Water resource deep storage five field coupling experiment simulation system and method

Abstract

The present application relates to the core physical simulation technology in the field of water resource deep geological storage and groundwater engineering, in particular to a water resource deep storage five-field coupling experiment simulation system and method, the system comprises an injection unit, a core clamping and multi-field coupling simulation unit, a water collection and control unit, an online detection unit and an integrated control and data fusion platform. The core holder integrates electrode array and acoustic wave transmission rod to realize acoustic-electric dual-mode monitoring; the liquid storage tank is provided with a stirring device at the bottom; the system is provided with an anaerobic sampling device and a flow calibration device at the end. The method comprises the following steps: synchronously applying and monitoring stress field, temperature field, chemical field, electric field and acoustic field; collecting acoustic emission and resistivity data for fusion imaging; collecting and detecting enzyme activity of effluent; establishing a multi-field coupling constitutive model and verifying it. The present application solves the problems of invisible, non-faithful sampling and non-quantitative mechanism in the traditional experiment process.

Description

Technical Field

[0001] This invention relates to core physics simulation technology in the field of deep geological storage of water resources and groundwater engineering, specifically an experimental simulation system and method for the five-field coupling effect of deep water storage. Background Technology

[0002] Geological storage of unconventional water resources such as mine water, urban stormwater, and reclaimed water is an important way to realize their resource utilization. Indoor core experiments are a core method for studying fluid-rock interactions and evaluating reservoir performance. However, existing core testing systems have significant shortcomings in simulating real underground multi-physical and chemical field coupling environments: first, they lack in-situ, real-time quantitative characterization methods for hydraulic fracturing processes; second, the evolution of microbial and hydrochemical parameters is mainly analyzed through offline sampling, lacking online monitoring capabilities, and the sampling process is prone to oxidation interference; third, the coupling effects of multiple physicochemical fields lack quantitative description and prediction capabilities. Therefore, there is an urgent need for an integrated experimental system and method that can achieve process visualization, sample fidelity, and mechanism quantification. Summary of the Invention

[0003] The purpose of this invention is to provide an experimental simulation system and method for the five-field coupling effect of deep water storage, so as to solve the problems of "invisible process, unreliable sampling, and unquantified mechanism" in the existing technology.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an experimental simulation system for the five-field coupling effect of deep water storage, wherein the five-field coupling includes stress field, temperature field, chemical field, electric field and acoustic field; the system includes: an injection unit, including at least one storage tank, each of the storage tanks is equipped with a homogenizing stirring device and is connected to an injection pump through a pipeline, and a flow meter is installed on the main injection pipeline after the convergence of multiple fluids.

[0005] The core clamping and multi-field coupling simulation unit includes a core clamp with a core receiving cavity, and a multi-field application component and a dual-mode monitoring component integrated on the core clamp; the core clamp is provided with a fluid injection port and a fluid outlet communicating with the injection unit.

[0006] The multi-field application components include an annular pressure system, a heating unit and a temperature sensor, as well as an online hydrochemical sensor that runs through the core holder body.

[0007] The dual-modal monitoring component includes an electrode array embedded in the wall of the core holder and an acoustic wave transmitter penetrating the end cap of the core holder; the electrode array is in electrical contact with the core sample, and its signal is led out through a feedthrough interface and electrically connected to an external electrical resistivity instrument; the acoustic wave transmitter is attached to the end face of the core and coupled to an acoustic emission receiver.

[0008] The effluent preservation collection and control unit includes a back pressure system and an anaerobic preservation sampling device; the anaerobic preservation sampling device includes an effluent water collection tank, which is connected to an inert gas source and placed on a measuring balance.

[0009] The online detection unit includes an online microbial detection device, which is connected to the effluent collection tank.

[0010] An integrated control and data fusion platform is used to synchronously collect parameters from multiple fields and coordinate the operation of each unit.

[0011] As a further aspect of the present invention: the storage tank includes a microbial storage tank and a raw water storage tank, a filter is connected in series on the pipeline connected to the raw water storage tank, the homogenizing stirring device is a stirrer; the ring pressure system includes a ring pressure pump.

[0012] As a further aspect of the present invention: the electrode array is composed of microelectrodes, which are integrated with the core holder cylinder through an insulating sleeve; the feedthrough interface is a sealed connector.

[0013] As a further aspect of the present invention: the acoustic emission receiver is electrically connected to the acoustic emission instrument, which is used to spatially locate micro-fracture events.

[0014] As a further aspect of the present invention: the back pressure system includes a back pressure pump; the inert gas source is a nitrogen tank; the measuring balance is an electronic balance; and the online microbial detection device is an online flow cytometer, used to detect the microbial characteristics of the liquid in the aqueous solution collection tank.

[0015] A testing method using the above-mentioned experimental simulation system for deep water storage with five-field coupling includes the following steps: S1, obtaining a core sample from the target aquifer and determining its initial porosity and initial permeability; filling the core sample into the core receiving cavity, making the electrode array electrically contact the core, and the acoustic wave transmitter attached to the end face of the core; determining the physicochemical parameters of the injected water and the activity parameters of the functional microbial system; and introducing inert gas into the effluent collection tank and pipeline to construct an anaerobic environment.

[0016] S2. Apply confining pressure through the ring pressure system and establish pore fluid pressure through the back pressure system; use the metering balance to weigh the mass increment of the liquid in the effluent collection tank in real time, calculate the cumulative flow rate and instantaneous flow velocity, and correct the reading of the flow meter according to the calculation results.

[0017] S3. Turn on the injection pump, mix the water containing the characteristic pollutant components with the functional microbial system in a preset ratio and inject it into the core, triggering the dual-mode monitoring component; collect acoustic emission signals, and when the signal intensity exceeds a preset threshold, determine it as a micro-fracture event and record it; use the electrode array to obtain the resistivity distribution map.

[0018] S4. After the fluid flows out, it enters the effluent collection tank for microbial detection, water chemistry determination, and enzyme activity determination.

[0019] S5. Calculate the spatial coordinates of the fracture source using acoustic emission signals to form a damage point cloud map; superimpose the point cloud map with the resistivity distribution map, and confirm the fracture trajectory when the dense area of ​​the acoustic emission point cloud coincides with the low resistivity anomaly zone in space.

[0020] S6. Based on the acquired data, perform multi-field coupling calculations using a mathematical model system, and compare the theoretical outflow calculated by the model with the measured flow in step S2. If the error is less than the preset value, output the model parameters.

[0021] As a further aspect of the present invention: the microbial detection in step S4 includes detecting the concentration, inactivation / deactivation ratio and morphology and size of microbial cells; and the enzyme activity in step S4 is determined by electrochemical or colorimetric methods.

[0022] As a further aspect of the present invention: the mathematical model system described in step S6 includes a permeability calculation model based on Darcy's law: In the formula: The Darcy velocity of the fluid inside the core; This represents the current absolute permeability of the core. This represents the hydraulic gradient along the seepage direction.

[0023] And a saturation field reconstruction model based on Archie's formula: In the formula: The resistivity of water-bearing rocks obtained by ERT inversion; The resistivity of formation water; Current porosity; Pore ​​fluid saturation; Lithology coefficient; The cementation index; This is the saturation index.

[0024] As a further aspect of the present invention: the mathematical model system described in step S6 further includes a convection-diffusion equation containing a blocking factor for characterizing enzyme migration: In the formula: This represents the enzyme's activity concentration; The hydrodynamic dispersion coefficient; This is the enzyme's natural inactivation / degradation constant; This refers to the source of enzyme production or reaction.

[0025] And the equation defining the retardation factor: In the formula: It is a blocking factor; This refers to the core bulk density. The adsorption partition coefficient; Effective porosity.

[0026] The enzyme reaction source term Following the Michaelis-Menten dynamic equations: In the formula: The maximum reaction rate; Substrate concentration; It is the Michaelis constant; Pre-exponential factors; Activation energy; The molar gas constant; Absolute temperature; It is a pH correction factor.

[0027] As a further aspect of the present invention: the mathematical model system described in step S6 further includes a stress-seepage-chemical-damage coupled constitutive model to quantitatively describe the nonlinear response of the core. This model includes: damage evolution equation: In the formula: For damage variables; Accumulate energy for real-time acoustic emission; The total energy at complete destruction; To prepare for the current situation; To prevent damage and strain.

[0028] Stress-damage coupling equation: In the formula: This is the total stress tensor; This is the initial elastic stiffness tensor; The effective stress coefficient of Biot; Pore ​​pressure; For Kroneck's symbol.

[0029] Stress-porosity evolution equation: In the formula: Initial porosity; Porosity stress sensitivity coefficient; For Biot's effective stress; The damage-induced pore expansion coefficient; This is the porosity change term caused by the chemical reaction.

[0030] Chemical-porosity evolution equation: In the formula: Current porosity; The molar volume of the mineral; The reaction rate constant; Specific surface area; It is the ion activity product; It is the equilibrium constant; It is an enzyme activity corrector.

[0031] Multi-field coupled permeability evolution model: In the formula: Initial penetration rate; Porosity after chemical reaction; This represents the current effective stress. This is the initial effective stress; The damage-to-penetration coefficient; The damage penetration index; Microbial concentration; The bioclogging coefficient.

[0032] Compared with the prior art, the beneficial effects of the present invention are: 1. It realizes "in-situ authentic sampling" of deep reducing environment fluids: By constructing a positive pressure anaerobic sampling device based on inert gas replacement, and combining it with online flow cytometer and deep ORP in-situ monitoring, the effluent is protected from oxygen throughout the entire process from the core outlet to the detection end, effectively preventing the oxidation and precipitation of reducing components and the inactivation of anaerobic enzymes.

[0033] 2. High-precision closed-loop metering of minute flow rates in tight reservoirs has been achieved: A high-precision electronic balance has been introduced as a metering and calibration unit. By monitoring the incremental mass of the effluent in real time and combining it with the fluid density to perform "mass-volume" conversion, dynamic closed-loop correction of the upstream flow meter readings has been performed, which has significantly improved the measurement accuracy of hydrodynamic field parameters under extremely low flow velocity displacement conditions.

[0034] 3. A multi-field coupled constitutive model incorporating enzyme kinetics was established: Based on multi-source monitoring data, a mathematical model system was constructed that includes acoustic emission damage evolution equation, Michaelis-Menten enzyme-catalyzed reaction kinetic equation, and permeability evolution equation with multi-mechanism competition, which quantitatively coupled microscopic enzyme-catalyzed reaction rate, mesoscopic rock damage factor, and macroscopic seepage law.

[0035] 4. Ensures long-term homogeneity and stability of the injected fluid: By integrating a magnetic stirring device below the microbial storage tank and the raw water storage tank, the uniformity of dispersion of mine water or microbial liquid containing suspended solids is ensured during the long-term displacement process, eliminating the fluctuation of the injected concentration gradient caused by sedimentation and stratification.

[0036] 5. A three-dimensional perception system integrating "sound-electricity-chemistry" was constructed: resistivity tomography and acoustic emission three-dimensional positioning technology were integrated simultaneously, realizing the spatial superposition of acoustic emission damage point cloud and resistivity fluid distribution image, intuitively presenting the extension trajectory of hydraulic fracturing fractures and the spatial morphology of fluid movement along the fractures. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of the experimental system in an embodiment of the present invention.

[0038] Figure 2 This is a partially enlarged structural diagram of the core holder and dual-mode monitoring component in an embodiment of the present invention.

[0039] In the diagram: 1. Microbial storage tank; 2. Microbial injection pump; 3. Raw water storage tank; 4. Filter; 5. Injection pump; 6. Online water chemistry sensor; 7. Valve; 8. Electrode array; 9. Acoustic emission receiver; 10. Acoustic wave transmission metal rod; 11. Pressure sensor; 12. Flow meter; 13. Heating unit; 14. Temperature sensor; 15. Ring pressure gauge; 16. Ring pressure buffer; 17. Ring pressure pump; 18. Back pressure gauge; 19. Back pressure buffer; 20. Back pressure pump; 21. Measuring balance; 22. Effluent water collection tank; 23. Inert gas source; 24. Online microbial detection device; 25. Homogenizing stirring device. Detailed Implementation

[0040] The technical solution of this application will be further described in detail below with reference to specific embodiments.

[0041] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0042]

Example 1: Experimental System

[0043] Please see Figure 1 and Figure 2 In one embodiment of the present invention, an experimental simulation system for the five-field coupling effect of deep water storage is provided.

[0044] The system is divided into an upstream injection unit, a midstream core clamping and multi-field coupling simulation unit, a downstream effluent fidelity collection and control unit, and an online detection unit according to the fluid flow direction. It is then uniformly coordinated and controlled by an integrated control and data fusion platform.

[0045] I. Injection Unit.

[0046] The injection unit is used to prepare and transport experimental fluids. It comprises a microbial storage tank 1 and a raw water storage tank 3, used to store bacterial solutions containing functional microorganisms (such as urease-producing bacteria) and simulated raw water (such as mine water), respectively. To prevent sedimentation of microorganisms or solid particles, each tank is equipped with a homogenizing stirring device 25 at its bottom. The homogenizing stirring device 25 is a magnetic stirrer that operates continuously during the experiment. The microbial storage tank 1 is connected in sequence to a microbial injection pump 2 and an adjustable valve 7 via pipelines; the raw water storage tank 3 is connected in sequence to a filter 4, an injection pump 5, and another adjustable valve 7 via pipelines. The two fluid streams converge downstream of valve 7 and are connected to the main injection pipeline. A high-precision pressure sensor 11 and a high-precision flow meter 12 are connected in series on the main injection pipeline for real-time monitoring of injection pressure and flow rate.

[0047] II. Core clamping and multi-field coupling simulation unit.

[0048] The core of this unit is a core holder suitable for large-diameter cores (not less than 100mm in diameter).

[0049] The multi-field application components include: a stress field, applied via an annular pressure system comprising an annular pressure pump 17, an annular pressure buffer 16, and an annular pressure gauge 15 connected in sequence, capable of simulating formation confining pressures up to 100 MPa; and a backpressure system (backpressure pump 20, backpressure buffer 19, and backpressure gauge 18) used to control the pore pressure at the core outlet.

[0050] Temperature field: The core holder has a multi-section independently temperature-controlled heating unit 13 and a temperature sensor 14 embedded in its cylinder wall, which can realize precise control and monitoring of the axial temperature gradient of the core.

[0051] Chemical field: The online water chemistry sensor 6 penetrates radially through the wall of the holder, with its probe end extending into the core receiving cavity at approximately 2 / 3 of its axial length, for in-situ monitoring of the redox potential of fluids after they have flowed through the main reaction zone.

[0052] Electric field: An embedded electrode array 8 is used for resistivity tomography data acquisition and three-dimensional inversion.

[0053] Sound field: Used for acoustic emission monitoring and spatial positioning of micro-fracture events via acoustic emission receiver 9 and sound wave transmission metal rod 10.

[0054] The dual-modal monitoring component includes: resistivity monitoring: employing an embedded electrode array 8. Multiple micro-cylindrical probes made of corrosion-resistant alloy are embedded in the holder cylinder wall via high-strength ceramic insulating sleeves using an interference fit. The inner end face of the probe forms point contact with the side of the core sample. All electrode signals are conditioned through a low-voltage electrical chamber within the cylinder wall and then led out through a metal-ceramic sealed feedthrough interface to an external resistivity tomography instrument for resistivity tomography data acquisition and three-dimensional inversion.

[0055] Acoustic emission monitoring: Multiple acoustic wave transmission metal rods 10 axially penetrate both end caps of the core holder. Their inner end faces fit tightly against the core end faces after core loading, forming good acoustic coupling; the outer end faces are mechanically coupled to a high-sensitivity acoustic emission receiver 9. The acoustic emission receiver 9 converts the acoustic signals into electrical signals and transmits them to a multi-channel acoustic emission instrument. This instrument incorporates a three-dimensional positioning algorithm based on time difference of arrival, which can calculate the spatial coordinates of micro-fracture events in real time.

[0056] III. Water Fidelity Collection and Control Unit.

[0057] The core outlet fluid first passes through a backpressure system and then enters the anaerobic precision sampling device. The core of this device is the effluent collection tank 22. Before the experiment starts, nitrogen gas is introduced into the effluent collection tank 22 and the upstream connecting pipeline through an inert gas source 23 (such as a high-purity nitrogen cylinder) to completely replace the air and create a positive pressure anaerobic environment. The bottom of the effluent collection tank 22 is placed on a high-precision measuring balance 21. The balance measures the mass increment of the effluent collection tank 22 in real time, and the data is uploaded to the control platform. Combined with the fluid density, the cumulative flow rate and instantaneous flow velocity can be calculated for dynamic closed-loop calibration of the upstream flow meter 12.

[0058] IV. Online Detection Unit.

[0059] The inlet of the online microbial detection device 24 (in this embodiment, an online flow cytometer) is connected to the downstream outlet of the effluent collection tank 22 via a pipeline. Under anaerobic protection, a portion of the effluent is directly introduced into the device to detect the concentration, viable / dead ratio, and morphology and size of microbial cells in real time.

[0060] V. Integrated Control and Data Fusion Platform.

[0061] This platform is a high-performance industrial control computer equipped with customized software, connecting to all sensors and actuators via a data acquisition card and communication interface. Its core functions include: millisecond-level synchronous acquisition of all pressure, temperature, flow rate, balance, ORP, acoustic emission waveforms, and resistivity tomography measurement data; real-time 3D inversion imaging of resistivity tomography data; real-time positioning calculation of acoustic emission data; fusion and display of acoustic emission event point clouds, resistivity tomography resistivity volume data, and other multi-field parameters under a unified spatiotemporal reference; and automatic control of the injection pump, valve 7, heating, and confining pressure according to preset programs, thus automating the experimental process.

[0062]

Example 2: Test Method

[0063] This embodiment describes the test method for conducting deep water storage simulation experiments using the above-mentioned five-field coupling effect experimental simulation system.

[0064] Step S1: Sample preparation and system initialization.

[0065] Core samples from the target aquifer were selected, and their initial porosity was determined. Initial penetration rate The lithology, electrical properties, and mechanical parameters are analyzed. A large-diameter core sample, pre-prepared and saturated with fluid and containing a prefabricated wellbore, is filled into the core container cavity of the core holder. The fluid injection port of the injection unit is inserted into the prefabricated wellbore hole inside the core via a sealed connector. The microprobe of the embedded electrode array 8 is ensured to pass through the ceramic insulating sleeve and make tight point contact with the side surface of the core, establishing an effective electrical pathway for resistivity imaging. The acoustic wave transmission metal rod 10 is passed through the end cap, with its inner end face directly abutting against the end face of the core, and the outer side connected to the acoustic emission receiver 9, constructing a waveguide for lossless transmission of microfracture signals from the inside of the core to the outside. The online hydrochemical sensor 6 is installed at two-thirds (2 / 3L) of the core's axial length for in-situ monitoring of the redox potential evolution after fluid flows through the main reaction zone. Before the experiment begins, the pH / ORP and concentration of characteristic pollutants in the water body, as well as the active cell concentration of the functional microbial system, are measured. Specific enzyme activities Inert gas source 23 is introduced into the effluent collection tank 22 and connecting pipeline system to completely remove air from the system using gas displacement, creating a positive pressure anaerobic environment. This step aims to prevent external oxygen from intruding and contaminating the effluent, ensuring accurate sampling of anaerobic microorganisms and oxidation-sensitive chemical components in subsequent experiments. The homogenizing stirring device 25 located below the microbial storage tank 1 and the raw water storage tank 3 is activated. Continuous stirring is maintained throughout the entire experimental preparation and execution to ensure uniform dispersion of the microbial suspension and complete dissolution of chemical solutes, eliminating injection concentration gradient errors caused by precipitation.

[0066] Step S2: Apply stress boundary and flow calibration.

[0067] The axial and annular pressure loading system is activated, and a preset confining pressure (e.g., 20-100 MPa) is applied according to the simulated formation depth through the annular pressure system of the multi-field application components. Subsequently, the back pressure system is activated to establish stable pore fluid pressure. After the pressure reading stabilizes, the core is in a state of compaction equilibrium. The metering balance 21 is installed at the bottom of the aqueous solution collection tank 22. The fluid density is input. The mass increment of the liquid in the aqueous solution collection tank 22 is measured in real time. Using the formula Calculate cumulative outflow The instantaneous flow velocity is also recorded. This data is fed back to the integrated control and data fusion platform in real time to dynamically correct the readings of the upstream high-precision flow meter 12, ensuring the accuracy of the hydrodynamic field data.

[0068] Step S3: Injection and Synchronization Monitoring.

[0069] The injection pump is activated, and the valve 7 is instructed via the integrated control and data fusion platform to inject a mixture of water containing characteristic pollutants and functional microbial systems into the core at a preset ratio. Simultaneously, the dual-modal monitoring component is triggered at the start of injection. When new cracks form inside the core due to stress concentration or fluid fracturing, the released elastic waves are transmitted to the acoustic emission receiver 9 via the acoustic wave transmission metal rod 10. The system acquires waveforms in real time; once the signal strength exceeds a preset threshold, it is determined as a "micro-fracture event," and its trigger time, energy, and ring count are recorded. The electrode array 8 continuously scans the core at millisecond frequencies to obtain a three-dimensional resistivity distribution map. The system monitors for sudden image changes in real time; if a connected band with a sharp drop in resistivity (fluid filling the crack) or the disappearance of a local high-resistivity anomaly (mineral dissolution) appears, it indicates a macroscopic change in the internal structure.

[0070] Step S4: Fidelity sampling and testing of the produced liquid.

[0071] After the fluid flows out of the core, it directly enters the nitrogen-protected effluent collection tank 22 and is subjected to graded detection according to the following process: Microbial flow cytometry detection: The high-fidelity effluent is led to the online microbial detection device 24 located downstream of the effluent collection tank 22 to detect the cell concentration, dead / live ratio and morphology and size in the effluent in real time, characterizing the migration and penetration ability of microorganisms in porous media.

[0072] Water chemistry and enzyme activity determination: Samples were taken from the effluent collection tank 22 at regular intervals, and the concentration of key ions was determined by ion chromatography; at the same time, for the functional microorganisms involved in the experiment, the activity of specific enzymes in the effluent was detected by the following methods: Urease: The concentration of ammonium ions produced by urea hydrolysis was determined by conductivity method or Nessler's reagent colorimetric method.

[0073] Carbonic anhydrase: The rate of increase in absorbance at a specific wavelength was monitored using the p-nitrophenylacetic acid esterase method and a spectrophotometer.

[0074] Dehydrogenases: The absorbance of substrates after reduction under anaerobic conditions was measured using the TTC reduction method to characterize the metabolic activity of microorganisms.

[0075] Step S5: Acoustic-electric data fusion and crack identification.

[0076] The time difference of arrival (TDOA) of the same rupture event was obtained using receivers distributed at different locations. Combined with a core acoustic velocity model, the three-dimensional spatial coordinates of the rupture source were calculated. An internal damage point cloud map is generated. The point cloud data located by AE is superimposed on the three-dimensional resistivity model inverted by ERT. If the dense area of ​​the AE point cloud and the low-resistivity anomaly zone in the ERT image highly overlap in space, it is confirmed that hydraulic fracturing or shear slip has occurred in this area, and the extension trajectory of the fracture is determined.

[0077] Step S6: Quantitative modeling and verification of multi-field coupling.

[0078] Based on the multi-source heterogeneous data obtained from the above steps, the following mathematical model system is used to perform step-by-step calculations from "basic parameter inversion" to "multi-field coupling mechanism": (1) First, the measurement data is converted into rock physical parameters using classical physical equations: a) Permeability calculation (Darcy's law): Equation (1); where: The Darcy velocity of the fluid inside the core; This represents the current absolute permeability of the core. This represents the hydraulic gradient along the seepage direction.

[0079] b) Saturation field reconstruction (Archie formula): Equation (2); where: The resistivity of water-bearing rocks obtained by ERT inversion; The resistivity of formation water; Current porosity; Pore ​​fluid saturation; Lithology coefficient; The cementation index; This is the saturation index.

[0080] (2) Biochemical reaction kinetics simulation.

[0081] c) Enzyme migration control equations (including adsorption retardation and spontaneous decay): Equation (3); where: This represents the enzyme's activity concentration; The hydrodynamic dispersion coefficient; This is the enzyme's natural inactivation / degradation constant; This refers to the source of enzyme production or reaction.

[0082] d) Definition equation of the retardation factor: Equation (4); where: It is a blocking factor; This refers to the core bulk density. The adsorption partition coefficient; Effective porosity.

[0083] e) Enzyme-catalyzed reaction kinetic equation (based on the Michaelis-Menten mechanism): source term used in specific calculation equation (3) : Equation (5); where: The maximum reaction rate; Substrate concentration; It is the Michaelis constant; Pre-exponential factors; Activation energy; The molar gas constant; Absolute temperature; It is a pH correction factor.

[0084] (3) Stress-seepage-chemical-damage coupled constitutive model: Construct a coupled model containing the following four equations to quantitatively describe the nonlinear response of the core.

[0085] f) Damage evolution equation (based on acoustic emission): Equation (6); where: For damage variables; Accumulate energy for real-time acoustic emission; The total energy at complete destruction; To prepare for the current situation; To prevent damage and strain.

[0086] g) Stress-damage coupling equations (mechanical field): Equation (7); where: This is the total stress tensor; This is the initial elastic stiffness tensor; The effective stress coefficient of Biot; Pore ​​pressure; For Kroneck's symbol.

[0087] h) Stress-porosity evolution equation (mechanical field): Equation (8); where: Initial porosity; Porosity stress sensitivity coefficient; For Biot's effective stress; The damage-induced pore expansion coefficient; This is the porosity change term caused by the chemical reaction.

[0088] i) Chemical-porosity evolution equation (chemical field): Equation (9); where: The molar volume of the mineral; The reaction rate constant; Specific surface area; It is the ion activity product; It is the equilibrium constant; It is an enzyme activity corrector.

[0089] j) Multi-field coupled permeability evolution model: Equation (10); where: Initial penetration rate; Porosity after chemical reaction; This is the stress sensitivity coefficient; This represents the current effective stress. This is the initial effective stress; The damage-to-penetration coefficient; The damage penetration index; Microbial concentration; The bioclogging coefficient.

[0090] (4) Model closed-loop verification.

[0091] The theoretical cumulative outflow calculated by the model was compared with the cumulative outflow measured by the metering balance 21, and the error was less than 5%. After successful verification, the platform output all calibrated model parameters as constitutive characteristic parameters of the core under the experimental conditions.

[0092] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. An experimental simulation system for the five-field coupling effect of deep water storage, characterized in that, The five-field coupling includes a stress field, a temperature field, a chemical field, an electric field, and an acoustic field; the system includes: The injection unit includes at least one liquid storage tank, each of which is equipped with a homogenizing and stirring device and is connected to an injection pump via a pipeline. A flow meter is installed on the main injection pipeline after the convergence of multiple fluids. The core clamping and multi-field coupling simulation unit includes a core clamp with a core receiving cavity, and a multi-field application component and a dual-mode monitoring component integrated on the core clamp; the core clamp is provided with a fluid injection port and a fluid outlet communicating with the injection unit; The multi-field application components include an annular pressure system, a heating unit and a temperature sensor, as well as an online hydrochemical sensor that penetrates the core holder body; The dual-modal monitoring component includes an electrode array embedded in the wall of the core holder and an acoustic wave transmitter penetrating the end cap of the core holder; the electrode array is in electrical contact with the core sample, and its signal is led out through a feedthrough interface and electrically connected to an external electrical resistivity instrument; the acoustic wave transmitter is attached to the end face of the core and coupled to an acoustic emission receiver. The effluent preservation collection and control unit includes a back pressure system and an anaerobic preservation sampling device; the anaerobic preservation sampling device includes an effluent water collection tank, which is connected to an inert gas source and placed on a measuring balance; An online detection unit includes an online microbial detection device, which is connected to the effluent collection tank; An integrated control and data fusion platform is used to synchronously collect parameters from multiple fields and coordinate the operation of each unit.

2. The experimental simulation system for five-field coupling effects in deep water storage according to claim 1, characterized in that, The storage tank includes a microbial storage tank and a raw water storage tank. A filter is connected in series on the pipeline connected to the raw water storage tank. The homogenizing stirring device is a stirrer. The ring pressure system includes a ring pressure pump.

3. The experimental simulation system for five-field coupling effects in deep water storage according to claim 1, characterized in that, The electrode array is composed of microelectrodes, which are integrated with the core holder cylinder through an insulating sleeve; the feedthrough interface is a sealed connector.

4. The experimental simulation system for five-field coupling effects in deep water storage according to claim 1, characterized in that, The acoustic emission receiver is electrically connected to the acoustic emission instrument, which is used to spatially locate micro-fracture events.

5. The experimental simulation system for five-field coupling effects in deep water storage according to claim 1, characterized in that, The back pressure system includes a back pressure pump; the inert gas source is a nitrogen tank; the measuring balance is an electronic balance; and the online microbial detection device is an online flow cytometer used to detect the microbial characteristics of the liquid in the aqueous solution collection tank.

6. A method for simulating the five-field coupling effect of deep water storage, using the experimental simulation system for the five-field coupling effect of deep water storage as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Obtain core samples from the target aquifer and determine their initial porosity and initial permeability; fill the core sample into the core receiving cavity, make the electrode array electrically contact the core, and fit the acoustic wave transmitter against the end face of the core; determine the physicochemical parameters of the injected water and the activity parameters of the functional microbial system. An anaerobic environment is created by introducing an inert gas into the aqueous solution collection tank and pipelines. S2. Apply confining pressure through the ring pressure system and establish pore fluid pressure through the back pressure system; use the metering balance to weigh the mass increment of the liquid in the effluent collection tank in real time, calculate the cumulative flow rate and instantaneous flow velocity, and correct the reading of the flow meter based on the calculation results; S3. Turn on the injection pump, mix the water containing the characteristic pollutant components with the functional microbial system in a preset ratio and inject it into the core, triggering the dual-modal monitoring component; collect acoustic emission signals, and when the signal intensity exceeds a preset threshold, determine it as a micro-fracture event and record it. The resistivity distribution map is obtained using the electrode array. S4. After the fluid flows out, it enters the effluent collection tank for microbial detection, water chemistry determination, and enzyme activity determination. S5. Calculate the spatial coordinates of the fracture source using acoustic emission signals to form a damage point cloud map; superimpose the point cloud map with the resistivity distribution map, and confirm the fracture trajectory when the dense area of ​​the acoustic emission point cloud coincides with the low resistivity anomaly zone in space. S6. Based on the acquired data, perform multi-field coupling calculations using a mathematical model system, and compare the theoretical outflow calculated by the model with the measured flow in step S2. If the error is less than the preset value, output the model parameters.

7. The experimental simulation method for the five-field coupling effect of deep water storage according to claim 6, characterized in that, The microbial detection in step S4 includes detecting the concentration, inactivation / deactivation ratio, and size of microbial cells; the enzyme activity in step S4 is determined by electrochemical or colorimetric methods.

8. The experimental simulation method for the five-field coupling effect of deep water storage according to claim 6, characterized in that, The mathematical model system described in step S6 includes a permeability calculation model based on Darcy's law: ； In the formula: The Darcy velocity of the fluid inside the core; This represents the current absolute permeability of the core. The hydraulic gradient along the seepage direction; and the saturation field reconstruction model based on Archie's formula: ； In the formula: The resistivity of water-bearing rocks obtained by ERT inversion; The resistivity of formation water; Current porosity; Pore ​​fluid saturation; Lithology coefficient; The cementation index; This is the saturation index.

9. The experimental simulation method for the five-field coupling effect of deep water storage according to claim 6, characterized in that, The mathematical model system described in step S6 also includes a convection-diffusion equation with a hindrance factor for characterizing enzyme migration: ； In the formula: This represents the enzyme's activity concentration; The hydrodynamic dispersion coefficient; This is the enzyme's natural inactivation / degradation constant; The equations define the enzyme production or reaction source term and the repression factor: ； In the formula: It is a blocking factor; This refers to the core bulk density. The adsorption partition coefficient; Effective porosity; The enzyme reaction source term Following the Michaelis-Menten dynamic equations: ； In the formula: The maximum reaction rate; Substrate concentration; It is the Michaelis constant; Pre-exponential factors; It is the activation energy; The molar gas constant; Absolute temperature; It is a pH correction factor.

10. The experimental simulation method for the five-field coupling effect of deep water storage according to claim 6, characterized in that, The mathematical model system described in step S6 also includes a stress-seepage-chemical-damage coupled constitutive model to quantitatively describe the nonlinear response of the core. This model includes: Damage evolution equation: ； In the formula: For damage variables; Accumulate energy for real-time acoustic emission; The total energy at complete destruction; To prepare for the current situation; To disrupt the strain; Stress-damage coupling equation: ； In the formula: This is the total stress tensor; This is the initial elastic stiffness tensor; This represents the effective stress coefficient of Biot. Pore ​​pressure; The symbol for Kronecker; Stress-porosity evolution equation: ； In the formula: Initial porosity; Porosity stress sensitivity coefficient; For Biot's effective stress; The damage-induced pore expansion coefficient; This refers to the change in porosity caused by chemical reactions. Chemical-porosity evolution equation: ； In the formula: The molar volume of the mineral; The reaction rate constant; Specific surface area; It is the ion activity product; It is the equilibrium constant; It is an enzyme activity corrector; Multi-field coupled permeability evolution model: ； In the formula: Initial penetration rate; Porosity after chemical reaction; This represents the current effective stress. This is the initial effective stress; The damage-to-penetration coefficient; The damage penetration index; Microbial concentration; The bioclogging coefficient.

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