An intelligent zonal control well system and control method suitable for multiple aquifers

Abstract

The application provides a kind of intelligent layered control well system and control method suitable for multiple aquifers, relating to foundation pit dewatering and groundwater recharge technical field, it includes well pipe, pumping and irrigation device, controllable plugging component, pore pressure sensing unit, pressure sensing unit and wellhead control device, controllable plugging component is set in well pipe corresponding to aquiclude of aquifer, including annular waterproof layer and spherical inflatable grouting bag, pore pressure sensing unit detects pore water pressure of target aquifer and non-target aquifer respectively, pressure sensing unit detects the pressure of grouting bag acting on well wall, wellhead control device determines the plugging effectiveness in real time based on the pore pressure change of non-target aquifer during pumping and irrigation process, and automatically triggers grouting supplement when determining that plugging is insufficient, the application realizes flexible switching of multiple working conditions in single well and dynamic maintenance of plugging reliability through active dynamic closed-loop control, effectively reduces the number of wells, reduces construction cost, and reduces disturbance to surrounding groundwater environment.

Description

Technical Field

[0001] This invention relates to the field of foundation pit dewatering and groundwater recharge technology, and in particular to an intelligent stratified control well system and control method applicable to multiple aquifers. Background Technology

[0002] In deep foundation pit dewatering projects, the hydrogeological conditions of the construction site are often very complex. Influenced by factors such as sedimentary environment, stratigraphic structure, and geological formation, underground aquifer systems often exhibit multi-layered superposition and varying hydraulic connections between layers. In actual projects, a site may simultaneously contain unconfined aquifers, first confined aquifers, second confined aquifers, or even more aquifers, separated by weakly permeable or impermeable layers. However, due to factors such as stratigraphic heterogeneity, fracture development, or overflow recharge, varying degrees of hydraulic connection often exist between the layers. For ease of explanation, this section and the following text use a typical three-layer structure of unconfined aquifer, first confined aquifer, and second confined aquifer as an example; however, it should be understood that the number of aquifers applicable to this invention is not limited to this.

[0003] The need for groundwater control varies significantly across different construction stages: some stages only require draining the upper unconfined aquifer, while others require simultaneous water level control of both the unconfined aquifer and the first confined aquifer. In special circumstances, combined dewatering of deeper confined aquifers is also necessary. Furthermore, to control the subsidence of surrounding strata and protect groundwater resources, stratified recharge of specific aquifers is often required during construction.

[0004] Currently, traditional dewatering wells typically employ a fixed perforated pipe and a fixed pumping depth. Once the well is completed, the various aquifers within it remain interconnected for an extended period. This continuous well structure presents several problems in practical applications: First, when pumping only a specific target aquifer, the interconnectedness of the well's layers inevitably causes a coordinated drop in the water levels of non-target aquifers during pumping. This leads to an expansion of groundwater disturbance, increased effective stress in surrounding strata, and potentially triggers a series of environmental risks, such as ground subsidence, deformation of nearby buildings, and even damage to underground pipelines. Second, the inability to achieve layered sealing results in the ineffective drainage of water resources from non-target aquifers, leading to a waste of groundwater resources.

[0005] To address these issues, engineering practice often employs a multi-well approach, which involves separately installing unconfined groundwater wells, confined water depressurization wells, and deep depressurization wells. However, this approach results in a large number of wells, high construction costs, complex site layout, and difficulties in subsequent operation and management. More importantly, when changes occur during construction and the dewatering layer needs to be adjusted, the existing fixed well types are often insufficient to meet the new requirements, often necessitating the addition of new wells or replacement of the pumping system, resulting in extremely low construction flexibility.

[0006] Therefore, there is an urgent need for a new well structure and control method that can flexibly switch between different aquifers, perform layered plugging, and convertible pumping and reinjection depths within the same well. This would reduce the number of wells and construction costs, while ensuring the long-term reliability of the plugging through proactive plugging status monitoring and dynamic maintenance, thereby minimizing disturbance to the surrounding groundwater environment and buildings. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an intelligent stratified control well system and control method applicable to multiple aquifers. The present invention realizes flexible switching of multiple working conditions in a single well and dynamic maintenance of sealing reliability through active dynamic closed-loop control, effectively reducing the number of wells, reducing construction costs, and reducing disturbance to the surrounding groundwater environment.

[0008] This invention is achieved through the following technical solution: A smart stratified control well system suitable for multiple aquifers includes a well casing installed inside the wellbore, and further includes a pumping and injection device, a wellhead control device, a pore pressure sensing unit, and a pressure sensing unit all connected to the inside of the well casing. A controllable sealing component is installed inside the well casing at a location corresponding to at least one aquifer bottom plate. The controllable sealing component includes an annular waterproof layer and a spherical expandable grouting bladder connected to the grouting pipe. The pore pressure sensing unit is embedded in the filter layer outside the well casing and corresponds to the target aquifer and the non-target aquifer respectively. It is used to detect the pore water pressure of the target aquifer and the non-target aquifer respectively. The pressure sensing unit is located between the outer side of the grouting bladder and the inner wall of the well casing, and is used to detect the pressure acting on the well wall after the grouting bladder expands. The wellhead control device is connected to the controllable plugging assembly, pumping device, pore pressure sensing unit, and pressure sensing unit, and performs the following controls: In the first operating condition, the expansion of the grouting bladder is controlled to form a seal, and the pumping device is activated to operate on the target aquifer. During the pumping process, the signal from the pore pressure sensing unit is acquired, and the effectiveness of the sealing is determined in real time based on the change in pore water pressure in the non-target aquifer. When insufficient sealing is detected, the grouting operation of the grouting bladder is automatically triggered.

[0009] According to the above technical solution, preferably, the real-time determination includes: calculating the ratio of the water level change of the non-target aquifer to the water level change of the target aquifer; when the ratio reaches or exceeds a preset threshold, it is determined that the sealing is insufficient.

[0010] According to the above technical solution, preferably, the preset threshold is 10%.

[0011] According to the above technical solution, preferably, the control also includes: after triggering the grouting operation, continuing to monitor the change in pore water pressure in the non-target aquifer; if the grouting is still determined to be insufficient and the preset time is reached after grouting, then controlling the pumping device to stop working and issuing an alarm signal.

[0012] According to the above technical solution, preferably, the control also includes: acquiring the signal of the pressure sensing unit, and automatically triggering the grouting operation when the pressure acting on the well wall after the grouting bladder expands is lower than the preset sealing pressure, so as to establish an initial seal. The establishment of the initial seal is completed before the pumping device is started to operate on the target aquifer.

[0013] According to the above technical solution, preferably, the annular waterproof layer is fixed to the inner wall of the well pipe, and the grouting bladder is set on one side of the annular waterproof layer. In the expanded state, the upper and lower ends of the grouting bladder extend beyond the corresponding edges of the annular waterproof layer, forming a top sealing area and a bottom sealing area that fit against the inner wall of the well pipe.

[0014] According to the above technical solution, preferably, the control further includes: acquiring the change in pore water pressure of the target aquifer; when the change reaches the preset drawdown or recharge target, controlling the pumping and recharge device to maintain stable operation; and when the water level corresponding to the change remains stable within the target range for a preset duration, controlling the pumping and recharge device to stop working.

[0015] According to the above technical solution, preferably, a controllable sealing component is provided inside the well casing corresponding to the bottom of the unconfined layer and the bottom of the first confined aquifer. The wellhead control device selectively controls the expansion or contraction state of each grouting bladder according to external commands or preset programs, so as to switch between the following multiple working conditions: When it is necessary to pump or recharge the unconfined aquifer, the grouting bladder at the bottom of the unconfined aquifer is expanded to form a seal, while the grouting bladder at the bottom of the first confined aquifer is kept contracted. When it is necessary to pump or reinject water into both the unconfined aquifer and the first confined aquifer at the same time, the grouting bladder at the bottom of the first confined aquifer is controlled to expand to form a seal, while the grouting bladder at the bottom of the unconfined aquifer is kept contracted. When it is necessary to pump or reinject water into the unconfined aquifer, the first confined aquifer, and the second confined aquifer simultaneously, both grouting bladders should be kept contracted.

[0016] According to the above technical solution, preferably, the pumping and injection device includes an independent pumping pump and a reinjection pump, the pore pressure sensing unit is a pore pressure gauge buried in the filter material layer of each aquifer outside the well pipe, and the pressure sensing unit is a pressure gauge installed on the outside of the grouting bladder.

[0017] This invention also discloses a multi-aquifer intelligent stratification control method, applied to the above-mentioned system, comprising: Step S1: Determine the target aquifer and non-target aquifer according to construction requirements, control the expansion of the grouting bladder of the controllable sealing component at the corresponding location to form a seal for the non-target aquifer, and keep the grouting bladder of the remaining controllable sealing components contracted. Step S2: Obtain the signal from the pressure sensing unit. When the pressure acting on the well wall after the grouting bladder expands reaches the preset sealing pressure and remains stable, confirm that the initial sealing is completed. If the pressure does not reach the preset sealing pressure or the pressure drops below the preset range, automatically perform grouting until the sealing conditions are met. Step S3: After initial sealing confirmation, start the pumping and recharge device to perform pumping or recharge operations on the target aquifer; Step S4: During the operation, acquire pore water pressure data of the target aquifer and non-target aquifers in real time, and calculate the water level change of each aquifer accordingly. Step S5: Calculate the ratio of the water level change of the non-target aquifer to the water level change of the target aquifer. When the ratio reaches or exceeds the preset threshold, it is determined that the sealing is insufficient and the grouting procedure is automatically executed. When the ratio is less than the preset threshold, the sealing is determined to be effective and the current operating state is maintained. Step S6: After the grouting procedure is executed, continue to monitor the water level change of the non-target aquifer. If the ratio continues to reach or exceed the preset threshold and reaches the preset time, control the pumping device to stop working and issue an alarm signal. Step S7: When the water level change of the target aquifer reaches the preset drawdown or recharge target, reduce the pumping flow rate to maintain stable operation; when the water level of the target aquifer remains stable within the target range for a preset duration, control the pumping device to stop working.

[0018] The beneficial effects of this invention are: (1) This invention, by setting controllable sealing components inside the well pipe corresponding to the bottom of the unconfined aquifer and the bottom of the first confined aquifer, and by utilizing the expansion or contraction of the grouting bladder, can flexibly switch between various working conditions in the same well, such as pumping only the unconfined aquifer, pumping both the unconfined aquifer and the first confined aquifer, and pumping all three aquifers. Compared with the traditional scheme that requires setting up multiple wells, such as unconfined wells, pressure-reducing wells and depressurization wells, this invention only requires one well to cover the groundwater control needs of multiple construction stages, significantly reducing the number of well points, lowering construction costs, and simplifying site layout; (2) This invention uses pore pressure sensing units installed in the filter media layers of each aquifer to continuously acquire the pore water pressure changes of non-target aquifers during the pumping process, and makes real-time judgments on the effectiveness of the sealing. When the ratio of the water level change of the non-target aquifer to the water level change of the target aquifer reaches a preset threshold, the system can automatically determine that the sealing is insufficient and trigger the grouting operation. This active dynamic closed-loop control mechanism effectively solves the problem of lag in traditional sealing methods, ensures the long-term reliability of the sealing, and effectively prevents cross-layering, bypassing and leakage. This invention uses pressure sensing units installed on the outside of the grouting bladder to detect the expansion pressure of the grouting bladder before starting the pumping operation. Only when the pressure applied to the well wall reaches the preset sealing pressure and remains stable is the initial sealing confirmed and pumping allowed to start. If the pressure does not meet the standard or drops abnormally, the system will automatically perform grouting until the sealing conditions are met. This initial sealing self-checking mechanism effectively avoids the risk of accidents caused by starting pumping before the initial sealing is in place. (3) The grouting bladder of the present invention is attached to the inner wall of the well pipe in the un-grouted state, which does not affect the normal lifting and operation of the pumping pump and the reinjection pump in the well. The grouting bladder, grouting pipe and each sensing unit can be pre-installed before the well pipe is lowered. Later, the switching of different working conditions can be realized only through the wellhead control device. There is no need for complicated downhole mechanical disassembly and assembly operations, and the construction and maintenance are extremely convenient. (4) This invention is applicable not only to stratified pumping of unconfined aquifers, first confined aquifers, and second confined aquifers, but also to stratified recharge of different aquifers, realizing integrated well pumping and recharge functions. This has significant application value for engineering scenarios that require simultaneous dewatering construction and groundwater recharge compensation. Attached Figure Description

[0019] Figure 1 A schematic diagram of the main structure of the present invention is shown; Figure 2 A top view of the grouting bladder of the present invention in its uninflated state is shown; Figure 3 A cross-sectional structural schematic diagram of the grouting bladder of the present invention in its unexpanded state is shown; Figure 4 A schematic diagram of the grouting bladder in its expanded state is shown. Explanation of reference numerals in the attached figures: 1. Well casing; 2. Pore pressure sensing unit; 3. Pressure sensing unit; 4. Controllable plugging assembly; 5. Annular waterproof layer; 6. Grouting bladder; 7. Filter layer; 8. Grouting pipe; 9. Top sealing area; 10. Bottom sealing area; 11. Wellhead control device. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] In the description of the invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., 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 invention and simplifying the description, and do not 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 invention.

[0022] As shown in the figure, this invention provides an intelligent stratified control well system suitable for multiple aquifers, including a well pipe 1 installed inside the wellbore, a pumping device (not shown in the figure) connected to the inside of the well pipe, a wellhead control device 11, a pore pressure sensing unit 2, and a pressure sensing unit 3. A controllable sealing component 4 is provided inside the well pipe at a position corresponding to at least one aquifer bottom plate. The controllable sealing component includes an annular waterproof layer 5 and a spherical expandable grouting bladder 6 connected to the grouting pipe 8. A pore pressure sensing unit is embedded in the filter layer 7 outside the well pipe, and corresponds to the target aquifer and the non-target aquifer respectively, and is used to detect the pore water pressure of the target aquifer and the non-target aquifer respectively. The pressure sensing unit is located between the outer side of the grouting bladder and the inner wall of the well casing, and is used to detect the pressure acting on the well wall after the grouting bladder expands. The wellhead control device is connected to the controllable plugging assembly, pumping device, pore pressure sensing unit, and pressure sensing unit, and performs the following controls: In the first operating condition, the expansion of the grouting bladder is controlled to form a seal, and the pumping device is activated to operate on the target aquifer. During the pumping process, the signal from the pore pressure sensing unit is acquired, and the effectiveness of the sealing is determined in real time based on the change in pore water pressure in the non-target aquifer. When insufficient sealing is detected, the grouting operation of the grouting bladder is automatically triggered.

[0023] Optionally, in one possible implementation, the real-time determination includes: calculating the ratio of the water level change of the non-target aquifer to the water level change of the target aquifer; when the ratio reaches or exceeds a preset threshold, it is determined that the sealing is insufficient.

[0024] Optionally, in one possible implementation, the preset threshold is 10%.

[0025] Optionally, in one possible implementation, the control further includes: after triggering the grouting operation, continuing to monitor the change in pore water pressure in the non-target aquifer; if the grouting is still determined to be insufficient and the preset time is reached after grouting, then controlling the pumping device to stop working and issuing an alarm signal.

[0026] Optionally, in one possible implementation, the control further includes: acquiring a signal from the pressure sensing unit, and automatically triggering a grouting operation when the pressure acting on the well wall after the grouting bladder expands is lower than the preset sealing pressure, so as to establish an initial seal. The establishment of the initial seal is completed before the pumping device is started to operate on the target aquifer.

[0027] Optionally, in one possible implementation, the annular waterproof layer is fixed to the inner wall of the well pipe, and the grouting bladder is disposed on one side of the annular waterproof layer. In the expanded state, the upper and lower ends of the grouting bladder extend beyond the corresponding edges of the annular waterproof layer, forming a top sealing area 9 and a bottom sealing area 10 that fit against the inner wall of the well pipe.

[0028] Optionally, in one possible implementation, the control further includes: acquiring the change in pore water pressure of the target aquifer; when the change reaches a preset drawdown or recharge target, controlling the pumping and recharge device to maintain stable operation; and when the water level corresponding to the change remains stable within the target range for a preset duration, controlling the pumping and recharge device to stop operating.

[0029] Optionally, in one possible implementation, a controllable plugging component is installed inside the well casing corresponding to the bottom of the unconfined aquifer and the bottom of the first confined aquifer. The wellhead control device selectively controls the expansion or contraction of each grouting bladder according to external commands or a preset program, switching between various operating conditions: When it is necessary to pump or recharge the unconfined aquifer, the grouting bladder at the bottom of the unconfined aquifer is expanded to form a seal, while the grouting bladder at the bottom of the first confined aquifer is kept contracted. When it is necessary to pump or reinject water into both the unconfined aquifer and the first confined aquifer at the same time, the grouting bladder at the bottom of the first confined aquifer is controlled to expand to form a seal, while the grouting bladder at the bottom of the unconfined aquifer is kept contracted. When it is necessary to pump or reinject water into the unconfined aquifer, the first confined aquifer, and the second confined aquifer simultaneously, both grouting bladders should be kept contracted.

[0030] According to the above technical solution, preferably, the pumping and injection device includes an independent pumping pump and a reinjection pump, the pore pressure sensing unit is a pore pressure gauge buried in the filter material layer of each aquifer outside the well pipe, and the pressure sensing unit is a pressure gauge installed on the outside of the grouting bladder.

[0031] This invention also discloses a multi-aquifer intelligent stratification control method, applied to the above-mentioned system, comprising: Step S1: Determine the target aquifer and non-target aquifer according to construction requirements, control the expansion of the grouting bladder of the controllable sealing component at the corresponding location to form a seal for the non-target aquifer, and keep the grouting bladder of the remaining controllable sealing components contracted. Step S2: Obtain the signal from the pressure sensing unit. When the pressure acting on the well wall after the grouting bladder expands reaches the preset sealing pressure and remains stable, confirm that the initial sealing is completed. If the pressure does not reach the preset sealing pressure or the pressure drops below the preset range, automatically perform grouting until the sealing conditions are met. Step S3: After initial sealing confirmation, start the pumping and recharge device to perform pumping or recharge operations on the target aquifer; Step S4: During the operation, acquire pore water pressure data of the target aquifer and non-target aquifers in real time, and calculate the water level change of each aquifer accordingly. Step S5: Calculate the ratio of the water level change of the non-target aquifer to the water level change of the target aquifer. When the ratio reaches or exceeds the preset threshold, it is determined that the sealing is insufficient and the grouting procedure is automatically executed. When the ratio is less than the preset threshold, the sealing is determined to be effective and the current operating state is maintained. Step S6: After the grouting procedure is executed, continue to monitor the water level change of the non-target aquifer. If the ratio continues to reach or exceed the preset threshold and reaches the preset time, control the pumping device to stop working and issue an alarm signal. Step S7: When the water level change of the target aquifer reaches the preset drawdown or recharge target, reduce the pumping flow rate to maintain stable operation; when the water level of the target aquifer remains stable within the target range for a preset duration, control the pumping device to stop working.

[0032] Unified Formula Explanation To facilitate the control device in determining the water level changes of each aquifer based on the monitoring results of the pore pressure gauge, the conversion relationship between the pore water pressure u measured by the pore pressure gauge and the water level change is as follows: (1) When the elevation of the pore pressure gauge installation point is z, the corresponding water level elevation H at this monitoring point is: ; Where u is the pore water pressure measured by the pore pressure gauge. Let g be the density of water and g be the acceleration due to gravity. (2) Under pumping conditions, taking the initial pore water pressure u0 as the reference, the pore water pressure at a certain moment is u t At that time, the corresponding water level drop Δh is: ; (3) Under the reinjection condition, taking the initial pore water pressure u0 as the reference, the pore water pressure at a certain moment is u t At that time, the corresponding water level rise Δh is: ; in, The density of the water is taken, and g is the acceleration due to gravity. The control device converts the measured data of the pore pressure gauge into the water level drop, water level rise and corresponding water level elevation in real time according to the above formula, and performs operation judgment and start-stop control accordingly.

[0033] Example 1: Example 1 illustrates the installation process of an intelligent stratified control well system suitable for multiple aquifers, including the following steps: Step (1): Drill a well with a radius of 350mm according to the designed location; Step (2): Process a steel well pipe with a radius of 273mm, and pre-weld the grouting bladder installation bracket to the inner wall of the well pipe; Step (3): Tie the grouting pipe along the outer wall of the well pipe and connect it to the grouting bladders corresponding to the bottom of the unconfined layer and the bottom of the first confined aquifer, respectively; Step (4): Install annular waterproof layers at the bottom of the phreatic layer and the bottom of the first confined aquifer, respectively; Step (5): Install pore pressure gauges in the filter material layer outside the well casing at the locations corresponding to the unconfined aquifer, the first confined aquifer, and the second confined aquifer, respectively; Step (6): Install a pressure gauge on the outside of the grouting bladder to monitor the force exerted by the grouting bladder on the well wall after expansion; Step (7): Lower the entire well casing to the designed depth; Step (8): Fill the outside of the well casing with filter material, with sand filling the outside of the aquifer and clay balls filling the outside of the impermeable layer; Step (9): Install the water pump, reinjection pump and wellhead control device; Step (10): The control device first injects grout into the grouting bladder at the target location, causing the grouting bladder to expand and adhere tightly to the well wall; Step (11): The pressure gauge monitors the force exerted by the grouting bladder after expansion in real time. When the pressure gauge reading reaches the design sealing pressure of 1.0 × 10⁻⁶, the pressure is released. 5 After Pa, the control device confirms that the seal is complete; if the pressure does not reach the design sealing pressure of 1.0 × 10⁻⁶ Pa, the control device will confirm that the seal is complete. 5 If the pressure drops below the preset range, the control device will continue to replenish the slurry; Step (12): Start the water pump or recharge pump; Step (13): The pore pressure gauge monitors the changes in pore pressure of each aquifer in real time, and applies the formula... The measured pore pressure is converted into the corresponding water level elevation of each aquifer and then fed back to the control device. Step (14): If the pore pressure of the target aquifer changes in the preset direction, and the change in pore pressure of the non-target aquifer is less than the preset threshold, the control device maintains the current operating state. Step (15): If the pore pressure of the non-target aquifer changes abnormally, the control device will automatically determine that the sealing is insufficient and continue to replenish grout or adjust the pumping and recharge flow rate; when the water level change of the non-target aquifer is less than 10% of the water level change of the target aquifer, the interlayer isolation effect is determined to be good; when the water level change of the non-target aquifer is greater than or equal to 10% of the water level change of the target aquifer, it is determined that there is a strong interlayer hydraulic connection or insufficient sealing.

[0034] Step (16): When the target aquifer reaches the designed drawdown or recharge target, the control device maintains the current operating state.

[0035] Step (17): When the target aquifer water level remains stable within the set range for a preset duration, the control device stops the pumping pump or the reinjection pump. Step (18): When the target aquifer water level is lower than the preset lower limit water level, the control device immediately stops pumping; when the target aquifer water level is higher than the preset upper limit water level, the control device immediately stops reinjection. Step (19): When any orifice pressure gauge, pressure gauge or pump set shows an abnormal signal, the control device will automatically stop and alarm.

[0036] Example 2: Example 2 describes a scenario where only the groundwater level is pumped out.

[0037] Step (1): Inject grout into the grouting bladder corresponding to the bottom of the unwater layer to expand it and seal the lower space inside the well; Step (2): Keep the grouting bladder corresponding to the bottom of the first confined aquifer in an un-grouted state; Step (3): The pressure gauge monitors the force exerted by the grouting bladder at the bottom of the submerged layer after expansion in real time, ensuring that it reaches the design sealing pressure of 1.0 × 10⁻⁶. 5 Pa; if the design value of 1.0 × 10⁻⁶ is not reached. 5 If the pressure fluctuation exceeds the allowable range, the control device will continue to replenish the slurry; Step (4): Start the water pump to pump water only from the groundwater level; Step (5): The reading of the pore pressure gauge in the shallow water layer gradually decreases, and according to the formula... ; Converted to the drop in groundwater level, of which, This represents the drop in the water level of the phreatic layer. The initial pore water pressure of the unconfined layer. The pore water pressure in the unconfined layer at a certain moment; The pore pressure gauge readings for the first confined aquifer are calculated using the formula... ; Converted to the water level drop of the first confined aquifer, of which, This represents the drop in water level of the first confined aquifer. The initial pore water pressure of the first confined aquifer. The pore water pressure of the first confined aquifer at a certain moment; Step (6): The pore pressure gauge readings of the first and second confined aquifers should remain basically stable; Step (7): When the rate of drop in the water level of the phreatic layer is greater than the upper limit of the preset rate, the control device automatically reduces the pumping flow rate; when the rate of drop in the water level of the phreatic layer is less than the lower limit of the preset rate, the control device may appropriately increase the pumping flow rate. Step (8): If the water level of the first confined aquifer drops by a certain amount With the drop in water level of the groundwater layer satisfy <0.1 If so, the sealing at the bottom of the shallow water layer is deemed effective, and the interlayer isolation effect is good; if ≥0.1 If the sealing at the bottom of the phreatic layer is insufficient or the hydraulic connection between layers is too strong, the control device will automatically determine that the grouting is insufficient and continue to add grout; if the grouting still fails to meet the requirements... ≥0.1 Once the preset time is reached, the control device will automatically stop pumping and sound an alarm.

[0038] Step (9): If the pore pressure of the first confined aquifer continues to drop after grouting, the control device will automatically stop pumping and sound an alarm. Step (10): When the water level drop of the unconfined layer is calculated from the pore pressure gauge When the designed drawdown depth is reached, the control device automatically reduces the pumping flow rate and maintains stable operation; Step (11): When the real-time water level of the groundwater layer calculated by the pore pressure gauge is lower than the preset minimum control water level, the control device immediately stops pumping to prevent excessive precipitation. Step (12): When the water level of the phreatic layer calculated by the pore pressure gauge reaches the preset time continuously and stably within the target range, the control device automatically stops the pump.

[0039] Example 3 Example 3 describes a scenario where water is pumped from both the unconfined aquifer and the first confined aquifer simultaneously.

[0040] Step (1): Keep the grouting bladder at the bottom of the water sluice in an un-grouted state; Step (2): Inject grout into the grouting bladder corresponding to the bottom of the first confined aquifer to expand it and seal the second confined aquifer; Step (3): The pressure gauge monitors the force exerted by the grouting bladder at the bottom of the first confined aquifer after expansion in real time; Step (4): When the expansion pressure of the grouting bladder reaches the design value of 1.0 × 10⁻⁶ 5 Once the pressure reaches and stabilizes, start the water pump. Step (5): The pore pressure gauge readings of the unconfined aquifer and the first confined aquifer gradually decrease, and are respectively calculated according to the formula. and Converted to the water level drop of the unconfined aquifer and the first confined aquifer; The pore pressure gauge reading of the second confined aquifer is calculated according to the formula. ; Converted to the water level drop of the second confined aquifer, of which, This represents the drop in water level of the second confined aquifer. This represents the initial pore water pressure of the second confined aquifer. This represents the pore water pressure in the second confined aquifer at a certain moment. Step (6): The pore pressure gauge reading of the second confined aquifer should remain stable; Step (7): When the difference in the rate of drop between the water level of the unconfined layer and the first confined aquifer exceeds the preset threshold, the control device automatically adjusts the pumping flow rate so that the drawdown of the two layers meets the design requirements. Step (8): If the water level of the second confined aquifer drops by a certain amount With the drop in water level of the first confined aquifer satisfy <0.1 If so, the sealing of the bottom of the first confined aquifer is deemed effective, and the second confined aquifer is deemed not significantly disturbed; if ≥0.1 If the grouting chamber at the bottom of the first confined aquifer is not properly sealed or the hydraulic connection between layers is too strong, the control device will automatically continue to add grout; if the grouting still fails to meet the requirements after adding grout... ≥0.1 Once the preset time is reached, the control device will automatically stop pumping and sound an alarm.

[0041] Step (9): If the pore pressure of the second confined aquifer still drops abnormally after grouting, the control device will automatically stop pumping and sound an alarm. Step (10): When the water level drop of the unconfined layer is calculated from the pore pressure gauge and the drop in water level of the first confined aquifer Once the designed drawdown depth has been achieved, the control device automatically reduces the pumping flow rate and maintains stable operation. Step (11): When the real-time water level of any target aquifer calculated by the pore pressure gauge is lower than the corresponding preset lower limit water level, the control device automatically stops pumping. Step (12): When the water levels of the two target aquifers calculated by the pore pressure gauge are stable within the target range for a preset time, the control device automatically stops the pump.

[0042] Example 4 Example 4 describes a scenario where water is pumped simultaneously from a shallow aquifer, a first confined aquifer, and a second confined aquifer.

[0043] Step (1): Keep all grouting bladders in an un-grouted state; Step (2): Start the water pump to connect all aquifers in the well; Step (3): The pore pressure gauge readings of the unconfined aquifer, the first confined aquifer, and the second confined aquifer all gradually decrease, and are respectively calculated according to the formula. , and Converted to the water level drop of each of the three aquifers; Step (4): The control device automatically adjusts the pumping flow rate according to the rate of change of pore pressure in the three aquifers; Step (5): When the rate of water level drop of a certain aquifer calculated by the pore pressure gauge is significantly higher than that of other aquifers, the control device automatically reduces the pumping flow rate to prevent the aquifer from being drawn too deep. Step (6): When the water level of a certain aquifer calculated by the pore pressure gauge has reached the design drawdown while the water levels of the other aquifers have not, the control device will switch the system to a low flow balance operation mode. Step (7): When the water level of any aquifer calculated by the pore pressure gauge is lower than its preset lower limit water level, the control device immediately stops pumping; Step (8): When the three aquifers calculated by the pore pressure gauge have all reached the design drawdown and have been stably maintained within the allowable range for the preset time, the control device will automatically stop the pump. Step (9): If any orifice pressure gauge or pump unit malfunctions during operation, the control device will automatically stop and alarm.

[0044] Example 5 Example 5 describes a scenario where only the groundwater layer is recharged.

[0045] Step (1): Inject grout into the grouting bladder corresponding to the bottom of the unconfined aquifer to expand it and seal the first and second confined aquifers; Step (2): Keep the grouting bladder corresponding to the bottom of the first confined aquifer in an un-grouted state; Step (3): When the pressure outside the grouting bladder reaches the design sealing pressure value of 1.0 × 10⁻⁶ 5 After Pa stabilizes, start the reinjection pump to reinject only into the groundwater layer; Step (4): The reading of the pore pressure gauge in the shallow water layer gradually increases, and according to the formula... Converted to a rise in the groundwater level, of which, This represents the rise in the water level of the phreatic layer. The first confined aquifer is calculated according to the formula. Converted to the rise in water level of the first confined aquifer, among which, This represents the rise in water level of the first confined aquifer. Step (5): The pore pressure gauge readings of the first and second confined aquifers should remain basically stable; Step (6): If the rate of rise of the water level in the groundwater layer exceeds the preset upper limit, the control device will automatically reduce the reinjection flow rate; Step (7): If the water level of the first confined aquifer drops by a certain amount With the drop in water level of the groundwater layer satisfy <0.1 If so, the sealing at the bottom of the shallow water layer is deemed effective, and the interlayer isolation effect is good; if ≥0.1 If the sealing at the bottom of the phreatic layer is insufficient or the hydraulic connection between layers is too strong, the control device will automatically determine that the grouting is insufficient and continue to add grout; if the grouting still fails to meet the requirements... ≥0.1 Once the preset time is reached, the control device will automatically stop pumping and sound an alarm.

[0046] Step (8): If the pore pressure of the first confined aquifer continues to rise after grouting, the control device will automatically stop the reinjection and sound an alarm. Step (9): When the rise in water level of the unconfined layer is calculated by the pore pressure gauge When the designed recharge target is achieved, the control device automatically reduces the recharge flow rate and maintains stable operation; Step (10): When the real-time water level of the unconfined layer calculated by the pore pressure gauge is higher than the preset maximum control water level, the control device immediately stops the recharge; Step (11): When the water level of the phreatic layer calculated by the pore pressure gauge stabilizes within the target range for a preset duration, the control device automatically stops the pump.

[0047] Example 6 Example 6 describes a scenario where only the unconfined aquifer and the first confined aquifer are reinjected.

[0048] Step (1): Keep the grouting bladder corresponding to the bottom of the water-bearing layer in an un-grouted state; Step (2): Inject grout into the grouting bladder corresponding to the bottom of the first confined aquifer to expand it and seal the second confined aquifer; Step (3): The pressure gauge monitors the force exerted by the grouting bladder at the bottom of the first confined aquifer after expansion in real time. When it reaches the design sealing pressure of 1.0 × 10⁻⁶, the pressure is released. 5After the pressure reaches Pa and remains stable within a preset time, the control device confirms that the seal is complete; if the pressure does not reach the design value of 1.0 × 10⁻⁶ Pa, the control device will confirm the seal is complete. 5 If the pressure drops below the preset range, the control device will continue to replenish the slurry. Step (4): Start the reinjection pump so that the reinjection water enters the unconfined aquifer and the first confined aquifer at the same time; Step (5): The pore pressure gauge readings of the unconfined aquifer and the first confined aquifer gradually increase, and are respectively calculated according to the formula. and calculate, in, For the rise in water level of the groundwater layer, This represents the rise in water level of the first confined aquifer. The second confined aquifer is determined according to the formula. Calculation, where This represents the rise in water level of the second confined aquifer.

[0049] Step (6): The pore pressure gauge reading of the second confined aquifer should remain basically stable; Step (7): When the difference in the rate of rise of the water level between the unconfined aquifer and the first confined aquifer calculated by the pore pressure gauge exceeds the preset threshold, the control device automatically adjusts the reinjection flow rate so that the reinjection effect of the two layers meets the design requirements. Step (8): If the water level of the second confined aquifer drops by a certain amount With the drop in water level of the first confined aquifer satisfy <0.1 If so, the sealing of the bottom of the first confined aquifer is deemed effective, and the second confined aquifer is deemed not significantly disturbed; if ≥0.1 If the grouting chamber at the bottom of the first confined aquifer is not properly sealed or the hydraulic connection between layers is too strong, the control device will automatically continue to add grout; if the grouting still fails to meet the requirements after adding grout... ≥0.1 Once the preset time is reached, the control device will automatically stop pumping and sound an alarm.

[0050] Step (9): If the pore pressure of the second confined aquifer continues to rise after grouting, the control device will automatically stop the reinjection and sound an alarm. Step (10): When the rise in water level of the unconfined layer is calculated by the pore pressure gauge and the rise in water level of the first confined aquifer When the designed recharge target is achieved, the control device automatically reduces the recharge flow rate and maintains stable operation; Step (11): When the real-time water level of any target aquifer calculated by the pore pressure gauge is higher than the corresponding preset upper limit water level, the control device immediately stops the recharge to prevent excessive recharge or local overpressure. Step (12): When the water levels of the two target aquifers calculated by the pore pressure gauge are continuously and stably maintained within the target range for a preset duration, the control device automatically stops the pump.

[0051] Example 7 Example 7 describes a combined reinjection of three layers: the unconfined aquifer, the first confined aquifer, and the second confined aquifer.

[0052] Step (1): Keep all grouting bladders in an unexpanded state; Step (2): Start the reinjection pump to connect all aquifers in the well; Step (3): The readings of the three aquifer pore pressure gauges gradually increase, and are respectively calculated according to the formula. , and Converted to the water level rise of each of the three aquifers; Step (4): The control device automatically adjusts the reinjection flow rate according to the rate of change of pore pressure in the three aquifers; Step (5): When the rate of rise of the water level of a certain aquifer calculated by the pore pressure gauge is significantly higher than that of the other aquifers, the control device automatically reduces the reinjection flow to avoid local overpressure. Step (6): When the water level of any aquifer calculated by the pore pressure gauge is higher than the corresponding preset upper limit water level, the control device immediately stops the reinjection; Step (7): When the pore pressure gauge determines that all three aquifers in the well have reached the designed reinjection target and stabilized within the allowable error range for a preset time, the control device automatically stops the pump; Step (8): When any pore pressure gauge, reinjection pump or control unit malfunctions, the control device will automatically shut down and alarm.

[0053] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A smart stratified control well system suitable for multiple aquifers, comprising a well casing installed within a wellbore, characterized in that, It also includes a pumping and irrigation device connected to the inside of the well casing, a wellhead control device, a pore pressure sensing unit, and a pressure sensing unit, among which, A controllable sealing component is provided inside the well pipe at a position corresponding to at least one aquifer bottom plate. The controllable sealing component includes an annular waterproof layer and a spherical expandable grouting bladder connected to the grouting pipe. The pore pressure sensing unit is embedded in the filter layer outside the well pipe and corresponds to the target aquifer and the non-target aquifer respectively, and is used to detect the pore water pressure of the target aquifer and the non-target aquifer respectively. The pressure sensing unit is disposed between the outer side of the grouting bladder and the inner wall of the well pipe, and is used to detect the pressure acting on the well wall after the grouting bladder expands. The wellhead control device is signal-connected to the controllable plugging assembly, the pumping device, the pore pressure sensing unit, and the pressure sensing unit, and performs the following controls: In the first operating condition, the grouting bladder is controlled to expand to form a seal, and the pumping device is started to operate on the target aquifer; During the pumping process, the signal from the pore pressure sensing unit is acquired, and the effectiveness of the sealing is determined in real time based on the change in pore water pressure in the non-target aquifer. When insufficient sealing is detected, the grouting operation of the grouting bladder is automatically triggered.

2. The intelligent stratified control well system applicable to multiple aquifers according to claim 1, characterized in that, The real-time determination includes: calculating the ratio of the water level change of the non-target aquifer to the water level change of the target aquifer; when the ratio reaches or exceeds a preset threshold, it is determined that the sealing is insufficient.

3. The intelligent stratified control well system applicable to multiple aquifers according to claim 2, characterized in that, The preset threshold is 10%.

4. The intelligent stratified control well system applicable to multiple aquifers according to claim 1, characterized in that, The control also includes: after triggering the grouting operation, continuing to monitor the change in pore water pressure in the non-target aquifer; if the grouting is still insufficient and the preset time is reached after grouting, then controlling the pumping device to stop working and issuing an alarm signal.

5. The intelligent stratified control well system applicable to multiple aquifers according to claim 1, characterized in that, The control also includes: acquiring the signal from the pressure sensing unit; when the pressure exerted on the well wall after the grouting bladder expands is lower than the preset sealing pressure, automatically triggering a grouting operation to establish an initial seal; the establishment of the initial seal is completed before the pumping device is started to operate on the target aquifer.

6. The intelligent stratified control well system applicable to multiple aquifers according to claim 1, characterized in that, The annular waterproof layer is fixed to the inner wall of the well pipe, and the grouting bladder is disposed on one side of the annular waterproof layer. In the expanded state, the upper and lower ends of the grouting bladder extend beyond the corresponding edges of the annular waterproof layer, forming a top sealing area and a bottom sealing area that fit against the inner wall of the well pipe.

7. The intelligent stratified control well system applicable to multiple aquifers according to claim 1, characterized in that, The control also includes: acquiring the change in pore water pressure of the target aquifer; when the change reaches the preset drawdown or recharge target, controlling the pumping and recharge device to maintain stable operation; and when the water level corresponding to the change remains stable within the target range for a preset duration, controlling the pumping and recharge device to stop working.

8. The intelligent stratified control well system applicable to multiple aquifers according to claim 1, characterized in that, The well casing contains one controllable plugging assembly corresponding to the bottom of the unconfined aquifer and the bottom of the first confined aquifer. The wellhead control device selectively controls the expansion or contraction of each grouting bladder according to external commands or a preset program, switching between various operating conditions: When it is necessary to pump or recharge the aquifer, the grouting bladder at the bottom of the aquifer is controlled to expand to form a seal, while the grouting bladder at the bottom of the first confined aquifer is kept contracted. When it is necessary to pump or reinject water into both the unconfined aquifer and the first confined aquifer at the same time, the grouting bladder at the bottom of the first confined aquifer is controlled to expand to form a seal, while the grouting bladder at the bottom of the unconfined aquifer is kept contracted. When it is necessary to pump or reinject water into the unconfined aquifer, the first confined aquifer, and the second confined aquifer simultaneously, both grouting bladders should be kept contracted.

9. The intelligent stratified control well system applicable to multiple aquifers according to claim 1, characterized in that, The pumping and injection device includes an independent pumping pump and a reinjection pump. The pore pressure sensing unit is a pore pressure gauge buried in the filter material layer of each aquifer outside the well pipe. The pressure sensing unit is a pressure gauge installed on the outside of the grouting bladder.

10. A multi-aquifer intelligent stratification control method, applied to the system according to any one of claims 1 to 9, characterized in that, include: Step S1: Determine the target aquifer and non-target aquifer according to construction requirements, control the expansion of the grouting bladder of the controllable sealing component at the corresponding location to form a seal for the non-target aquifer, and keep the grouting bladder of the remaining controllable sealing components contracted. Step S2: Obtain the signal from the pressure sensing unit. When the pressure acting on the well wall after the grouting bladder expands reaches the preset sealing pressure and remains stable, confirm that the initial sealing is completed. If the pressure does not reach the preset sealing pressure or the pressure drops below the preset range, automatically perform grouting until the sealing conditions are met. Step S3: After initial sealing confirmation, start the pumping and recharge device to perform pumping or recharge operations on the target aquifer; Step S4: During the operation, acquire pore water pressure data of the target aquifer and non-target aquifers in real time, and calculate the water level change of each aquifer accordingly. Step S5: Calculate the ratio of the water level change of the non-target aquifer to the water level change of the target aquifer. When the ratio reaches or exceeds the preset threshold, it is determined that the sealing is insufficient and the grouting procedure is automatically executed. When the ratio is less than the preset threshold, the sealing is determined to be effective and the current operating state is maintained. Step S6: After the grouting procedure is executed, continue to monitor the water level change of the non-target aquifer. If the ratio continues to reach or exceed the preset threshold and reaches the preset time, control the pumping device to stop working and issue an alarm signal. Step S7: When the water level change of the target aquifer reaches the preset drawdown or recharge target, reduce the pumping flow rate to maintain stable operation; when the water level of the target aquifer remains stable within the target range for a preset duration, control the pumping device to stop working.

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