An in-situ testing system and method for groundwater seepage

Abstract

The application provides a groundwater seepage in-situ test system and method, relates to the technical field of hydrogeological test, and forms a sealed test section through the upper packer of a double-sealing exploration cabin, the sidewall of a borehole and the lower packer, injects water into the sealed test section and releases a tracer by using a water injection and tracer module in the double-sealing exploration cabin, and an in-situ monitoring module collects test parameters of the sealed test section in real time, a central processing module dynamically compensates the test parameters, obtains compensated test parameters, performs seepage inversion based on the compensated test parameters, and obtains hydrogeological parameters of the borehole, so that the authenticity and accuracy of seepage test data in deep-buried long-tunnel hydrogeological exploration are improved, the identification ability of a fault dominant water channel is enhanced, and the adaptive control level and operation safety of the test process are improved.

Description

Technical Field

[0001] This invention relates to the field of hydrogeological testing technology, and more specifically, to an in-situ groundwater seepage testing system and method. Background Technology

[0002] In the exploration of deep-buried long tunnels, borehole water pressure tests and tracer tests are the main means of obtaining hydrogeological parameters of the rock mass. However, traditional methods have the following prominent problems: mud cake formed by mud wall protection blocks rock fissures, resulting in a significantly lower permeability coefficient measured by water pressure tests and data distortion; surface water injection equipment and in-hole monitoring devices are independent of each other, making it difficult to synchronize excitation and monitoring, and thus impossible to obtain in-situ dynamic response data; there is a lack of real-time compensation methods for dynamic seepage-pressure coupling effects, and sensor baseline drift and temperature interference under water injection excitation lead to insufficient reliability of dynamic test data; traditional methods can only provide macroscopic permeability indicators and are difficult to identify advantageous water-conducting channels such as fault fracture zones; fixed pressure injection mode lacks adaptability, blindly applying high pressure can easily cause hydraulic fracturing, and in dense rock layers, insufficient pressure often leads to test failure. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an in-situ groundwater seepage testing system and method to improve the authenticity and accuracy of seepage test data in hydrogeological exploration of deep buried long tunnels, enhance the ability to identify dominant water-conducting channels of faults, and improve the adaptive control level and operational safety of the testing process.

[0004] In a first aspect, this application provides an in-situ groundwater seepage testing system, comprising: The dual-packed test chamber, located inside the borehole, includes an upper packer and a lower packer. The upper packer, the sidewall of the borehole, and the lower packer form a sealed test section. The dual-packed test chamber is equipped with a water injection and tracer module and an in-situ monitoring module. The water injection and tracer module and the in-situ monitoring module are located between the upper and lower packers and are connected to the sealed test section. The water injection and tracer module is used to inject water into the sealed test section and release tracer; the in-situ monitoring module is used to collect the test parameters of the sealed test section in real time. The central processing module, located inside the double-sealed test chamber, is connected to the water injection and tracing module and the in-situ monitoring module, respectively. It is used to dynamically compensate the test parameters, obtain compensated test parameters, and perform seepage inversion based on the compensated test parameters to obtain the hydrogeological parameters of the borehole.

[0005] Optionally, the water injection and tracing module includes a water injection unit, and the test parameters include osmotic pressure parameters and concentration parameters. The water injection unit is connected to the central processing module. The central processing module is also used to obtain the rate of change of osmotic pressure based on osmotic pressure parameters; to obtain the rate of change of concentration based on concentration parameters; and to generate control commands for adjusting the output flow rate or pressure of the water injection unit based on the rate of change of osmotic pressure, a preset threshold, and the rate of change of concentration.

[0006] Optionally, the central processing module is also used to generate a control command to reduce the output flow of the water injection unit when the rate of change of seepage pressure exceeds a preset threshold. When the rate of change in osmotic pressure remains zero within a preset time and the rate of change in concentration is zero, a control command is generated to increase the output pressure of the water injection unit in a stepwise manner.

[0007] Optionally, the test parameters include injection temperature, hydrostatic pressure, and seepage pressure; the central processing module dynamically compensates for the test parameters to obtain compensated test parameters, including: The temperature deviation is obtained based on the water injection temperature parameters and the preset temperature; The hydrostatic pressure deviation is obtained based on the hydrostatic pressure parameters and the preset pressure. The pore pressure increment caused by water injection is obtained based on the difference between the osmotic pressure parameter and the hydrostatic pressure parameter. The compensation test parameters are obtained based on temperature deviation, hydrostatic pressure deviation, pore pressure increment, and correction coefficient.

[0008] Optionally, the correction factors include temperature compensation factor, hydrostatic pressure compensation factor, and osmotic pressure coupling compensation factor; the in-situ monitoring module includes a tracer concentration sensor and an osmotic pressure sensor; the central processing module is also used for: The concentration values ​​of the tracer concentration sensor under different temperature conditions are obtained, and the concentration values ​​are linearly fitted with the corresponding temperatures. The slope of the resulting straight line is determined as the temperature compensation coefficient. The concentration reading offset of the tracer concentration sensor under different hydrostatic pressure conditions is obtained. The concentration reading offset is linearly fitted with the corresponding hydrostatic pressure, and the slope of the obtained straight line is determined as the hydrostatic pressure compensation coefficient. Multiple sets of field-measured data were acquired. Each set of data included the actual concentration value of the tracer concentration sensor at the test site, the corresponding true concentration, the measured temperature, the measured hydrostatic pressure, and the osmotic pressure increment. Based on the multiple sets of field-measured data, the osmotic pressure coupling compensation coefficient was determined by a multivariate nonlinear regression algorithm. The osmotic pressure increment was determined based on the difference between the hydrostatic pressure baseline value of the osmotic pressure sensor before water injection activation and the real-time pore pressure value during the water injection activation process.

[0009] Optionally, the central processing module performs seepage inversion based on the compensated test parameters to obtain the borehole's hydrogeological parameters, including: Based on the boundary conditions and injection parameters of the sealed test section, an analytical solution model of the convection-dispersion equation was constructed, and the compensation test parameters at each sampling time point were used to construct the measured penetration curve. The permeability and dispersion of the sealed test section are used as variables to be inverted and input into the analytical solution model to obtain the simulated concentration change over time. With the goal of minimizing the fitting error between the measured penetration curve and the simulated curve, the particle swarm optimization algorithm is used to iteratively adjust the variables to be inverted, and the permeability coefficient and dispersion are obtained.

[0010] Optionally, the central processing module is also used for: Based on the compensation test parameters and the corresponding time, a change curve is obtained. When the change curve has multiple peaks or the response time is less than the preset time threshold, it is determined that there is an advantageous water guiding channel in the sealed test section.

[0011] Secondly, this application provides an in-situ groundwater seepage testing method, applicable to the aforementioned in-situ groundwater seepage testing system, comprising: The double-packed test chamber is placed at the target depth inside the borehole, and the expansion of the upper and lower packers of the double-packed test chamber is controlled so that the upper packer, the side wall of the borehole, and the lower packer form a sealed test section. Water is injected into the sealed test section and tracer is released through the water injection and tracer module; The test parameters of the sealed test section are collected in real time through the in-situ monitoring module; The test parameters are dynamically compensated by the central processing module to obtain compensated test parameters, and seepage inversion is performed based on the compensated test parameters to obtain the hydrogeological parameters of the borehole.

[0012] Optionally, before injecting water into the sealed test section and releasing the tracer via the water injection and tracer module, the method further includes: High-pressure pulsed water flow is used to flush the mud film off the sidewalls of the borehole.

[0013] Optionally, after obtaining the hydrogeological parameters of the borehole, the process also includes: Release the pressure on the upper and lower packers to cause them to contract; Control the inlet valve of the in-situ monitoring module to obtain in-situ water samples within the sealed test section.

[0014] This invention provides an in-situ groundwater seepage testing system and method. A sealed test section is formed by the upper packer of a double-sealed chamber, the sidewall of the borehole, and the lower packer. Water is injected into the sealed test section and a tracer is released using a water injection and tracer module within the double-sealed chamber. An in-situ monitoring module collects test parameters of the sealed test section in real time. A central processing module dynamically compensates the test parameters to obtain compensated test parameters. Based on these compensated test parameters, seepage inversion is performed to obtain the hydrogeological parameters of the borehole. This improves the authenticity and accuracy of seepage test data in the hydrogeological exploration of deeply buried long tunnels, enhances the ability to identify dominant water-conducting channels in faults, and improves the adaptive control level and operational safety of the testing process.

[0015] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the conventional water injection or tracer test separation and mud wall interference mode provided in the embodiments of the present invention is shown; Figure 2 A schematic diagram of the structure of the in-situ groundwater seepage testing system provided in an embodiment of the present invention is shown; Figure 3 A schematic diagram of the structure of the double-sealed probe compartment provided in an embodiment of the present invention is shown; Figure 4 A schematic diagram of the in-situ monitoring module provided in an embodiment of the present invention is shown; Figure 5 A schematic diagram of the tracer penetration curve provided in an embodiment of the present invention is shown; Figure 6 A schematic flowchart of an in-situ groundwater seepage testing method provided in an embodiment of the present invention is shown. Figure 7 A schematic diagram of the seepage inversion provided in an embodiment of the present invention is shown; Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present invention is shown.

[0018] Key component symbols: 1-Double-packed probe chamber; 2-Upper packer; 3-Lower packer; 4-Water injection and tracer module; 5-In-situ monitoring module; 6-Central processing module; 8-Composite cable; 9-Ground terminal; 11-Water inlet valve; 12-Tracer storage chamber; 13-Micro water injection pump; 14-Pressure sensor; 15-Tracer concentration sensor; 16-Multi-parameter water quality probe; 17-Composite cable winch; 18-Tension sensor; 19-Booster pump; 20-Gas-liquid distributor. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, existing deep-hole seepage testing methods have several drawbacks: mud cake blocks fissures, resulting in significantly lower permeability rates in pressure tests, distorted data, and potential safety hazards; water injection requires multi-hole and large-scale equipment, manual intermittent recording, lack of dynamic full-process monitoring, and large parameter errors; Bayer tube sampling for laboratory analysis is not in-situ testing, and temperature, pressure, and adsorption-induced concentration peaks are prone to leakage, making it difficult to identify water-conducting faults; high-pressure geothermal temperatures cause sensor drift, lack of in-situ compensation, poor dynamic accuracy, and the inability to adaptively adjust excitation parameters, leading to easy breakdown or insufficient flow rate causing test failure. Therefore, this application provides an in-situ groundwater seepage testing system to improve the authenticity and accuracy of seepage test data in hydrogeological exploration of deeply buried long tunnels, enhance the ability to identify dominant water-conducting channels in faults, and improve the adaptive control level and operational safety of the testing process.

[0021] This application provides an in-situ groundwater seepage testing system, including a double-sealed test chamber 1 and a central processing module 6. The double-sealed test chamber 1 is located inside a borehole and includes an upper packer 2 and a lower packer 3. The upper packer 2, the sidewall of the borehole, and the lower packer 3 form a sealed test section. The double-sealed test chamber 1 is equipped with a water injection and tracing module 4 and an in-situ monitoring module 5. The water injection and tracing module 4 and the in-situ monitoring module 5 are located between the upper packer 2 and the lower packer 3 and are connected to the sealed test section. The water injection and tracing module 4 is used to inject water into the sealed test section and release tracer; the in-situ monitoring module 5 is used to collect the test parameters of the sealed test section in real time. The central processing module 6 is located inside the double-sealed probe chamber 1 and is connected to the water injection and tracing module 4 and the in-situ monitoring module 5 respectively. It is used to dynamically compensate the test parameters, obtain the compensated test parameters, and perform seepage inversion based on the compensated test parameters to obtain the hydrogeological parameters of the borehole.

[0022] In the embodiments of this application, such as Figure 2 and Figure 3 As shown, the main body of the double-packed test chamber 1 is made of pressure-resistant and corrosion-resistant alloy tubing, with a high-pressure airbag packer at each end, namely the upper packer 2 and the lower packer 3. Both the upper packer 2 and the lower packer 3 use high-strength rubber inflatable airbags with a rated working pressure rating of 15MPa to 30MPa to adapt to different depths of ground stress and pore water pressure environments. For example, when the borehole depth is between 300m and 500m, a high-pressure airbag packer with a pressure rating of 15MPa can be selected; when the borehole depth is between 500m and 800m, a high-pressure airbag packer with a pressure rating of 30MPa can be selected. After the upper packer 2 and the lower packer 3 are filled with high-pressure gas or liquid through the ground gas-liquid distributor 20, they expand and adhere tightly to the sidewall of the borehole, thereby forming a closed sealing test section inside the borehole, reliably isolating the sealing test section from the upper and lower borehole sections.

[0023] The water injection and tracer module 4 and the in-situ monitoring module 5 are both located between the upper packer 2 and the lower packer 3, and are hydraulically connected to the sealing test section. The water injection and tracer module 4 includes a water injection unit, specifically a high-pressure micro-injection pump 13, which is electrically connected to the central processing module 6. The water injection and tracer module 4 also includes an intelligent tracer storage chamber 12, which releases a specific concentration of tracer controlled by a solenoid valve. The high-pressure micro-injection pump 13 can inject water directionally into the sealing test section through the water injection pipeline, or it can flush the mud film on the borehole wall with a high-pressure pulse water flow in the early stage of water injection to break up the mud film blockage formed by the mud slurry wall protection. For example, the pulse injection pressure increment of the high-pressure micro-injection pump 13, that is, the difference between the pressure and the original static water pressure, can be set to 0.5MPa to 3.0MPa, and the pulse frequency can be set to 0.1Hz to 1.0Hz, so as to ensure that the water flow can effectively penetrate the mud skin of the borehole wall and enter the rock mass, while avoiding micro-fractures in the formation due to excessive pressure.

[0024] like Figure 4As shown, the in-situ monitoring module 5 integrates a high-precision osmotic pressure sensor 14, a tracer concentration sensor 15, and a multi-parameter water quality probe 16. The osmotic pressure sensor 14 has a measurement accuracy of 0.1%FS and a response time ≤10ms; the tracer concentration sensor 15 uses high-precision fluorescence spectroscopy with a detection limit of 0.05mg / L and a measurement accuracy within ±2%; the multi-parameter water quality probe 16 has an electrode response accuracy better than ±1%. Each sensor probe in the in-situ monitoring module 5 is positioned in the sealed test section of the water body to collect real-time test parameters such as osmotic pressure, concentration, injection temperature, hydrostatic pressure, and water quality parameters. The in-situ monitoring module 5 also has a reserved interface for use with the intelligent water intake container, allowing reuse of its storage chamber and inlet valve 11 for in-situ sampling and storage.

[0025] The central processing module 6 is sealed and installed inside the double-sealed probe chamber 1, and is electrically connected to the high-pressure micro-injection pump 13, solenoid valve, seepage pressure sensor 14, tracer concentration sensor 15, water quality multi-parameter probe 16, and communication module. The central processing module 6 is used to collect the test parameters output by each sensor, execute the dynamic seepage pressure coupling compensation algorithm, seepage parameter inversion algorithm, and adaptive excitation control strategy, and transmit the processing results to the ground terminal 9 through the signal line in the composite cable 8.

[0026] The ground terminal 9 includes a ground intelligent deployment and retrieval module and a control console. The ground intelligent deployment and retrieval module integrates a variable frequency water injection booster pump 19, a tension sensor 18, a gas-liquid distributor 20, and an armored composite cable winch 17. The composite cable 8 contains air pipes, water pipes, and signal lines, providing isolation air pressure, water injection pressure, and data transmission channels for the downhole double-sealed detection chamber 1. The ground intelligent deployment and retrieval module and the control console are connected to the double-sealed detection chamber 1 via the composite cable 8, enabling power supply, gas supply, water supply, and data communication.

[0027] In this embodiment, the central processing module 6 is further configured to obtain the osmotic pressure change rate based on the osmotic pressure parameter; obtain the concentration change rate based on the concentration parameter; and generate a control command for adjusting the output flow rate or pressure of the water injection unit based on the osmotic pressure change rate, a preset threshold, and the concentration change rate. When the osmotic pressure change rate exceeds the preset threshold, a control command to reduce the output flow rate of the water injection unit is generated; when the osmotic pressure change rate remains zero for a preset time and the concentration change rate is zero, a control command to gradually increase the output pressure of the water injection unit is generated.

[0028] Specifically, the central processing module 6 acquires osmotic pressure parameters in real time through the osmotic pressure sensor 14 at a preset sampling frequency (e.g., 10Hz to 100Hz) and calculates the osmotic pressure change rate. Simultaneously, concentration parameters are acquired via tracer concentration sensor 15, and the concentration change rate is calculated. Preset threshold. The pressure rating can be determined based on the packer's rated pressure resistance and the estimated formation permeability. For example, It can be set to 0.1 MPa / min to 0.5 MPa / min. When the rate of change in osmotic pressure... Exceeding the preset threshold When the pressure change rate indicates the presence of high-permeability channels or cracks opening within the sealed test section, resulting in rapid loss of injection flow, the central processing module 6 generates a control command to reduce the output flow of the injection unit, such as reducing the output flow to 50% of the current flow or decreasing it in preset steps, to prevent excessive tracer loss and packer depressurization. If the concentration remains zero and the rate of change is zero within a preset time (e.g., 30s to 60s), it indicates that the rock mass is dense or the mud cake on the borehole wall has not been effectively flushed out, and the water injection has not formed an effective seepage. At this time, the central processing module 6 generates a control command to increase the output pressure of the water injection unit in a step-by-step manner, for example, by 0.2MPa to 0.5MPa each time, and observes the seepage pressure response by stabilizing the pressure at each pressure step until an effective head difference is generated or the upper limit of the packer's safe pressure is reached.

[0029] Furthermore, the central processing module 6 dynamically compensates the test parameters to obtain the compensated test parameters. The specific process is as follows: based on the injection temperature parameter and the preset temperature, the temperature deviation is obtained; based on the hydrostatic pressure parameter and the preset pressure, the hydrostatic pressure deviation is obtained; based on the difference between the osmotic pressure parameter and the hydrostatic pressure parameter, the pore pressure increment caused by the injection is obtained; based on the temperature deviation, hydrostatic pressure deviation, pore pressure increment, and correction coefficients, the compensated test parameters are obtained, where the correction coefficients include the temperature compensation coefficient, the hydrostatic pressure compensation coefficient, and the osmotic pressure coupling compensation coefficient. The in-situ monitoring module 5 includes a tracer concentration sensor 15 and an osmotic pressure sensor 14. The central processing module 6 is also used to: acquire the concentration values ​​of the tracer concentration sensor 15 under different temperature conditions, and process the concentration values... A linear fit was performed with the corresponding temperature, and the slope of the resulting line was determined as the temperature compensation coefficient. The concentration reading offset of the tracer concentration sensor 15 under different hydrostatic pressure conditions was obtained, and a linear fit was performed with the concentration reading offset and the corresponding hydrostatic pressure. The slope of the resulting line was determined as the hydrostatic pressure compensation coefficient. Multiple sets of field-measured data were obtained. Each set of data included the actual concentration value of the tracer concentration sensor 15 at the test site, the corresponding true concentration, the measured temperature, the measured hydrostatic pressure, and the osmotic pressure increment. Based on multiple sets of field-measured data, the osmotic pressure coupling compensation coefficient was determined by a multivariate nonlinear regression algorithm. The osmotic pressure increment was determined based on the difference between the hydrostatic pressure reference value of the osmotic pressure sensor 14 before water injection activation and the real-time pore pressure value during the water injection activation process.

[0030] Specifically, the compensation test parameters can be calculated using the following compensation formula:

[0031] In the formula, To compensate for test parameters (such as the compensated tracer concentration or pH value). The raw sensor readings. To measure the actual water injection temperature, To measure the hydrostatic pressure, This refers to the increase in pore pressure caused by water injection. and These are the standard reference temperature and pressure (e.g.) 25℃ is acceptable. (0.1 MPa can be used). This is the temperature compensation coefficient. This is the hydrostatic pressure compensation coefficient. This is the osmotic pressure coupling compensation coefficient.

[0032] Temperature compensation coefficient The determination method is as follows: Place the tracer concentration sensor 15 in an indoor constant temperature calibration water bath, keep the standard solution concentration constant, select at least 5 temperature gradient points (e.g., 5℃~45℃) within the sensor's operating temperature range (e.g., 5℃~45℃), and after the temperature stabilizes, record the original sensor readings at each temperature point. Calculate the drift at each temperature point based on the standard concentration value; perform a univariate linear regression fitting with temperature as the abscissa and drift as the ordinate, and the slope of the resulting straight line is the temperature compensation coefficient. ; hydrostatic pressure compensation coefficient The method for determining the hydrostatic pressure is as follows: Maintain constant temperature and concentration in an indoor high-pressure simulation chamber. Gradually change the hydrostatic pressure inside the chamber using an external servo booster pump 19 (e.g., 0 MPa to 10 MPa, with 1 MPa intervals). Record the concentration reading deviation of the tracer concentration sensor 15 under different hydrostatic pressures. Plot pressure on the x-axis and concentration reading deviation on the y-axis, and perform linear fitting using the least squares method. The slope of the resulting fitted line is the hydrostatic pressure compensation coefficient. ; Permeation-Pressure Coupling Compensation Coefficient The determination method is as follows: Within the same test section, an in-situ water sample is first extracted using a sampling mechanism, and the actual concentration is then determined with high precision by a laboratory. Simultaneously, the raw readings of the tracer concentration sensor 15 at the same time are recorded. ,temperature hydrostatic pressure and osmotic pressure increment Substituting into the above compensation formula, we establish the equation:

[0033] This can be solved by reverse reasoning. The above process was repeated in multiple strata with different permeabilities (such as intact rock masses, fractured sections, and fault fracture zones) to construct a dataset containing multiple sets of field-measured data. A multivariate nonlinear regression algorithm (such as the Levenberg-Marquardt algorithm) was used for iterative optimization to determine the permeability-pressure coupling compensation coefficient suitable for the current geological conditions. In actual operation, The value can be adaptively retrieved by the central processing module 6 based on the permeability baseline of different strata.

[0034] In this embodiment, the specific process by which the central processing module 6 performs seepage inversion based on the compensated test parameters to obtain the hydrogeological parameters of the borehole is as follows: Based on the boundary conditions and injection parameters of the sealed test section, an analytical solution model of the convection-dispersion equation is constructed, and the compensated test parameters at each sampling time point are used to construct measured penetration curves; the permeability coefficient and dispersion of the sealed test section are input into the analytical solution model as variables to be inverted, resulting in a simulated curve of the model's simulated concentration changing over time; with the optimization objective of minimizing the fitting error between the measured penetration curve and the simulated curve, a particle swarm optimization algorithm is used to iteratively adjust the variables to be inverted, obtaining the permeability coefficient and dispersion.

[0035] Specifically, based on the geometry and injection conditions of the sealed test section, the section can be generalized as a semi-infinite homogeneous medium. An analytical solution model of the one-dimensional convection-dispersion equation (such as the Ogata-Banks solution) can be used to calculate the change in tracer concentration over time. The model simulates the concentration... The permeability coefficient can be obtained through analytical formulas. By relating Darcy's law to average flow velocity, dispersion Correlation with hydrodynamic dispersion coefficient. The compensated tracer concentrations were arranged in chronological order to obtain the measured breakthrough curves, such as... Figure 5 As shown; the permeability coefficient of the variable to be inverted. and diffusion As the particle positions in the particle swarm optimization algorithm, the particle swarm is initialized (the number of particles can be set to 20-50), with each particle corresponding to a group. The values ​​are substituted into the analytical solution model to calculate the simulated concentration at each sampling time point, and the objective function is calculated:

[0036] In the formula, For the first The measured concentration at each sampling time point (i.e., the compensation test parameter). To simulate concentrations in the model, This represents the total number of sampling points. Through iterative updates of particle velocity and position (with adjustable inertia weights and learning factors, and iteration counts of 100-200), the objective function is improved. The coefficient is continuously reduced until it converges to the global optimum or reaches the preset number of iterations, and the optimal penetration coefficient is output. and diffusion This refers to the hydrogeological parameters of the borehole being measured.

[0037] In this embodiment of the application, the central processing module 6 is further configured to: obtain a change curve based on the compensation test parameters and the corresponding time; and determine that there is an advantageous water guiding channel in the sealed test section when the change curve has multiple peaks or the response time is less than a preset time threshold.

[0038] Specifically, the central processing module 6 arranges the compensated test parameters (such as the compensated tracer concentration) at each sampling time point in chronological order, generating a penetration curve showing the concentration changing over time. When the penetration curve shows two or more peaks, it indicates the existence of multiple water-conducting paths with different permeability within the sealed test section. The time it takes for the tracer to reach the monitoring point along different paths varies, thus indicating the presence of a dominant water-conducting channel (such as an open fracture, dissolution channel, or fault fracture zone) within the sealed test section. When the response time of the penetration curve is less than a preset time threshold, i.e., the time from the tracer release to the first significant increase in concentration (e.g., exceeding three times the baseline concentration) is much shorter than the response time calculated according to the homogeneous medium theory, it indicates the existence of a high-speed connecting channel within the test section, which also indicates the presence of a dominant water-conducting channel. The preset time threshold can be set based on the test section length and the estimated permeability coefficient using an analytical solution model to estimate the homogeneous response time; for example, it can be 50% or less of the homogeneous theoretical response time. Furthermore, an abnormally steep rising section or a significant tailing of the attenuation section of the concentration curve can also serve as an auxiliary criterion for the existence of a dominant water-conducting channel.

[0039] This application also provides an in-situ groundwater seepage testing method, applicable to the aforementioned in-situ groundwater seepage testing system, see reference. Figure 6 As shown, the in-situ groundwater seepage testing method provided in this application includes at least the following steps: Step 110: Place the double-packed test chamber at the target depth inside the borehole, and control the expansion of the upper and lower packers of the double-packed test chamber so that the upper packer, the sidewall of the borehole, and the lower packer form a sealed test section.

[0040] In this embodiment, the double-packed test chamber is connected to a ground-based intelligent deployment and retrieval module via an armored composite cable. The armored composite cable winch is operated to lower the double-packed test chamber at a uniform speed to a predetermined target depth within the borehole, such as a fault fracture zone or a section with anticipated abnormal seepage. During the lowering process, a tension sensor in the ground-based intelligent deployment and retrieval module monitors the tension of the composite cable in real time. Lowering is stopped promptly when the tension abnormally increases to prevent the test chamber from getting stuck. After the double-packed test chamber reaches the target depth, high-pressure gas or liquid is injected into the high-strength rubber expansion bladders of the upper and lower packers via a ground-based gas-liquid distributor. After expansion, the bladders adhere tightly to the sidewall of the borehole, reliably isolating the target test section from the upper and lower borehole sections, forming a closed, sealed test section. The rated working pressure rating of the upper and lower packers can be selected according to the borehole depth: a 15MPa pressure rating is used for borehole depths of 300m to 500m, and a 30MPa pressure rating is used for borehole depths of 500m to 800m.

[0041] To dislodge the mud cake formed by the mud slurry wall and restore hydraulic connectivity between the sealing test section and the surrounding rock, in this embodiment, after the sealing test section is formed, high-pressure pulsed water flow is used to flush the mud cake on the borehole sidewall. Specifically, the high-pressure micro-injection pump in the water injection and tracing module is activated to inject high-pressure water flow into the sealing test section in a pulsed manner. The pulse injection pressure increment (i.e., the difference from the in-situ hydrostatic pressure) is set to 0.5MPa to 3.0MPa, and the pulse frequency is set to 0.1Hz to 1.0Hz. Under the repeated impact of the pulsed water flow, the mud cake on the borehole wall is gradually flushed away. When the pore pressure sensor detects a significant response in the pore pressure or a significant increase in the injection flow rate, it indicates that the mud cake blockage has been effectively cleared, and the subsequent water injection or tracing activation stage can proceed.

[0042] Step 120: Inject water into the sealed test section and release tracer through the water injection and tracer module.

[0043] In this embodiment, either a pressure test mode or a tracer test mode is selected based on the testing objective. In the pressure test mode, a high-pressure micro-injection pump continuously injects water into the sealed test section at a set pressure or flow rate to stimulate a seepage response. In the tracer test mode, the solenoid valve of the intelligent tracer storage chamber is opened, releasing a tracer of a specific concentration into the sealed test section. During water injection or tracer release, the central processing module monitors the rate of change of osmotic pressure and the rate of change of concentration in real time, and adaptively adjusts the output flow rate or pressure of the injection unit based on the monitoring results: when the rate of change of osmotic pressure exceeds a preset threshold, the output flow rate of the injection unit is reduced; when the rate of change of osmotic pressure remains zero within a preset time and the rate of change of concentration is zero, the output pressure of the injection unit is increased in stages until an effective head difference is generated.

[0044] Step 130: Collect test parameters of the sealed test section in real time through the in-situ monitoring module.

[0045] In this embodiment, the in-situ monitoring module uses an integrated high-precision osmotic pressure sensor, tracer concentration sensor, and multi-parameter water quality probe to collect real-time test parameters such as osmotic pressure, concentration, injection temperature, hydrostatic pressure, and water quality within the sealed test section at a preset sampling frequency (e.g., 10Hz–100Hz). The osmotic pressure sensor has a measurement accuracy of 0.1%FS and a response time ≤10ms; the tracer concentration sensor uses high-precision fluorescence spectroscopy with a detection limit of 0.05mg / L and a measurement accuracy within ±2%; the multi-parameter water quality probe has an electrode response accuracy better than ±1%. Each sensor probe is directly exposed to the water in the sealed test section, and the collected test parameters are sent to the central processing module in real time.

[0046] Step 140: The test parameters are dynamically compensated by the central processing module to obtain the compensated test parameters, and the seepage inversion is performed based on the compensated test parameters to obtain the hydrogeological parameters of the borehole.

[0047] In this embodiment, after receiving the test parameters collected by the in-situ monitoring module, the central processing module executes a dynamic seepage pressure coupling compensation algorithm. Specifically, the temperature deviation is obtained based on the injection temperature parameter and the preset temperature; the hydrostatic pressure deviation is obtained based on the hydrostatic pressure parameter and the preset pressure; the pore pressure increment caused by injection activation is obtained based on the difference between the seepage pressure parameter and the hydrostatic pressure parameter; and the compensation test parameters are calculated according to the following formula based on the temperature deviation, hydrostatic pressure deviation, pore pressure increment, and correction coefficient:

[0048] In the formula, To compensate for test parameters (such as the compensated tracer concentration or pH value). The raw sensor readings. To measure the actual water injection temperature, To measure the hydrostatic pressure, This refers to the increase in pore pressure caused by water injection. and These are the standard reference temperature and pressure (e.g.) 25℃ is acceptable. (0.1 MPa can be used). This is the temperature compensation coefficient. This is the hydrostatic pressure compensation coefficient. This is the seepage pressure coupling compensation coefficient; Subsequently, the central processing module performs seepage inversion based on the compensated test parameters. Specifically, based on the boundary conditions and injection parameters of the sealed test section, an analytical solution model of the convection-dispersion equation is constructed, and the compensated test parameters at each sampling time point are used to construct measured penetration curves. The permeability coefficient and dispersion of the sealed test section are input into the analytical solution model as variables to be inverted, resulting in a simulated curve of the concentration changing over time. With the optimization objective of minimizing the fitting error between the measured penetration curve and the simulated curve, a particle swarm optimization algorithm is used to iteratively adjust the variables to be inverted, obtaining the permeability coefficient and dispersion, which are the hydrogeological parameters of the borehole, such as... Figure 7 As shown.

[0049] Furthermore, the central processing module also obtains the change curve based on the compensation test parameters and the corresponding time. When the change curve has multiple peaks or the response time is less than the preset time threshold, it is determined that there is an advantageous water-conducting channel in the sealed test section, such as an opening crack, a dissolution channel or a fault fracture zone.

[0050] To preserve physical water samples from the test section for verification of tracer concentration or water quality indicators, in this embodiment, after obtaining the hydrogeological parameters of the borehole, the pressure of the upper and lower packers is released to cause them to contract; the in-situ monitoring module's inlet valve is controlled to obtain in-situ water samples within the sealed test section. Specifically, after the test, the high-pressure gas or liquid inside the upper and lower packer airbags is released through the ground gas-liquid distributor, causing the airbags to contract and detach from the borehole sidewall; then, the intelligent water intake container interface reserved in the in-situ monitoring module is reused, the inlet valve is opened, and in-situ water samples are collected within the sealed test section; after collection, the inlet valve is closed, and the water samples are stored in the water storage chamber. After the double-packed probe is recovered to the ground, the water samples are exported and sent to the laboratory for analysis.

[0051] It should be noted that the principle of the in-situ groundwater seepage testing method provided in this application embodiment to solve the technical problem is similar to that of the in-situ groundwater seepage testing system provided in this application embodiment. Therefore, the implementation of the in-situ groundwater seepage testing method provided in this application embodiment can refer to the implementation of the in-situ groundwater seepage testing system provided in this application embodiment, and the repeated parts will not be described again.

[0052] After introducing the in-situ groundwater seepage testing method and apparatus provided in the embodiments of this application, the electronic equipment provided in the embodiments of this application will be briefly introduced next.

[0053] See Figure 8 As shown, the electronic device 500 provided in this application embodiment includes at least a processor 501, a memory 502, and a computer program stored in the memory 502 and capable of running on the processor 501. When the processor 501 executes the computer program, it implements the in-situ groundwater seepage testing method provided in this application embodiment.

[0054] The electronic device 500 provided in this application embodiment may further include a bus 503 connecting different components (including processor 501 and memory 502). The bus 503 represents one or more types of bus structures, including memory bus, peripheral bus, local area bus, etc.

[0055] Memory 502 may include a readable storage medium in the form of volatile memory, such as random access memory (RAM) 5021 and / or cache memory 5022, and may further include read-only memory (ROM) 5023. Memory 502 may also include a program tool 5025 having a set (at least one) of program modules 5024, including but not limited to an operating subsystem, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0056] Processor 501 can be a single processing element or a collective term for multiple processing elements. For example, processor 501 can be a central processing unit (CPU) or one or more integrated circuits configured to implement the in-situ groundwater seepage testing method provided in the embodiments of this application. Specifically, processor 501 can be a general-purpose processor, including but not limited to CPUs, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0057] Electronic device 500 can communicate with one or more external devices 504 (e.g., keyboard, remote control, etc.), and also with one or more devices that enable a user to interact with electronic device 500 (e.g., mobile phone, computer, etc.), and / or with devices that enable electronic device 500 to communicate with one or more other electronic devices 500 (e.g., router, modem, etc.). This communication can be performed through input / output (I / O) interface 505. Furthermore, electronic device 500 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) through network adapter 506. Figure 8As shown, network adapter 506 communicates with other modules of electronic device 500 via bus 503. It should be understood that, although... Figure 8 As not shown, other hardware and / or software modules may be used in conjunction with the electronic device 500, including but not limited to microcode, device drivers, redundant processors, external disk drive arrays, Redundant Arrays of Independent Disks (RAID) subsystems, tape drives, and data backup storage subsystems.

[0058] It should be noted that, Figure 8 The electronic device 500 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0059] The following describes the computer-readable storage medium provided in the embodiments of this application. The computer-readable storage medium provided in the embodiments of this application stores computer instructions, which, when executed by a processor, implement the in-situ groundwater seepage testing method provided in the embodiments of this application. Specifically, the computer instructions can be built into or installed in the processor, so that the processor can implement the in-situ groundwater seepage testing method provided in the embodiments of this application by executing the built-in or installed computer instructions.

[0060] In addition, the in-situ groundwater seepage testing method provided in this application embodiment can also be implemented as a computer program product. The computer program product includes program code, which implements the in-situ groundwater seepage testing method provided in this application embodiment when running on a processor.

[0061] The computer program product provided in this application embodiment may employ one or more computer-readable storage media, which may be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. Specifically, more specific examples (a non-exhaustive list) of computer-readable storage media include electrical connections with one or more wires, portable disks, hard disks, RAM, ROM, erasable programmable read-only memory (EPROM), optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0062] The computer program product provided in this application embodiment can be a CD-ROM and include program code, and can also run on electronic devices such as computers. However, the computer program product provided in this application embodiment is not limited thereto. In this application embodiment, the computer-readable storage medium can be any tangible medium that contains or stores program code, which can be used by or in conjunction with an instruction execution system, device, or apparatus.

[0063] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0064] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0065] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0066] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A groundwater seepage in-situ testing system, characterized in that, include: A dual-packed test chamber, located inside a borehole, includes an upper packer and a lower packer. The upper packer, the sidewall of the borehole, and the lower packer form a sealed test section. The dual-packed test chamber is equipped with a water injection and tracing module and an in-situ monitoring module. The water injection and tracing module and the in-situ monitoring module are located between the upper and lower packers and are connected to the sealed test section. The water injection and tracing module is used to inject water into the sealed test section and release a tracer; the in-situ monitoring module is used to collect test parameters of the sealed test section in real time. The central processing module, located inside the double-sealed probe chamber, is connected to the water injection and tracing module and the in-situ monitoring module, respectively. It is used to dynamically compensate the test parameters to obtain compensated test parameters, and to perform seepage inversion based on the compensated test parameters to obtain the hydrogeological parameters of the borehole.

2. The in-situ groundwater seepage testing system according to claim 1, characterized in that, The water injection and tracing module includes a water injection unit, and the test parameters include osmotic pressure parameters and concentration parameters. The water injection unit is connected to the central processing module. The central processing module is also used to obtain the osmotic pressure change rate based on the osmotic pressure parameter; obtain the concentration change rate based on the concentration parameter; and generate control commands for adjusting the output flow rate or pressure of the water injection unit based on the osmotic pressure change rate, a preset threshold, and the concentration change rate.

3. The in-situ groundwater seepage testing system according to claim 2, characterized in that, The central processing module is also used to generate a control command to reduce the output flow rate of the water injection unit when the rate of change of seepage pressure exceeds the preset threshold. When the rate of change of osmotic pressure remains zero within a preset time and the rate of change of concentration is zero, a control command is generated to increase the output pressure of the water injection unit in a stepwise manner.

4. The in-situ groundwater seepage testing system according to claim 1, characterized in that, The test parameters include water injection temperature, hydrostatic pressure, and seepage pressure. The central processing module dynamically compensates the test parameters to obtain compensated test parameters, including: Based on the water injection temperature parameters and the preset temperature, the temperature deviation is obtained; Based on the hydrostatic pressure parameters and the preset pressure, the hydrostatic pressure deviation is obtained; Based on the difference between the seepage pressure parameter and the hydrostatic pressure parameter, the pore pressure increment caused by water injection is obtained; Based on the temperature deviation, the hydrostatic pressure deviation, the pore pressure increment, and the correction coefficient, the compensation test parameters are obtained.

5. The in-situ groundwater seepage testing system according to claim 4, characterized in that, The correction coefficients include temperature compensation coefficients, hydrostatic pressure compensation coefficients, and osmotic pressure coupling compensation coefficients; the in-situ monitoring module includes a tracer concentration sensor and an osmotic pressure sensor; the central processing module is also used for: The concentration values ​​of the tracer concentration sensor under different temperature conditions are obtained, and the concentration values ​​are linearly fitted with the corresponding temperatures. The slope of the resulting straight line is determined as the temperature compensation coefficient. The concentration reading offset of the tracer concentration sensor under different hydrostatic pressure conditions is obtained, and the concentration reading offset is linearly fitted with the corresponding hydrostatic pressure. The slope of the obtained straight line is determined as the hydrostatic pressure compensation coefficient. Multiple sets of on-site measured data were acquired. Each set of data included the actual concentration value of the tracer concentration sensor at the test site, the corresponding true concentration, the measured temperature, the measured hydrostatic pressure, and the osmotic pressure increment. Based on the multiple sets of field measured data, the seepage pressure coupling compensation coefficient is determined by a multivariate nonlinear regression algorithm; wherein the seepage pressure increment is determined based on the difference between the hydrostatic pressure reference value of the seepage pressure sensor before water injection activation and the real-time pore pressure value during water injection activation.

6. The in-situ groundwater seepage testing system according to claim 1, characterized in that, The central processing module performs seepage inversion based on the compensation test parameters to obtain the hydrogeological parameters of the borehole, including: Based on the boundary conditions and injection parameters of the sealed test section, an analytical solution model of the convection-dispersion equation is constructed, and the compensation test parameters at each sampling time point are used to construct a measured penetration curve. The permeability and dispersion of the sealed test section are used as variables to be inverted and input into the analytical solution model to obtain the simulated curve of the concentration changing with time. With minimizing the fitting error between the measured penetration curve and the simulated curve as the optimization objective, the particle swarm optimization algorithm is used to iteratively adjust the variables to be inverted to obtain the penetration coefficient and dispersion.

7. The in-situ groundwater seepage testing system according to claim 1, characterized in that, The central processing module is also used for: Based on the compensation test parameters and the corresponding time, a change curve is obtained. When the change curve has multiple peaks or the response time is less than the preset time threshold, it is determined that the sealing test section has an advantageous water guiding channel.

8. A method for in-situ testing of groundwater seepage, applicable to the groundwater seepage in-situ testing system as described in any one of claims 1 to 7, characterized in that, include: The double-packed probe chamber is placed at the target depth inside the borehole, and the upper and lower packers of the double-packed probe chamber are controlled to expand, so that the upper packer, the side wall of the borehole, and the lower packer form a sealed test section. Water is injected into the sealed test section and tracer is released through the water injection and tracer module; The test parameters of the sealed test section are collected in real time by the in-situ monitoring module; The test parameters are dynamically compensated by the central processing module to obtain compensated test parameters, and seepage inversion is performed based on the compensated test parameters to obtain the hydrogeological parameters of the borehole.

9. The in-situ groundwater seepage testing method according to claim 8, characterized in that, Before injecting water into the sealed test section and releasing the tracer via the water injection and tracer module, the following steps are also included: High-pressure pulsed water jets are used to flush away the mud film on the sidewalls of the borehole.

10. The in-situ groundwater seepage testing method according to claim 8, characterized in that, After obtaining the hydrogeological parameters of the borehole, the process also includes: Release the pressure on the upper packer and the lower packer to cause them to contract; Control the inlet valve of the in-situ monitoring module to obtain in-situ water samples within the sealed test section.

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