Microwave radiation-pulse water pressure combined permeation enhancing device and method for low-permeability sandstone uranium ore

Abstract

The invention discloses a low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeation enhancing device, and relates to the technical field of uranium mine mining, the low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeation enhancing device comprises a microwave radiation mechanism, a sealing mechanism and a high-pressure pulse water injection mechanism, a microwave radiator is connected with a microwave antenna through a waveguide tube, and the microwave antenna is used for extending into a drilling well; the upper packer and the lower packer can be located in a drilling well and seal the space between the upper packer and the lower packer, a water conveying pipe of the high-pressure pulse water injection mechanism penetrates through the upper packer and reaches the position between the upper packer and the lower packer, and the microwave antenna is located between the upper packer and the lower packer. The invention further discloses a low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeation enhancing method which is implemented by adopting the low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeation enhancing device. According to the invention, a large-range fracture network with good uniformity can be formed in the ore rock layer, so that the permeability of the sandstone uranium ore layer is increased and the anisotropic permeability coefficient is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of uranium mining, in particular to a device and method for increasing the permeability of low-permeability sandstone uranium ore by microwave radiation and pulse water pressure. Background Art

[0002] The poor permeability of low-permeability sandstone uranium ore is a key issue restricting in-situ leaching mining. Existing permeability enhancement technologies (such as hydraulic fracturing and blasting permeability enhancement) are prone to forming local dominant cracks, resulting in uneven penetration of the leachate in the ore rock layer. Taking blasting permeability enhancement technology as an example, its main problem in practical application is equivalent control; when the blasting equivalent is too large, the strong impact can easily cause the pumping well wall to become unstable or even collapse, seriously affecting the normal circulation of the subsequent leaching solution; and when the equivalent is too small, although the well wall can be kept stable, the permeability enhancement effect is limited, and it is difficult to form an effective seepage channel network in the target area. Microwave radiation technology can induce a large number of uniform microcracks in the well wall, but the range of crack expansion under the action of microwave radiation is limited; high-pressure pulse water pressure can achieve a larger range of crack expansion, but the uniformity of crack expansion is significantly restricted by the initial crack distribution characteristics of the ore rock. Therefore, there is an urgent need for a low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device and method to solve the above-mentioned technical problems. Summary of the Invention

[0003] The purpose of the present invention is to provide a low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeability enhancement device and method to solve the problems existing in the above-mentioned prior art. It can combine the advantages of uniform crack distribution caused by microwave radiation and a large crack range expanded by pulse water pressure to form a large-scale and well-uniform crack network in the ore rock layer, thereby increasing the permeability of the sandstone uranium ore layer and reducing the anisotropic permeability coefficient.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a microwave radiation-pulse water pressure combined permeability enhancement device for low-permeability sandstone uranium mines, comprising a microwave radiation mechanism, a sealing mechanism and a high-pressure pulse water injection mechanism, wherein the microwave radiation mechanism comprises a microwave radiator and a microwave antenna, wherein the microwave radiator is connected to the microwave antenna via a waveguide tube, and the microwave antenna is used to extend into a wellbore, the sealing mechanism comprises an upper packer and a lower packer, wherein the upper packer and the lower packer can be located in the wellbore and seal the space between the upper packer and the lower packer, a water pipe of the high-pressure pulse water injection mechanism passes through the upper packer and reaches between the upper packer and the lower packer, the microwave antenna is located between the upper packer and the lower packer, the microwave radiation mechanism is used to generate uniform microcracks, and the high-pressure pulse water injection mechanism is used to extend the uniform microcracks generated by the microwave radiation mechanism into the ore rock.

[0006] In some embodiments, it also includes a base and a holding column, the base is fixedly set on the ground, the holding column is set on the base, and the holding column can be extended into the well, the axis of the holding column is parallel to the axis of the well, the base can drive the holding column to rise and fall or rotate, and the waveguide tube and the microwave antenna can pass through the holding column and extend between the upper packer and the lower packer.

[0007] In some embodiments, the upper packer and the lower packer are fixedly connected by an inner connecting rod, the upper packer is fixedly connected to the bottom of the holding column, the sealing mechanism also includes a pumping mechanism and a connecting pipe, the connecting pipe connects the pumping mechanism, the upper packer and the lower packer in sequence, the upper packer and the lower packer both include a sealing groove and a sealing ring, the sealing ring is arranged in the sealing groove in a sliding sealing manner, and the pumping mechanism can inject liquid into the sealing groove through the connecting pipe.

[0008] In some embodiments, a sensing rod is further included, which is connected to the inner connecting rod through a transmission device. The transmission device can drive the sensing rod radially closer to or away from the inner connecting rod. A temperature sensor is provided on the side of the sensing rod away from the inner connecting rod, and the temperature sensor is used to monitor the temperature of the drilling well wall.

[0009] In some embodiments, it also includes an elastic member and a pressure sensor, the pressure sensor is fixedly connected to a side of the sensing rod away from the inner connecting rod, the two ends of the elastic member are respectively fixedly connected to the pressure sensor and the temperature sensor, the transmission device includes a telescope and an X-shaped arm, the sensing rod is axially provided with a first slide groove, the inner connecting rod is axially provided with a second slide groove, the top and bottom of the second slide groove are both provided with the telescope, the X-shaped arm includes a first connecting rod and a second connecting rod, the middle parts of the first connecting rod and the second connecting rod are hinged, the first end of the first connecting rod and the first end of the second connecting rod are both extended into the second slide groove and respectively connected to the telescope at the top and the telescope at the bottom, the second end of the first connecting rod and the second end of the second connecting rod are both slidably set in the first slide groove.

[0010] In some embodiments, the microwave radiation mechanism further includes a microwave protective tube, which is fixedly mounted on the outer circumference of the waveguide tube and the microwave antenna.

[0011] In some embodiments, the high-pressure pulse water injection mechanism includes a pulse controller, a high-pressure pulse pump and a water pipe. The pulse controller is electrically connected to the high-pressure pulse pump, and the high-pressure pulse pump is connected to the water pipe.

[0012] In some embodiments, a microseismic server, a central control system, a pressure recorder, and a temperature recorder are also included. The pressure recorder is electrically connected to the pressure sensor signal, and the temperature recorder is electrically connected to the temperature sensor signal. The microseismic server is used to track the crack generation and expansion path. The microseismic server, the pressure recorder, the temperature recorder, the pulse controller, the microwave radiator, and the pumping mechanism are all electrically connected to the central control system signal.

[0013] In some embodiments, the wellbore further comprises a geophone, which is disposed on the ground and is evenly distributed around the circumference of the wellbore. The geophone is used to capture microseismic signals of fracture formation and expansion.

[0014] The present invention also provides a method for increasing the permeability of low-permeability sandstone uranium ore by microwave radiation and pulse water pressure, comprising the following steps:

[0015] Step 1: Drill vertically downward from the ground through the overburden, ore layer and bottom rock layer, clean the well wall debris, and the drilling position and well diameter are determined according to the location of the injection hole in the in-situ leaching mining process; arrange the detectors to form a detector array;

[0016] Step 2: Lower the permeability enhancement device into the well and adjust the position of the permeability enhancement device by controlling the holding column;

[0017] Step 3: Adjust the position of the sensing rod so that the temperature sensor is close to the well wall, and check whether it is close by using the pressure sensor;

[0018] Step 4: Turn on the microwave radiator to radiate microwaves to the wellbore wall. At the same time, the temperature sensor and detector transmit the wellbore wall temperature and crack conditions back to the central control system. The central control system dynamically adjusts the power and loading time of the microwave radiator until the wellbore wall crack density reaches the target level and is evenly distributed. The microwave radiator is turned off. The microwave radiator is intermittent. When the wellbore wall temperature rises to 300°C, the microwave radiation stops. When the temperature drops to 150°C, the microwave radiation starts again.

[0019] Step 5: Start the pumping mechanism and inject pressure liquid into the sealing groove to make the sealing ring close to the well wall, maintain the hydraulic pressure of the sealing groove, and achieve the purpose of sealing the space between the upper packer and the lower packer;

[0020] Step 6: Start the high-pressure pulse pump and apply stepped pulse water pressure to the space between the upper and lower packers, causing the evenly distributed microcracks on the wellbore wall to expand into the rock. Use microseismic signals to track the extension of the cracks until they reach the target range, then turn off the high-pressure pulse pump.

[0021] Step 7: Adjust the position of the sensing rod so that the temperature sensor is away from the well wall; turn off the pumping mechanism and rotate the holding column so that the sealing ring is away from the well wall;

[0022] Step 8: Adjust the position of the permeability enhancement device and repeat the above steps from bottom to top until the mineral strata are completely affected.

[0023] Compared with the prior art, the present invention has achieved the following technical effects:

[0024] The present invention provides a microwave radiation-pulse water pressure combined permeability enhancement device and method for low-permeability sandstone uranium mines. A microwave radiation mechanism is first used to generate a large number of uniform microcracks, and then the space between the upper packer and the lower packer is sealed. After sealing, a high-pressure pulse water injection mechanism is used to inject high-pressure pulse water into the sealed space, so that a large number of uniform microcracks are uniformly expanded to a larger range inside the ore rock, and a large-scale fracture network with good uniformity can be formed in the ore rock layer, so that the permeability of the sandstone uranium ore layer is increased and the anisotropic permeability coefficient is reduced. Low-permeability sandstone uranium mines often have anisotropy of permeability coefficient due to geological structure, which affects the subsequent mining efficiency (such as uneven distribution of leachate). The synergistic effect of microwaves and high-pressure pulse water can break the original directional structural limitations: the microcracks generated by microwaves have no obvious directionality, and the high-pressure pulse water applies uniform pressure in the sealed space, so that the cracks expand evenly in all directions, thereby weakening the original anisotropy, making the permeability coefficients of the ore rock layer in different directions closer, and improving the circulation stability of the leachate during the mining process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 Schematic diagram of the structure of a microwave radiation-pulse water pressure combined permeability enhancement device for low-permeability sandstone uranium ore in some embodiments of the present invention;

[0027] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0028] Figure 3 for Figure 2 Cross-sectional view at point Ⅰ;

[0029] Figure 4 Schematic diagram of a five-point well drilling arrangement and eight-station layout for geophones in some embodiments of the present invention.

[0030] In the figure: 1-base; 2-holding column; 3-microwave radiator; 4-waveguide tube; 5-microwave antenna; 6-microwave protective tube; 7-water pipe; 8-high-pressure pulse pump; 9-pulse controller; 10-microseismic server; 11-pressure recorder; 12-temperature recorder; 13-pumping mechanism; 14-central control system; 15-signal transmission line; 16-upper packer; 17-lower packer; 18-connecting pipe; 19-sealing groove; 20-sealing ring; 21-inner connecting rod; 22-X-arm; 23-sensing rod; 24-second slide; 25-expansion device; 26-first slide; 27-groove; 28-pressure sensor; 29-elastic member; 30-detector; 31-temperature sensor; 32-drilling; 33-overburden; 34-ore rock layer; 35-bottom rock layer. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] The purpose of the present invention is to provide a low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeability enhancement device and method to solve the problems existing in the prior art. It can combine the advantages of uniform crack distribution caused by microwave radiation and a large crack range expanded by pulse water pressure to form a large-scale and well-uniform crack network in the ore rock layer, thereby increasing the permeability of the sandstone uranium ore layer and reducing the anisotropic permeability coefficient.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] like Figure 1-Figure 4As shown, the present invention provides a low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeability enhancement device, including a microwave radiation mechanism, a sealing mechanism and a high-pressure pulse water injection mechanism. The microwave radiation mechanism includes a microwave radiator 3 and a microwave antenna 5. The microwave radiator 3 and the microwave antenna 5 are connected by a waveguide tube 4. The microwave antenna 5 is used to extend into the wellbore 32. The sealing mechanism includes an upper packer 16 and a lower packer 17. The upper packer 16 and the lower packer 17 can be located in the wellbore 32 and seal the space between the upper packer 16 and the lower packer 17. The water pipe 7 of the high-pressure pulse water injection mechanism passes through the upper packer 16 and reaches between the upper packer 16 and the lower packer 17. The microwave antenna 5 is located between the upper packer 16 and the lower packer 17. The microwave radiation mechanism is used to generate uniform microcracks, and the high-pressure pulse water injection mechanism is used to extend the uniform microcracks generated by the microwave radiation mechanism into the ore rock. First, a large number of uniform micro-cracks are generated using a microwave radiation mechanism, and then the space between the upper packer 16 and the lower packer 17 is sealed. After sealing, a high-pressure pulse water injection mechanism is used to inject high-pressure water into the sealed space, so that a large number of uniform micro-cracks are uniformly expanded to a larger range inside the ore rock, and a large-scale, well-uniform fracture network can be formed in the ore rock layer 34, thereby increasing the permeability of the sandstone uranium ore layer and reducing the anisotropic permeability coefficient. Low-permeability sandstone uranium ore often has anisotropy of permeability coefficient (large difference in permeability in different directions) due to geological structures (such as bedding and joints), which affects the subsequent mining efficiency (such as uneven distribution of leachate). The synergistic effect of microwaves and high-pressure pulse water can break the original directional structural limitations: the micro-cracks generated by microwaves have no obvious directionality, and the high-pressure pulse water applies uniform pressure in the sealed space, causing the cracks to expand evenly in all directions, thereby weakening the original anisotropy, making the permeability coefficients of the ore rock layer in different directions closer, and improving the flow stability of the leachate during the mining process.

[0036] In some embodiments, the low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeability enhancement device also includes a base 1 and a holding column 2. The base 1 is fixedly set on the ground, the holding column 2 is set on the base 1, and the holding column 2 can be extended into the borehole 32. The axis of the holding column 2 is parallel to the axis of the borehole. The base 1 can drive the holding column 2 to rise and fall or rotate. The waveguide tube 4 and the microwave antenna 5 can pass through the holding column 2 and extend between the upper packer 16 and the lower packer 17. The water pipe 7 of the high-pressure pulse water injection mechanism can pass through the holding column 2 and extend between the upper packer 16 and the lower packer 17. The axis of the holding column 2 is parallel to the axis of the wellbore 32 and can be extended into the wellbore 32 under the drive of the base 1, providing rigid support and guide channels for the microwave antenna 5, waveguide tube 4 and high-pressure pulse water pipe 7, ensuring that the microwave antenna 5 and the water pipe 7 always operate in the vertical or preset direction of the target mineral layer after entering the wellbore 32, avoiding position deviation caused by equipment shaking (such as ground vibration, friction on the wellbore 32 wall), and ensuring that the action points of microwave radiation and high-pressure pulse water injection are precisely corresponding to the sealed space (between the upper packer 16 and the lower packer 17). The base 1 is fixed to the ground and can evenly transfer the weight of equipment such as the microwave radiation mechanism and the high-pressure pulse water injection mechanism to the ground, avoiding sinking or tilting caused by the weight of the equipment. The base 1 can drive the holding column 2 to rise and fall, which means that the microwave antenna 5 and the water pipe 7 can flexibly adjust the length of the extension into the wellbore 32 according to the depth of the target mineral layer. Whether it is a shallow or deeper low-permeability sandstone uranium ore layer, the operating parts can be sent into the sealed space through the lifting function, without the need to replace equipment of different lengths, thereby improving the adaptability of the device to different mining depths.

[0037] In some embodiments, the upper packer 16 and the lower packer 17 are fixedly connected by an inner connecting rod 21. The upper packer 16 is fixedly connected to the bottom of the holding column 2. The sealing mechanism also includes a pumping mechanism 13 and a connecting pipe 18. The connecting pipe 18 connects the pumping mechanism 13, the upper packer 16, and the lower packer 17 in sequence. The upper packer 16 and the lower packer 17 each include a sealing groove 19 and a sealing ring 20. The sealing ring 20 is disposed in the sealing groove 19 in a sliding seal manner. The pumping mechanism 13 can inject fluid into the sealing groove 19 through the connecting pipe 18. It should be noted that the sealing ring 20 is preferably made of perfluoroether rubber. The spacing between the upper packer 16 and the lower packer 17 is 0.5-1m (i.e., the height of the inner connecting rod 21). The upper packer 16 and the lower packer 17 are fixed by the inner connecting rod 21, which can strictly ensure that the spacing and relative position between them remain unchanged. When working in the well 32 (such as the lifting and lowering of the holding column 2, the impact of high-pressure pulse water or slight deformation of the ore and rock formations), the sealing space range is prevented from being offset due to the misalignment of the packer, ensuring that the action area of ​​microwave radiation and high-pressure pulse water always accurately locks the target ore and rock section, thereby improving the targeted operation. The upper packer 16 is fixed to the bottom of the holding column 2, so that the sealing mechanism and the holding column 2 form a rigid whole. When the holding column 2 is lifted or rotated, the packer can synchronously follow the adjustment position and will not shake due to its own gravity or downhole pressure, further strengthening the stability of the sealing space and reducing the risk of sealing failure due to equipment displacement. The pumping mechanism 13 injects liquid (such as high-pressure oil) into the sealing groove 19 through the connecting pipe 18, pushing the sealing ring 20 to slide outward along the sealing groove 19 to fit tightly against the wall of the well 32 and expand up and down under compression until the target hydraulic pressure is stably maintained. The pumping mechanism 13 is preferably an oil pump that pumps high-pressure oil into the sealing groove 19.

[0038] In some embodiments, the combined microwave radiation and pulsed hydraulic pressure permeability enhancement device for low-permeability sandstone uranium deposits further includes a sensing rod 23 connected to an inner connecting rod 21 via a transmission mechanism. The transmission mechanism can drive the sensing rod 23 radially toward or away from the inner connecting rod 21. A temperature sensor 31 is provided on the side of the sensing rod 23 facing away from the inner connecting rod 21. The temperature sensor 31 is used to monitor the temperature of the wellbore wall. The temperature sensor 31 on the sensing rod 23 is in direct contact with the wellbore wall (adjusted to its position by the transmission mechanism). It can collect temperature data of the ore within the space (between the upper and lower packers 16 and 17), providing a direct reflection of the intensity of the microwave radiation. Temperature monitoring can be used to determine whether the ore has reached the desired thermal damage state (e.g., whether the temperature gradient is uniform, and whether there is overheating or hypothermia). Microwave power and radiation duration can be adjusted promptly to avoid insufficient microwave action leading to a lack of initial cracks, or excessive heating leading to localized melting and pore blockage. The transmission device can drive the sensing rod 23 to move radially (closer to or away from the inner connecting rod 21), so that the temperature sensor 31 can flexibly adjust its position according to the actual diameter of the drilling well (for example, sandstone drilling 32 may have local expansion or contraction of the diameter or uneven well wall due to uneven lithology), ensuring that the sensor always fits closely to the well wall, avoiding temperature measurement errors caused by poor contact (for example, when the sensor is suspended in the air, it is affected by air and the data is distorted).

[0039] In some embodiments, the low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeability enhancement device also includes an elastic member 29 and a pressure sensor 28. The pressure sensor 28 is fixedly connected to the side of the sensing rod 23 away from the inner connecting rod 21. The two ends of the elastic member 29 are respectively fixedly connected to the pressure sensor 28 and the temperature sensor 31. Specifically, a groove 27 is also provided on the sensing rod 23. The elastic member 29 and the pressure sensor 28 are arranged in the groove 27. The transmission device includes a telescopic device 25 and an X-shaped arm 22. The sensing rod 23 is axially provided with a first slide groove 26. The inner connecting rod 21 is axially provided with a second slide groove 24. The top and bottom of the second slide groove 24 are both provided with telescopic devices (electrically controlled). The X-shaped arm 22 includes a first connecting rod and a second connecting rod. The middle parts of the first connecting rod and the second connecting rod are hinged. The first end of the first connecting rod and the first end of the second connecting rod both extend into the second slide groove 24 and are respectively connected to the telescopic device 25 at the top and the telescopic device 25 at the bottom. The second end of the first connecting rod and the second end of the second connecting rod are both slidably arranged in the first slide groove 26. Elastic member 29 connects pressure sensor 28 and temperature sensor 31. When sensing rod 23 approaches the wellbore wall, elastic member 29 compresses due to the reaction force of the wellbore wall, allowing pressure sensor 28 to monitor contact pressure in real time. By adjusting the transmission mechanism to maintain pressure within a reasonable range (e.g., ensuring that temperature sensor 31 is tightly attached to the wellbore wall to reduce thermal resistance while avoiding damage to the sensor due to excessive pressure), measurement errors caused by poor contact (e.g., gaps caused by uneven wellbore walls) with conventional temperature sensor 31 can be resolved, ensuring that temperature data truly reflects the actual state of the ore. X-shaped arm 22 is hingedly connected by a first and second connecting rod. Through the synchronous extension and retraction of the top and bottom telescoping members 25 (e.g., when the telescoping member 25 extends, the angle of the X-shaped arm 22 increases, pushing sensing rod 23 outward; when the telescoping member 25 shortens, the angle of the X-shaped arm 22 decreases, driving sensing rod 23 inward), the sensing rod 23 can be smoothly and accurately moved radially toward or away from the inner connecting rod 21. Compared to traditional single-rod push-pull transmission, the symmetrical structure of the X-shaped arm 22 provides a more uniform radial thrust, ensuring that the sensing rod 23 moves without deflection, ensuring that the temperature sensor 31 always adheres perpendicularly to the wellbore wall. This is particularly suitable for local expansion, contraction, or irregular wellbore walls that may occur in low-permeability sandstone drilling. The elastic member 29 (such as a spring or elastic rubber) has a certain elastic deformation capacity. When the sensing rod 23 encounters a protrusion on the wellbore wall or is suddenly subjected to force (such as wellbore wall vibration caused by high-pressure pulse water impact) during movement, it can absorb the impact force through self-compression, avoiding wear or breakage caused by hard contact between the temperature sensor 31 and the wellbore wall, significantly extending the sensor's downhole service life.

[0040] It should be noted that there are two inner connecting rods 21 and two sensor rods 23, and the corresponding temperature sensor 31, pressure sensor 28, and X-shaped arm 22 structures are also provided with two sets. On the one hand, the structure is more stable, and on the other hand, the values ​​of the two sets of sensors can be verified with each other.

[0041] In some embodiments, the microwave radiation mechanism further includes a microwave protective tube 6, which is fixedly mounted around the outer periphery of the waveguide 4 and microwave antenna 5. Low-permeability sandstone uranium mines are subjected to high-pressure pulsed water in the drilling process. The interaction of microwave radiation and high-pressure pulsed water generates sandstone debris (such as quartz particles and clay minerals). The microwave protective tube 6 (typically made of high-pressure, corrosion-resistant materials such as specialty ceramics) forms a physical barrier, protecting the waveguide 4 and microwave antenna 5 from direct contact with water, debris, and corrosive media. This prevents component rust, clogging, or surface wear (such as deformation of the antenna oscillator by impact with debris), significantly extending their service life. The waveguide 4 is a critical channel for microwave transmission. If its outer wall comes into contact with water or humid air, changes in the dielectric medium may cause microwave reflection and scattering (i.e., energy leakage). The interior of the microwave protective tube 6 can be kept dry, ensuring that the waveguide 4 is always in a stable dielectric environment. This reduces microwave attenuation during transmission, allowing more energy to be effectively radiated to the ore layer through the microwave antenna 5, thereby improving the efficiency of microcrack generation.

[0042] In some embodiments, the high-pressure pulse water injection mechanism includes a pulse controller 9, a high-pressure pulse pump 8, and a water pipe 7. The pulse controller 9 is electrically connected to the high-pressure pulse pump 8, which is in turn connected to the water pipe 7. The high-pressure pulse pump 8 can provide pulse pressures far higher than those of conventional water injection, sufficient to overcome the dense structural resistance of low-permeability sandstone, allowing microwave-generated microcracks to break through the natural strength limitations of the ore rock and expand to deeper and wider areas. Simultaneously, the high-pressure pulse water flow can flush sandstone debris (such as quartz and feldspar particles) within the cracks, preventing debris deposition and clogging the channels, thereby ensuring the connectivity of the crack network.

[0043] In some embodiments, the low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeability enhancement device also includes a microseismic server 10, a central control system 14, a pressure recorder 11, and a temperature recorder 12. The pressure recorder 11 is electrically connected to the pressure sensor 28, and the temperature recorder 12 is electrically connected to the temperature sensor 31. The microseismic server 10 is used to track the crack expansion path. The microseismic server 10, the pressure recorder 11, the temperature recorder 12, the pulse controller 9, the microwave radiator 3, and the pumping mechanism 13 are all electrically connected to the central control system 14. The signal transmission line 15 used is a high-temperature and high-pressure resistant signal line. The central control system 14 integrates the crack tracking data of the microseismic server 10, the real-time monitoring data of the pressure recorder 11 and the temperature recorder 12, and the operating status of the pulse controller 9, the microwave radiator 3, and the pumping mechanism 13. Through a preset algorithm (such as parameter matching logic based on the ore-rock response model), the operation rhythm of each link can be automatically coordinated. For example, when the microcracks generated by microwave radiation reach a preset target, the microwaves are automatically stopped and the pumping mechanism 13 is started to seal; when the sealing pressure reaches the standard, the high-pressure pulse pump 8 is automatically triggered to inject water; when the microseismic monitoring shows that the crack expansion range reaches the standard, the high-pressure pulse pump 8 is automatically shut down.

[0044] In some embodiments, the low-permeability sandstone uranium mine microwave radiation-pulse water pressure combined permeability enhancement device also includes a detector 30, which is set on the ground, and a plurality of detectors 30 are evenly arranged around the circumference of the borehole, preferably eight are evenly arranged around the circumference. The core function of the detector 30 is to receive microseismic signals released when rock cracks are generated and expanded (i.e., microseismic signals generated by the generation and expansion of cracks caused by microwave radiation and high-pressure pulse water, including vibration waves generated by rock fracture and friction). Multiple detectors 30 are evenly arranged around the circumference of the borehole, and signals can be captured from different directions and angles. By comparing the time difference of the arrival of the microseismic signals and combining the known coordinates of the detector 30, the three-dimensional spatial position (depth, horizontal distance, azimuth) of the crack expansion can be inverted and calculated, thereby realizing the positioning of the generated and expanded cracks.

[0045] Example 2

[0046] The present invention also provides a method for increasing the permeability of low-permeability sandstone uranium ore by microwave radiation and pulse water pressure, comprising the following steps:

[0047] Step 1: Drilling a vertical well 32 from the ground downward through the overburden 33, the ore layer 34, and the bottom rock layer 35, clearing the well wall debris. The location and diameter of the well 32 are determined based on the location of the injection hole in the in-situ leaching mining process; arranging the detectors 30 to form a detector array 30;

[0048] Step 2: Lower the permeability enhancement device into the well 32 and adjust the position of the permeability enhancement device by controlling the holding column 2;

[0049] Step 3: Adjust the position of the sensing rod 23 so that the temperature sensor 31 is close to the well wall, and check whether it is close by the pressure sensor 28;

[0050] Step 4: Turn on the microwave radiator 3 to radiate microwaves to the wellbore wall. Simultaneously, the temperature sensor 31 and the detector 30 transmit the wellbore wall temperature and crack conditions back to the central control system 14. The central control system 14 dynamically adjusts the power and loading time of the microwave radiator 3 until the wellbore wall crack density reaches the target level and is evenly distributed. The microwave radiator 3 is then turned off. The microwave radiator 3 is intermittent microwave radiator. When the wellbore wall temperature rises to 300°C, the microwave radiation stops. When the temperature drops to 150°C, the microwave radiation starts again.

[0051] Step 5: Start the pumping mechanism 13 and inject pressure liquid into the sealing groove 19 to make the sealing ring 20 close to the well wall, maintain the hydraulic pressure of the sealing groove 19, and achieve the purpose of sealing the space between the upper packer 16 and the lower packer 17;

[0052] Step 6: Start the high-pressure pulse pump 8 and apply stepped pulse water pressure to the space between the upper packer 16 and the lower packer 17, so that the microcracks evenly distributed on the wellbore wall expand into the ore rock; use the microseismic signal to track the expansion range of the cracks until the cracks expand to the target range, and then turn off the high-pressure pulse pump 8;

[0053] Step 7: Adjust the position of the sensing rod 23 so that the temperature sensor 31 is away from the well wall; close the pumping mechanism 13 and rotate the holding column 2 so that the sealing ring 20 is away from the well wall;

[0054] Step 8: Adjust the position of the permeability enhancement device and repeat the above steps from bottom to top until the mineral rock layer 34 is fully acted on in sections.

[0055] Specific application examples:

[0056] a. Drilling was performed using a five-point well pattern, with the four corner wells 32 spaced 30 meters apart and the center well 32 located at the center of the four corner wells 32. A vertical well 32 (215 mm diameter) was drilled downward from the surface through the overburden 33, the ore layer 34, and the floor stratum 35, clearing debris from the wellbore. Eight geophones 30 were deployed on the ground using an eight-station layout, with the projection of the well 32 on the ground serving as the coordinate origin.

[0057] b. Lowering the permeability enhancement device into the well 32, first adjusting the permeability enhancement device position to the bottom of the ore layer 34;

[0058] c. Adjust the position of the sensing rod 23 so that the temperature sensor 31 is in close contact with the well wall, and check the close contact with the pressure sensor 28;

[0059] d. Turn on the microwave radiator 3, the temperature sensor 31, and the pressure sensor 28 to radiate microwaves to the wellbore wall. Simultaneously, the temperature sensor 31 and the detector 30 transmit the wellbore wall temperature and crack conditions back to the central control system 14. The central control system 14 dynamically adjusts the power and loading time of the microwave radiator 3 until the wellbore wall crack density reaches the target level and is evenly distributed. The microwave radiation is then turned off.

[0060] e. Turn on the oil pump to inject pressurized oil into the sealing groove 19 so that the sealing ring 20 is close to the well wall, maintaining the oil pressure in the sealing groove 19 to achieve the purpose of sealing the space;

[0061] f. Start the high-pressure pulse pump 8 and apply stepped pulse water pressure to the space between the upper packer 16 and the lower packer 17, so that a large number of evenly distributed microcracks on the wellbore wall expand into the ore rock; use microseismic signals to track the expansion range of the cracks until the cracks expand inward to the target range, and then turn off the high-pressure pulse pump 8;

[0062] g. Adjust the position of the sensing rod 23 so that the temperature sensor 31 is away from the well wall; turn off the oil pump and rotate the holding column 2 so that the sealing rubber ring is away from the well wall;

[0063] h. Adjust the position of the permeability enhancement device and repeat the above steps from bottom to top until the mineral layer 34 is fully activated;

[0064] i. Repeat the above steps for each well until all wells have been drilled.

[0065] The above method can form a large-scale, well-uniform fracture network in the ore rock layer, thereby increasing the permeability of the sandstone uranium ore layer and reducing the anisotropic permeability coefficient.

[0066] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device, characterized by: It includes a microwave radiation mechanism, a sealing mechanism and a high-pressure pulse water injection mechanism. The microwave radiation mechanism includes a microwave radiator and a microwave antenna. The microwave radiator is connected to the microwave antenna through a waveguide tube. The microwave antenna is used to extend into the well. The sealing mechanism includes an upper packer and a lower packer. The upper packer and the lower packer can be located in the well and seal the space between the upper packer and the lower packer. The water pipe of the high-pressure pulse water injection mechanism passes through the upper packer and reaches between the upper packer and the lower packer. The microwave antenna is located between the upper packer and the lower packer. The microwave radiation mechanism is used to generate uniform microcracks. The high-pressure pulse water injection mechanism is used to extend the uniform microcracks generated by the microwave radiation mechanism into the ore rock.

2. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 1, characterized in that: It also includes a base and a holding column, the base is fixedly set on the ground, the holding column is set on the base, and the holding column can be extended into the well, the axis of the holding column is parallel to the axis of the well, the base can drive the holding column to rise and fall or rotate, and the waveguide tube and the microwave antenna can pass through the holding column and extend between the upper packer and the lower packer.

3. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 2, characterized in that: The upper packer and the lower packer are fixedly connected by an inner connecting rod, and the upper packer is fixedly connected to the bottom of the holding column. The sealing mechanism also includes a pumping mechanism and a connecting pipe. The connecting pipe connects the pumping mechanism, the upper packer and the lower packer in sequence. The upper packer and the lower packer both include a sealing groove and a sealing ring. The sealing ring is arranged in the sealing groove in a sliding sealing manner. The pumping mechanism can inject liquid into the sealing groove through the connecting pipe.

4. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 3, characterized in that: It also includes a sensing rod, which is connected to the inner connecting rod through a transmission device. The transmission device can drive the sensing rod radially close to or away from the inner connecting rod. A temperature sensor is provided on the side of the sensing rod away from the inner connecting rod. The temperature sensor is used to monitor the temperature of the drilling well wall.

5. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 4, characterized in that: It also includes an elastic member and a pressure sensor, the pressure sensor is fixedly connected to a side of the sensing rod away from the inner connecting rod, the two ends of the elastic member are respectively fixedly connected to the pressure sensor and the temperature sensor, the transmission device includes a telescope and an X-shaped arm, the sensing rod is axially provided with a first slide groove, the inner connecting rod is axially provided with a second slide groove, the top and bottom of the second slide groove are both provided with the telescope, the X-shaped arm includes a first connecting rod and a second connecting rod, the middle parts of the first connecting rod and the second connecting rod are hinged, the first end of the first connecting rod and the first end of the second connecting rod are both extended into the second slide groove and are respectively connected to the telescope at the top and the telescope at the bottom, the second end of the first connecting rod and the second end of the second connecting rod are both slidably set in the first slide groove.

6. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 1, characterized in that: The microwave radiation mechanism further includes a microwave protective tube, which is fixedly sleeved on the outer periphery of the waveguide tube and the microwave antenna.

7. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 5, characterized in that: The high-pressure pulse water injection mechanism includes a pulse controller, a high-pressure pulse pump and a water pipe. The pulse controller is electrically connected to the high-pressure pulse pump, and the high-pressure pulse pump is connected to the water pipe.

8. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 7, characterized in that: It also includes a microseismic server, a central control system, a pressure recorder, and a temperature recorder. The pressure recorder is electrically connected to the pressure sensor signal, and the temperature recorder is electrically connected to the temperature sensor signal. The microseismic server is used to track the crack generation and expansion path. The microseismic server, the pressure recorder, the temperature recorder, the pulse controller, the microwave radiator and the pumping mechanism are all electrically connected to the central control system signal.

9. The low-permeability sandstone uranium ore microwave radiation-pulse water pressure combined permeability enhancement device according to claim 8, characterized in that: The system also includes a geophone, which is arranged on the ground. A plurality of geophones are evenly arranged around the circumference of the wellbore. The geophone is used to capture microseismic signals of crack generation and expansion.

10. A method for increasing the permeability of low-permeability sandstone uranium ore by combining microwave radiation and pulse water pressure, characterized by: Includes the following steps Step 1: Drill vertically downward from the ground through the overburden, ore layer and bottom rock layer, clean the well wall debris, and the drilling position and well diameter are determined according to the location of the injection hole in the in-situ leaching mining process; arrange the detectors to form a detector array; Step 2: Lower the permeability enhancement device into the well and adjust the position of the permeability enhancement device by controlling the holding column; Step 3: Adjust the position of the sensing rod so that the temperature sensor is close to the well wall, and check whether it is close by using the pressure sensor; Step 4: Turn on the microwave radiator to radiate microwaves to the wellbore wall. At the same time, the temperature sensor and detector transmit the wellbore wall temperature and crack conditions back to the central control system. The central control system dynamically adjusts the power and loading time of the microwave radiator until the wellbore wall crack density reaches the target level and is evenly distributed. The microwave radiator is turned off. The microwave radiator is intermittent. When the wellbore wall temperature rises to 300°C, the microwave radiation stops. When the temperature drops to 150°C, the microwave radiation starts again. Step 5: Start the pumping mechanism and inject pressure liquid into the sealing groove to make the sealing ring close to the well wall, maintain the hydraulic pressure of the sealing groove, and achieve the purpose of sealing the space between the upper packer and the lower packer; Step 6: Start the high-pressure pulse pump and apply stepped pulse water pressure to the space between the upper and lower packers, causing the evenly distributed microcracks on the wellbore wall to expand into the rock. Use microseismic signals to track the extension of the cracks until they reach the target range, then turn off the high-pressure pulse pump. Step 7: Adjust the position of the sensing rod so that the temperature sensor is away from the well wall; turn off the pumping mechanism and rotate the holding column so that the sealing ring is away from the well wall; Step 8: Adjust the position of the permeability enhancement device and repeat the above steps from bottom to top until the mineral strata are completely affected.

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