of tracers, shorten the test period, and improve the tracer test effect.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0106] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A high-pressure tracer test device for in-situ leaching of uranium low-permeability multi-layer ore, characterized in that: include: A storage tank group, wherein a plurality of tracers are stored in the storage tank group; An injection well (2), wherein the injection well (2) sequentially passes through a plurality of mineral-bearing layers in the underground layer, and a first filter (21) is arranged in a layer section where each mineral-bearing layer is located; An injection pipeline (3), one end of which is connected to the storage tank group, and the other end of which extends downward into the injection well (2), and a liquid distribution device is installed for each ore-bearing layer section; A plurality of extraction wells (4) are arranged around the injection well (2), wherein the extraction wells (4) sequentially pass through a plurality of mineral-bearing layers in the underground layer, and a second filter (41) is arranged in the layer section where each mineral-bearing layer is located, wherein the distance between the extraction well and the injection well is calculated by the following formula: Where a represents half of the distance between the extraction well and the injection well; P is the formation pressure at any point in the formation; P w is the bottom flow pressure of the extraction well; Q is the flow rate of the pumping and injection well during the tracer test; K is the formation permeability; h is the thickness of the mineral-bearing aquifer; μ is the viscosity of the leaching solution; α is the well diameter coefficient; r w is the wellbore radius; A water storage tank (5), one end of which is connected to a plurality of extraction wells (4), and one end of which is connected to an injection pipeline (3) via a high-pressure injection pump (6) to form a passage; A control room (9), wherein one port of the control room (9) is connected to a plurality of extraction wells (4) respectively through a plurality of extraction pipelines (10), and another port is connected to a water storage tank (5) through a liquid collection pipeline (11), and a sampling port is provided on the extraction pipeline (10).

2. The high pressure tracer test device for in-situ leaching of uranium low permeability multilayer mine according to claim 1, characterized in that: One port of the high-pressure liquid injection pump (6) is respectively connected to a plurality of storage tanks (1) in the storage tank group through a plurality of injection pipelines (7), and another port is connected to the water storage tank (5) through a water injection pipeline (8).

3. The high pressure tracer test device for in-situ leaching of uranium low permeability multilayer mine according to claim 1, characterized in that: A thread plug (31) is provided at the end of the injection pipeline (3), and a hydraulic anchor and a plurality of groups of liquid distribution devices are provided above the thread plug (31), each group of liquid distribution devices comprises a water distributor and a packer, and the packer is located above the water distributor.

4. The high pressure tracer test device for in-situ leaching of uranium low permeability multilayer mine according to claim 1, characterized in that: A submersible pump (42) is provided in the extraction well (4), and the submersible pump (42) is located above the second filter (41) of the top mineral-bearing layer and below the dynamic water level.

5. The high pressure tracer test device for in-situ leaching of uranium low permeability multilayer mine according to claim 1, characterized in that: A high-pressure wellhead device (22) is provided at the wellhead of the injection well (2), and a valve for controlling the opening or closing of the injection pipeline (3) is provided on the high-pressure wellhead device (22).

6. A high pressure tracer test method for in situ leaching of uranium in low permeability multilayer mines, characterized in that: The underground layer comprises two ore-bearing layers, namely an upper ore-bearing layer (12) and a lower ore-bearing layer (13). The high-pressure tracer test device for in-situ leaching of uranium low-permeability multilayer mines according to any one of claims 1 to 5 is used, comprising: A first liquid distribution device is installed on the upper part of the upper ore-bearing layer (12), and a second liquid distribution device is installed between the upper ore-bearing layer (12) and the lower ore-bearing layer (13); The first tracer and the second tracer are respectively injected into different storage tanks (1), and the first tracer and the second tracer respectively enter the high-pressure injection pump (6) through corresponding injection pipelines (7); The submersible pumps (42) of the plurality of extraction wells (4) are turned on, and the groundwater enters the control room (9) through the extraction pipeline (10). After the extraction flow rate is stabilized, the high-pressure injection pump (6) is started; The second liquid dispensing device is closed, the first liquid dispensing device is opened, and the high-pressure liquid injection pump (6) injects the first tracer into the upper mineral-bearing layer (12); after the first tracer is injected, the first liquid dispensing device is closed, the second liquid dispensing device is opened, and the high-pressure liquid injection pump (6) injects the second tracer into the lower mineral-bearing layer (13); The first tracer and the second tracer are transported along with the groundwater to a plurality of extraction wells (4), the groundwater is extracted by a submersible pump (42) and pumped into corresponding extraction pipelines (10), the extracted liquid is taken at a sampling port and the contents of the first tracer and the second tracer are analyzed; The extracted liquids from the plurality of extraction wells (4) are collected in the liquid collecting pipeline (11) in the centralized control room (9) to form a mixed liquid. The mixed liquid flows into the water storage tank (5) through the liquid collecting pipeline (11) and is injected into the liquid injection pipeline (3) by the high-pressure liquid injection pump (6) to form a pumping and injection cycle.

7. The high pressure tracer test method for in-situ leaching of uranium in low permeability multilayer mines according to claim 6, characterized in that: A first liquid distribution device is installed on the upper part of the upper ore-bearing layer (12), and a second liquid distribution device is installed between the upper ore-bearing layer (12) and the lower ore-bearing layer (13), wherein the first liquid distribution device includes a first water distributor (32) and a first packer (33), and the second liquid distribution device includes a second water distributor (34) and a second packer (35), including: Installing a thread plug (31) at the end of the liquid injection pipeline (3); A second packer (35) and a second water distributor (34) are sequentially arranged on the injection pipeline (3), wherein the second packer (35) is located between the lower ore-bearing layer (13) and the upper ore-bearing layer (12), and the second water distributor (34) is located below the second packer (35); A first packer (33) and a first water distributor (32) are sequentially arranged on the injection pipeline (3), wherein the first packer (33) is located above the upper mineral-bearing layer (12), and the distance between the first packer (33) and the upper mineral-bearing layer (12) is a first preset value; and the first water distributor (32) is located below the first packer (33); A hydraulic anchor is installed on the injection pipeline (3), and the hydraulic anchor is located above the first packer (33).

8. The high pressure tracer test method for in-situ leaching of uranium in low permeability multilayer mines according to claim 7, characterized in that: The second liquid dispensing device is closed, the first liquid dispensing device is opened, and the high-pressure liquid injection pump (6) injects the first tracer into the upper ore-bearing layer (12), comprising: The first water distributor (32) is opened, the second water distributor (34) is closed, and the first tracer enters the injection well (2) through the injection pipeline (3); The first tracer enters the upper mineral-bearing layer (12) from the first filter (21) of the upper mineral-bearing layer (12) and diffuses into the stratum; After the injection of the first tracer is completed, clean water having the same volume as that of the injection well (2) is injected to flush the first tracer in the injection pipeline (3), and the first water distributor (32) is closed to stop injecting water into the upper ore-bearing layer (12).

9. The high pressure tracer test method for in situ leaching of uranium low permeability multilayer mine according to claim 7, characterized in that: The first liquid dispensing device is closed, the second liquid dispensing device is opened, and the high-pressure liquid injection pump (6) injects the second tracer into the lower ore-bearing layer (13), comprising: The second water distributor (34) is opened, and the second tracer enters the injection well (2) through the injection pipeline (3); The second tracer enters the lower mineral-bearing layer (13) from the first filter (21) of the lower mineral-bearing layer (13) and diffuses into the stratum; After the injection of the second tracer is completed, clean water having the same volume as that of the injection well (2) is injected to flush the second tracer in the injection pipeline (3), the second water distributor (34) is closed, and water injection into the lower ore-bearing layer (13) is stopped; Injecting water in the water storage tank (5) into the high-pressure injection pump (6) through the water injection pipeline (8); The first water distributor (32) and the second water distributor (34) are opened, and the high-pressure injection pump (6) injects water into the upper mineral-bearing layer (12) and the lower mineral-bearing layer (13).

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