Preparation method of polymer dry powder online mixed fracturing fluid

Abstract

The invention discloses a preparation method of a polymer dry powder online mixed fracturing fluid, which relates to the technical field of fracturing fluid preparation, and adopts a high-precision sensor and measuring equipment to accurately collect water source flow, pressure, temperature, water quality and feeding speed, feeding amount and particle size distribution parameters of polymer dry powder in real time; based on a preset fracturing fluid formula and collected real-time data, the optimal ratio of the water source to the polymer dry powder is dynamically calculated. By means of real-time data acquisition and intelligent calculation, accurate control over the fracturing fluid mixing process can be achieved, accurate control over online mixing of the polymer dry powder and the fracturing fluid can be achieved, and therefore the quality and performance stability of the fracturing fluid are improved, and through real-time data acquisition, intelligent calculation and feedback adjustment, accurate control over the fracturing fluid mixing process can be achieved. The system can quickly adapt to different operation conditions and requirements, can quickly respond to parameter changes, adjusts control strategies in real time, adapts to different operation conditions and requirements, and improves the production efficiency and adaptability.

Description

Technical Field

[0001] The invention relates to the technical field of fracturing fluid preparation, and in particular to a method for preparing a fracturing fluid by online mixing of polymer dry powder. Background Art

[0002] In the fracturing operation of oil extraction, the performance of the fracturing fluid has a crucial impact on the fracturing effect. The traditional fracturing fluid preparation method has problems such as low efficiency, poor ratio accuracy, and difficulty in real-time adjustment, which cannot meet the complex downhole operation requirements. In addition, the existing technology does not accurately control environmental factors such as temperature and pressure during the mixing process, which can easily lead to unstable fracturing fluid performance and affect the effect and safety of fracturing construction.

[0003] In view of this, the present invention is proposed to solve the above technical problems. Summary of the invention

[0004] The present invention aims to provide a method for preparing a fracturing fluid by online mixing of polymer dry powder, so as to solve the technical problems of low efficiency, poor ratio accuracy and difficulty in real-time adjustment in the existing fracturing fluid preparation methods.

[0005] The object of the present invention is to provide a method for preparing a polymer dry powder online mixing fracturing fluid, comprising the following steps: S1. Data collection: Use high-precision sensors and measuring equipment to collect real-time and accurate data on water source flow, pressure, temperature, water quality, feed rate, feed amount and particle size distribution parameters of polymer dry powder; S2. Ratio calculation: Based on the preset fracturing fluid formula and the collected real-time data, dynamically calculate the optimal ratio of water source and polymer dry powder; S3, Mixing control: Use a multi-stage stirring device to accurately control the stirring speed and stirring time according to the real-time monitoring of the mixing degree to ensure that the polymer dry powder and water are fully and evenly mixed; S4. Quality monitoring: Use online testing equipment to comprehensively test the viscosity, density, pH value, sand carrying performance and residue content of the mixed fracturing fluid to ensure that the quality of the fracturing fluid meets the requirements; S5, feedback adjustment: compare and analyze the detected fracturing fluid parameters with the preset quality standards; if deviations are found, the intelligent control system automatically adjusts the feed rate, stirring speed, and water source temperature until the fracturing fluid performance reaches the standard; S6. Intelligent prediction: Establish an intelligent control model based on big data and machine learning, and use historical data and real-time feedback information to predict the optimal control parameter combination under different operating conditions; S7. Safety monitoring: During the mixing process, continuously monitor the pressure and temperature in the mixing device. When abnormalities occur, take protective measures in time to ensure the safety and stability of the entire mixing process.

[0006] Furthermore, the collection accuracy of water source flow is ±0.1L / min, the pressure collection accuracy is ±0.01MPa, the temperature collection accuracy is ±0.1℃, and the water quality parameters should include hardness, pH and ion concentration.

[0007] Furthermore, the measurement accuracy of the polymer dry powder feed rate is ±0.1g / min, the measurement accuracy of the feed amount is ±0.01g, and the measurement of the particle size distribution should be able to accurately distinguish the proportion of different particle size ranges.

[0008] Furthermore, the number of stages of the multi-stage stirring device is not less than three, the rotation speed of each stage of the stirring paddle can be adjusted independently, and the speed adjustment range is 100-1000rpm.

[0009] Furthermore, the online detection equipment has a detection accuracy of ±1mPa・s for fracturing fluid viscosity, ±0.01g / cm³ for density, ±0.1 for pH value, a detection error of no more than ±2% for sand carrying performance, and a detection accuracy of ±1mg / L for residue content.

[0010] Furthermore, the intelligent control system's response time for adjusting control parameters should not exceed 1 second to achieve timely and accurate control of the mixing process.

[0011] Furthermore, the intelligent control model should have a prediction accuracy of no less than 90% for the optimal control parameters and should be able to quickly learn and optimize based on new operating conditions and data.

[0012] Furthermore, the pressure monitoring accuracy in the mixing device is ±0.01MPa, and the temperature monitoring accuracy is ±0.1℃. When the pressure or temperature exceeds the preset safety range, the system should be able to automatically take protective measures such as shutdown or alarm.

[0013] By adopting the above technical solution, the present invention has the following beneficial effects: Through real-time data collection and intelligent calculation, it is possible to achieve precise control of the fracturing fluid mixing process, ensure accurate ratio and uniform mixing, and achieve precise control of polymer dry powder online mixing of fracturing fluid, thereby improving the quality and performance stability of fracturing fluid. Through real-time data collection, intelligent calculation and feedback adjustment, it can quickly adapt to different operating conditions and requirements, can quickly respond to parameter changes, adjust control strategies in real time, adapt to different operating conditions and requirements, improve production efficiency and adaptability, and can optimize key indicators such as fracturing fluid viscosity, sand carrying performance and residue content according to specific needs, meet various complex downhole operation requirements, and provide reliable, efficient and flexible technical support for fracturing operations in oil production. At the same time, optimized mixing control and quality monitoring methods help reduce costs and improve construction efficiency and safety. DETAILED DESCRIPTION

[0014] The specific embodiments of the present invention are described in further detail.

[0015] The present application provides a method for preparing a polymer dry powder online mixing fracturing fluid, comprising the following steps: S1. Data collection: Use high-precision sensors and measuring equipment to collect real-time and accurate data on water source flow, pressure, temperature, water quality, and feed rate, feed amount, and particle size distribution parameters of polymer dry powder.

[0016] During the data collection process, a high-precision electromagnetic flowmeter is used to measure the flow of the water source, with a measurement accuracy of ±0.1L / min, which can obtain accurate water flow information in real time. The pressure of the water source is monitored by a pressure transmitter with an accuracy of ±0.01MPa to ensure the reliability of the pressure data. A platinum resistance temperature sensor is used to detect the temperature of the water source with a measurement accuracy of ±0.1℃ to accurately grasp the change in water temperature. For the detection of water quality parameters, an ion chromatograph is used to analyze the hardness, pH, and various ion concentrations in the water to provide a comprehensive and accurate water quality status.

[0017] In terms of polymer dry powder feeding, a high-precision mass flow meter is used to measure the feeding speed, with a measurement accuracy of no less than ±0.1g / min, and a weighing sensor is used to accurately measure the feeding amount, with an accuracy of ±0.01g. The particle size distribution of polymer dry powder is detected by a laser particle size analyzer, which can accurately distinguish the proportion of different particle size ranges and provide accurate data for subsequent ratio calculations.

[0018] S2. Ratio calculation: Based on the preset fracturing fluid formula and the real-time data collected, the optimal ratio of water source and polymer dry powder is dynamically calculated.

[0019] The preset fracturing fluid formula contains the ideal ratio range of water source and polymer powder under different working conditions. The real-time data collected includes the flow, pressure, temperature, water quality of the water source, and the feed rate, feed amount and particle size distribution of the polymer powder. Advanced algorithms based on artificial intelligence and mathematical models are used to comprehensively consider the changes in these real-time parameters and their interrelationships. For example, changes in water temperature may affect the dissolution rate of the polymer, the hardness of the water quality may affect the hydration effect of the polymer, and the particle size distribution will affect the uniformity of the mixing. Through real-time analysis and calculation, the ratio of water source and polymer powder is dynamically adjusted to ensure that the ratio is always kept within the optimal range under various complex and changeable working conditions, so as to achieve the accuracy and real-time adaptability of the ratio.

[0020] S3. Mixing control: Use a multi-stage stirring device to accurately control the stirring speed and stirring time according to the real-time monitoring of the mixing degree to ensure that the polymer dry powder and water are fully and evenly mixed.

[0021] The multi-stage stirring device used is composed of multiple independently controlled stirring units, with no less than three stages. The shape of the stirring paddle of each stirring unit has been optimized through fluid mechanics simulation and experiments, and a streamlined design is adopted to reduce resistance and improve stirring efficiency. The layout of the stirring paddle fully considers the characteristics of fluid flow to ensure the formation of a uniform and effective flow field in the stirring container.

[0022] The torque sensor and speed sensor installed on the multi-stage stirring device monitor the mixing degree in real time during the stirring process. When the mixing degree does not reach the preset standard, the control system will accurately adjust the speed of each stirring unit. The speed adjustment range is 100-1000rpm to meet different mixing needs. At the same time, according to the characteristics of the material and the mixing progress, the stirring time is intelligently controlled to avoid over-stirring or under-stirring, thereby ensuring that the polymer dry powder and water are fully and evenly mixed, improving the mixing effect and efficiency.

[0023] S4. Quality monitoring: Use online testing equipment to comprehensively test the viscosity, density, pH value, sand carrying performance and residue content of the mixed fracturing fluid to ensure that the quality of the fracturing fluid meets the requirements.

[0024] The viscosity of the mixed fracturing fluid is tested with an online rotational viscometer, with a detection accuracy of ±1mPa・s, which can reflect the viscosity of the fracturing fluid in real time. The density of the fracturing fluid is measured with a high-precision electronic density meter, with an accuracy of ±0.01g / cm³, to ensure that the density meets the requirements. The pH value of the fracturing fluid is tested with a pH meter, with a measurement accuracy of ±0.1, to ensure that the pH is within the appropriate range.

[0025] For the detection of sand carrying performance, the test is carried out by simulating the downhole sand carrying experimental device, with an error of no more than ±2%, accurately evaluating the ability of the fracturing fluid to carry proppant. The chemical analysis method is used to detect the residue content, with a detection accuracy of ±1mg / L, strictly controlling the insoluble content in the fracturing fluid. These comprehensive and high-precision detection methods can timely and accurately reflect the key parameters of the fracturing fluid, providing a reliable basis for judging whether the quality of the fracturing fluid meets the requirements.

[0026] S5. Feedback adjustment: Compare and analyze the detected fracturing fluid parameters with the preset quality standards; if deviations are found, the intelligent control system will automatically adjust the feed rate, stirring speed, and water source temperature until the fracturing fluid performance reaches the standard.

[0027] The detected fracturing fluid parameters such as viscosity, density, pH value, sand carrying capacity and residue content are compared and analyzed with the preset strict quality standards. The quality standards are customized according to different fracturing operation requirements and downhole conditions, covering the allowable range and optimal value of each parameter.

[0028] Once the detection parameters deviate from the preset standards, the intelligent control system will respond immediately. For example, if the viscosity is lower than the standard, the system will automatically increase the feed rate of polymer dry powder or increase the stirring speed; if the sand carrying performance is insufficient, the stirring time may be adjusted or certain additives may be added. The adjustment process is real-time and continuous until the performance indicators of the fracturing fluid meet or exceed the preset quality standards. The response time of the entire feedback adjustment process does not exceed 1 second, ensuring timely and accurate control of the mixing process and ensuring the quality stability and reliability of the fracturing fluid.

[0029] S6. Intelligent prediction: Establish an intelligent control model based on big data and machine learning, and use historical data and real-time feedback information to predict the optimal control parameter combination under different operating conditions.

[0030] The intelligent control model established is based on a big data platform and machine learning algorithms, such as neural networks, decision trees, etc. First, a large amount of historical mixing data is collected and sorted, including different water source conditions, polymer dry powder characteristics, mixing parameters, and corresponding fracturing fluid quality data, etc. These data are used to train the model so that it can learn the complex relationships and rules between various parameters.

[0031] In the actual mixing process, the model receives new operating data and real-time feedback information in real time. Through rapid analysis and calculation of these data, the optimal control parameter combination under the current operating conditions is predicted, such as feed rate, stirring speed, water source temperature, etc. The prediction results not only take into account the current parameter status, but also proactively predict the possible future change trends, make adjustments and optimizations in advance, thereby further improving the accuracy and foresight of control, reducing trial and error costs, and improving mixing efficiency and fracturing fluid quality.

[0032] S7. Safety monitoring: During the mixing process, continuously monitor the pressure and temperature in the mixing device. When abnormalities occur, take protective measures in time to ensure the safety and stability of the entire mixing process.

[0033] High-precision pressure sensors and temperature sensors are installed inside the mixing device. The measurement accuracy of the pressure sensor is ±0.01MPa, and the measurement accuracy of the temperature sensor is ±0.1℃. The sensors collect pressure and temperature data in real time and transmit them to the central control system.

[0034] The central control system continuously analyzes and judges the pressure and temperature data. When the pressure exceeds the preset safety upper limit or the temperature exceeds the normal working range, the system immediately triggers an alarm and automatically takes corresponding protective measures, such as stopping feeding, reducing the stirring speed, starting the cooling or pressure relief device, etc. At the same time, the system sends the fault information to the operator in real time for timely manual intervention and maintenance. Through continuous safety monitoring and timely protective measures, the mixing process is always carried out under safe and stable conditions, effectively preventing accidents and ensuring the safety of personnel and equipment.

[0035] Precise control: Through real-time data collection and intelligent calculation, precise control of the fracturing fluid mixing process can be achieved to ensure accurate ratio and uniform mixing, thereby improving the quality and performance stability of the fracturing fluid.

[0036] Efficient and flexible: It can quickly respond to parameter changes, adjust control strategies in real time, adapt to different operating conditions and requirements, and improve production efficiency and adaptability.

[0037] Optimized performance: The key indicators of fracturing fluid such as viscosity, sand carrying performance and residue content can be optimized according to specific needs to meet various complex downhole operation requirements.

[0038] Safe and reliable: Real-time monitoring of the pressure and temperature in the mixing device ensures the safe and stable operation of the mixing process and reduces the risk of accidents.

[0039] The collection accuracy of water source flow is ±0.1L / min, the pressure collection accuracy is ±0.01MPa, the temperature collection accuracy is ±0.1℃, and the water quality parameters should include hardness, pH and ion concentration.

[0040] The measurement accuracy of the polymer dry powder feed rate is ±0.1g / min, the measurement accuracy of the feed amount is ±0.01g, and the measurement of the particle size distribution should be able to accurately distinguish the proportion of different particle size ranges.

[0041] The number of stages of the multi-stage stirring device is not less than three, and the speed of each stirring paddle can be adjusted independently, and the speed adjustment range is 100-1000rpm.

[0042] The online detection equipment has a detection accuracy of ±1mPa・s for fracturing fluid viscosity, ±0.01g / cm³ for density, ±0.1 for pH value, a detection error of no more than ±2% for sand carrying performance, and a detection accuracy of ±1mg / L for residue content.

[0043] The intelligent control system's response time for adjusting control parameters should not exceed 1 second to achieve timely and accurate control of the mixing process.

[0044] The intelligent control model’s prediction accuracy for the optimal control parameters should be no less than 90%, and it should be able to quickly learn and optimize based on new operating conditions and data.

[0045] The monitoring accuracy of the pressure in the mixing device is ±0.01MPa, and the temperature monitoring accuracy is ±0.1℃. When the pressure or temperature exceeds the preset safety range, the system should be able to automatically take protective measures such as shutdown or alarm.

[0046] Experimental preparation Build an experimental device for online mixing of polymer dry powder with fracturing fluid, and install high-precision sensors and measuring equipment, such as electromagnetic flowmeters for measuring water source flow, pressure transmitters for measuring water source pressure, platinum resistance temperature sensors for measuring water temperature, mass flowmeters for measuring polymer dry powder feed rate, and weighing sensors for measuring feed amount.

[0047] Prepare stirring devices of different specifications, as well as online rotational viscometers, electronic density meters, pH meters, simulated downhole sand carrying experimental devices and chemical analysis equipment for testing the performance of fracturing fluids.

[0048] Comparative Example 1 Set the water source flow rate to 50L / min, the polymer dry powder feed rate to 150g / min, the stirring speed to 200rpm, the water source temperature to 20℃, and start the device for mixing. During the mixing process, various data are collected in real time, and after the mixing is completed, the corresponding testing equipment is used to test the viscosity of the fracturing fluid to be 30mPa・s, the sand carrying performance to be 50%, and the residue content to be 180mg / L.

[0049] Experimental Example 1 Set the water source flow rate to 50L / min, the polymer dry powder feed rate to 200g / min, the stirring speed to 300rpm, the water source temperature to 25℃, and start the device for mixing. During the mixing process, various data are collected in real time, and after the mixing is completed, the corresponding testing equipment is used to test the viscosity of the fracturing fluid to 60mPa・s, the sand carrying performance to 75%, and the residue content to 120mg / L.

[0050] Comparing Comparative Example 1 and Experimental Example 1, under the same water source flow rate, due to the lower polymer dry powder feed rate, stirring speed and lower water source temperature, the viscosity and sand carrying performance of the fracturing fluid in Comparative Example 1 are significantly poorer, and the residue content is higher, indicating that the optimization parameters have a significant effect on improving the performance of the fracturing fluid.

[0051] Experimental Example 2 Set the water source flow rate to 60L / min, the polymer dry powder feed rate to 250g / min, the stirring speed to 350rpm, the water source temperature to 30℃, and start the device for mixing. During the mixing process, various data are collected in real time, and after the mixing is completed, the corresponding testing equipment is used to test the viscosity of the fracturing fluid to 80mPa・s, the sand carrying performance to 82%, and the residue content to 100mg / L.

[0052] In Experimental Example 2, compared with Experimental Example 1, the water source flow rate increased from 50 L / min to 60 L / min, which helps to improve the material transmission and mixing efficiency during the mixing process; the polymer dry powder feed rate increased from 200 g / min to 250 g / min, indicating that more dry powder feed may increase the effective ingredients in the fracturing fluid, thereby affecting its performance; the stirring speed was increased from 300 rpm to 350 rpm, and the increase in speed helped to mix the materials more fully and make the polymer dry powder more evenly distributed in the water; the water source temperature increased from 25°C to 30°C, and the increase in temperature affected the dissolution rate and reaction activity of the polymer.

[0053] By adjusting these parameters, compared with Experimental Example 1, Experimental Example 2 further improves the performance of the fracturing fluid, such as increasing the viscosity of the fracturing fluid, improving the sand carrying performance, and reducing the residue content. At the same time, compared with Comparative Example 1, Experimental Example 2 has obvious optimization and improvement in various parameters, and its fracturing fluid performance is significantly better than Comparative Example 1.

[0054] Experimental Example 3 Set the water source flow rate to 70L / min, the polymer dry powder feed rate to 300g / min, the stirring speed to 400rpm, the water source temperature to 35℃, and start the device for mixing. During the mixing process, various data are collected in real time, and after the mixing is completed, the corresponding testing equipment is used to test the viscosity of the fracturing fluid to be 100mPa・s, the sand carrying performance to be 88%, and the residue content to be 85mg / L.

[0055] Compared with Experimental Example 2, the water source flow rate in Experimental Example 3 increased from 60L / min to 70L / min, and the flow rate further increased by 10L / min. This shows that more water source flow helps to better disperse and dissolve the polymer dry powder and promote more uniform mixing. The polymer dry powder feed rate increased from 250g / min to 300g / min, an increase of 50g / min. This shows that more dry powder feed will increase the viscosity of the fracturing fluid and improve the sand carrying capacity. The stirring speed increased from 350rpm to 400rpm, indicating that a higher stirring speed can more effectively break up agglomerations and make the mixing more complete and uniform. The water source temperature increased from 30℃ to 35℃, indicating that the continued increase in temperature will accelerate the chemical reaction rate and optimize the hydration and dissolution process of the polymer.

[0056] Compared with Experimental Example 2, Experimental Example 3 can obtain better fracturing fluid performance by further increasing the water source flow rate, polymer dry powder feed rate, stirring speed and water source temperature. For example, higher viscosity, better sand carrying performance and lower residue content will be achieved. In general, Experimental Example 3 goes a step further than Experimental Example 2 in parameter optimization and can achieve better fracturing fluid quality.

[0057] Experimental Example 4 Set the water source flow rate to 80L / min, the polymer dry powder feed rate to 350g / min, the stirring speed to 450rpm, the water source temperature to 40℃, and start the device for mixing. During the mixing process, various data are collected in real time, and after the mixing is completed, the corresponding testing equipment is used to test the fracturing fluid viscosity to 120mPa・s, the sand carrying performance to 90%, and the residue content to 70mg / L.

[0058] Compared with Experimental Example 3, the water source flow rate in Experimental Example 4 increased from 70L / min to 80L / min, and the flow rate increased by another 10L / min. This will further improve the mixing effect of the materials and make the components more evenly distributed. The polymer dry powder feed rate increased from 300g / min to 350g / min, an increase of 50g / min. This shows that more dry powder input will increase the viscosity of the fracturing fluid and improve the sand carrying capacity.

[0059] The stirring speed increased from 400 rpm to 450 rpm, indicating that a higher stirring speed helps to more thoroughly break the existing agglomeration phenomenon and ensure the full fusion of the polymer powder and water. The water source temperature increased from 35°C to 40°C. The continued increase in temperature will promote the chemical reaction and further optimize the dissolution and dispersion of the polymer in water.

[0060] Compared with Experimental Example 3, Experimental Example 4 further optimizes the performance of the fracturing fluid by continuously improving the water source flow rate, polymer dry powder feed rate, stirring speed and water source temperature. It will obtain higher viscosity, better sand carrying performance and lower residue content, thereby better meeting the requirements of fracturing operations. Experimental Example 4 is moving towards a more optimized direction in parameter adjustment in order to obtain better quality fracturing fluid.

[0061] Experimental Example 5 Set the water source flow rate to 90L / min, the polymer dry powder feed rate to 400g / min, the stirring speed to 500rpm, the water source temperature to 45℃, and start the device for mixing. During the mixing process, various data are collected in real time, and after the mixing is completed, the corresponding testing equipment is used to test the viscosity of the fracturing fluid to be 140mPa・s, the sand carrying performance to be 93%, and the residue content to be 60mg / L.

[0062] Compared with Experimental Example 4, the water source flow rate in Experimental Example 5 increased from 80L / min to 90L / min, and the flow rate increased by another 10L / min. This shows that more water flow helps to more fully infiltrate and dissolve the polymer dry powder, making the mixing more uniform and more complete. The polymer dry powder feed rate increased from 350g / min to 400g / min, an increase of 50g / min. This will further increase the polymer content in the fracturing fluid and enhance its viscosity and structural strength. The stirring speed was increased from 450rpm to 500rpm, indicating that a higher stirring speed can more effectively eliminate local unevenness and ensure the uniformity of the entire system. The water source temperature increased from 40°C to 45°C, indicating that the increase in temperature will accelerate the hydration and dissolution process of the polymer and optimize the performance of the fracturing fluid.

[0063] Compared with Experimental Example 4, Experimental Example 5 further improves the performance of the fracturing fluid by further increasing the water source flow rate, polymer dry powder feed rate, stirring speed and water source temperature. This is manifested as higher viscosity, stronger sand carrying performance and lower residue content, thereby better adapting to complex fracturing operation conditions. Experimental Example 5 goes a step further in parameter optimization to obtain better fracturing fluid quality and performance.

[0064] Experimental Example 6 Set the water source flow rate to 1000L / min, the polymer dry powder feed rate to 400g / min, the stirring speed to 500rpm, the water source temperature to 45℃, and start the device for mixing. During the mixing process, various data are collected in real time, and after the mixing is completed, the corresponding testing equipment is used to test the viscosity of the fracturing fluid to 80mPa・s, the sand carrying performance to 70%, and the residue content to 100mg / L.

[0065] Compared with Experimental Example 5, Experimental Example 6 only increased the water source flow rate by 10 L / min, which resulted in a decrease in the relative concentration of the polymer powder in water, thereby affecting its chemical reaction and interaction. Although the polymer powder feed rate, stirring speed and water source temperature remained unchanged, too much water may cause the distribution of polymer molecules to be too dispersed, affecting the crosslinking and interaction between polymer chains.

[0066] Compared with Experimental Example 5, in Experimental Example 6, due to the excessive increase in water source flow, the viscosity of the fracturing fluid will decrease because the effective connection between polymer molecules is reduced. The sand carrying performance will also decrease because the decrease in viscosity will weaken the carrying capacity of sand particles. At the same time, due to the inadequate reaction, the residue content will also increase.

[0067] Table 1 shows the viscosity, sand carrying performance and residue content of the fracturing fluid under different parameters. It can be seen from Experimental Examples 1-6 in Table 1 that with the increase of water source flow rate, polymer dry powder feed rate and stirring speed, the viscosity and sand carrying performance of the fracturing fluid are significantly improved. Increasing the feed rate and stirring speed usually improves the viscosity and sand carrying performance. Comparing Experimental Examples 5 and 6, it can be seen that with the continuous increase of water source flow rate, the viscosity, sand carrying performance and residue content of the fracturing fluid will continue to decrease. The water source temperature also has a certain influence on the performance of the fracturing fluid. Properly increasing the temperature helps to improve the performance, but too high or too low a temperature may lead to undesirable results.

[0068] This specific embodiment is merely an explanation of the invention and is not a limitation of the invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as they are within the scope of protection of the invention, they are protected by patent law.

Claims

1. A method for preparing a polymer dry powder online mixing fracturing fluid, characterized in that: The following steps are involved: S1. Data collection: Use high-precision sensors and measuring equipment to collect real-time and accurate data on water source flow, pressure, temperature, water quality, feed rate, feed amount and particle size distribution parameters of polymer dry powder; S2. Ratio calculation: Based on the preset fracturing fluid formula and the collected real-time data, dynamically calculate the optimal ratio of water source and polymer dry powder; S3, Mixing control: Use a multi-stage stirring device to accurately control the stirring speed and stirring time according to the real-time monitoring of the mixing degree to ensure that the polymer dry powder and water are fully and evenly mixed; S4. Quality monitoring: Use online testing equipment to comprehensively test the viscosity, density, pH value, sand carrying performance and residue content of the mixed fracturing fluid to ensure that the quality of the fracturing fluid meets the requirements; S5, feedback adjustment: compare and analyze the detected fracturing fluid parameters with the preset quality standards; if deviations are found, the intelligent control system automatically adjusts the feed rate, stirring speed, and water source temperature until the fracturing fluid performance reaches the standard; S6. Intelligent prediction: Establish an intelligent control model based on big data and machine learning, and use historical data and real-time feedback information to predict the optimal control parameter combination under different operating conditions; S7. Safety monitoring: During the mixing process, continuously monitor the pressure and temperature in the mixing device. When abnormalities occur, take protective measures in time to ensure the safety and stability of the entire mixing process.

2. The method for preparing a polymer dry powder online mixing fracturing fluid according to claim 1, characterized in that: The collection accuracy of the water source flow is ±0.1L / min, the pressure collection accuracy is ±0.01MPa, the temperature collection accuracy is ±0.1℃, and the water quality parameters should include hardness, pH and ion concentration.

3. The method for preparing a polymer dry powder online mixing fracturing fluid according to claim 2, characterized in that: The measurement accuracy of the polymer dry powder feed rate is ±0.1 g / min, the measurement accuracy of the feed amount is ±0.01 g, and the measurement of the particle size distribution should be able to accurately distinguish the proportion of different particle size ranges.

4. The method for preparing a polymer dry powder online mixing fracturing fluid according to claim 3, characterized in that: The multi-stage stirring device has no less than three stages, and the rotation speed of each stirring paddle can be adjusted independently, and the speed adjustment range is 100-1000rpm.

5. The method for preparing a polymer dry powder online mixing fracturing fluid according to claim 4, characterized in that: The online detection equipment has a detection accuracy of ±1mPa・s for fracturing fluid viscosity, a density detection accuracy of ±0.01g / cm³, a pH value detection accuracy of ±0.1, a sand carrying performance detection error of no more than ±2%, and a residue content detection accuracy of ±1mg / L.

6. The method for preparing a polymer dry powder online mixing fracturing fluid according to claim 5, characterized in that: The intelligent control system should have a response time of no more than 1 second to adjust the control parameters, so as to achieve timely and accurate control of the mixing process.

7. The method for preparing a polymer dry powder online mixing fracturing fluid according to claim 6, characterized in that: The prediction accuracy of the intelligent control model for the optimal control parameters should be no less than 90%, and it should be able to quickly learn and optimize according to new operating conditions and data.

8. The method for preparing a polymer dry powder online mixing fracturing fluid according to claim 7, characterized in that: The monitoring accuracy of the pressure in the mixing device is ±0.01MPa, and the temperature monitoring accuracy is ±0.1°C. When the pressure or temperature exceeds the preset safety range, the system should be able to automatically take protective measures such as shutdown or alarm.

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