Wall surface electromagnetic control closed stress system of multi-scale propping agent transportation flat plate device

Abstract

The invention discloses an electromagnetic control closed stress system for a wall surface of a multi-scale propping agent migration flat plate device. The system comprises a flat plate device wall surface used for simulating a formation fracture channel, an electromagnetic generating device is arranged around the outer portion of the wall face of the panel device and used for generating electromagnetic force to control the wall face of the panel device and regulating and controlling the closing stress of the wall face of the panel device through the generated electromagnetic force. Arranging a stress monitoring module on the wall surface of the panel device, wherein the stress monitoring module is used for monitoring the stress condition of the wall surface of the panel device in real time and feeding back data; and the control system is used for receiving data fed back by the stress monitoring module and controlling the working state of each electromagnetic coil in the electromagnetic generating device according to preset stress parameters. According to the invention, the stress environment under various complex formation conditions can be accurately simulated, a reliable experimental means is provided for deeply researching the migration rule of the propping agent, the research and development efficiency and level of an oil and gas field fracturing exploitation technology are improved, and the development of the oil and gas industry is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploitation, and in particular to a wall electromagnetic controlled closed stress system of a multi-scale proppant transport flat plate device. Background Art

[0002] During the fracturing process of oil and gas fields, the migration characteristics of proppants have a crucial impact on the conductivity of fractures and oil and gas production.

[0003] Traditional proppant migration research equipment is often difficult to accurately simulate and control the complex stress conditions in actual formations. Especially in large-scale multi-scale experimental environments, how to effectively regulate the closure stress of the flat-plate device wall to more realistically reflect the formation conditions has become a key issue in current research.

[0004] Currently available technical means have many deficiencies in terms of stress control accuracy, flexibility, and compatibility with multi-scale proppant migration experiments, making it difficult to meet the growing demand for oil and gas extraction technology research and development. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-scale proppant transport flat plate device wall electromagnetic controlled closed stress system to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides a multi-scale proppant transport flat plate device wall electromagnetic controlled closed stress system, comprising: The wall of the flat device is used to simulate the formation fracture channel, and the wall of the flat device is made of concrete, a visualization module and an electromagnetic induction material; An electromagnetic generating device is disposed around the outside of the wall of the flat device; the electromagnetic generating device includes a plurality of electromagnetic coils, and the electromagnetic generating device is used to generate electromagnetic force to control the wall of the flat device, and to adjust the closing stress of the wall of the flat device through the generated electromagnetic force; A stress monitoring module is arranged on the wall surface of the flat device, and is used to monitor the stress condition of the wall surface of the flat device in real time and feed back data; The control system is used to receive the data fed back by the stress monitoring module and control the working state of each electromagnetic coil in the electromagnetic generating device according to preset stress parameters.

[0007] Preferably, the electromagnetic coil is made of a material that is resistant to high temperatures and has high electrical conductivity.

[0008] Preferably, the stress monitoring module adopts a high-precision strain gauge sensor and / or a fiber grating sensor.

[0009] An operating method of a wall electromagnetic controlled closed stress system based on a multi-scale proppant transport flat plate device comprises the following steps: S1. According to the formation stress conditions to be simulated, the target closing stress parameters of each area of ​​the flat plate device wall are preset in the control system; S2, start the electromagnetic generating device, and the control system sends a control signal to each electromagnetic coil according to the preset parameters, so that the electromagnetic coil generates an electromagnetic field of corresponding strength and direction; S3, carry out proppant migration experiment, use stress monitoring module to monitor stress change of the wall of flat device in real time, and transmit monitoring data back to control system; S4. The control system analyzes and processes the data fed back by the stress monitoring module and compares it with the preset stress parameters. According to the comparison results, the electromagnetic field parameters of each electromagnetic coil in the electromagnetic generating device are dynamically adjusted to ensure that the closing stress of the wall of the flat device is always maintained within the preset range.

[0010] Compared with the prior art, the present invention has the following advantages and technical effects: 1. The present invention can accurately simulate the stress environment under various complex formation conditions in a large-scale multi-scale proppant migration flat plate device, providing a reliable experimental means for in-depth research on the proppant migration law, helping to improve the research and development efficiency and level of oil and gas field fracturing production technology and promote the development of the oil and gas industry.

[0011] 2. The wall of the proppant laying and migration device simulates the real tortuous fracture wall and has different tortuous structures. By adjusting the fracture width, the proppant laying and migration test at different sizes can be realized, thereby achieving the effect of multi-scale simulation. By designing fluid channels of various sizes, the proppant migration behavior at different geological levels can be simulated, increasing the adaptability and extensiveness of the experimental results.

[0012] 3. Electromagnetic control of wall closure stress. The wall stress is controlled by electromagnetic coils to adjust the stability of the proppant during migration, avoid proppant blockage or deviation, and ensure that the proppant is evenly distributed in the fluid.

[0013] 4. Real-time monitoring and regulation. The built-in stress monitoring system and feedback control mechanism enable the device to automatically adjust the electromagnetic field parameters according to the real-time stress changes during the experiment, thereby improving the accuracy and stability of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a schematic diagram of the electromagnetically controlled closed stress system on the wall of the multi-scale proppant transport flat plate device of the present invention; Figure 2 is a schematic diagram of the wall surface of the flat-plate device of the present invention; In the figure: 1. Flat plate device wall; 2. Electromagnetic generating device; 3. Stress monitoring module; 4. Control system. DETAILED DESCRIPTION

[0016] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0017] like Figure 1 to Figure 2 As shown, the present invention provides a multi-scale proppant transport flat plate device wall electromagnetic control closed stress system, comprising: The flat device wall 1 is used to simulate the formation fracture channel. The flat device wall 1 is made of concrete, a visualization module and an electromagnetic induction material, and can produce stress changes under the action of an electromagnetic field; The electromagnetic generating device 2 is arranged around the outside of the flat device wall 1; the electromagnetic generating device 2 includes a plurality of electromagnetic coils, and is used to generate electromagnetic force to control the flat device wall 1, and regulate the closing stress of the flat device wall 1 through the generated electromagnetic force; the electromagnetic coils can independently generate electromagnetic fields of different strengths and directions, and accurately control the electromagnetic force of the flat device wall 1 by changing the parameters of the electromagnetic field, thereby realizing the regulation of the closing stress; A stress monitoring module 3 is arranged on the wall surface 1 of the flat device. The stress monitoring module 3 is used to monitor the stress condition of the wall surface 1 of the flat device in real time and feedback data; The control system 4 is used to receive the data fed back by the stress monitoring module 3, and intelligently control the current size, direction and on-off time of each electromagnetic coil in the electromagnetic generating device 2 according to the preset stress parameters, so as to realize the accurate and dynamic control of the closing stress of the wall surface 1 of the flat plate device, so that it can simulate the stress environment under different formation conditions and meet the needs of multi-scale proppant migration experiments.

[0018] The present invention can accurately simulate the stress environment under various complex formation conditions in a large-scale multi-scale proppant migration flat plate device, providing a reliable experimental means for in-depth research on the proppant migration law, helping to improve the research and development efficiency and level of oil and gas field fracturing production technology, and promoting the development of the oil and gas industry.

[0019] To further optimize the solution, the electromagnetic coil is made of high temperature resistant and high conductivity materials to ensure stable operation under long-term and high-intensity electromagnetic fields, and can quickly respond to the instructions of the control system 4 to achieve precise adjustment of the electromagnetic field.

[0020] To further optimize the solution, the stress monitoring module 3 uses a high-precision strain gauge sensor and / or a fiber grating sensor. It can accurately measure tiny stress changes and has high sensitivity, high reliability and anti-interference ability, ensuring the accuracy and stability of feedback data, and providing a reliable basis for the precise control of the control system 4.

[0021] To further optimize the solution, the control system 4 adopts an advanced programmable logic controller PLC or digital signal processor DSP, which can independently, quickly and accurately control multiple electromagnetic coils, and also has data storage, analysis and visualization functions, so that the experimenters can monitor the stress data in real time and conduct subsequent analysis and research during the experiment.

[0022] To further optimize the solution, the wall material on one side of the flat device wall 1 is cement gravel prepared using real stratum characteristics or a tortuous wall precisely prepared from rock samples after fracturing to simulate real roughness and filtration; the other side is a visualized tortuous transparent wall obtained through 3D scanning and printing. Both are integrated with an electromagnetic force control system to apply different closing stresses to the wall through an electromagnetic field. Under the action of the electromagnetic field, the wall can respond and adjust in real time to simulate the effect of rock formations on proppants under different pressures. While ensuring the electromagnetic induction performance, it has sufficient strength and wear resistance to resist the scouring and wear of the wall by the proppant during migration, thereby extending the service life of the device and ensuring the stability and reliability of stress control during the experiment.

[0023] An operating method of a wall electromagnetic controlled closed stress system based on a multi-scale proppant transport flat plate device comprises the following steps: S1. According to the formation stress conditions to be simulated, the target closing stress parameters of each area of ​​the flat plate device wall 1 are preset in the control system 4; S2, start the electromagnetic generating device 2, and the control system 4 sends a control signal to each electromagnetic coil according to the preset parameters, so that the electromagnetic coil generates an electromagnetic field of corresponding strength and direction; S3, perform proppant migration experiment, use stress monitoring module 3 to monitor stress changes of flat device wall surface 1 in real time, and transmit monitoring data back to control system 4; S4, the control system 4 analyzes and processes the data fed back by the stress monitoring module 3, and compares it with the preset stress parameters, and dynamically adjusts the electromagnetic field parameters of each electromagnetic coil in the electromagnetic generating device 2 according to the comparison results to ensure that the closing stress of the wall surface 1 of the flat device is always maintained within the preset range.

[0024] Embodiment 1 The proppant migration experiment under the simulated low permeability formation stress environment is as follows: 1. The experimenter sets the closing stress parameters of the simulated low permeability formation in the control system 4; for the formation conditions, the average closing stress of the wall 1 of the flat device is preset to be 50MPa, and the stress is slightly lower at the entrance of the channel, which is 45MPa, and gradually increases along the channel to 55MPa at the exit, so as to simulate the stress gradient caused by the change of formation fluid pressure; 2. Check the electromagnetic coils of the electromagnetic generating device 2 to ensure that they work normally; the electromagnetic coils are made of copper alloy material, have good high temperature resistance and high conductivity, and can withstand long-term high-intensity electromagnetic fields; 3. The stress monitoring module 3 uses a high-precision fiber Bragg grating sensor with an accuracy of ±0.1MPa. It is calibrated before the experiment to ensure accurate measurement of the stress change on the wall 1 of the flat device; 4. Start the electromagnetic generating device 2, and the control system 4 sends a control signal to each electromagnetic coil according to the preset parameters; the electromagnetic coil generates a specific distributed electromagnetic field, which acts on the electromagnetic induction wall surface of the flat device wall 1, so that the flat device wall 1 generates a corresponding electromagnetic force, thereby forming a closed stress distribution that meets the preset requirements; 5. Injecting a simulated fracturing fluid mixed with multi-scale proppants (including proppants of three different particle sizes, 20 / 40 mesh, 40 / 70 mesh and 70 / 140 mesh, in a ratio of 3:5:2) into the simulated formation fracture channel on the wall 1 of the flat device at a flow rate of 1 m / s; 6. During the proppant migration process, the stress monitoring module 3 monitors the wall stress changes in real time and feeds the data back to the control system 4; for example, when the stress at a certain position of the channel is monitored to fluctuate by 2MPa due to proppant accumulation, the control system 4 quickly adjusts the current of the electromagnetic coil near the area to increase the electromagnetic field strength, thereby increasing the electromagnetic force on the wall and adjusting the closing stress back to the preset value to ensure the stability of the stress environment during the experiment; 7. By observing and recording the migration trajectory, settlement distribution, etc. of the proppant in a simulated low permeability formation stress environment, it was found that proppant with smaller particle size is more likely to aggregate in low stress areas, while proppant with larger particle size is more inclined to distribute in high stress areas. This is consistent with theoretical expectations, verifying that the present invention can effectively simulate the stress conditions of low permeability formations, and provides reliable experimental data for further studying the migration laws of proppant in such formations.

[0025] Embodiment 2 The proppant migration experiment simulating high stress and complex fracture network formations, the experimental scheme is as follows: 1. To simulate high-stress complex fracture network formations, a complex stress parameter mode is set in the control system 4. For example, the average closing stress is set to 80MPa on the wall of the main fracture channel of the flat device wall 1, and a stress concentration area is set at the beginning of the branch fracture, with a stress peak value of up to 100MPa, and the stress direction has a certain angle change in different areas to simulate the complex stress distribution in the actual formation fracture network; 2. The electromagnetic coil of the electromagnetic generating device 2 is made of a special silver-based composite material, which has higher conductivity and better electromagnetic response performance, and can meet the needs of rapid changes in high-intensity electromagnetic fields; 3. Stress monitoring module 3 uses a highly sensitive strain gauge sensor array, which can monitor stress changes at multiple locations at the same time, and has anti-interference capabilities, and can work accurately in complex electromagnetic field environments; 4. Turn on the electromagnetic generating device 2, and the control system 4 controls the electromagnetic coils to work according to the preset complex stress parameters, accurately generating the required electromagnetic field distribution, so that the wall surface 1 of the flat device forms a corresponding high-stress complex distribution pattern; 5. A simulated fracturing fluid containing proppants of various shapes (spherical, elliptical and cylindrical) and particle sizes (16 / 30 mesh, 30 / 50 mesh and 40 / 70 mesh, with a ratio of 4:3:3) was injected into the main fracture channel of the flat plate device wall 1 at a flow rate of 1.5 m / s, and part of the fracturing fluid and proppants were allowed to enter the branch fractures through a special diversion device; 6. During the experiment, the stress monitoring module 3 continuously monitors the wall stress changes and transmits the data to the control system 4 in real time; when it is found that the stress distribution changes abnormally due to the accumulation of proppant at the entrance of the branch fracture, the control system 4 immediately adjusts the electromagnetic field parameters of the electromagnetic coil in the area and coordinates the work of the electromagnetic coils in the adjacent areas to maintain the stability of the wall stress of the entire fracture network and the preset complex distribution state; 7. After the experiment, a detailed analysis of the migration of proppant in the simulated high-stress complex fracture network formation was conducted.

[0026] The results show that proppants of different shapes and sizes show obvious sorting under complex stress environments. Spherical proppants migrate relatively smoothly in the main fractures, while columnar proppants are more likely to be retained and bridged at the beginning of branch fractures where stress is concentrated. This result further verifies that the electromagnetic controlled closed stress system can accurately simulate the stress conditions of high-stress complex fracture network formations, providing strong experimental support for the optimal design of proppants for complex fracture networks in oil and gas field fracturing production, which helps to improve the efficiency and effect of oil and gas production.

[0027] The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A multi-scale proppant transport flat plate device wall electromagnetic controlled closed stress system, characterized in that: include: The flat device wall (1) is used to simulate a stratum fracture channel, and the flat device wall (1) is made of concrete, a visualization module and an electromagnetic induction material; An electromagnetic generating device (2) is arranged around the outside of the flat device wall (1); the electromagnetic generating device (2) comprises a plurality of electromagnetic coils, and the electromagnetic generating device (2) is used to generate electromagnetic force to control the flat device wall (1), and to regulate the closing stress of the flat device wall (1) through the generated electromagnetic force; A stress monitoring module (3) is arranged on the wall surface (1) of the flat device, and the stress monitoring module (3) is used to monitor the stress condition of the wall surface (1) of the flat device in real time and to feed back data; A control system (4) is used to receive data fed back by the stress monitoring module (3) and control the working state of each electromagnetic coil in the electromagnetic generating device (2) according to preset stress parameters.

2. The multi-scale proppant transport flat plate device wall electromagnetic controlled closed stress system according to claim 1, characterized in that: The electromagnetic coil is made of high temperature resistant and high conductivity material.

3. The multi-scale proppant transport flat plate device wall electromagnetic controlled closed stress system according to claim 1, characterized in that: The stress monitoring module (3) adopts a high-precision strain gauge sensor and / or a fiber grating sensor.

4. The multi-scale proppant transport flat plate device wall electromagnetic controlled closed stress system according to any one of claims 1 to 3, characterized in that: The operation method includes the following steps: S1. According to the formation stress conditions to be simulated, the target closing stress parameters of each area of ​​the flat plate device wall (1) are preset in the control system (4); S2, starting the electromagnetic generating device (2), and the control system (4) sends a control signal to each electromagnetic coil according to preset parameters, so that the electromagnetic coil generates an electromagnetic field of corresponding strength and direction; S3, conducting a proppant migration experiment, using the stress monitoring module (3) to monitor the stress change of the wall surface (1) of the flat device in real time, and transmitting the monitoring data back to the control system (4); S4, the control system (4) analyzes and processes the data fed back by the stress monitoring module (3), and compares the data with the preset stress parameters, and dynamically adjusts the electromagnetic field parameters of each electromagnetic coil in the electromagnetic generating device (2) according to the comparison result, so as to ensure that the closing stress of the wall surface (1) of the flat device is always maintained within the preset range.

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