Permeation-increasing blockage-removing well mining system and method

Abstract

The invention discloses a permeability-increasing and blockage-removing mining well system and method. In the in-situ leaching process of sandstone type uranium ore, the problems of permeability reduction, channel blockage and the like often face, the liquidity of leachate and the dissolving efficiency of uranium are affected, and the expected effect is difficult to achieve through conventional in-situ leaching operation. The novel permeation-increasing and blockage-removing mining well system comprises a geological unit, a ground processing unit, a liquid injection permeation-increasing unit and a liquid pumping and blockage-removing unit. Forming permeation enhancing cracks and filter strips; the high-energy fluid flows to form a fracturing and permeability-increasing seam net; close cooperation of the four units is achieved, the mining efficiency of the low-permeability uranium mine reservoir is effectively improved, the uranium mine recovery cost is reduced, and green and sustainable development of resources is promoted.

Description

Technical Field

[0001] The present invention belongs to the field of uranium mining, and in particular relates to a system and method for increasing permeability and removing blockage in mining wells. Background Art

[0002] Sandstone-type uranium deposits are important nuclear material resources, and their mining and utilization have profound implications for national energy security and economic development. Compared to traditional uranium mining methods, in-situ leaching has gradually become the mainstream method for uranium mine development, due to its advantages such as high economic benefits, minimal environmental impact, and high resource utilization. In the mining of sandstone-type uranium deposits, in-situ leaching has been widely used, as it effectively improves uranium recovery rates and reduces costs. However, in-situ leaching of sandstone-type uranium deposits often faces problems such as decreased permeability and channel blockage, which directly affect the fluidity of the leachate and the efficiency of uranium dissolution. Due to the physical properties of sandstone and the complex ore body structure, conventional in-situ leaching operations often fail to achieve the desired results. Therefore, the development of a new permeability enhancement and blockage removal technology is particularly important.

[0003] Currently, in-situ leaching wells for sandstone-type uranium deposits primarily involve injecting a leaching agent into the formation through a liquid injection device, attempting to chemically react it with the uranium in the ore body, and then collecting the liquid through a pumping device. While these measures have improved mining efficiency to a certain extent, they still cannot effectively solve problems such as uneven fluid distribution within the formation and blockage of liquid channels.

[0004] Therefore, there is an urgent need for a new type of permeability-enhancing and plug-removing mining well and its application method, capable of achieving more efficient permeability enhancement and plug-removal under realistic formation conditions. This new type of mining well must not only possess excellent fluid transport capabilities but also form effective leaching pathways within the formation to enable sustained and efficient uranium mining. The development and application of this new type of permeability-enhancing and plug-removing mining well will provide important technical support for the efficient mining of sandstone-type uranium deposits and promote the sustainable development of uranium resources. Summary of the Invention

[0005] 1. Purpose

[0006] The purpose of the present invention is to propose a new type of permeability-enhancing and blockage-removing mining well system, which realizes fracturing and permeability enhancement of low-permeability uranium reservoirs based on a liquid injection permeability-enhancing unit. The system precisely injects leaching liquid to enhance the permeability of the ore layer and improve the recoverability of uranium. At the same time, the liquid extraction and blockage-removing unit is used to provide a solution to precipitation blockage for the actual formation environment on site, ensuring the smooth flow of fluid. The ground processing unit can not only continuously supply high-quality fracturing fluid, but also convert it into high-energy fluid for use in jet fracture creation. In this way, the mining cost of resources is effectively reduced, while the mining efficiency of low-permeability uranium reservoirs is significantly improved, promoting the safe, green and efficient use of uranium resources.

[0007] 2. Technical solution

[0008] A novel permeability enhancement and blockage removal mining well system comprises a geological unit, a ground processing unit, a liquid injection permeability enhancement unit, and a liquid pumping and blockage removal unit; the geological unit comprises a surface layer and a uranium ore reservoir; the ground processing unit comprises a water pump truck, a high-pressure fracturing device, and a jet trustee, and the high-pressure fracturing device is installed above the water pump truck; the liquid injection permeability enhancement unit comprises an injection well, an injection well casing, a column well plug, a jet plug, a jet window, a positive pressure flat-mouth screen pipe, and a fracturing and permeability enhancement seam network, the injection well casing is arranged on the outer wall of the injection well, and the column well plug is installed at the inner bottom of the injection well; the liquid pumping and blockage removal unit comprises a pumping well, a pumping well casing, a negative pressure funnel-mouth screen pipe, gravel, and a filled filter stone hole; the ground processing unit is located above the ground, the injection well in the liquid injection permeability enhancement unit and the pumping well in the pumping and blockage removal unit pass through the surface layer of the geological unit and penetrate into the uranium ore reservoir.

[0009] One end of the high-pressure fracturing device generates high-energy fluid with a water pump truck, and the other end is connected to a jet tube.

[0010] The injection well is connected to the high-pressure fracturing device through the jet hosting, and the column well plug controls the injection of liquid; the jet plug is cylindrical, with a circular hole on the side, and is placed in the cylindrical column well plug.

[0011] The liquid passes through the jet plug and the positive pressure flat screen pipe into the jet window to cause fracturing and permeability enhancement, forming a wide range of fracturing and permeability enhancement seam networks.

[0012] The outer wall of the pumping well is equipped with the pumping well casing, the negative pressure funnel mouth screen pipe is installed at the bottom of the pumping well, the outer wall of the negative pressure funnel mouth screen pipe contacts the gravel to form a filter belt; the filling filter stone hole is filled with gravel.

[0013] A novel permeability enhancement and blockage removal method for production wells comprises: step one: carrying out preparatory work; step two: forming permeability enhancement fractures and filter zones; step three: high-energy fluid flow to form a fracture-induced permeability enhancement fracture network; and step four: extracting the leachate after dissolution.

[0014] Step 1: Carry out preparatory work, drill the pumping well and injection well, arrange the pumping well casing and injection well casing, and provide a basis for subsequent injection and pumping operations.

[0015] Step 2: Forming permeability-enhancing cracks and filter zones; performing preset jet windowing in the uranium reservoir at the bottom of the injection well to ensure that the injection liquid effectively enters the uranium reservoir and permeability-enhancing cracks are formed; setting the filling filter stone hole at the bottom of the pumping well and filling it with gravel to form a filter zone.

[0016] Step 3: High-energy fluid flows to form a fracture-inducing and permeability-enhancing fracture network; a positive-pressure flat-mouth screen pipe and a negative-pressure funnel-mouth screen pipe are respectively set on the outer walls of the bottom of the pumping well and the injection well, and a column well plug is installed in the pumping well at the same time, the upper end of the column well plug is connected to the jet tube, and the lower end is installed with a jet plug; the high-energy fluid is controlled by the column well plug and introduced into the jet plug, and the positive-pressure flat-mouth screen pipe is injected into the jet window to form the fracture-inducing and permeability-enhancing fracture network in the uranium reservoir.

[0017] Step 4: After dissolution, the leachate is extracted and injected into the injection well, and in-situ leaching is achieved using a fracture-inducing and permeability-enhancing fracture network; the leachate reacts chemically with the uranium ore to dissolve the uranium element in the ore; the extraction well extracts the leachate through negative pressure to bring out the dissolved uranium minerals; the negative pressure funnel mouth screen prevents fine particles from entering the extraction liquid, and the gravel filled in the filter stone hole effectively filters out large particles of impurities.

[0018] After the fracturing in-situ leaching of the uranium ore reservoir in one area is completed, the next area of ​​the uranium ore reservoir is entered and steps 1 to 4 are repeated.

[0019] The present invention has the following advantages:

[0020] 1. The novel permeability enhancement and blockage removal mining well system proposed in the present invention includes a liquid injection permeability enhancement unit and a liquid extraction and blockage removal unit. The liquid injection permeability enhancement unit achieves fracture-induced permeability enhancement of the low-permeability uranium ore reservoir by precisely injecting leaching liquid, significantly improving the permeability of the ore layer, thereby improving the mineability of uranium.

[0021] 2. The pumping and unblocking unit provides an efficient unblocking solution for the sedimentation blockage problem in the actual formation environment on site, ensuring the smooth flow of fluids and reducing the downtime losses caused by blockage.

[0022] 3. The ground processing unit can continuously supply high-quality fracturing fluid and convert it into high-energy fluid for jet fracture creation, further forming a fracture network, which not only effectively reduces mining costs but also significantly improves the mining efficiency of low-permeability uranium reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the overall diagram of the system;

[0024] Figure 2 Detailed diagram of the liquid injection and permeation unit in the system;

[0025] Figure 3 Detailed diagram of the pumping and unblocking unit in the system;

[0026] Description of the accompanying drawings: 1-1. Surface layer; 1-2. Uranium reservoir; 2-1. Water pump truck; 2-2. High-pressure fracturing device; 2-3. Jet trustee; 3-1. Pumping well; 3-2. Pumping well casing; 3-3. Negative pressure funnel mouth gravel; 3-4. Gravel; 3-5. Filling filter stone hole; 4-1. Injection well; 4-2. Injection well casing; 4-3. Column well plug; 4-4. Jet plug; 4-5. Jet window; 4-6. Positive pressure flat-mouth screen; 4-7. Fracturing and permeability enhancement seam network. DETAILED DESCRIPTION

[0027] Combine Figure 1 、 Figure 2 、 Figure 3 As shown, a new type of permeability enhancement and blockage removal mining well system includes a geological unit, a ground processing unit, a liquid injection permeability enhancement unit, and a liquid pumping and blockage removal unit. Through the close cooperation of the four units, the permeability enhancement and blockage removal of low-permeability uranium reservoirs are completed, thereby improving the mining efficiency of uranium mines.

[0028] In the geological unit, the uranium reservoir 1-2 is located below the surface layer 1-1.

[0029] In the surface processing unit, the pump truck 2-1 provides high-pressure fluid to the system, which is converted into high-energy fluid by the high-pressure fracturing device 2-2. The high-energy fluid is precisely delivered to the injection well through the jet tube 2-3 for jet fracture creation, expanding the fracture network.

[0030] In the liquid injection and permeation enhancement unit, the injection well 4-1 is provided with an injection well casing 4-2 on its outer wall, and a well plug 4-3 is installed within the injection well. The injection well 4-1 is connected to the high-pressure fracturing device 2-2 via a jet tube 2-3. The well plug 4-3 controls the injection of liquid, which flows through the jet plug 4-4 ​​and into the jet window 4-5, forming a permeation-enhancing fracture. A positive pressure flat screen 4-6 ensures that the injected fracturing liquid efficiently spreads into the ore layer.

[0031] In the pumping and unblocking unit, the outer wall of the pumping well 3-1 is fitted with the pumping well casing 3-2. The negative pressure funnel screen 3-3 is installed at the bottom of the well. The outer wall of the screen contacts the gravel 3-4 to form a filter belt. The gravel filling cavity 3-5 is filled with gravel to effectively prevent sediment from clogging the system and ensure the smooth flow of the leachate.

[0032] The specific steps are as follows:

[0033] a. In actual engineering, the pumping well 3-1 and the injection well 4-1 are drilled, and the pumping well casing 3-2 and the injection well casing 4-2 are arranged to provide a basis for subsequent injection and pumping operations.

[0034] b. Jet windows 4-5 are created at the bottom of the injection well to ensure that the injection liquid can effectively enter the uranium reservoir 1-2, thereby forming permeability-enhancing fractures. Simultaneously, a filling filter hole 3-5 is provided at the bottom of the extraction well 3-1 and filled with gravel 3-4 to form an effective filter zone.

[0035] c. The water pump truck 2-1 converts the liquid fracturing fluid into high-energy fluid through the high-pressure fracturing device 2-2. The high-energy fluid is transported to the injection well 4-1 through the jet tube 2-3.

[0036] d. The high-energy fluid is controlled through the column well plug 4-3 and introduced into the jet plug 4-4, and then injected into the jet window 4-5 through the positive pressure flat screen pipe 4-6, forming the fracture-inducing and permeability-enhancing fracture network 4-7 in the uranium reservoir 1-2, thereby improving the permeability of the ore layer.

[0037] e. Leaching liquid is injected into the injection well 4-1, and in-situ leaching is achieved using the fracture-inducing and permeability-enhancing fracture network 4-7. The leachate chemically reacts with the uranium ore, dissolving the uranium in the ore. The extraction well 3-1 extracts the leachate using negative pressure, removing the dissolved uranium minerals. The negative pressure funnel screen 3-3 prevents fine particles from entering the extraction liquid, and the gravel 3-4 in the filter stone filling hole 3-5 effectively filters large impurities.

[0038] f. After completing uranium mining in a certain area, the system can enter the next area and repeat steps a to e to continue permeation and solution mining.

[0039] The above embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineers and technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A permeability enhancement and blockage removal system for production wells, characterized by: The invention comprises a geological unit, a ground processing unit, a liquid injection and permeability enhancement unit, and a liquid pumping and unblocking unit; the geological unit comprises a surface layer (1-1) and a uranium reservoir (1-2); the ground processing unit comprises a water pump truck (2-1), a high-pressure fracturing device (2-2), and a jet trustee (2-3); the high-pressure fracturing device (2-2) is installed above the water pump truck (2-1); the liquid injection and permeability enhancement unit comprises an injection well (4-1), an injection well casing (4-2), a column well plug (4-3), a jet plug (4-4), a jet window (4-5), a positive pressure flat screen pipe (4-6), a fracturing and permeability enhancement seam network (4-7), the injection well casing (4-2) is provided on the outer wall of the injection well (4-1), and the column well plug (4-3) is installed at the inner bottom of the injection well (4-1); the pumping and unblocking unit comprises a pumping well (3-1), a pumping well casing (3-2), a negative pressure funnel mouth screen pipe (3-3), gravel (3-4), and a filling filter stone hole (3-5); the ground processing unit is located above the ground, the injection well (4-1) in the injection and permeability enhancement unit and the pumping well (3-1) in the pumping and unblocking unit pass through the surface layer (1-1) of the geological unit and penetrate into the uranium reservoir (1-2).

2. The permeability enhancement and blockage removal production well system according to claim 1, characterized in that: One end of the high-pressure fracturing device (2-2) generates high-energy fluid with the water pump truck (2-1), and the other end is connected to the jet tube (2-3).

3. The permeability enhancement and blockage removal production well system according to claim 1, characterized in that: The injection well (4-1) is connected to the high-pressure fracturing device (2-2) through the jet trustee (2-3), and the column well plug (4-3) controls the injection of liquid; the jet plug (4-4) is cylindrical, with a circular hole on the side, and is placed in the cylindrical column well plug (4-3).

4. The permeability enhancement and blockage removal production well system according to claim 3, characterized in that: The liquid passes through the jet plug (4-4) and the positive pressure flat screen pipe (4-6) and enters the jet window (4-5), causing fracturing and permeability enhancement, thereby forming a wide fracturing and permeability enhancement fracture network.

5. The permeability enhancement and blockage removal production well system according to claim 1, characterized in that: The outer wall of the pumping well (3-1) is provided with the pumping well casing (3-2), a negative pressure funnel mouth screen pipe (3-3) is installed at the bottom of the pumping well (3-1), the outer wall of the negative pressure funnel mouth screen pipe (3-3) contacts the gravel (3-4) to form a filter belt; the filling filter stone hole (3-5) is filled with gravel (3-4).

6. A method for increasing permeability and removing blockage in production wells, characterized by: Step 1: Carry out preparatory work; Step 2: Form permeability-enhancing cracks and filter zones; Step 3: High-energy fluid flows to form a fracture-inducing permeability-enhancing crack network; Step 4: Extract the leachate after dissolution.

7. A method for increasing permeability and removing blockage in production wells according to claim 6, characterized in that: Step 1: Carry out preparatory work, drill the pumping well (3-1) and the injection well (4-1), and arrange the pumping well casing (3-2) and the injection well casing (4-2) to provide a basis for subsequent injection and pumping operations.

8. A method for increasing permeability and removing blockage in production wells according to claim 6, characterized in that: Step 2: forming a permeability-enhancing crack and a filter zone; performing a preset jet windowing in the uranium reservoir at the bottom of the injection well (4-1) to ensure that the injection liquid effectively enters the uranium reservoir (1-2), thereby forming a permeability-enhancing crack; setting the filling filter stone hole (3-5) at the bottom of the pumping well (3-1), and filling gravel (3-4) to form a filter zone.

9. A method for increasing permeability and removing blockage in production wells according to claim 6, characterized in that: Step 3: High-energy fluid flows to form a fracture-increasing fracture network; a positive-pressure flat-mouth screen pipe (4-6) and a negative-pressure funnel-mouth screen pipe (3-3) are respectively arranged on the outer walls of the bottom of the pumping well (3-1) and the injection well (4-1); at the same time, a column well plug (4-3) is installed in the pumping well (3-1); the upper end of the column well plug is connected to the jet tube (2-3), and the lower end is installed with a jet plug (4-4); the high-energy fluid is controlled by the column well plug (4-3) and introduced into the jet plug (4-4), and the positive-pressure flat-mouth screen pipe (4-6) is injected into the jet window (4-5), so that the fracture-increasing fracture network (4-7) is formed in the uranium reservoir (1-2).

10. A method for increasing permeability and removing blockage in production wells according to claim 6, characterized in that: Step 4: After dissolution, the leachate is extracted, and the leachate is injected into the injection well (4-1), and in-situ leaching is achieved using the fracture-inducing and permeability-enhancing seam network (4-7); the leachate reacts chemically with the uranium ore to dissolve the uranium element in the ore; the extraction well (3-1) extracts the leachate through negative pressure to carry out the dissolved uranium minerals; the negative pressure funnel mouth screen tube (3-3) prevents fine particles from entering the extracted liquid, and the gravel (3-4) filled in the filter stone hole (3-5) effectively filters large particles of impurities.

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