A deep well full-drilling integrated aquifer water level and water temperature observation system

Abstract

The application discloses a deep well full-drilling integrated aquifer water level and water temperature observation system, and belongs to the technical field of deep well water level observation. Each group of pipe groups comprises a filter pipe and two protection pipes connected with the filter pipe and located at both ends of the filter pipe. The peripheral wall of the filter pipe is provided with water permeable holes through which underground water can seep into the pipe. The peripheral wall of the protection pipe and the pipe are both provided with expansion members capable of absorbing water and expanding, so as to realize physical isolation. A load-bearing cable is arranged in the pipe column. The load-bearing cable comprises an outer sleeve and at least two communication lines and at least one load-bearing cable for bearing the communication lines arranged in the outer sleeve. The outer sleeve of the load-bearing cable in the corresponding height space of the filter pipe is broken and connected with a water level and water temperature sensor. Through the above arrangement, each filter pipe corresponds to different aquifers. The expansion members physically isolate the upper and lower sides of the filter pipe. The water level and water temperature sensor independently collects data after being connected through the load-bearing cable, so as to realize independent layered monitoring of multiple aquifers in a kilometer-level deep well.

Description

Technical Field

[0001] This invention belongs to the field of deep well water level observation technology, specifically relating to a deep well fully borehole integrated aquifer water level and temperature observation system. Background Technology

[0002] In the fields of deep hydrogeological exploration, groundwater resource development and management, deep mine water hazard prevention, and geotechnical engineering construction, dynamic monitoring of deep groundwater is a fundamental task for project implementation. Changes in groundwater level and temperature reflect the water storage status of aquifers, the development of rock fissures, and the patterns of groundwater recharge and runoff. These are basic parameters for analyzing geological structure stability, predicting mine water inrush hazards, and assessing water resource reserves. During mine construction and mining, as tunnels and excavation work extend deeper, they will traverse multiple underground aquifers. Before tunneling operations, it is necessary to determine the water level, water pressure, and recharge direction of each aquifer. If this is not determined, tunneling may expose water-rich areas, causing high-pressure groundwater to rush into the tunnels, triggering water inrush accidents and threatening the safety of workers and mine property.

[0003] Monitoring aquifers requires acquiring three types of data: water level data, used to determine the hydraulic head of the aquifer; source direction data, used to determine the main recharge direction of groundwater; and incoming aquifer layer data, used to pinpoint the specific depth range from which the groundwater originates. By monitoring the trends in water level and incoming direction over a long period, it is possible to determine whether there is a risk of sudden water inrush. Once a water inrush occurs, the outflow layer can be located based on the incoming aquifer layer data, allowing for targeted grouting borehole placement for sealing. By tracing the recharge channel based on the incoming water direction, curtain grouting or dewatering measures can be implemented to eliminate the flooding hazard.

[0004] Currently, most conventional deep-hole monitoring equipment in China adopts a single-point, single-layer monitoring mode. A single borehole can only complete data acquisition for a single aquifer. To complete multi-layer groundwater monitoring, multiple monitoring boreholes need to be constructed, increasing construction costs and time. Traditional layered monitoring methods employ nested water level observation, also known as nested layered water level monitoring. The principle is to install multiple independent monitoring pipes within the same borehole using a layered water-stopping process. Each monitoring pipe corresponds to a different target aquifer depth. The monitoring pipe for each target aquifer is a perforated filter pipe, i.e., the inlet section, while the remaining pipe sections are closed solid pipes, allowing only groundwater from the corresponding layer to enter. Between adjacent monitoring layers, layered water-stopping structures such as bentonite plugs, cement grout, or rubber stoppers are used to seal the water, blocking the hydraulic connection between adjacent aquifers and preventing cross-contamination of water. Each monitoring tube has a sedimentation tube at the bottom for sediment deposition. An immersion-type pressure level gauge is installed inside the tube or the water level is measured by a manual measuring rope. The water level inside the tube directly represents the pressure level of the corresponding aquifer.

[0005] In terms of pipe configuration, nested water level monitoring requires the diameter of the monitoring pipe to increase gradually with the number of monitoring layers, with the bottom section having the smallest diameter and increasing in diameter upwards, reaching the largest diameter at the top. This is because the lower pipe sections need to bear the weight of the upper pipe sections, and increasing in diameter section by section helps improve the stability of the overall structure. The diameter of each pipe section is pre-designed based on the depth and number of the target aquifers, the borehole diameter needs to match the maximum pipe diameter, and sufficient annular gaps are reserved for injecting sealing materials and installing packers.

[0006] This nested structure is feasible when monitoring a limited number of layers. In shallow wells, the number of aquifers is limited, typically only one or two, requiring fewer pipe sections and a smaller maximum diameter. The borehole diameter is sufficient to accommodate pipe insertion and annular clearance. However, kilometer-deep wells need to traverse multiple aquifers, which may have different water pressures, qualities, and recharge sources. In kilometer-deep wells, if a nested structure is used for layered monitoring, the number of pipe sections needs to increase proportionally with the number of aquifer layers. The progressive diameter-increasing principle of the nested structure dictates that with each additional pipe section, the diameter of the section above it must increase accordingly, and the maximum diameter of the topmost section also increases. This necessitates a corresponding increase in borehole diameter; otherwise, the pipe cannot be smoothly lowered into the borehole, or the annular clearance between the pipe and the borehole wall will be too small to allow for effective sealing of the aquifers with sealing material.

[0007] Increasing the borehole diameter to accommodate more pipe sections increases drilling costs. Regarding drill bit costs, the purchase price of large-diameter drill bits is significantly higher than that of conventional diameter drill bits. During drilling deep wells (kilometers), multiple drill bits are consumed due to wear, leading to a significant increase in drill bit costs. In terms of drilling time, the increased borehole diameter results in a larger volume of rock cut by the drill bit, a decrease in drilling speed, and a longer drilling period for the entire well. Since drilling rig operations are charged per shift, the extended period leads to increased shift costs. Regarding mud consumption, large-diameter boreholes require larger mud pumps and larger mud pits to maintain in-hole circulation, resulting in a corresponding increase in mud raw material consumption. Regarding pipe costs, the increased borehole diameter necessitates a corresponding increase in the diameter of each monitoring pipe section, increasing the amount of steel used and the procurement cost of the pipe. Regarding maintenance difficulty, with multiple pipes nested within a single borehole, the inner diameter of each monitoring pipe is limited, requiring specific dimensions for the monitoring equipment. Maintenance operations such as well cleaning, dredging, and equipment replacement are more difficult than in a single-layer monitoring well.

[0008] In addition, existing stratified monitoring devices suffer from the following technical problems: The sealing structure is easily damaged by friction against the borehole wall during the lowering process; the rubber seals have poor sealing performance, easily causing water leakage between layers; the sensor inlet ports are easily clogged by sediment and impurities; and water seepage and short circuits at the wiring points in deep, high-pressure environments lead to large signal transmission fluctuations and data distortion. These problems make existing equipment unsuitable for long-term monitoring operations in kilometer-deep boreholes and high-pressure water environments.

[0009] In summary, the problems with existing monitoring technologies are as follows: under the condition of kilometer-level deep wells, as the number of monitoring layers increases, the maximum pipe diameter and borehole diameter required for the nested structure increase accordingly. Increasing the borehole diameter will lead to increased drilling costs and maintenance difficulties. Furthermore, existing layered monitoring devices have several technical defects in terms of sealing, anti-clogging, waterproofing, and signal transmission, making it difficult to meet the long-term layered monitoring needs under the high-pressure water environment of kilometer-level deep wells. Summary of the Invention

[0010] The purpose of this invention is to provide an integrated aquifer water level and temperature monitoring system for deep wells with full borehole drilling. Each filter pipe corresponds to a different aquifer, and expansion joints physically seal the upper and lower sides of the filter pipe. Water level and temperature sensors independently collect data after the load-bearing cable is disconnected and connected, so as to realize independent stratified monitoring of multiple aquifers in a kilometer-deep well.

[0011] To achieve the above objectives, this invention provides a deep well fully borehole integrated aquifer water level and temperature monitoring system, comprising: a tubing string for extending into a deep well borehole, the tubing string comprising multiple sets of tubing, each set of tubing comprising a filter pipe and two protective pipes connected to the filter pipe and located at both ends of the filter pipe, the filter pipe having permeable holes on its peripheral wall that allow groundwater to seep into the pipe; Multiple sets of filter pipes are placed in underground aquifers at different heights. The outer periphery and the inside of the protective pipe are equipped with expansion components that can absorb water and expand, so as to achieve physical isolation of the underground aquifer where the filter pipe is located in terms of height space. The load-bearing cable is installed inside the pipe column. The load-bearing cable includes an outer jacket and at least two communication lines and at least one support cable for carrying the communication lines located inside the outer jacket. The outer jacket of the load-bearing cable in the height space corresponding to the water filter pipe is broken and connected to the water level and temperature sensor.

[0012] In one possible implementation, the communication line has at least three strands, each of which is connected to a carrier cable and each carrier cable is connected to two corresponding communication lines.

[0013] In one possible implementation, the number of carrying cables is c, and the number of communication lines is m, where c = m - 1. The multiple communication lines are arranged in a circle, the carrying cables are located in the middle of the circle of the multiple communication lines, and at least three communication lines can be connected to two carrying cables at the same time.

[0014] In one possible implementation, the expansion components provided on the outer periphery and inside the protective pipe are an outer expansion body and an inner expansion body, respectively. The outer expansion body and / or the inner expansion body include, along the axial direction, a main sealing area located in the middle and gap filling areas located on the upper and lower sides of the main sealing area. The expansion ratio of the main sealing area is 200%~250%, and the expansion ratio of the gap filling area is 250%~300%.

[0015] In one possible implementation, the expansion element is set to have a full expansion time t ≥ 72h.

[0016] In one possible implementation, the inner expansion body adopts a split-opening C-shaped structure. The inner expansion body includes a main sealing area in the middle and gap filling areas on the upper and lower sides of the main sealing area along the axial direction. The outer periphery of both gap filling areas is fitted with inner clamps and fixed to the inner wall of the protective pipe by the inner clamps.

[0017] In one possible implementation, the protective pipe includes a main pipe and two spaced-apart joints, the outer diameter of which is larger than that of the protective pipe, to allow for wellbore trimming through the joints. An external expansion body is located between the two joints to prevent contact with the borehole wall during the lowering process.

[0018] One possible implementation also includes: A waterproof junction box is installed around the perimeter of the area where the load-bearing cable is damaged. The waterproof junction box has a wiring space inside, with wire through holes at the top and bottom. This allows the signal wires extending from the damaged load-bearing cable to pass through the upper wire through hole and into the wiring space, while the signal wires of the water level and temperature sensors can pass through the lower wire through hole and into the wiring space to be electrically connected to the signal wires extending from the damaged load-bearing cable.

[0019] In one possible implementation, the outer periphery of the wiring space also has a protective space through which the wiring hole passes. The protective space is used to fill the wiring space with waterproof sealant after the signal line extends into the wiring space to isolate the wiring space from the outside.

[0020] In one possible implementation, a waterproof heat shrink tubing is fitted over the electrical connection between the signal line extending from the broken load-bearing cable and the signal line of the water level and temperature sensor. The distance between the two ends of the waterproof heat shrink tubing and the electrical connection is greater than 15mm, and both the waterproof heat shrink tubing and the electrical connection are coated with waterproof sealant.

[0021] The significant technical effect of this invention is that each filter pipe corresponds to a different aquifer, the expansion joint physically seals the upper and lower sides of the filter pipe, and the water level and temperature sensors independently collect data after the load-bearing cable is disconnected and connected, so as to realize independent stratified monitoring of multiple aquifers in a kilometer-deep well. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a schematic diagram of the structure of a deep well fully borehole integrated aquifer water level and temperature monitoring system according to one embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of electrical connections in the area where the communication line was damaged; Figure 3 for Figure 1 A schematic diagram of the structure when the communication line has 5 strands.

[0024] In the diagram: 100, Pipe column; 110, Pipe assembly; 120, Filter pipe; 121, Water permeable hole; 130, Protective pipe; 131, Pipe section; 132, Joint section; 200, Expansion piece; 210, Inner expansion body; 220, Outer expansion body; 230, Main sealing area; 240, Gap filling area; 300, Load-bearing cable; 310, Communication line; 311, Demolition area; 320, Outer jacket; 330, Load-bearing cable; 400, Electrical connection; 500, Inner clamp; 600, Waterproof junction box; 610, Wiring space; 620, Wiring hole; 700, Water level and temperature sensor; 800, Waterproof heat shrink tubing. Detailed Implementation

[0025] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0030] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0031] In the description of the embodiments in this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. It can be the internal connection between two components or the interaction between two components.

[0032] In deep hydrogeological exploration and deep mine water hazard prevention, kilometer-deep wells need to penetrate multiple underground aquifers. If the traditional nested water level monitoring method is used, multiple monitoring pipes of different diameters are nested within the same borehole. As the number of aquifers increases, the diameter of the topmost monitoring pipe increases accordingly, requiring a larger borehole diameter and thus increasing drilling costs. If a single-hole, single-layer monitoring mode is used, multiple boreholes need to be drilled, similarly increasing costs. For more information on this issue, please refer to [link to relevant documentation]. Figures 1-3 This invention illustrates an integrated deep well borehole aquifer water level and temperature monitoring system according to one embodiment of the present invention. Multiple sets of pipe groups 110 correspond to different aquifers. The aquifers above and below the filter pipe 120 are physically isolated by the expansion member 200 absorbing water and expanding. Water level and temperature sensors 700 are broken and connected to the load-bearing cable 300 at the positions corresponding to each filter pipe 120. This enables independent stratified monitoring of multiple aquifers within the same borehole without increasing the borehole diameter as the number of aquifers increases.

[0033] Specifically, the observation system includes a tubing string 100 and a load-bearing cable 300. The tubing string 100 is used to extend into a deep well borehole and is composed of multiple sets of tubing assemblies 110 connected sequentially along the axial direction. Each set of tubing assemblies 110 includes a filter pipe 120 and two protective pipes 130 located at both ends of the filter pipe 120. The peripheral wall of the filter pipe 120 has permeable holes 121, through which groundwater can seep into the interior of the filter pipe 120. Preferably, the permeable holes 121 are circular holes, evenly spaced along the axial direction of the filter pipe 120, and arranged in a spiral staggered distribution pattern in the circumferential direction to reduce stress concentration caused by the openings. The filter pipes 120 of the multiple sets of tubing assemblies 110 are placed in underground aquifers at different heights, and the installation height of each filter pipe 120 corresponds to the depth of the target aquifer, so that each filter pipe 120 is located within a different aquifer zone. Expansion members 200 are provided on both the outer periphery and inside the protective pipe 130. These expansion members 200 are capable of absorbing water and expanding. Preferably, the expansion member 200 is a ring-shaped or cylindrical component made of a water-swellable material, with an adhesive layer coated on its inner wall. It is fixed to the outer or inner periphery of the protective pipe 130 via the adhesive layer, or secured by clamps. After the pipe string 100 is lowered into the borehole, the expansion member 200 comes into contact with the groundwater in the borehole. Upon absorbing water, it expands in volume, filling and sealing the annular gap between the outer periphery of the protective pipe 130 and the borehole wall, as well as the gap between the inner wall of the protective pipe 130 and the load-bearing cable 300. This physically isolates the aquifer containing the filter pipe 120 from other aquifers or impermeable layers above and below it, blocking the hydraulic connection between different aquifers along the inner and outer sides of the pipe string 100.

[0034] The load-bearing cable 300 is installed inside the pipe column 100 and runs through each pipe assembly 110 along the axial direction of the pipe column 100. The load-bearing cable 300 includes an outer jacket 320 and at least two communication lines 310 and at least one support cable 330 located inside the outer jacket 320. The outer jacket 320 may be made of polyurethane material, which wraps the communication lines 310 and the support cable 330 inside. In this example, each communication line 310 contains two power lines and two signal lines. The power lines are used to power the water level and temperature sensor 700, and the signal lines are used to transmit the data collected by the water level and temperature sensor 700. The power lines and signal lines are wrapped with independent shielding layers. The communication lines 310 are used to transmit signals, and the support cable 330 is used to support the weight of the load-bearing cable 300 when it is lowered into the pipe column 100. Within the height space corresponding to the filter pipe 120, the outer jacket 320 of the load-bearing cable 300 is broken to expose the internal communication lines 310. The broken area 311 is as follows: Figure 2 As shown, the communication line 310 is electrically connected to the water level and temperature sensor 700. The water level and temperature sensor 700 is located within the height range of the filter pipe 120 and is used to collect water level and temperature data of the corresponding aquifer.

[0035] With the above setup, each filter pipe 120 corresponds to a different aquifer. The expansion joint 200 seals the upper and lower sides of the filter pipe 120. The water level and temperature sensor 700 collects the water level and temperature signals of each aquifer after the load-bearing cable 300 is disconnected and connected. The water level and temperature data of each aquifer are transmitted independently, realizing independent stratified monitoring of multiple aquifers in the same borehole.

[0036] In a further example, the communication wires 310 inside the load-bearing cable 300 have at least three strands. Each communication wire 310 is connected to the support cable 330, and each support cable 330 is connected to two communication wires 310. The communication wires 310 and the support cables 330 can be fixed together by binding or other methods, or by clamping devices, or the communication wires 310 and the support cables 330 can be twisted together. During the lowering of the load-bearing cable 300, the support cables 330 bear tensile force, and the communication wires 310 are supported by their connection to the support cables 330 and will not bear tensile loads independently due to their own weight.

[0037] In a further example, the number of carrying cables 330 is c, and the number of communication lines 310 is m, satisfying the relationship c = m - 1. The multiple communication lines 310 are arranged in a circle, with the carrying cables 330 located at the center of the circle, and at least three communication lines 310 can be connected to two carrying cables 330 simultaneously. Taking a five-strand communication line as an example, there are four carrying cables 330, with the five communication lines 310 surrounding the four carrying cables 330. Each communication line 310 can be connected to two adjacent carrying cables 330. The communication lines 310 are distributed on the periphery, while the carrying cables 330 are concentrated in the central area. The cross-sectional layout of the load-bearing cable 300 is compact, with the carrying cables 330 bearing the load centrally, and the communication lines 310 evenly distributed on the periphery.

[0038] Specifically, in a well thousands of meters deep, the load-bearing cable 300 needs to withstand the tensile force generated by its own weight. According to Hooke's Law, the elongation of the cable under tension is S=F. L / E Let A be the elastic modulus of the material, where E is the elastic modulus and A is the cross-sectional area. The elastic modulus E of the steel wire rope is approximately 210 GPa. Taking a steel wire rope diameter of 3 mm and a cable length of 1000 m as an example, and F as 2 kN, the total cross-sectional area A of four 3 mm diameter steel wire ropes is approximately 28.27 mm². Substituting into the formula, the elongation S of the steel wire rope is approximately 0.337 m. Under actual stress, the steel wire rope and the signal line form a parallel load-bearing structure, and both elongate synchronously under tension, with equal elongation. The elastic modulus of the steel wire rope (210 GPa) is much greater than the equivalent elastic modulus of the signal line, and the stiffness of the steel wire rope is approximately 11.4 times that of the equivalent stiffness of the signal line. According to the stiffness distribution principle of parallel structures, the steel wire rope bears most of the load, while the signal line bears only a small portion of the load. The actual elongation of the cable is determined by the elongation of the steel wire rope, which is approximately 0.337m, resulting in an overall tensile rate of approximately 0.034%, far less than the allowable tensile rate threshold of 1%. This deformation is within the engineering tolerance range and will not cause irreversible plastic deformation of the internal conductors of the signal line due to stretching. The delay and attenuation of signal transmission are negligible, and the cable will not be damaged by cumulative deformation during long-term use in wells thousands of meters deep.

[0039] In a well thousands of meters deep, the hydrostatic pressure increases with depth, and the cables are constantly exposed to a high-pressure water environment. In one example arrangement, for ease of understanding, the five communication lines 310 are labeled a, b, c, d, and e, and the four support cables 330 are labeled S1, S2, S3, and S4. The five communication lines 310 are arranged in a circle, and the four support cables 330 are located inside the circle. The connection relationships between the support cables 330 and the communication lines 310 are as follows: S1 connects a and b, S2 connects a and e, S3 connects b and c, and S4 connects e and d. Based on the above connection relationships, communication line a connects to two load-bearing cables 330 (S1 and S2), communication line b connects to two load-bearing cables 330 (S1 and S3), communication line e connects to two load-bearing cables 330 (S2 and S4), communication line c connects to only one load-bearing cable 330 (S3), and communication line d connects to only one load-bearing cable 330 (S4). Each load-bearing cable 330 and communication line 310 are cross-connected to form a force transmission mechanism. When the cable is subjected to external hydrostatic pressure in a well at a depth of kilometer, the water pressure acts radially on the cable cross-section. The communication lines 310 are arranged in a circle, with the load-bearing cables 330 located inside the circle. The external water pressure is transmitted to the communication lines 310 through the outer jacket 320, and the communication lines 310 then transmit the pressure to the load-bearing cables 330. Because the load-bearing cable 330 and the communication line 310 are cross-connected, the pressure is distributed to different load-bearing cables 330 through multiple connection points. The load-bearing cables 330 restrain each other, and the cable cross-section maintains a circular structure under radial pressure, preventing cross-sectional collapse or deformation due to uneven local stress. The stability of the cross-sectional structure ensures that the spacing of the communication lines 310 in the circumferential direction remains constant, and signal transmission is not affected by changes in external water pressure.

[0040] Taking communication line c 310 as an example, it is only connected to one load-bearing cable 330, S3, but S3 is also connected to communication line b 310. When communication line c 310 is subjected to tension due to its own weight in a kilometer-deep well, the tensile force is transmitted to S3 through c, S3 transmits part of the force to communication line b 310, and communication line b 310 transmits the force to S1 and S3. Through this cross connection, the force on communication line c 310 is transmitted to communication line b 310 through S3, and then distributed by communication line b 310 to the two load-bearing cables 330, S1 and S3. In the circumferential direction, the cross connections between each load-bearing cable 330 and the communication line 310 form a continuous force transmission. When a communication line 310 experiences local stress, the load-bearing cable 330 connected to it distributes the stress to the adjacent communication lines 310 and load-bearing cables 330, avoiding stress concentration at a single point. In summary, in a well at a depth of over 1,000 meters, the cable experiences axial tensile stress under its own weight. Simultaneously, during lowering and raising, friction within the inner wall of the tubing string 100 and the rotation of the winch may subject it to torsional torque. The four support cables 330 form a quadrilateral support frame within the circumference. The cables 330 are interconnected through cross-connections, creating a mutual restraint relationship that constrains the circumferential arrangement of the communication lines 310, preventing them from collapsing towards the center under tensile stress. The communication lines 310 maintain a circumferential distribution under tensile stress, and the spacing between each strand remains uniform, reducing the risk of signal crosstalk.

[0041] In a further example, the number of support cables 330 is one less than the number of communication lines 310. Taking a five-strand communication line 310 as an example, if each communication line 310 is equipped with two support cables 330, then five support cables 330 are required. The diameter of each support cable 330 is typically around 3mm, and the weight of a single support cable 330 over a kilometer length is approximately 55.5kg. In a kilometer-deep well, the cable's self-weight is a crucial parameter for selecting the lowering equipment and designing the wellhead fixing device. For every 55.5kg reduction in self-weight, the locking force required for the wellhead cable fixing device is reduced by approximately 555N, and the bending stress of the cable at the wellhead is correspondingly reduced. Simultaneously, because the support cables 330 form a force network through cross-connection within their circumference, four support cables 330 can form a quadrilateral support structure, providing sufficient support for the five-strand communication lines 310. By reducing the number of support cables 330 by one, the cross-sectional diameter of the cable can be reduced accordingly. This increases the gap between the cable and the pipe wall when it passes through the string 100, reducing frictional resistance during descent and lowering the risk of wear on the cable's outer sheath 320. Within the confined space of the string 100 in a kilometer-deep well, for every 1mm reduction in the cable's cross-sectional diameter, the radial gap between the cable and the pipe wall increases by 0.5mm. This improves the cable's passage through the joints of the string 100 during descent, reducing the risk of jamming.

[0042] In a further example, the expansion member 200 disposed on the outer periphery of the protective pipe 130 is an outer expansion body 220, and the expansion member 200 disposed inside the protective pipe 130 is an inner expansion body 210. The outer expansion body 220 is a cylindrical structure and is fitted onto the outer peripheral wall of the protective pipe 130. The inner expansion body 210 is fitted onto the outer periphery of the load-bearing cable 300. Both the outer expansion body 220 and the inner expansion body 210 include, along the axial direction, a main sealing area 230 located in the middle and gap filling areas 240 located on the upper and lower sides of the main sealing area 230. The expansion ratio of the main sealing area 230 is 200% to 250%, and it can be made of a fluororubber matrix. Fluororubber has good resistance to compression deformation, and its structure is not easily compressed or squeezed out of the sealing area when subjected to water pressure differences between aquifers. The expansion ratio of the gap filling area 240 is 250% to 300%, and it can be made of a hydrogenated nitrile rubber matrix. The hydrogenated nitrile rubber has a higher volume expansion rate after absorbing water than the main sealing area 230. After expansion, it can fill irregular depressions and gaps on the surface of the hole wall. After the expansion component 200 absorbs water and expands, the central main sealing area 230 relies on the structural strength of the fluororubber to withstand the water pressure difference, while the upper and lower gap filling areas 240 rely on the expansion amount of the hydrogenated nitrile rubber to fill the rough surface of the hole wall. In the axial direction, it achieves the functions of pressure-bearing sealing and fitting filling in segments.

[0043] In a further example, the expansion element 200 is set to have a full expansion time t greater than or equal to 72 hours. The full expansion time refers to the time from when the expansion element 200 begins to absorb water until its volume no longer increases. During the lowering of the tubing string 100 and the load-bearing cable 300, the expansion element 200 absorbs water for a short time, resulting in a small volume change. Gaps remain between the outer expansion body 220 and the external borehole wall, and between the inner expansion body 210 and the internal load-bearing cable 300, preventing increased lowering resistance. After lowering, the expansion element 200 is immersed in groundwater for more than 72 hours, expanding to its maximum volume and filling all gaps. Specifically, in a kilometer-deep well monitoring scenario, the lowering process of the tubing string 100 and the load-bearing cable 300 itself requires a considerable amount of time. For kilometer-level deep boreholes, the tubing string 100 is lowered in sections by connecting multiple standard pipe sections one by one, and the entire lowering process typically takes a long time. If the expansion element 200's full expansion time is too short, for example, within 24 hours, then in the later stages of lowering the tubing string 100, the portion of the expansion element 200 that first enters the borehole will begin to absorb water and expand. The outer diameter of the outer expansion body 220 will increase, reducing or eliminating the gap between it and the borehole wall. Subsequent tubing sections will need to overcome the friction between the expansion element 200 and the borehole wall, increasing the lowering resistance. If the friction is too great, the tubing string 100 may become stuck in the borehole and unable to continue lowering. If the expansion element 200 expands too quickly, its surface may be damaged due to friction during lowering, affecting the subsequent sealing effect. Setting the full expansion time of the expansion element 200 to greater than or equal to 72 hours ensures that the entire lowering operation of the tubing string 100 and the load-bearing cable 300 is completed within the time window before the expansion element 200 has fully expanded. During the lowering process, the volume change of the expansion element 200 is small. Gaps remain between the outer expansion body 220 and the borehole wall, and between the inner expansion body 210 and the load-bearing cable 300. The tubing 100 and the cable can pass smoothly without generating lowering resistance due to the premature expansion of the expansion element 200. After lowering is completed, the expansion element 200 expands to its maximum volume after 72 hours, fully filling all gaps and forming a seal.

[0044] In a further example, the inner expansion body 210 can adopt a split-open C-shaped structure, that is, the inner expansion body 210 is split into two halves along the axial direction. During installation, the two halves of the inner expansion body 210 are joined together from the radial sides of the load-bearing cable 300, and can be wrapped around the outer periphery of the load-bearing cable 300 without having to pass through the end of the load-bearing cable 300. The inner expansion body 210 includes a main sealing area 230 located in the middle and gap filling areas 240 located on the upper and lower sides of the main sealing area 230 along the axial direction. The outer periphery of both gap filling areas 240 is fitted with inner clamps 500, which can be stainless steel clamps, and they are tightly wrapped around the outer periphery of the gap filling areas 240, pressing and fixing the inner expansion body 210 to the inner wall of the protective tube 130. The clamping force of the inner clamp 500 makes the inner expansion body 210 fit against the inner wall of the protective tube 130, restricting the displacement of the inner expansion body 210 along the axial direction of the protective tube 130, and keeping the inner expansion body 210 in the designed position during the lowering process.

[0045] In a further example, the protective pipe 130 includes a pipe section 131 and two spaced-apart connector sections 132. The outer diameter of the connector section 132 is larger than the outer diameter of the pipe section 131 of the protective pipe 130. When the pipe assembly 110 is connected, one connector section 132 connects to the connector section 132 of the adjacent pipe assembly 110 or the filter pipe 120. The external expansion body 220 is located between the two connector sections 132, and the outer diameter of the external expansion body 220 is smaller than the outer diameter of the connector section 132. When the pipe string 100 is lowered, the connector section 132 at the upper end of the pipe assembly 110 enters the borehole first. Its larger outer diameter pushes aside the protrusions on the borehole wall, making the borehole wall relatively smooth and providing a passage for the subsequent external expansion body 220 to pass through. The external expansion body 220 is located between the two connector sections 132 and does not directly contact the borehole wall during entry into the borehole and lowering, thus avoiding scraping or impact from the borehole wall.

[0046] In a further example, the monitoring system also includes a waterproof junction box 600. The waterproof junction box 600 is fitted around the periphery of the area 310 where the load-bearing cable 300 has been damaged. The waterproof junction box 600 can be made of stainless steel or engineering plastic. The waterproof junction box 600 has a built-in wiring space 610, with wire-passing holes 620 at both the top and bottom. These holes 620 are through-holes penetrating the wall of the waterproof junction box 600. The communication cable 310 extending from the damaged load-bearing cable 300 passes through the upper wire-passing hole 620 into the wiring space 610, and the signal cable of the water level and temperature sensor 700 passes through the lower wire-passing hole 620 into the wiring space 610. The communication cable 310 and the signal cable are electrically connected inside the wiring space 610, which isolates the electrical connection area from the outside environment.

[0047] In a further example, the outer periphery of the wiring space 610 also has a protective space through which the wiring hole passes. The protective space is an annular or partially annular cavity located outside the wiring space 610. After the signal line extends into the wiring space 610, the protective space is filled with a waterproof sealant, which can be a polyurethane waterproof sealant. The waterproof sealant is filled between the inner wall of the wiring hole and the outer wall of the communication line 310 or signal line, blocking the passage of the wiring hole and preventing external moisture from entering the wiring space 610 through the gap between the wiring hole and the cable.

[0048] In a further example, a waterproof heat shrink tubing 800 is fitted over the electrical connection 400 between the communication line 310 (extended from the load-bearing cable 300) and the signal line of the water level / temperature sensor 700. The waterproof heat shrink tubing 800 is a double-walled, adhesive-coated heat shrink tubing with a pre-coated hot melt adhesive layer on the inner wall. For example, after inserting the waterproof heat shrink tubing 800 into the electrical connection 400, it is heated to 120°C to 150°C with a heat gun. The heat shrink tubing shrinks radially, melting the hot melt adhesive on the inner wall and filling the gap between the heat shrink tubing and the communication line 310 and the signal line. The distance between both ends of the waterproof heat shrink tubing 800 and the electrical connection 400 is greater than 15mm, meaning the heat shrink tubing extends at least 15mm on each side of the electrical connection 400. Both the waterproof heat shrink tubing 800 and the electrical connection 400 are coated with waterproof sealant, which can be polyurethane waterproof sealant. Waterproof heat shrink tubing 800 is tightly attached to the cable surface to form the first waterproof layer. Waterproof sealant is applied to the joints between the two ends of the heat shrink tubing and the cable jacket 320 to form the second waterproof layer. The two waterproof layers together protect the electrical connection 400 from the intrusion of external moisture.

[0049] Furthermore, it is important to note that in deep wells, after the 100mm tubing string is lowered, the 300mm load-bearing cable needs to be lowered segment by segment. At the corresponding depths of each target aquifer, the cable must be broken, sensors connected, and waterproof sealing performed. The waterproof sealant is typically polyurethane, and its curing process is a chemical cross-linking reaction from liquid to solid. After the liquid sealant is injected into the wiring area, the prepolymer in the sealant reacts with moisture in the air or the curing agent inside the sealant, and the molecular chains gradually cross-link to form a three-dimensional network structure. The sealant transforms from a flowable liquid into an elastic solid with a certain strength. This reaction process takes time to complete; at room temperature, polyurethane sealant typically takes about 24 hours from injection to complete curing. During the curing process, the sealant gradually loses its fluidity. If the wiring area is immersed in water during this period, the incompletely cross-linked sealant will be dispersed or diluted by the water pressure, failing to form a continuous and dense waterproof layer, and the wiring area will lose its waterproof protection. Once the sealant has fully cured, a dense three-dimensional network structure forms inside, capable of withstanding a certain water pressure and effectively preventing the penetration of external moisture, providing waterproof protection for the wiring area. Before the sealant has fully cured, if the wiring area is immersed in water, the sealant has not yet formed an effective waterproof barrier, and groundwater can seep in along the wiring area, causing short circuits in the signal lines or damage to the sensor.

[0050] Traditional cable lowering methods involve winding the cable onto a winch and lowering it segment by segment via electric control. Operators must first lower the cable to the first target depth, pause the descent, break the cable at that location, connect the sensor, inject waterproof sealant, and wait 24 hours for it to cure. Only after confirming the sealant is completely cured can the cable be lowered to the second target depth, and the process is repeated. For a kilometer-deep well requiring monitoring of five aquifers, the cable needs to be broken and connected at five different depths, with each connection requiring the sealant to cure, a waiting period of five days. During the long-term static period of a kilometer-deep well, the borehole wall may partially collapse or narrow due to groundwater seepage and formation stress release, reducing the effective borehole diameter. This could cause the tubing and cable to become stuck, increasing the risks of subsequent lowering operations.

[0051] Based on the above issues, this example can add a second winding spool. During operation, all cables are first wound from the first spool to the second. During the winding process, according to the design depth of each target aquifer, dismantling, wiring, and sealant injection are performed at the corresponding length positions, completing the pretreatment of all five wiring points in one go. After wiring is completed, each wiring point is allowed to solidify on the ground for 24 hours. Once the sealant is confirmed to be completely cured, the cable is then lowered uniformly from the second winding spool into the pipe column 100mm deep. Since all wiring and solidification processes are completed on the ground, the cable does not need to be stopped during the lowering process. All wiring points of the five sensors are already solidified and sealed, allowing direct lowering to the design depth. The lowering process is continuous, reducing the borehole settling time from five days to several hours, and minimizing the impact of borehole instability on the lowering operation.

[0052] It should be noted that in a kilometer-deep well, if a multi-segment structure is used, each set of filter pipes requires an independent monitoring pipe and a communication cable, with all monitoring pipes and cables arranged in parallel within the borehole. As the number of monitoring layers increases, the number of pipes and cables within the borehole also increases, making them prone to entanglement and compression, and increasing the risk of interference during lowering. If a single pipe becomes stuck or breaks in the middle of the deep well, the entire sensor set will fail, and the faulty pipe is difficult to pull out and repair individually in a kilometer-deep well. Furthermore, the multi-segment structure requires independent sealing devices at each filter pipe layer. Each sealing device withstands pressure independently in a long-term high-pressure water environment; failure of any sealing section will cause water leakage between layers, affecting the accuracy of the data at that layer. In contrast, the integrated structure combines multiple sets of filter pipes into a single pipe column and multiple communication cables and load-bearing cables into a single load-bearing cable. Only one pipe column and one cable need to be lowered into the borehole, avoiding the risks of entanglement and jamming caused by multiple parallel pipes. The sealing expansion joints of each filter pipe are uniformly installed on the pipe column, and the sealing structure is arranged continuously in the axial direction. The lowering and lifting operations are completed in one go, and the fault diagnosis and maintenance of a single pipe column and a single cable are clearly defined.

[0053] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of protection of the claims of the present invention.

Claims

1. A deep well fully borehole integrated aquifer water level and temperature monitoring system, characterized in that, include: A tubing string (100) is used to extend into a deep well borehole. The tubing string (100) includes multiple sets of tubing groups (110). Each set of tubing groups (110) includes a filter pipe (120) and two protective pipes (130) connected to the filter pipe (120) and located at both ends of the filter pipe (120). The filter pipe (120) has permeable holes (121) on its peripheral wall that allow groundwater to seep into the pipe. The filter pipes (120) of the multiple sets of pipe groups (110) are respectively placed in underground aquifers at different heights. The outer periphery and the inside of the protective pipe (130) are provided with expansion members (200) that can absorb water and expand, so as to achieve physical isolation of the underground aquifer where the filter pipe (120) is located in the height space. A load-bearing cable (300) is installed inside the pipe column (100). The load-bearing cable (300) includes an outer jacket (320) and at least two communication lines (310) located inside the outer jacket (320) and at least one load-bearing cable (330) for carrying the communication lines (310). The outer jacket (320) of the load-bearing cable (300) in the height space corresponding to the water filter pipe (120) is broken and the communication lines (310) are connected to the water level and temperature sensor (700).

2. The integrated deep well borehole aquifer water level and temperature monitoring system according to claim 1, characterized in that, The communication line (310) has at least three strands, each of the communication lines (310) is connected to the carrying cable (330), and each carrying cable (330) is connected to two of the communication lines (310).

3. The integrated deep well borehole aquifer water level and temperature monitoring system according to claim 2, characterized in that, The number of the carrying cables (330) is c, and the number of the communication lines (310) is m, where c = m-1. The multiple strands of the communication lines (310) are arranged in a circle. The carrying cables (330) are located in the middle of the circle of the multiple strands of the communication lines (310), and at least three strands of the communication lines (310) can be connected to two carrying cables (330) at the same time.

4. The integrated deep well borehole aquifer water level and temperature monitoring system according to claim 1, characterized in that, The expansion components (200) provided on the outer periphery and inside the protective tube (130) are an outer expansion body (220) and an inner expansion body (210), respectively. The outer expansion body (220) and / or the inner expansion body (210) include a main sealing area (230) located in the middle and gap filling areas (240) located on the upper and lower sides of the main sealing area (230) along the axial direction. The expansion ratio of the main sealing area (230) is 200%~250%, and the expansion ratio of the gap filling area (240) is 250%~300%.

5. The deep well fully borehole integrated aquifer water level and temperature monitoring system according to claim 4, characterized in that, The expansion member (200) is set to have a full expansion time t ≥ 72h.

6. The deep well fully borehole integrated aquifer water level and temperature monitoring system according to claim 4, characterized in that, The inner expansion body (210) adopts a split-opening C-shaped structure. The inner expansion body (210) includes the main sealing area (230) located in the middle and the gap filling area (240) located on the upper and lower sides of the main sealing area (230) along the axial direction. The outer periphery of the two gap filling areas (240) is fitted with an inner clamp (500) and fixed to the inner wall of the protective tube (130) by the inner clamp (500).

7. The integrated deep well borehole aquifer water level and temperature monitoring system according to claim 6, characterized in that, The protective pipe (130) includes a pipe section (131) and two spaced-apart joint sections (132). The outer diameter of the joint section (132) is larger than that of the protective pipe (130) so as to smooth the well wall through the joint section (132). The external expansion body (220) is located between the two joint sections (132) so as to prevent it from contacting the borehole wall during the lowering process.

8. A deep well fully borehole integrated aquifer water level and temperature monitoring system according to any one of claims 1-7, characterized in that, Also includes: A waterproof junction box (600) is fitted around the periphery of the ruptured area (310) of the load-bearing cable (300). The waterproof junction box (600) has a wiring space (610) inside. The wiring space (610) has wire holes (620) at the top and bottom, so that the signal wires protruding from the ruptured load-bearing cable (300) can pass through the upper wire hole (620) and extend into the wiring space (610). The signal wires of the water level and temperature sensor (700) can pass through the lower wire hole (620) and extend into the wiring space (610) and be electrically connected to the signal wires protruding from the ruptured load-bearing cable (300).

9. The integrated deep well borehole aquifer water level and temperature monitoring system according to claim 8, characterized in that, A waterproof heat shrink tube (800) is fitted at the electrical connection point (400) between the signal line extending from the broken load-bearing cable (300) and the signal line of the water level and temperature sensor (700). The distance between the two ends of the waterproof heat shrink tube (800) and the electrical connection point (400) is greater than 15mm.

10. The deep well fully borehole integrated aquifer water level and temperature monitoring system according to claim 9, characterized in that, Apply waterproof sealant to the surface of the waterproof heat shrink tubing (800), the electrical connection (400), and the junction between the waterproof heat shrink tubing (800) and the outer jacket (320).

Images