Temporary plugging agent performance evaluation method based on large physical model experiment

Abstract

The invention discloses a large physical model experiment-based temporary plugging agent performance evaluation method, which comprises: preparing an experiment rock sample and a plurality of temporary plugging agent samples comprising different chemical components and different concentrations, the experiment rock sample being a large physical model rock sample with a size specification of more than one meter level; the experimental device adopts a large physical model experimental device, experimental parameters are adjusted by adjusting the type, concentration and injection rate of temporary plugging agents, the experimental rock samples are placed in the large physical model experimental device, and different types of temporary plugging agent samples are sequentially injected into the experimental rock samples connected in series through the large physical model experimental device. Starting a temporary plugging agent performance evaluation simulation experiment; pressure and flow data, sound wave detection data, optical imaging data, nuclear magnetic resonance detection data and CT scanning data in the temporary plugging agent performance evaluation simulation experiment process are monitored in real time; by combining five-dimensional data of pressure, sound wave, optics, nuclear magnetism and CT, a multi-dimensional analysis system of the plugging effect of the temporary plugging agent is constructed, and the performance of the temporary plugging agent is evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and in particular to a temporary plugging agent performance evaluation method based on large-scale physical model experiments. Background Art

[0002] In oil and gas field development and geological engineering, the application of temporary plugging agents is a key technology for improving oil recovery and optimizing drilling operations. Temporary plugging agents are primarily used to seal high-permeability layers or fractures, thereby directing fluids into lower-permeability layers, achieving balanced displacement and enhancing oil recovery. With the advancement of oil and gas field development, reservoir conditions are becoming increasingly complex, and the performance requirements for temporary plugging agents are becoming increasingly stringent. Therefore, developing an effective method for evaluating the performance of temporary plugging agents is crucial for optimizing their selection and application.

[0003] Traditional methods for evaluating the performance of temporary plugging agents rely primarily on small-scale experiments and numerical simulations. While these methods can provide some guidance, due to their small scale, they often fail to accurately reflect the temporary plugging effects under actual reservoir conditions. Furthermore, small-scale experiments fail to fully account for factors such as reservoir heterogeneity, fracture development, and the complexity of fluid flow, leading to significant deviations between evaluation results and actual application results.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a temporary plugging agent performance evaluation method based on large-scale physical model experiments. By simulating actual reservoir conditions and combining a variety of high-precision detection technologies, the temporary plugging agent's plugging effect, pressure resistance, temperature resistance and distribution in different permeability layers are comprehensively and accurately evaluated. This method aims to solve the limitations of traditional small-scale experiments and numerical simulation methods in evaluating the performance of temporary plugging agents, such as small experimental scale, inability to truly reflect complex reservoir conditions, and large deviations between evaluation results and actual applications. By systematically adjusting the type and dosage of temporary plugging agents, optimizing the selection and application of temporary plugging agents, reducing the cost of oil and gas field development and geological engineering, improving construction efficiency, and providing a reliable experimental platform and data support for the research and development of temporary plugging agents, further innovation and development of temporary plugging agent technology will be promoted, ultimately achieving efficient development and utilization of oil and gas resources.

[0006] Specifically, the following technical solutions are adopted: A temporary plugging agent performance evaluation method based on large-scale physical model experiments, including: Prepare experimental rock samples and various temporary plugging agent samples with different chemical compositions and concentrations. The experimental rock samples are large-scale mock-up rock samples with a size of more than one meter. The experimental device uses a large-scale physical model experimental device. The experimental parameters are adjusted by adjusting the type, concentration and injection volume of the temporary plugging agent. The experimental rock sample is placed in the large-scale physical model experimental device. Different types of temporary plugging agent samples are sequentially injected into multiple series-connected experimental rock samples through the large-scale physical model experimental device to start the temporary plugging agent performance evaluation simulation experiment. Real-time monitoring of pressure and flow data, acoustic wave detection data, optical imaging data, nuclear magnetic resonance detection data, and CT scan data during the simulation experiment for temporary plugging agent performance evaluation; Combining the five-dimensional data of pressure, acoustic wave, optics, nuclear magnetic resonance and CT, a multi-dimensional analysis system for the plugging effect of temporary plugging agents was constructed to evaluate the performance of temporary plugging agents.

[0007] As an optional embodiment of the present invention, in a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of the present invention, the large-scale physical model experiment device includes: A casing, wherein the casing is connected in series with a plurality of the experimental rock samples, and the experimental rock samples include at least one transparent artificial rock core; a fracturing pump truck system, connected to the casing, for simulating a fluid displacement process; The stress loading system includes multiple sets of stress loading modules set around each experimental rock sample to simulate the interlayer stress difference of the target reservoir; A temperature control system includes a plurality of temperature control devices, each corresponding to the experimental rock sample, and controlling the temperature control devices to adjust the temperature of the experimental rock sample according to the target reservoir temperature to simulate the temperature conditions of the target reservoir; The data acquisition system is used to monitor and record in real time the pressure and flow data, acoustic wave detection data, optical imaging data, nuclear magnetic resonance detection data, and CT scan data during the temporary plugging agent performance evaluation simulation experiment.

[0008] As an optional embodiment of the present invention, in a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of the present invention, the data acquisition system includes: The pressure sensor and flow meter are respectively installed at the inlet and outlet of the casing to monitor the pressure and flow changes of the fluid before and after passing through the temporary plugging agent plugging area in the experimental rock sample in real time, and calculate the change of the borehole friction resistance based on the pressure difference and flow data.

[0009] An acoustic wave transmitter and receiver are installed on the casing to evaluate the distribution and plugging effect of the temporary plugging agent in the test rock sample through the attenuation or reflection of the acoustic wave signal; High-speed camera, real-time monitoring and observation of the distribution of temporary plugging agent and fluid flow status in the transparent artificial core; A nuclear magnetic resonance instrument is used to place the experimental rock sample that has completed the temporary plugging agent performance evaluation simulation experiment in the nuclear magnetic resonance instrument to detect the distribution of fluid in the experimental rock sample and evaluate the plugging effect of the temporary plugging agent; A CT scanner is used to place the experimental rock sample that has completed the temporary plugging agent performance evaluation simulation experiment in the CT scanner to obtain a three-dimensional distribution image of the temporary plugging agent in the experimental rock sample and quantitatively analyze its plugging performance.

[0010] As an optional embodiment of the present invention, a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of the present invention is based on the basic mechanical data provided by the pressure sensor and the flow meter, combined with the acoustic detection data provided by the acoustic transmitter and receiver for real-time monitoring and calibration, and dynamically updates the friction calculation formula parameters through a Bayesian filtering algorithm; The friction calculation formula is modified based on the Darcy-Weisbach formula model in fluid mechanics: In the formula, λ is called the longitudinal resistance coefficient, which is dimensionless and is related to the viscosity of the fluid, the Reynolds number Re, and the relative roughness of the pipe wall; l is the length of the pipe, d is the diameter of the pipe (for non-circular cross-section pipes, d is the equivalent diameter), and v is the average flow velocity on the effective cross-section of the pipe.

[0011] As an optional embodiment of the present invention, in a temporary plugging agent performance evaluation method based on a large-scale physical model experiment, the five-dimensional data of pressure, acoustic wave, optical, nuclear magnetic resonance, and CT are combined to construct a multi-dimensional analysis system for the temporary plugging agent's plugging effect. The temporary plugging agent performance evaluation includes: Mechanical response analysis: Based on the real-time monitoring data of the pressure sensor and the flow meter, the perforation friction resistance is calculated in real time, and the model is corrected in real time using the Bayesian algorithm to dynamically monitor the pressure difference before and after plugging; Spatial distribution analysis: Based on the acoustic detection data provided by the acoustic transmitter and receiver, acoustic tomography and multi-channel array scanning are performed to construct a two-dimensional velocity field of temporary plugging agent distribution; Dynamic process analysis: Based on real-time image data collected by high-speed cameras, the distribution of temporary plugging agents and fluid flow status can be observed intuitively; 3D reconstruction analysis: After positioning and drilling the experimental rock samples from the temporary plugging agent performance evaluation simulation experiment, the spatial distribution of the temporary plugging agent is reconstructed in 3D. Microstructure analysis: Based on the measurement of pore fluid permeability changes using nuclear magnetic resonance, the permeability changes of the fluid in the pores are analyzed to quantify the permeability reduction rate caused by plugging.

[0012] As an optional embodiment of the present invention, a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of the present invention includes: By designing a multi-gradient coupling experiment of pressure and temperature, we can simulate the extreme conditions of high temperature and high pressure in deep reservoirs; The pressure is loaded in stages of P1, P2, ..., Pn. The leakage is monitored at a preset time interval T0 for each constant pressure level. The temperature is divided into multiple levels of t1, t2, ..., tn to test the thermal stability of the temporary plugging agent. The thermal shear resistance of the temporary plugging agent was tested by using temperature-pressure synergistic loading technology and nuclear magnetic resonance to detect the internal fluid diffusion coefficient of the temporary plugging agent. Based on experimental data, the performance of temporary plugging agents under different pressure and temperature conditions was evaluated.

[0013] As an optional embodiment of the present invention, a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of the present invention includes: Using L9 (3 4 ) Orthogonal experimental design, designing 9 groups of experiments covering temporary plugging agent type (3 types), concentration (3 levels), particle size (3 levels), and injection speed (3 levels); Constructing a multi-index weighted scoring model , where E represents the plugging efficiency, P r Withstand voltage retention rate, T s Represents temperature stability, D r represents the degradation rate, are their respective preset weight coefficients; The multi-index weighted scoring model S is used to score each group of temporary plugging agent types and select the temporary plugging agent formula that best suits the target reservoir conditions.

[0014] As an optional embodiment of the present invention, in a temporary plugging agent performance evaluation method based on a large-scale physical model experiment, the plugging efficiency E is defined as the ability of the temporary plugging agent to hinder fluid flow after plugging, and is measured by the flow rate or pressure change before and after plugging: Formula: or ; Parameter Description: Q after , Q before Indicates the flow rate before and after plugging (m³ / s); ΔP after , ΔP before Indicates the pressure difference before and after plugging (Pa); The pressure retention rate Pr is defined as the stability of the temporary plugging agent under continuous pressure, which is characterized by the retention rate of the plugging ability after a period of pressure application: formula:

[0015] Parameter description: E0 represents the initial plugging efficiency, E t Indicates the plugging efficiency after a certain period of pressurization; Temperature stability Ts is defined as the ability of the temporary plugging agent to maintain its performance in a high temperature environment: formula: ; Parameter Description: E 常温 Indicates the plugging efficiency at room temperature, E T Indicates the plugging efficiency at the target temperature; The degradation rate Dr is defined as the degradation ability of the temporary plugging agent under reservoir conditions, which affects the subsequent plugging removal effect: formula: ; Parameter description: m0 represents the initial temporary plugging agent mass (g), m t Indicates the remaining mass (g) after a certain degradation period.

[0016] As an optional embodiment of the present invention, a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of the present invention includes: Based on the data analysis results, a performance prediction model is trained based on the random forest algorithm, and the Bayesian optimization algorithm is used to iteratively search for optimal parameters to recommend the optimized formulation and injection parameters of the temporary plugging agent. The optimization effect was verified by repeated experiments.

[0017] As an optional embodiment of the present invention, in a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of the present invention, the temporary plugging agent performance evaluation simulation experiment includes the temporary plugging agent injection process: Pulse injection is used for the low permeability layer of the experimental rock sample to promote the nano-temporary plugging agent to penetrate into the micropores; For the high permeability layer of the experimental rock sample, slug injection was used to form a composite sealing layer of "particle bridging + gel filling".

[0018] Compared with the prior art, the present invention has the following beneficial effects: This paper presents a method for evaluating the performance of temporary plugging agents based on large-scale physical modeling experiments. By simulating actual reservoir conditions, these experiments can more realistically reflect the performance of temporary plugging agents in complex geological environments. By adjusting the type and dosage of the temporary plugging agent, this method systematically evaluates its plugging effectiveness, pressure resistance, temperature tolerance, and distribution in different permeability layers, thereby providing a scientific basis for oil and gas field development.

[0019] Large-scale physical modeling experiments typically utilize cores or artificial cores similar to actual reservoirs. By manipulating experimental conditions (such as pressure, temperature, and fluid properties), they simulate reservoir environments at different development stages. During the experiment, the performance of the temporary plugging agent is comprehensively evaluated by monitoring fluid flow characteristics, pressure changes, and the distribution of the temporary plugging agent. Furthermore, the application of detection technology is crucial in large-scale physical modeling experiments. High-precision pressure sensors, flow meters, acoustic detection, optical imaging, nuclear magnetic resonance (NMR), and CT scanning, among other detection technologies, can monitor changes in perforation friction in real time and evaluate the plugging effectiveness of the temporary plugging agent. For example, pressure sensors and flow meters can record real-time pressure and flow changes before and after the fluid passes through the temporary plugging agent blockage area, thereby calculating changes in perforation friction. Acoustic detection and optical imaging can visually observe the distribution of the temporary plugging agent and fluid flow. NMR and CT scanning can provide high-resolution three-dimensional images of fluid distribution and temporary plugging agent migration. The combined application of these detection technologies not only improves the accuracy and reliability of experimental data but also provides intuitive data support for optimizing temporary plugging agent formulations and application parameters.

[0020] The present invention's method for evaluating the performance of temporary plugging agents based on large-scale physical model experiments has the advantage of being able to overcome similarity criterion conversion errors, directly simulate complex conditions such as temperature, pressure, permeability, and fracture development in actual reservoirs, and avoid errors introduced by similarity criterion conversion in small-scale experiments. In addition, large-scale physical model experiments are suitable for a variety of types of temporary plugging agents and can flexibly adjust the type, concentration, and injection volume of temporary plugging agents to meet the needs of different reservoir conditions. At the same time, large-scale physical model experiments can simulate two typical scenarios: temporary plugging of pores and temporary plugging within fractures, comprehensively evaluate the plugging effect of temporary plugging agents in pores and fractures, and provide more accurate guidance for on-site construction.

[0021] More importantly, the present invention provides a method for evaluating the performance of temporary plugging agents based on large-scale physical model experiments. These large-scale physical model experiments can realistically reproduce the reservoir stress environment, simulating the reservoir's actual geomechanical state by precisely controlling the temperature, pressure, and stress conditions of the experimental apparatus. This high-precision environmental reproduction capability enables the experiment to simulate industrial-scale temporary plugging experiments, providing highly reliable predictions of the performance of temporary plugging agents in actual reservoirs. Large-scale physical model experiments can more realistically reflect the performance of temporary plugging agents in actual reservoirs, providing a scientific basis for cost reduction and efficiency improvement in oil and gas field development and geological engineering.

[0022] In summary, the present method for evaluating temporary plugging agent performance based on large-scale physical model experiments not only improves the accuracy and reliability of evaluation results but also provides strong support for cost reduction and efficiency improvement in oil and gas field development and geological engineering. With continued technological advancement, this method is expected to be applied in a wider range of fields, further promoting the development of temporary plugging agent technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of a temporary plugging agent performance evaluation method based on a large-scale physical model experiment according to an embodiment of the present invention; Figure 2 Schematic diagram of the structural principle of a large-scale physical model experimental device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in 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 part of the embodiments of the present invention, not all of them.

[0025] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein may be combined with each other.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] In the description of the present invention, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art. Such terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0029] See also Figure 1 As shown, a temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment includes: Experimental preparation: Prepare experimental rock samples and various temporary plugging agent samples with different chemical compositions and concentrations. The experimental rock samples are large-scale model rock samples with a size of more than one meter. Experimental condition setting: The experimental device adopts a large-scale physical model experimental device. The experimental parameters are adjusted by adjusting the type, concentration and injection volume of the temporary plugging agent, and the experimental rock sample is placed in the large-scale physical model experimental device; Injecting temporary plugging agents: injecting different types of temporary plugging agent samples into a plurality of experimental rock samples connected in series in sequence through a large-scale physical model experimental device to start a simulation experiment for evaluating the performance of the temporary plugging agent; Real-time monitoring and data collection: Real-time monitoring of pressure and flow data, acoustic wave detection data, optical imaging data, nuclear magnetic resonance detection data, and CT scan data during the temporary plugging agent performance evaluation simulation experiment; Data analysis: Combining the five-dimensional data of pressure, acoustic wave, optical, nuclear magnetic resonance, and CT, a multi-dimensional analysis system for the plugging effect of temporary plugging agents was constructed to evaluate the performance of temporary plugging agents.

[0030] This embodiment presents a method for evaluating the performance of temporary plugging agents based on large-scale physical modeling experiments. By simulating actual reservoir conditions, these experiments can more realistically reflect the performance of temporary plugging agents in complex geological environments. By adjusting the type and dosage of the temporary plugging agent, this method systematically evaluates its plugging effectiveness, pressure resistance, temperature tolerance, and distribution in different permeability layers, thereby providing a scientific basis for oil and gas field development.

[0031] Large-scale physical modeling experiments typically utilize cores or artificial cores similar to actual reservoirs. By manipulating experimental conditions (such as pressure, temperature, and fluid properties), they simulate reservoir environments at different development stages. During the experiment, the performance of the temporary plugging agent is comprehensively evaluated by monitoring fluid flow characteristics, pressure changes, and the distribution of the temporary plugging agent. Furthermore, the application of detection technology is crucial in large-scale physical modeling experiments. High-precision pressure sensors, flow meters, acoustic detection, optical imaging, nuclear magnetic resonance (NMR), and CT scanning, among other detection technologies, can monitor changes in perforation friction in real time and evaluate the plugging effectiveness of the temporary plugging agent. For example, pressure sensors and flow meters can record real-time pressure and flow changes before and after the fluid passes through the temporary plugging agent blockage area, thereby calculating changes in perforation friction. Acoustic detection and optical imaging can visually observe the distribution of the temporary plugging agent and fluid flow. NMR and CT scanning can provide high-resolution three-dimensional images of fluid distribution and temporary plugging agent migration. The combined application of these detection technologies not only improves the accuracy and reliability of experimental data but also provides intuitive data support for optimizing temporary plugging agent formulations and application parameters.

[0032] The method for evaluating the performance of temporary plugging agents based on large-scale physical model experiments in this embodiment has the advantage of overcoming similarity criterion conversion errors, directly simulating complex conditions such as temperature, pressure, permeability, and fracture development in actual reservoirs, and avoiding errors introduced by similarity criterion conversion in small-scale experiments. In addition, large-scale physical model experiments are compatible with a variety of temporary plugging agents and can flexibly adjust the type, concentration, and injection volume of temporary plugging agents to meet the needs of different reservoir conditions. At the same time, large-scale physical model experiments can simulate two typical scenarios: temporary plugging of pores and temporary plugging within fractures, comprehensively evaluating the plugging effect of temporary plugging agents in pores and fractures, and providing more accurate guidance for on-site construction.

[0033] More importantly, this embodiment provides a method for evaluating the performance of temporary plugging agents based on large-scale physical model experiments. These large-scale physical model experiments can realistically reproduce the reservoir stress environment. By precisely controlling the temperature, pressure, and stress conditions of the experimental apparatus, they simulate the reservoir's actual geomechanical state. This high-precision environmental reproduction capability enables the experiment to simulate industrial-scale temporary plugging experiments, providing highly reliable predictions of the performance of temporary plugging agents in actual reservoirs. Large-scale physical model experiments can more realistically reflect the performance of temporary plugging agents in actual reservoirs, providing a scientific basis for cost reduction and efficiency improvement in oil and gas field development and geological engineering.

[0034] In summary, the temporary plugging agent performance evaluation method based on large-scale physical model experiments in this embodiment not only improves the accuracy and reliability of evaluation results but also provides strong support for cost reduction and efficiency improvement in oil and gas field development and geological engineering. With the continuous advancement of technology, this method is expected to be applied in a wider range of fields, promoting the further development of temporary plugging agent technology.

[0035] A temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment includes: defining a research objective and a scale range, and determining the scale range to be covered, including temporary plugging agent type, concentration, injection volume, and core type.

[0036] The research objectives and scope are defined, covering: At the mineral level, the interaction between the temporary plugging agent and the mineral surface is analyzed to evaluate its effect on the wettability and adsorption of the mineral.

[0037] Fracture level, which evaluates the sealing effect of temporary plugging agents in fractures, including changes in fracture width, length and permeability.

[0038] At the pore level, the migration and plugging behavior of temporary plugging agents in the pores are studied, and their adaptability to the pore structure is evaluated.

[0039] At a large range of rock formation levels, the overall distribution and plugging effect of temporary plugging agents in the rock formation are simulated, their impact on fluid flow is evaluated, and the differentiated distribution patterns of temporary plugging agents in high permeability layers (500mD) and low permeability layers (10mD) are analyzed.

[0040] A temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment is as follows: Figure 2 As shown in the figure, the large-scale physical model experimental device used includes: A casing 600, wherein the casing is connected in series with a plurality of the experimental rock samples 100, wherein the experimental rock samples 100 include at least one transparent artificial rock core; A fracturing pump truck system 300 , in communication with the casing 600 , is used to simulate a fluid displacement process; A stress loading system, comprising a plurality of stress loading modules disposed on the periphery of each experimental rock sample 100, for simulating interlayer stress differences in the target reservoir; A temperature control system includes a plurality of temperature control devices, each corresponding to the experimental rock sample, and controlling the temperature control devices to adjust the temperature of the experimental rock sample according to the target reservoir temperature to simulate the temperature conditions of the target reservoir; The data acquisition system is used to monitor and record in real time the pressure and flow data, acoustic wave detection data, optical imaging data, nuclear magnetic resonance detection data, and CT scan data during the temporary plugging agent performance evaluation simulation experiment.

[0041] Specifically, in a temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment, the data acquisition system includes: The pressure sensor and flow meter are respectively installed at the inlet and outlet of the casing to monitor the pressure and flow changes of the fluid before and after passing through the temporary plugging agent plugging area in the experimental rock sample in real time, and calculate the change of the borehole friction resistance based on the pressure difference and flow data.

[0042] An acoustic wave transmitter and receiver are installed on the casing to evaluate the distribution and plugging effect of the temporary plugging agent in the test rock sample through the attenuation or reflection of the acoustic wave signal; High-speed camera, real-time monitoring and observation of the distribution of temporary plugging agent and fluid flow status in the transparent artificial core; A nuclear magnetic resonance instrument is used to place the experimental rock sample that has completed the temporary plugging agent performance evaluation simulation experiment in the nuclear magnetic resonance instrument to detect the distribution of fluid in the experimental rock sample and evaluate the plugging effect of the temporary plugging agent; A CT scanner is used to place the experimental rock sample that has completed the temporary plugging agent performance evaluation simulation experiment in the CT scanner to obtain a three-dimensional distribution image of the temporary plugging agent in the experimental rock sample and quantitatively analyze its plugging performance.

[0043] In a temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment, based on the basic mechanical data provided by the pressure sensor and the flow meter, combined with the acoustic detection data provided by the acoustic transmitter and receiver, real-time monitoring and calibration are performed, and the friction calculation formula parameters are dynamically updated through the Bayesian filtering algorithm.

[0044] The friction calculation formula is usually modified based on the Darcy-Weisbach formula model in fluid mechanics. The Darcy-Weisbach formula is a mathematical term used to calculate the flow loss of viscous fluids in pipes: The dimensionless λ in the formula is called the longitudinal drag coefficient and is related to the fluid viscosity, Reynolds number (Re), and the relative roughness of the pipe wall. l is the pipe length, d is the pipe diameter (for non-circular pipes, d is the equivalent diameter), and v is the average flow velocity over the effective cross-section of the pipe. The Darcy-Weisbach formula is applicable to fully developed laminar and turbulent flows (often referred to in engineering as turbulent flows) in smooth and rough pipes of any cross-sectional shape, and holds significant engineering significance.

[0045] In a temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment, the five-dimensional data of pressure, acoustic wave, optical, nuclear magnetic resonance, and CT are combined to construct a multi-dimensional analysis system for the temporary plugging agent's plugging effect. The temporary plugging agent performance evaluation includes: Mechanical response analysis: Based on the real-time monitoring data of the pressure sensor and the flow meter, the perforation friction resistance is calculated in real time, and the model is corrected in real time using the Bayesian algorithm to dynamically monitor the pressure difference before and after plugging; Spatial distribution analysis: Based on the acoustic detection data provided by the acoustic transmitter and receiver, acoustic tomography and multi-channel array scanning are performed to construct a two-dimensional velocity field of temporary plugging agent distribution; Dynamic process analysis: Based on real-time image data collected by high-speed cameras, the distribution of temporary plugging agents and fluid flow status can be observed intuitively; 3D reconstruction analysis: After positioning and drilling the experimental rock samples from the temporary plugging agent performance evaluation simulation experiment, the spatial distribution of the temporary plugging agent is reconstructed in 3D. Microstructure analysis: Based on the measurement of pore fluid permeability changes using nuclear magnetic resonance, the permeability changes of the fluid in the pores are analyzed to quantify the permeability reduction rate caused by plugging.

[0046] As an optional implementation of this embodiment, a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of this embodiment includes: By designing a multi-gradient coupling experiment of pressure and temperature, we can simulate the extreme conditions of high temperature and high pressure in deep reservoirs; The pressure is loaded in stages of P1, P2, ..., Pn. The leakage is monitored at a preset time interval T0 for each constant pressure level. The temperature is divided into multiple levels of t1, t2, ..., tn to test the thermal stability of the temporary plugging agent. The thermal shear resistance of the temporary plugging agent was tested by using temperature-pressure synergistic loading technology and nuclear magnetic resonance to detect the internal fluid diffusion coefficient of the temporary plugging agent. Based on experimental data, the performance of temporary plugging agents under different pressure and temperature conditions was evaluated.

[0047] Therefore, the temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment realizes the evaluation of the pressure resistance and temperature resistance of the temporary plugging agent: based on the experimental data, the performance of the temporary plugging agent under different pressure and temperature conditions is evaluated.

[0048] As an optional implementation of this embodiment, a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of this embodiment includes: Using L9 (3 4 ) Orthogonal experimental design, designing 9 groups of experiments covering temporary plugging agent type (3 types), concentration (3 levels), particle size (3 levels), and injection speed (3 levels); Constructing a multi-index weighted scoring model , where E represents the plugging efficiency, P r Withstand voltage retention rate, T s Represents temperature stability, D r represents the degradation rate, are their respective preset weight coefficients; The multi-index weighted scoring model S is used to score each group of temporary plugging agent types and select the temporary plugging agent formula that best suits the target reservoir conditions.

[0049] Therefore, the temporary plugging agent performance evaluation method based on large-scale physical model experiments in this embodiment realizes temporary plugging agent performance comparison: by comparing the experimental data of different temporary plugging agent samples, the temporary plugging agent formula that best suits the target reservoir conditions is selected.

[0050] Specifically, the plugging efficiency E, pressure retention rate Pr, temperature stability Ts, and degradation rate Dr need to be calculated through experimental data or theoretical models.

[0051] 1. Plugging efficiency E Definition: The ability of a temporary plugging agent to hinder fluid flow after plugging, usually measured by the flow rate or pressure change before and after plugging. Formula: or .

[0052] Parameter Description: Q after , Q before : flow rate before and after plugging (m³ / s); ΔP after , ΔP before : Pressure difference before and after plugging (Pa).

[0053] Experimental operation: In core flow experiments or fracture models, measure the flow rate / pressure difference before and after the injection of temporary plugging agents.

[0054] 2. Withstand voltage retention rate Pr Definition: The stability of temporary plugging agents under sustained pressure is characterized by the retention rate of plugging capacity after a period of pressurization.

[0055] formula: .

[0056] Parameter Description: E0: initial plugging efficiency; E t : Plugging efficiency after pressurization for a certain period of time.

[0057] Experimental operation: Apply target reservoir pressure to the plugged system, continuously monitor the pressure difference change, and calculate E t .

[0058] 3. Temperature stability Ts Definition: The ability of temporary plugging agents to maintain performance in high temperature environments.

[0059] formula: .

[0060] Parameter Description: E 常温 : Plugging efficiency at room temperature; E T : Plugging efficiency at target temperature.

[0061] Experimental operation: Heat the experimental system to the reservoir temperature, and measure the plugging efficiency after constant temperature.

[0062] 4. Degradation rate Dr Definition: The degradation ability of temporary plugging agents under reservoir conditions affects the subsequent plugging removal effect.

[0063] formula: .

[0064] Parameter Description: m0: initial temporary plugging agent mass (g); m t : Remaining mass after a certain degradation period (g).

[0065] Experimental operation: Place the temporary plugging agent in the simulated reservoir fluid, filter, dry and weigh it regularly.

[0066] 5. Multi-index weighted scoring model (S) formula: .

[0067] Weight setting: Weight coefficients (w1, w2, w3, w4) must be determined based on reservoir requirements. Weights can also be determined using the Analytic Hierarchy Process (AHP) or expert scoring method.

[0068] A temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment also includes: Based on the data analysis results, a performance prediction model is trained based on the random forest algorithm, and the Bayesian optimization algorithm is used to iteratively search for optimal parameters to recommend the optimized formulation and injection parameters of the temporary plugging agent. The optimization effect was verified by repeated experiments.

[0069] In a temporary plugging agent performance evaluation method based on a large-scale physical model experiment of this embodiment, the temporary plugging agent performance evaluation simulation experiment includes the temporary plugging agent injection process: Pulse injection is used for the low permeability layer of the experimental rock sample to promote the nano-temporary plugging agent to penetrate into the micropores; For the high permeability layer of the experimental rock sample, slug injection was used to form a composite sealing layer of "particle bridging + gel filling".

[0070] In a temporary plugging agent performance evaluation method based on large-scale physical model experiments in this embodiment, the experimental rock samples include natural rock cores similar to actual reservoirs, and artificial rock cores prepared with specific permeability and porosity. Both the natural and artificial cores are large physical model rock samples with dimensions of one meter or more.

[0071] A temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment includes data analysis and optimization: Borehole friction calculation: Based on the data from the pressure sensor and flow meter, calculate the change in borehole friction before and after the fluid passes through the temporary plugging agent plugging area.

[0072] Plugging effect analysis: Combined with data from acoustic wave detection, optical imaging, MRI and CT scans, the plugging effect of the temporary plugging agent and its impact on fluid flow are analyzed.

[0073] Pressure resistance and temperature resistance evaluation: Based on experimental data, the performance of temporary plugging agents under different pressure and temperature conditions is evaluated.

[0074] Temporary plugging agent performance comparison: Compare the experimental data of different temporary plugging agent samples to screen out the temporary plugging agent formula that best suits the target reservoir conditions.

[0075] Optimization and verification: Based on the data analysis results, optimize the temporary plugging agent formula (such as adjusting the concentration or chemical composition) and injection parameters (such as injection rate or injection volume), and verify the optimization effect through repeated experiments.

[0076] This embodiment provides a temporary plugging agent performance evaluation method based on a large-scale physical model experiment, including result output and application: Temporary plugging agent performance evaluation report: Summarize the experimental data and optimization results to generate a temporary plugging agent performance evaluation report, which describes in detail the temporary plugging agent's plugging effect, pressure resistance, temperature resistance and other performance indicators.

[0077] Optimization suggestions: Based on the experimental results, optimization suggestions for temporary plugging agent formula and injection parameters are provided to provide a scientific basis for on-site construction.

[0078] Field application: Apply experimental results and optimization suggestions to on-site construction to improve the actual application effect of temporary plugging agents, helping to reduce costs and increase efficiency in oil and gas field development and geological engineering.

[0079] A specific implementation of a temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment is as follows: 1. Experimental Setup and Preparation The experimental device consists of: casing for fixing the core; a fracturing pump truck for simulating the fluid displacement process; an independent confining pressure loading module: 8 sets of independent stress loading units, which can simulate interlayer stress differences of up to 15MPa (such as 20MPa confining pressure in high-permeability layers and 35MPa confining pressure in low-permeability layers); a temperature and pressure coordination system with a temperature range of room temperature to 180°C (accuracy of ±1°C) and a pressure range of 0-80MPa (pulse loading frequency of 0.1-10Hz) for simulating reservoir conditions; and a data acquisition system for real-time recording of experimental data.

[0080] Core Selection and Processing: Select natural cores similar to the actual reservoir, or prepare artificial cores with specific permeability and porosity. Core dimensions are typically 2m x 2m x 2m. Before the experiment, clean and dry the cores to ensure they are free of surface impurities.

[0081] Temporary plugging agent sample preparation: Prepare a variety of temporary plugging agent samples, including different chemical compositions (such as polymers, gels, particles, etc.) and different concentrations (such as 1%, 3%, 5%, etc.). Each temporary plugging agent sample must be clearly labeled to facilitate subsequent experimental comparison.

[0082] 2. Experimental Conditions Setup Temperature setting: Set the thermostat or heating device of the experimental device according to the actual temperature of the target reservoir. For example, if the reservoir temperature is 80℃, set the experimental temperature to 80℃.

[0083] Pressure setting: Based on the actual pressure of the target reservoir, the pressure in the experimental device is adjusted through the pressure control system. For example, if the reservoir pressure is 20 MPa, the experimental pressure is set to 20 MPa.

[0084] Fluid injection parameter settings: Set the injection speed and injection volume of the fracturing pump truck. For example, set the injection speed to 1mL / min and the injection volume to 100mL.

[0085] 3. Temporary plugging agent injection and plugging effect monitoring Temporary plugging agent injection: Pulsed injection (0.5 Hz frequency) is used in low-permeability zones to promote the penetration of the nano-temporary plugging agent into micropores. Slug injection is used in high-permeability zones to form a composite plugging layer composed of "particle bridging + gel filling." The temporary plugging agent sample is injected into the core in the casing via a fracturing pump truck. The injection process must be smooth to avoid air bubbles. Different temporary plugging agent samples are injected sequentially, and the type, concentration, and injection volume of each sample are recorded.

[0086] Pressure and flow monitoring: Pressure sensors and flow meters are installed at the inlet and outlet of the casing to monitor in real time the pressure and flow changes before and after the fluid passes through the temporary plugging agent plugging area. The pressure difference and flow data are used to calculate the change in perforation friction.

[0087] Acoustic testing: Install an acoustic transmitter and receiver on the outside of the casing to evaluate the distribution and plugging effect of the temporary plugging agent in the core by observing the attenuation or reflection of the acoustic signal.

[0088] Optical imaging: If transparent or translucent cores are used, the distribution of temporary plugging agents and fluid flow status can be observed in real time using high-speed cameras or fiber optic sensors.

[0089] Nuclear magnetic resonance (NMR) testing: The core is placed in a nuclear magnetic resonance instrument to detect the distribution of fluid in the core and evaluate the plugging effect of the temporary plugging agent.

[0090] CT scanning: Place the core in a CT scanner to obtain a three-dimensional distribution image of the temporary plugging agent in the core and quantitatively analyze its plugging performance.

[0091] 4. Data analysis and optimization Borehole friction calculation: Based on the basic mechanical data provided by the pressure sensor (accuracy ±0.1MPa) and the flow meter (accuracy ±0.5%), combined with real-time monitoring and calibration of acoustic wave detection data (resolution 1cm), the friction calculation formula parameters are dynamically updated through the Bayesian filtering algorithm.

[0092] Plugging effect analysis: Combining the five-dimensional data of pressure, acoustic wave, optical, nuclear magnetic resonance and CT, a multi-dimensional analysis system for the plugging effect of temporary plugging agents is constructed: ① Mechanical response: The pressure sensor (accuracy ±0.1MPa) and flow meter (accuracy ±0.5%) calculate the perforation friction in real time, and the Bayesian algorithm is used to modify the model in real time to dynamically monitor the pressure difference before and after plugging. ② Spatial distribution: Acoustic tomography, 16-channel array scanning, to construct a two-dimensional velocity field of temporary plugging agent distribution with a resolution of 1 cm; ③ Dynamic process: Use high-speed cameras and fiber optic sensors to visually observe the distribution of temporary plugging agents and fluid flow status; ④ Three-dimensional reconstruction: Large-scale CT reconstruction, scanning after positioning drilling of 2m core (resolution 50μm), and three-dimensional reconstruction of the spatial distribution of plugging agents; ⑤ Microstructure: Nuclear magnetic resonance (NMR) is used to measure the changes in pore fluid permeability, analyze the changes in fluid permeability within the pores, and quantify the permeability reduction rate caused by plugging.

[0093] Pressure resistance and temperature resistance evaluation: Based on experimental data, the performance of temporary plugging agents under different pressure and temperature conditions is evaluated.

[0094] A multi-gradient coupled experiment involving pressure (0-80 MPa) and temperature (room temperature - 180°C) was conducted to simulate the extreme high-temperature and high-pressure conditions of deep reservoirs. Pressures were applied in stages of 20 MPa, 40 MPa, 60 MPa, and 80 MPa, with leakage monitored (accuracy ±5 mL / h) at each constant pressure for 24 hours. The thermal stability of the temporary plugging agent was tested at four temperatures: 60°C, 120°C, 150°C, and 180°C (mass loss ≤ 5%). A combined temperature-pressure loading technique (e.g., 150°C + 60 MPa) was employed, combined with nuclear magnetic resonance (NMR) to measure the internal fluid diffusion coefficient (D < 10⁻10 m² / s) within the temporary plugging agent and assess its thermal shear resistance. This approach overcomes the limitations of traditional single-temperature and pressure testing, improving the consistency of the experimental results with actual reservoir conditions by 30%.

[0095] Temporary plugging agent performance comparison: Compare the experimental data of different temporary plugging agent samples to screen out the temporary plugging agent formula that best suits the target reservoir conditions.

[0096] Using the L9 (34) orthogonal experimental design, only 9 groups of experiments were needed to cover 81 variable combinations of temporary plugging agent type (3 types), concentration (3 levels), particle size (3 levels), and injection speed (3 levels), reducing the test volume by 89% compared with the traditional full-factor experiment. A multi-index weighted scoring model (S=0.4E+0.3Pr+0.2Ts+0.1Dr) was constructed, in which the weights of plugging efficiency (E), pressure retention rate (Pr), temperature stability (Ts), and degradation rate (Dr) were 40%, 30%, 20%, and 10%, respectively. For example, the comprehensive score of nano-temporary plugging agent C (concentration 1.8%) was 89.5 points, which was significantly better than that of polymer gel (78.2 points). The quantitative results provide an objective basis for formula screening.

[0097] Optimization and verification: Based on the data analysis results, optimize the temporary plugging agent formula (such as adjusting the concentration or chemical composition) and injection parameters (such as injection rate or injection volume), and verify the optimization effect through repeated experiments.

[0098] Using a performance prediction model trained using a random forest algorithm (n=500+ historical data, with a prediction accuracy of 92%), combined with a Bayesian optimization algorithm to iteratively search for optimal parameters, the optimal formulation (e.g., a nano-temporary plugging agent with a concentration of 1.8% and a particle size of 35nm) can be recommended within 10 rounds, achieving a 60% improvement in efficiency compared to manual trial and error. A three-tiered validation process was established: ① Initial screening using small cores (Φ2.5cm) to eliminate inefficient formulations; ② Large-scale mock-ups (2m×2m×2m) to verify plugging stability at an industrial-grade flow rate (2m³ / min); and ③ Field pilot testing to ensure an application error of ≤5%. This closed-loop system shortened the temporary plugging agent R&D cycle from 3 months to 1.5 months, and increased the field application success rate to over 90%.

[0099] 5. Result output and application Temporary plugging agent performance evaluation report: Summarize the experimental data and optimization results to generate a temporary plugging agent performance evaluation report, which describes in detail the temporary plugging agent's plugging effect, pressure resistance, temperature resistance and other performance indicators.

[0100] Optimization suggestions: Based on the experimental results, optimization suggestions for temporary plugging agent formula and injection parameters are provided to provide a scientific basis for on-site construction.

[0101] Field application: Apply experimental results and optimization suggestions to on-site construction to improve the actual application effect of temporary plugging agents, helping to reduce costs and increase efficiency in oil and gas field development and geological engineering.

[0102] Example 1 A temporary plugging agent performance evaluation method based on a large-scale physical model experiment in this embodiment includes: 1. Experimental Setup and Preparation Experimental device composition: Multi-environment coupling experimental cabin: The core cabin is made of high-strength alloy steel (pressure resistance 100MPa, temperature resistance 200℃), with built-in natural / artificial rock cores (size 2m×2m×2m); integrated annular heating belt (temperature control accuracy ±0.5℃), six-axis hydraulic loading system (simulating non-uniform ground stress, maximum load 50MPa), and corrosive fluid circulation unit (supporting carbon dioxide / H2S mixed gas injection).

[0103] Multi-scale detection system, including: Mineral level: Atomic force microscope (AFM) probe is embedded in the core surface to scan the interface adsorption energy between temporary plugging agent and mineral in real time; Pore ​​level: Microfluidic chips (pore size 1-100 μm) are linked with high-speed fluorescence microscopes to quantify the retention rate of temporary plugging agents in micropores; Crack level: A transparent sapphire crack model (crack width adjustable from 0.1 to 5 mm) is combined with laser particle velocimetry (PIV) to dynamically capture the formation process of the sealing band; Rock layer level: 4D-CT scanner (resolution 1μm, scanning interval ≤10 seconds) to reconstruct the three-dimensional distribution of temporary plugging agents and fracture propagation trends.

[0104] Intelligent decision-making unit: The edge computing terminal processes multi-source data in real time, runs the deep reinforcement learning (DRL) model, and dynamically optimizes temporary plugging agent parameters (concentration, injection rate, etc.); Degradability test module: microbial reactor (simulating anaerobic environment) and oxidant injection device, to evaluate the degradation rate of temporary plugging agent and permeability recovery rate.

[0105] Core selection and processing: Natural cores (permeability 10-1000mD) or 3D-printed artificial cores (porosity 5-30%) are selected, cleaned, dried, and placed in the experimental chamber. AFM scanning points and microfluidic chip interfaces are pre-installed on the core surface to ensure multi-scale detection compatibility.

[0106] Temporary plugging agent sample preparation: preparation of polymer gels, nanoparticles, biodegradable temporary plugging agents, etc., with concentration gradient (1%-10%); labeling of chemical components and degradation characteristics (such as temporary plugging agents containing enzymatic degradation groups).

[0107] 2. Experimental Conditions Setup Temperature: Set an annular heating zone according to the actual reservoir temperature (e.g. 150°C for shale gas reservoir) and control the temperature constantly; Pressure: Apply axial / confining pressure (e.g. 30 MPa) through the hydraulic system to simulate reservoir stress state; Chemical environment: injection of formation water containing H2S (1000ppm), circulation of corrosive fluids; Injection parameters: Initial injection rate 1-5m³ / min (industrial-grade displacement), dynamically adjusted by the DRL model.

[0108] 3. Temporary plugging agent injection and plugging effect monitoring Multi-scale simultaneous monitoring, including: Mineral level: AFM outputs the adsorption curve of temporary plugging agent on calcite / clay mineral surface in real time; Pore ​​level: Microfluidic chip records the migration path of temporary plugging agent in 50μm pores (fluorescent labeling); Crack level: The PIV system calculates the sealing band formation speed (e.g. 0.2 mm / s); Rock layer level: 4D-CT generates a three-dimensional density distribution map every 10 seconds to identify areas rich in temporary plugging agents.

[0109] Dynamic optimization, including: the DRL model identifies unevenly sealed areas based on CT data and automatically increases the injection rate (e.g., from 2 m³ / min to 3.5 m³ / min); If the microfluidic chip shows a pore retention rate of less than 50%, it is recommended to add a nanosilica modifier.

[0110] 4. Data analysis and optimization Plugging effect: Calculate the change in perforation friction (ΔP = inlet pressure - outlet pressure) and generate a plugging efficiency heat map based on CT data.

[0111] Pressure resistance test: Step-by-step pressure increase to 50 MPa to monitor the stability of the sealing band (no crack expansion in CT images).

[0112] Environmental assessment, including: Degradation experiment: After 28 days of anaerobic culture, LC-MS is used to detect degradation products (such as acetic acid and carbon dioxide). The toxicity index is ≤ 0.5, which is considered qualified. Permeability recovery experiment: The permeability recovery rate of the core after degradation is ≥90%.

[0113] Intelligent decision-making output: Multi-objective optimization Pareto front diagram (plugging efficiency vs. environmental protection vs. cost), recommending the optimal temporary plugging agent formula (such as biodegradable temporary plugging agent C, concentration 4%).

[0114] 5. Result Output and Application Report generation: key indicators such as plugging efficiency (e.g. 92%), pressure resistance limit (e.g. 45MPa), degradation rate (e.g. 95% degradation in 28 days), etc. On-site implementation: Import optimized parameters into the fracturing pump truck, synchronize the DRL model to the downhole control system in real time, and realize dynamic adjustment.

[0115] Example 2 The temporary plugging agent performance evaluation method of this embodiment based on a large-scale physical model experiment realizes the performance evaluation of temporary plugging agents in high-temperature and high-pressure reservoirs.

[0116] Experimental parameters Core size: 2m×2m×2m.

[0117] Core permeability: high permeability layer (500 mD), low permeability layer (50 mD).

[0118] Experimental temperature: 120°C.

[0119] Experimental pressure: 30 MPa.

[0120] Temporary plugging agent type: Temporary plugging agent A: polymer gel, concentration 3%.

[0121] Temporary plugging agent B: granular temporary plugging agent, particle size range 50-100 μm, concentration 5%.

[0122] Injection parameters: Injection speed: 2 m³ / min (industrial-grade displacement).

[0123] Injection volume: 2000 L (industrial scale).

[0124] Detection technology: Pressure sensor: monitors inlet and outlet pressure.

[0125] Flow meter: monitors fluid flow.

[0126] Acoustic testing: Evaluate the distribution of temporary plugging agents.

[0127] CT scan: obtain the three-dimensional distribution image of temporary plugging agent.

[0128] Experimental procedures Experimental Preparation: Select a natural rock core, clean it, and dry it. Configure the experimental apparatus, set the temperature and pressure, and prepare samples of temporary plugging agent A and temporary plugging agent B.

[0129] Temporary plugging agent injection: Inject temporary plugging agent A and record the pressure, flow rate and acoustic wave signal. Inject temporary plugging agent B and record the pressure, flow rate and acoustic wave signal.

[0130] Data monitoring: real-time monitoring of pressure and flow changes, and calculation of hole friction.

[0131] CT scanning is used to obtain a three-dimensional distribution image of the temporary plugging agent in the core.

[0132] Data analysis: Compare the plugging effects of temporary plugging agents A and B. Evaluate the pressure resistance and temperature resistance of temporary plugging agents under high temperature and high pressure conditions.

[0133] Result output: Generate a temporary plugging agent performance evaluation report and recommend the optimal temporary plugging agent type and injection parameters.

[0134] Experimental results Temporary plugging agent A showed good plugging effect under high temperature and high pressure conditions, but its pressure resistance was poor.

[0135] Temporary plugging agent B has a significant plugging effect in the high permeability layer, and its pressure resistance and temperature resistance are better than those of temporary plugging agent A.

[0136] It is recommended to use temporary plugging agent B with an injection concentration of 5% and an injection rate of 2 m³ / min.

[0137] Example 3 The present embodiment provides a temporary plugging agent performance evaluation method based on a large-scale physical model experiment, which enables the performance evaluation of temporary plugging agents for low permeability reservoirs.

[0138] Experimental parameters Core size: 2m×2m×2m.

[0139] Core permeability: 10 mD.

[0140] Experimental temperature: 60°C.

[0141] Experimental pressure: 15 MPa.

[0142] Temporary plugging agent type: Temporary plugging agent C: nanoparticle temporary plugging agent, particle size range 10-50 nm, concentration 1%.

[0143] Temporary plugging agent D: polymer gel, concentration 2%.

[0144] Injection parameters: Injection speed: 0.5 m³ / min (industrial-grade displacement).

[0145] Injection volume: 1000 L (industrial scale).

[0146] Detection technology: Pressure sensor: monitors inlet and outlet pressure.

[0147] Flow meter: monitors fluid flow.

[0148] Nuclear Magnetic Resonance (NMR): Detects fluid distribution.

[0149] Optical imaging: observe the distribution of temporary plugging agents.

[0150] Experimental procedures Experimental Preparation: Select a low-permeability artificial core, clean it, and dry it. Configure the experimental apparatus, set the temperature and pressure, and prepare samples of temporary plugging agent C and temporary plugging agent D.

[0151] Temporary plugging agent injection: Inject temporary plugging agent C and record the pressure, flow rate, and NMR signal. Inject temporary plugging agent D and record the pressure, flow rate, and NMR signal.

[0152] Data monitoring: Real-time monitoring of pressure and flow changes, calculation of borehole friction, and use of optical imaging to observe the distribution of temporary plugging agents in the core.

[0153] Data analysis: Compare the plugging effects of temporary plugging agents C and D. Evaluate the adaptability of temporary plugging agents under low permeability conditions.

[0154] Result output: Generate a temporary plugging agent performance evaluation report and recommend the optimal temporary plugging agent type and injection parameters.

[0155] Experimental results Temporary plugging agent C exhibits excellent plugging effect under low permeability conditions and can effectively enter tiny pores.

[0156] Temporary plugging agent D has poor plugging effect in low permeability layers and is difficult to distribute evenly.

[0157] It is recommended to use temporary plugging agent C with an injection concentration of 1% and an injection rate of 0.5 m³ / min. The above examples are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; all technical solutions and improvements that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A temporary plugging agent performance evaluation method based on large-scale physical model experiments, characterized in that: include: Prepare experimental rock samples and various temporary plugging agent samples with different chemical compositions and concentrations. The experimental rock samples are large-scale mock-up rock samples with a size of more than one meter. The experimental device uses a large-scale physical model experimental device. The experimental parameters are adjusted by adjusting the type, concentration and injection volume of the temporary plugging agent. The experimental rock sample is placed in the large-scale physical model experimental device. Different types of temporary plugging agent samples are sequentially injected into multiple series-connected experimental rock samples through the large-scale physical model experimental device to start the temporary plugging agent performance evaluation simulation experiment. Real-time monitoring of pressure and flow data, acoustic wave detection data, optical imaging data, nuclear magnetic resonance detection data, and CT scan data during the simulation experiment for temporary plugging agent performance evaluation; Combining the five-dimensional data of pressure, acoustic wave, optics, nuclear magnetic resonance and CT, a multi-dimensional analysis system for the plugging effect of temporary plugging agents was constructed to evaluate the performance of temporary plugging agents.

2. A temporary plugging agent performance evaluation method based on large-scale physical model experiments according to claim 1, characterized in that: The large-scale physical model experimental device comprises: A casing, wherein the casing is connected in series with a plurality of the experimental rock samples, and the experimental rock samples include at least one transparent artificial rock core; a fracturing pump truck system, connected to the casing, for simulating a fluid displacement process; The stress loading system includes multiple sets of stress loading modules set around each experimental rock sample to simulate the interlayer stress difference of the target reservoir; A temperature control system includes a plurality of temperature control devices, each corresponding to the experimental rock sample, and controlling the temperature control devices to adjust the temperature of the experimental rock sample according to the target reservoir temperature to simulate the temperature conditions of the target reservoir; The data acquisition system is used to monitor and record in real time the pressure and flow data, acoustic wave detection data, optical imaging data, nuclear magnetic resonance detection data, and CT scan data during the temporary plugging agent performance evaluation simulation experiment.

3. A temporary plugging agent performance evaluation method based on large-scale physical model experiments according to claim 2, characterized in that: The data acquisition system includes: The pressure sensor and flow meter are respectively installed at the inlet and outlet of the casing to monitor the pressure and flow changes of the fluid before and after passing through the temporary plugging agent plugging area in the experimental rock sample in real time. The change of the borehole friction resistance is calculated based on the pressure difference and flow data; An acoustic wave transmitter and receiver are installed on the casing to evaluate the distribution and plugging effect of the temporary plugging agent in the test rock sample through the attenuation or reflection of the acoustic wave signal; High-speed camera, real-time monitoring and observation of the distribution of temporary plugging agent and fluid flow status in the transparent artificial core; A nuclear magnetic resonance instrument is used to place the experimental rock sample that has completed the temporary plugging agent performance evaluation simulation experiment in the nuclear magnetic resonance instrument to detect the distribution of fluid in the experimental rock sample and evaluate the plugging effect of the temporary plugging agent; A CT scanner is used to place the experimental rock sample that has completed the temporary plugging agent performance evaluation simulation experiment in the CT scanner to obtain a three-dimensional distribution image of the temporary plugging agent in the experimental rock sample and quantitatively analyze its plugging performance.

4. A temporary plugging agent performance evaluation method based on large-scale physical model experiments according to claim 3, characterized in that: Based on the basic mechanical data provided by the pressure sensor and the flow meter, combined with the acoustic detection data provided by the acoustic transmitter and receiver, real-time monitoring and calibration are carried out, and the parameters of the friction calculation formula are dynamically updated through the Bayesian filtering algorithm; The friction calculation formula is modified based on the Darcy-Weisbach formula model in fluid mechanics: In the formula, λ is called the longitudinal resistance coefficient, which is dimensionless and is related to the viscosity of the fluid, the Reynolds number Re, and the relative roughness of the pipe wall; l is the length of the pipe, d is the diameter of the pipe (for non-circular cross-section pipes, d is the equivalent diameter), and v is the average flow velocity on the effective cross-section of the pipe.

5. The method for evaluating the performance of temporary plugging agents based on large-scale physical model experiments according to claim 3, characterized in that: The five-dimensional data of pressure, acoustic wave, optical, nuclear magnetic resonance and CT are combined to construct a multi-dimensional analysis system for the plugging effect of the temporary plugging agent, and the performance evaluation of the temporary plugging agent includes: Mechanical response analysis: Based on the real-time monitoring data of the pressure sensor and the flow meter, the perforation friction resistance is calculated in real time, and the model is corrected in real time using the Bayesian algorithm to dynamically monitor the pressure difference before and after plugging; Spatial distribution analysis: Based on the acoustic detection data provided by the acoustic transmitter and receiver, acoustic tomography and multi-channel array scanning are performed to construct a two-dimensional velocity field of temporary plugging agent distribution; Dynamic process analysis: Based on real-time image data collected by high-speed cameras, the distribution of temporary plugging agents and fluid flow status can be observed intuitively; 3D reconstruction analysis: After positioning and drilling the experimental rock samples from the temporary plugging agent performance evaluation simulation experiment, the spatial distribution of the temporary plugging agent is reconstructed in 3D. Microstructure analysis: Based on the measurement of pore fluid permeability changes using nuclear magnetic resonance, the permeability changes of the fluid in the pores are analyzed to quantify the permeability reduction rate caused by plugging.

6. The method for evaluating the performance of temporary plugging agents based on large-scale physical model experiments according to claim 3, characterized in that: include: By designing a multi-gradient coupling experiment of pressure and temperature, we can simulate the extreme conditions of high temperature and high pressure in deep reservoirs; The pressure is loaded in stages of P1, P2, ..., Pn. The leakage is monitored at a preset time interval T0 for each constant pressure level. The temperature is divided into multiple levels of t1, t2, ..., tn to test the thermal stability of the temporary plugging agent. The thermal shear resistance of the temporary plugging agent was tested by using temperature-pressure synergistic loading technology and nuclear magnetic resonance to detect the internal fluid diffusion coefficient of the temporary plugging agent. Based on experimental data, the performance of temporary plugging agents under different pressure and temperature conditions was evaluated.

7. The method for evaluating the performance of temporary plugging agents based on large-scale physical model experiments according to claim 3, characterized in that: include: Using L9 (3 4 ) Orthogonal experimental design, designing 9 groups of experiments covering temporary plugging agent type (3 types), concentration (3 levels), particle size (3 levels), and injection speed (3 levels); Constructing a multi-index weighted scoring model , where E represents the plugging efficiency, P r Withstand voltage retention rate, T s Represents temperature stability, D r represents the degradation rate, are their respective preset weight coefficients; The multi-index weighted scoring model S is used to score each group of temporary plugging agent types and select the temporary plugging agent formula that best suits the target reservoir conditions.

8. A temporary plugging agent performance evaluation method based on large-scale physical model experiments according to claim 7, characterized in that: The plugging efficiency E is defined as the ability of the temporary plugging agent to hinder the flow of fluid after plugging, and is measured by the flow rate or pressure change before and after plugging: Formula: or ; Parameter Description: Q after , Q before Indicates the flow rate before and after plugging (m³ / s); ΔP after , ΔP before Indicates the pressure difference before and after plugging (Pa); The pressure retention rate Pr is defined as the stability of the temporary plugging agent under continuous pressure, which is characterized by the retention rate of the plugging ability after a period of pressure application: official: ; Parameter description: E0 represents the initial plugging efficiency, E t Indicates the plugging efficiency after a certain period of pressurization; Temperature stability Ts is defined as the ability of the temporary plugging agent to maintain its performance in a high temperature environment: official: ; Parameter Description: E 常温 Indicates the plugging efficiency at room temperature, E T Indicates the plugging efficiency at the target temperature; The degradation rate Dr is defined as the degradation ability of the temporary plugging agent under reservoir conditions, which affects the subsequent plugging removal effect: official: ; Parameter description: m0 represents the initial temporary plugging agent mass (g), m t Indicates the remaining mass (g) after a certain degradation period.

9. The method for evaluating temporary plugging agent performance based on large-scale physical model experiments according to claim 3, characterized in that: include: Based on the data analysis results, a performance prediction model is trained based on the random forest algorithm, and the Bayesian optimization algorithm is used to iteratively search for optimal parameters to recommend the optimized formulation and injection parameters of the temporary plugging agent. The optimization effect was verified by repeated experiments.

10. The method for evaluating temporary plugging agent performance based on large-scale physical model experiments according to claim 1, characterized in that: The temporary plugging agent performance evaluation simulation experiment includes the temporary plugging agent injection process: Pulse injection is used for the low permeability layer of the experimental rock sample to promote the nano-temporary plugging agent to penetrate into the micropores; Segment injection was used for the high permeability layer of the experimental rock sample to form a composite sealing layer of "particle bridging + gel filling".

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