Multi-component proppant transport analysis apparatus and experimental methods

Abstract

This application provides a multi-component proppant migration analysis device and experimental method. The device includes multiple independent sand tanks, multiple flow control valves, a surface manifold, a screw pump, a proppant migration simulation system, a laser particle size sensor, and a data acquisition system. The outlet of each independent sand tank is connected to a corresponding flow control valve. The outlet of each flow control valve is connected to the inlet of the surface manifold, and the outlet of the surface manifold is connected to the feed inlet of the screw pump. The discharge outlet of the screw pump is connected to the inlet of the proppant migration simulation system. The laser particle size sensor is fixed to the outside of the proppant migration simulation system. The data acquisition system is connected to the laser particle size sensor, the multiple flow control valves, and the screw pump. This device provides reliable experimental data support for optimizing on-site hydraulic fracturing schemes.

Description

Technical Field

[0001] This application relates to the field of petroleum engineering, and in particular to a multi-component proppant transport analysis apparatus and experimental method. Background Technology

[0002] As oil and gas reservoir development extends to deeper and ultra-deeper layers, single-size proppants are gradually being replaced by multi-component mixed proppants due to problems such as limited migration distance and poor fracture support uniformity. Therefore, accurate analysis of the migration patterns and deposition effects of multi-component proppants within fractures has become a key prerequisite for optimizing fracturing schemes and improving development efficiency.

[0003] Currently, most analytical devices for proppant migration in the industry focus on single-component proppants and conduct overall migration tests. However, existing technologies cannot distinguish the sorting and deposition patterns of proppants of different particle sizes in real time, making it difficult to screen out mixed particle size combinations that can meet the needs of deep oil and gas reservoirs from experimental data. Summary of the Invention

[0004] This application provides a multi-component proppant migration analysis device and experimental method to provide reliable experimental data support for the optimization of on-site hydraulic fracturing schemes.

[0005] In a first aspect, embodiments of this application provide a multi-component proppant migration analysis device, comprising: multiple independent sand tanks, multiple flow control valves, a ground manifold, a screw pump, a proppant migration simulation system, a laser particle size sensor, and a data acquisition system; the outlet of each independent sand tank is connected to a corresponding flow control valve, each independent sand tank is used to store proppant of a single particle size, and each flow control valve is used to control the start and stop of the outflow of proppant in the corresponding independent sand tank; the outlet of each flow control valve is connected to the inlet of the ground manifold, which is used to collect proppant of different particle sizes flowing out of each flow control valve to form a mixed proppant; the outlet of the ground manifold is connected to the inlet of the screw pump, and the outlet of the screw pump is connected to the inlet of the proppant migration simulation system. A pump is used to deliver the mixed proppant to the proppant migration simulation system. A laser particle size sensor is fixed to the outside of the proppant migration simulation system to scan the distribution profile of the mixed proppant within the system in real time, capturing the distribution differences of proppant with different particle sizes. A data acquisition system is connected to the laser particle size sensor, multiple flow control valves, and a screw pump. Based on the mixed proppant distribution profile data, flow control valve opening data, and screw pump delivery pressure and flow data, the system outputs the corresponding proppant migration and deposition parameters within the proppant migration simulation system. These parameters are used to compare the migration and deposition effects of proppant combinations with different particle size combinations to screen for target mixed particle size combinations.

[0006] Optionally, each independent sand tank is equipped with a feed inlet with a filter screen and a pressure balancing valve on its top; each independent sand tank is equipped with a liquid level observation window on its outer side; the pressure balancing valve is connected to the inside of the corresponding independent sand tank to maintain the air pressure inside each independent sand tank consistent with atmospheric pressure; the filter screen at the feed inlet is used to filter impurities when the corresponding proppant is loaded; the liquid level observation window is connected to the inside of the corresponding independent sand tank to monitor the remaining amount of proppant in the corresponding independent sand tank in real time; the inner wall of each independent sand tank is polished to reduce the residue of the corresponding proppant on the inner wall of the tank.

[0007] Optionally, the proppant migration simulation system includes a channel that simulates the spatial characteristics of fractures in actual oil and gas wells. The inner wall of the channel is smooth and free of scratches to simulate the proppant migration environment within fractures in actual hydraulic fracturing scenarios. The proppant migration simulation system has multiple laser particle size sensor monitoring points along the length of the channel. Each laser particle size sensor monitoring point is equipped with a mounting bracket adapted to the laser particle size sensor. Each laser particle size sensor monitoring point is used to cooperate with the laser particle size sensor to collect the distribution profile data of the mixed proppant from the inlet to the outlet of the channel. The proppant migration simulation system is made of transparent resin material to observe the migration trajectory, deposition location, and sorting phenomenon of proppant of different particle sizes within the channel.

[0008] Optionally, the laser particle size sensor includes multiple sensor probes; each sensor probe corresponds one-to-one with a laser particle size sensor monitoring point of the proppant migration simulation system, and each sensor probe is fixed by a mounting bracket corresponding to the laser particle size sensor monitoring point. Each sensor probe is vertically aligned with the channel cross-section of the proppant migration simulation system, and each sensor probe is used to collect the distribution profile data of the mixed proppant at the corresponding laser particle size sensor monitoring point in real time; the signal output terminal of the laser particle size sensor is connected to the signal input terminal of the data acquisition system, and is used to send the distribution profile data to the data acquisition system.

[0009] Secondly, embodiments of this application provide a method for multi-component proppant transport analysis, comprising: selecting proppants of different particle sizes corresponding to a preset particle size combination, and drying the proppants of different particle sizes; checking whether the connections of each component of the multi-component proppant transport analysis device are normal; if the connections of each component of the multi-component proppant transport analysis device are normal, then loading the dried proppants of different particle sizes into corresponding independent sand tanks; starting the data acquisition system, adjusting the laser particle size sensor to monitoring state, the flow control valve to initial closed state, and the screw pump to standby state; and adjusting the opening of the flow control valve corresponding to the outlet of each independent sand tank according to a preset mixing ratio, so that the proppant of different particle sizes can be transported through the ground manifold. A mixed proppant is formed; a screw pump is started to deliver the mixed proppant to the proppant migration simulation system at a preset pressure and flow rate; the distribution profile of the mixed proppant in the proppant migration simulation system is scanned in real time using a laser particle size sensor to capture the migration difference data of proppant with different particle sizes, and a settling velocity curve of the mixed proppant is generated; the data acquisition system outputs the proppant migration and deposition parameters corresponding to the mixed proppant in the proppant migration simulation system based on the settling velocity curve, the opening data of the flow control valve, and the delivery pressure and flow rate data of the screw pump, and completes the migration analysis experiment corresponding to the preset particle size combination. The proppant migration and deposition parameters are used to compare the migration and deposition effects of proppant with different particle size combinations in order to screen the target mixed particle size combination.

[0010] Optionally, the distribution profile of the mixed proppant within the proppant migration simulation system is scanned in real time using a laser particle size sensor to capture the migration differences of proppant particles of different sizes and generate a sedimentation velocity curve of the mixed proppant. This includes: activating the laser particle size sensor at a preset frequency to continuously scan the distribution profile of the mixed proppant within the proppant migration simulation system and recording the mixed proppant particle size distribution data at different times at each laser particle size sensor monitoring point; by comparing the mixed proppant particle size distribution data at the same laser particle size sensor monitoring point at different times, capturing the first migration difference data of proppant particles of different sizes at the laser particle size sensor monitoring point, wherein the first migration difference data indicates the difference between different particle sizes of proppant particles. The distribution ratio or profile position shift of proppant of the same particle size at the monitoring point of the laser particle size sensor is observed. By comparing the particle size distribution data of the mixed proppant at different monitoring points of the laser particle size sensor at the same time, the second migration difference data of proppant of different particle sizes is captured. The second migration difference data indicates the difference in the migration progress of proppant of different particle sizes along the channel of the proppant migration simulation system from the inlet to the outlet. Based on the first and second migration difference data and the preset scanning time interval of the laser particle size sensor, the settling velocity data of proppant of different particle sizes is calculated. By fitting the settling velocity data of proppant of different particle sizes, the settling velocity curve of the mixed proppant is generated.

[0011] Optionally, proppant migration and deposition parameters include the sandbank equilibrium height and non-uniformity index. Correspondingly, the data acquisition system outputs the proppant migration and deposition parameters corresponding to the mixed proppant within the proppant migration simulation system based on the settling velocity curve, flow control valve opening data, and screw pump delivery pressure and flow rate data. This includes: the data acquisition system receiving the settling velocity curve, flow control valve opening data, and screw pump delivery pressure and flow rate data, and aligning the settling velocity curve, flow control valve opening data, and screw pump delivery pressure and flow rate data with timestamps to obtain a time-consistent experimental dataset; and inputting the time-consistent experimental dataset and the channel size parameters of the proppant migration simulation system. A preset algorithm model outputs the deposition height difference of the mixed proppant within the channel of the proppant migration simulation system. The channel size parameter is used to characterize the simulated fracture space characteristics of actual oil and gas wells in the proppant migration simulation system. When the deposition height difference output for a consecutive preset number of times is within a first preset range, the average value of the deposition height difference output for a consecutive preset number of times is determined as the sand embankment equilibrium height. Based on the settling velocity curves in the experimental dataset with consistent time dimension and the migration difference data of proppant of different particle sizes, the actual proportion of each particle size proppant at different locations within the proppant migration simulation system is calculated. The non-uniformity index is obtained based on the deviation between the actual proportion of each particle size proppant and the preset mixing ratio.

[0012] Optionally, after completing the migration analysis experiment corresponding to the preset particle size combination, the method further includes: conducting experiments on proppant corresponding to at least two different particle size combinations to obtain proppant migration and deposition parameters for each particle size combination; comparing the sand embankment equilibrium heights obtained from at least two experiments to screen out the particle size combination with the lower sand embankment equilibrium height; if the screened particle size combination is a single set, then the screened particle size combination is determined as the target mixed particle size combination; if there are at least two screened particle size combinations, then the particle size combination with the higher non-uniformity index is eliminated; if the remaining particle size combinations after elimination are a single set, then the remaining particle size combinations are determined as the target mixed particle size combination; if there are at least two remaining particle size combinations after elimination, then the sand embankment laying distance improvement rate corresponding to each particle size combination is calculated based on the proppant migration and deposition parameters; and the particle size combination with the highest sand embankment laying distance improvement rate is determined as the target mixed particle size combination.

[0013] Optionally, the improvement rate of sand embankment laying distance corresponding to each group of grain size combinations is calculated based on the proppant migration and deposition parameters, including: obtaining the deposition length data of the sand embankment along the channel of the proppant migration simulation system corresponding to each group of grain size combinations, wherein the deposition length data is the straight-line distance from the end deposition point of the sand embankment to the entrance of the channel; and calculating the improvement rate of sand embankment laying distance corresponding to each group of grain size combinations based on the deposition length data and the benchmark laying distance, wherein the benchmark laying distance is the deposition length data of a preset single grain size proppant under the same experimental conditions as each group of grain size combinations.

[0014] Optionally, the proppant of different particle sizes is dried, including: placing proppant of different particle sizes into independent constant temperature drying ovens, setting the drying temperature of each oven, and starting the drying program of each oven; during the drying process, extracting proppant samples from each oven at preset intervals and recording the mass of the samples; when the mass difference between two consecutive extractions of the same particle size is within a second preset range, the proppant of that particle size is determined to have reached the drying endpoint and the heating of the corresponding oven is stopped; at room temperature, the dried proppant is transferred to a moisture-proof sealed container for cooling, and after cooling, the dried proppant of different particle sizes is obtained.

[0015] The multi-component proppant migration analysis device and experimental method provided in this application form a closed-loop analysis system adapted to multi-stage pumping conditions in the field. This system encompasses proppant pretreatment, experimental device debugging, mixing ratio control, dynamic transport simulation, and full-process migration data acquisition and deposition parameter calculation. It not only realistically recreates the migration and deposition process of proppants of different particle sizes in a simulated fracture environment but also captures multi-particle-size migration differences using a laser particle size sensor and quantifies parameters such as sandbank equilibrium height and non-uniformity index using a preset algorithm model. Finally, the optimal mixing particle size combination is selected through parameter comparison. This process solves the problem of single-particle-size analysis being unsuitable for actual construction and compensates for the shortcomings of traditional devices in dynamic ratio control, real-time accurate monitoring, and quantitative analysis capabilities. It provides reliable experimental data support for optimizing on-site hydraulic fracturing schemes and helps to extend the proppant fracture length and improve fracture conductivity. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] Figure 1 A schematic diagram of the multi-component proppant transport analysis apparatus provided in this application;

[0018] Figure 2A schematic flowchart of the experimental method for multi-component proppant transport analysis provided in the embodiments of this application. Figure 1 ;

[0019] Figure 3 A schematic flowchart of the experimental method for multi-component proppant transport analysis provided in the embodiments of this application. Figure 2 .

[0020] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0022] To clearly understand the technical solution of this application, the existing technical solutions will first be described in detail. In oil and gas field development, hydraulic fracturing is the core means to improve the recovery rate of low-permeability oil and gas reservoirs. As a key material for maintaining the opening of artificial fractures and constructing oil and gas flow channels, the migration law and deposition effect of proppant within the fracture directly determine the final benefit of fracturing operations. As oil and gas reservoir development extends to deeper and ultra-deep layers, single-size proppant is no longer able to meet field requirements due to its limited migration distance, susceptibility to sand blockage during flowback, and poor fracture support uniformity. The industry has gradually adopted a multi-stage pumping mode, with small-size proppant injected in the front, medium-size proppant injected in the middle, and large-size proppant injected in the rear, to optimize the fracture support effect through the synergistic effect of multi-component proppant. To investigate proppant migration patterns, laboratory experiments have evolved from resin transparent plate experiments and complex staggered plate experiments to 3D printed rough fracture sand-added experiments and triaxial core loading sand-carrying fracturing simulation experiments, continuously improving experimental methods. However, existing technologies have significant limitations. Most proppant migration analysis devices in the industry focus on single-component proppants or only perform overall migration tests on simply mixed proppants. They lack independent multi-particle-size storage units and dynamic ratio control structures, making it impossible to monitor the sorting and deposition patterns of proppants of different particle sizes in real time. This results in limited research on the impact of different particle size combinations on proppant migration patterns, and the migration patterns of multi-component proppants remain unclear, failing to provide effective support for optimizing mixed particle size combinations and extending proppant fracture length in the field.

[0023] To address the aforementioned technical challenges, the inventors devised a method for dynamically controlling the proportions of multi-component proppant. This method involves using multiple independent sand tanks to store proppant particles of different sizes. Each tank outlet is equipped with a flow control valve. By adjusting the opening of these valves, precise mixing of proppant particles of different sizes can be achieved. This avoids proportion deviations caused by premixing and allows for dynamic adjustment of the mixing ratio according to experimental needs, simulating the actual conditions of multi-stage pumping in the field. Secondly, to capture the real-time migration differences of proppant particles of different sizes, the inventors conceived of introducing a laser particle size sensor. Multiple monitoring points were set up on the proppant migration simulation system. The laser particle size sensor scans the proppant distribution profile in real time, capturing the differences in sedimentation velocity and sorting characteristics of proppant particles of different sizes.

[0024] The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0025] Figure 1 A schematic diagram of the multi-component proppant transport analysis apparatus provided in this application is shown below. Figure 1 As shown, the multi-component proppant migration analysis device includes: multiple independent sand tanks, multiple flow control valves, a ground manifold, a screw pump, a proppant migration simulation system, a laser particle size sensor, and a data acquisition system.

[0026] Each independent sand tank has a corresponding flow control valve connected to its outlet. Each independent sand tank is used to store proppant of a single particle size, and each flow control valve is used to control the start and stop of the outflow of proppant in the corresponding independent sand tank.

[0027] Specifically, multiple independent sand tanks serve as storage units for the proppant. Each independent sand tank is used to store proppant of a single particle size, and each independent sand tank is connected to a flow control valve at its outlet. The flow control valve can control the flow of proppant in the corresponding independent sand tank by opening and closing, thereby achieving independent control of the delivery of proppant of different particle sizes.

[0028] In this embodiment, each independent sand tank is equipped with a feed inlet with a filter screen and a pressure balancing valve at its top; each independent sand tank is equipped with a liquid level observation window on its outer side; the pressure balancing valve is connected to the inside of the corresponding independent sand tank to maintain the air pressure inside each independent sand tank consistent with atmospheric pressure; the filter screen at the feed inlet is used to filter impurities when the corresponding proppant is loaded; the liquid level observation window is connected to the inside of the corresponding independent sand tank to monitor the remaining amount of proppant in the corresponding independent sand tank in real time; the inner wall of each independent sand tank is polished to reduce the residue of the corresponding proppant on the inner wall of the tank.

[0029] Specifically, each independent sand tank integrates two key components on its top: a feed inlet with a filter screen, directly connected to the inside of the sand tank. When proppant of the corresponding particle size is added, the filter screen at the feed inlet intercepts impurities mixed in with the proppant, such as particles and foreign objects, preventing them from entering the subsequent conveying and simulation systems and affecting experimental accuracy. The second component is a pressure balancing valve, also connected to the inside of the sand tank. Its core function is to maintain the internal pressure consistent with the external atmospheric pressure. When the proppant volume decreases due to reduced delivery, leading to increased internal space and decreased pressure, the pressure balancing valve automatically adjusts the pressure to prevent negative pressure from hindering the smooth flow of proppant. Simultaneously, each independent sand tank has a liquid level observation window on its exterior, connected to the inside of the sand tank and made of transparent material. Researchers can visually monitor the remaining amount of proppant in the tank in real time through the observation window, facilitating timely replenishment of proppant or assessment of experimental progress. In addition, the inner walls of each individual sand tank are polished to reduce the surface roughness of the inner wall, thereby reducing the friction and adhesion between the proppant particles and the tank wall, and effectively preventing proppant residue on the inner wall of the tank.

[0030] The outlet of each flow control valve is connected to the inlet of the ground manifold, which is used to collect the different particle sizes of proppant flowing out of each flow control valve to form a mixed proppant.

[0031] Specifically, the outlets of each flow control valve converge and connect to the inlet of the ground manifold. The ground manifold, as a mixing unit, can collect and mix proppant of different particle sizes flowing out from different flow control valves, ultimately forming a mixed proppant that meets the experimental requirements.

[0032] The outlet of the ground manifold is connected to the inlet of the screw pump, and the outlet of the screw pump is connected to the inlet of the proppant transport simulation system. The screw pump is used to deliver the mixed proppant to the proppant transport simulation system.

[0033] Specifically, the outlet end of the surface manifold is sealed to the inlet of the screw pump. The screw pump, as the power delivery unit, has its outlet connected to the inlet of the proppant migration simulation system. This system can deliver the mixed proppant, which has been mixed in the surface manifold, to the proppant migration simulation system at a stable pressure and flow rate, simulating the proppant migration environment in the fracture in actual hydraulic fracturing scenarios.

[0034] In this embodiment, the proppant migration simulation system is equipped with a channel that simulates the spatial characteristics of fractures in actual oil and gas wells. The inner wall of the channel is smooth and free of scratches, which is used to simulate the migration environment of proppant in fractures in actual hydraulic fracturing scenarios. The proppant migration simulation system is equipped with multiple laser particle size sensor monitoring points along the length of the channel. Each laser particle size sensor monitoring point is equipped with a mounting bracket adapted to the laser particle size sensor. Each laser particle size sensor monitoring point is used to cooperate with the laser particle size sensor to collect the distribution profile data of the mixed proppant from the inlet to the outlet of the channel. The proppant migration simulation system is made of transparent resin material, which is used to observe the migration trajectory, deposition location, and sorting phenomenon of proppant of different particle sizes in the channel.

[0035] Specifically, the core component of the proppant migration simulation system is a channel that simulates the spatial characteristics of fractures in actual oil and gas wells. The dimensions of this channel, such as width, height, and length, and its cross-sectional shape, such as rectangular or trapezoidal, are designed to match the geometric characteristics of actual fractures, referencing the real parameters of artificial fractures in deep and ultra-deep oil and gas reservoirs. This ensures that the proppant migration space in the experiment is consistent with the in-situ fracturing fractures. The inner wall of the channel is treated with a smooth, scratch-free process to replicate the proppant migration environment within actual fractures.

[0036] Specifically, multiple laser particle size sensor monitoring points are set along the length of the channel to construct a full-process monitoring link from the channel inlet to the outlet. These multiple laser particle size sensor monitoring points synchronously collect distribution profile data of the proppant at different locations during transport, tracking the changes in the mixed proppant from its entry into the channel to its final deposition. Each laser particle size sensor monitoring point is equipped with a mounting bracket adapted for the laser particle size sensor to fix the sensor position and detection angle, ensuring that each sensor is perpendicularly aligned with the channel cross-section and avoiding scanning deviations caused by sensor misalignment.

[0037] Specifically, the proppant transport simulation system uses transparent resin material, which allows direct observation of the dynamic transport trajectory of the mixed proppant in the channel, the final deposition location, and the sorting phenomenon of proppant with different particle sizes.

[0038] A laser particle size sensor is fixed to the outside of the proppant transport simulation system to scan the distribution profile of the mixed proppant within the system in real time and capture the distribution differences of proppant with different particle sizes.

[0039] Specifically, the laser particle size sensor is fixedly installed on the outer wall of the proppant migration simulation system, with its detection direction aligned with the internal channel of the proppant migration simulation system. It can scan the distribution profile of the mixed proppant in the channel in real time and accurately capture the spatial distribution differences of proppants of different particle sizes during the migration process.

[0040] In this embodiment, the laser particle size sensor includes multiple sensor probes; each sensor probe corresponds one-to-one with a laser particle size sensor monitoring point of the proppant migration simulation system. Each sensor probe is fixed by a mounting bracket corresponding to the laser particle size sensor monitoring point, and each sensor probe is vertically aligned with the channel cross-section of the proppant migration simulation system. Each sensor probe is used to collect real-time distribution profile data of the mixed proppant at the corresponding laser particle size sensor monitoring point. The signal output terminal of the laser particle size sensor is connected to the signal input terminal of the data acquisition system, and is used to send the distribution profile data to the data acquisition system.

[0041] The data acquisition system is connected to a laser particle size sensor, multiple flow control valves, and a screw pump. Based on the mixed proppant distribution profile data output by the laser particle size sensor, the opening data of the flow control valves, and the delivery pressure and flow rate data of the screw pump, it outputs the corresponding proppant migration and deposition parameters in the proppant migration simulation system. This completes the migration analysis experiment corresponding to the preset particle size combination. The proppant migration and deposition parameters are used to compare the migration and deposition effects of proppant with different particle size combinations in order to screen the target mixed particle size combination.

[0042] Specifically, the data acquisition system, as an information integration unit, establishes signal connections with the laser particle size sensor, multiple flow control valves, and screw pumps via lines, and can synchronously collect three types of key data in real time: mixed proppant distribution profile data output by the laser particle size sensor, opening data of each flow control valve, and delivery pressure and flow data during the operation of the screw pump.

[0043] In summary, by storing single-size proppant in multiple independent sand tanks and using corresponding flow control valves for independent start-stop control, and combining this with surface manifolds to achieve precise mixing of proppant of different sizes, it is possible to simulate multi-component proppant injection scenarios in the field, including small-size front-end injection, medium-size mid-stage injection, and large-size tail-end injection. Simultaneously, the screw pump can stably deliver the mixed proppant to a proppant migration simulation system equipped with channels simulating the spatial characteristics of fractures in actual oil and gas wells, thus recreating the real migration environment. A laser particle size sensor can scan the mixed proppant distribution profile in real time to capture the distribution differences of proppant of different sizes. The data acquisition system synchronously integrates sensor data, flow control valve opening data, and screw pump delivery parameters, providing data support for selecting target mixed particle size combinations and reliable experimental basis for optimizing on-site hydraulic fracturing schemes.

[0044] Figure 2 A schematic flowchart of the experimental method for multi-component proppant transport analysis provided in the embodiments of this application. Figure 1 .like Figure 2 As shown, using Figure 1 The multi-component proppant transport analysis apparatus shown was used in the experiment, which included the following steps:

[0045] S201: Select proppant with different particle sizes corresponding to the preset particle size combination, and dry the proppant with different particle sizes.

[0046] Specifically, the process of drying proppant of different particle sizes includes: placing proppant of different particle sizes into independent constant temperature drying ovens, setting the drying temperature of each oven, and starting the drying program of each oven; during the drying process, extracting proppant samples from each oven at preset intervals and recording the mass of the samples; when the mass difference between two consecutive extractions of the same particle size proppant is within a second preset range, the proppant of that particle size is considered to have reached the drying endpoint and the heating of the corresponding oven is stopped; and at room temperature, transferring the dried proppant to a moisture-proof sealed container for cooling, and obtaining the dried proppant of different particle sizes after cooling.

[0047] Specifically, firstly, based on the pre-set particle size combinations, such as 20 / 40 mesh, 40 / 70 mesh, and 70 / 140 mesh combinations, proppant with corresponding particle sizes is selected. Then, each particle size proppant is dried separately. During the operation, proppants of different particle sizes are placed one by one into an independent constant-temperature drying oven. The appropriate drying temperature for each oven is set according to the proppant material characteristics, and the drying program is started. During the drying process, proppant samples are randomly selected from each drying oven at preset time intervals, such as every 1.5-2 hours, and then dried using a precision-matched... Weigh and record the sample mass using a balance, such as an electronic balance with an accuracy of 0.001g. When the mass difference between two consecutive samples of the same particle size proppant is within a second preset range, such as when the mass difference is ≤0.1% of the previous mass, it is determined that the particle size proppant has reached the drying endpoint, and the heating of the corresponding constant temperature drying oven is immediately stopped. Then, at room temperature, transfer the dried particle size proppant to a moisture-proof sealed container with built-in desiccant to cool. After cooling to room temperature and without significant moisture absorption, the dried particle size proppant is obtained.

[0048] S202: Check whether the connections of each component of the multi-component proppant migration analysis device are normal.

[0049] Specifically, the researchers checked the connections between each component of the multi-component proppant transport analysis device, comparing them against its structural composition. They inspected whether the connection between the independent sand tank outlet and the corresponding flow control valve was securely sealed and free of leaks; whether the pipeline connection between the flow control valve outlet and the ground manifold inlet was unobstructed; whether the sealing connection between the ground manifold outlet and the screw pump inlet was reliable; and whether the pipeline between the screw pump outlet and the proppant transport simulation system inlet was unblocked. Simultaneously, they checked the signal line connections between the data acquisition system and the laser particle size sensor, flow control valve, and screw pump to ensure they were normal, guaranteeing no loose connections, leaks, or poor wiring contact between components.

[0050] S203: If all components of the multi-component proppant transport analysis device are properly connected, then the dried proppant of different particle sizes should be loaded into their respective independent sand containers.

[0051] Specifically, if the connection of all components of the multi-component proppant transport analysis device is confirmed to be normal after inspection, the dry proppant of different particle sizes is loaded into the device's independent sand tanks according to the preset particle size combination correspondence. Each independent sand tank is loaded with only a single particle size proppant. During the loading process, the loading amount is controlled through the liquid level observation window on the outside of the sand tank to avoid proppant overflow. At the same time, the feed inlet with a filter screen on the top of the sand tank is used to filter out any trace impurities that may remain, ensuring that the loaded proppant is pure and free of foreign matter, and that each particle size proppant is matched with its corresponding independent sand tank to prevent mixing.

[0052] S204: Start the data acquisition system, adjust the laser particle size sensor to monitoring status, the flow control valve to initial closed status, and the screw pump to standby status.

[0053] Specifically, the power supply to the multi-component proppant migration analysis device is turned on, and the data acquisition system is started to enter working condition. Then, the laser particle size sensor is debugged, and each sensor probe is fixed through the mounting bracket of the proppant migration simulation system monitoring point to ensure that the probe is vertically aligned with the channel cross-section of the simulation system. The sensor scanning function is turned on and debugged to a monitoring state that can clearly capture the distribution profile of the mixed proppant. The flow control valves corresponding to the outlets of all independent sand tanks are adjusted to the initial closed state to prevent proppant from flowing out before the mixing ratio is set. At the same time, the screw pump is started and debugged to the standby state. The pressure and flow control modules of the screw pump are checked to ensure that they respond normally and that all equipment is in a ready state to be started at any time.

[0054] S205: Adjust the opening of the flow control valve corresponding to the outlet of each independent sand tank according to the preset mixing ratio so that proppant of different particle sizes can be mixed through the ground manifold.

[0055] Specifically, based on preset mixing ratios of different particle size proppants, such as a 1:1 mixture of 40 / 70 mesh and 70 / 140 mesh, or a 1:2 mixture of 20 / 40 mesh and 40 / 70 mesh, the opening of the flow control valves corresponding to the outlets of each independent sand tank is adjusted via a data acquisition system or manually. For example, when the preset mixing ratio is 1:1, the opening of the flow control valves of the two corresponding sand tanks is adjusted to the same value, so that the two particle size proppants flow out in equal amounts. During the adjustment process, the opening data of the flow control valves is monitored in real time through the data acquisition system to ensure that the opening adjustment meets the preset ratio requirements. After the proppant of each particle size flows out from the corresponding flow control valve, it flows into the ground manifold for thorough mixing, ultimately forming a mixed proppant that meets the experimental ratio.

[0056] S206: Start the screw pump to deliver the mixed proppant to the proppant migration simulation system at a preset pressure and flow rate.

[0057] Specifically, after the flow control valve opening is adjusted and the mixed proppant is initially formed in the surface manifold, the screw pump, which is in standby mode, is started. The screw pump is operated according to the preset delivery pressure and flow parameters, such as a pressure of 5MPa and a flow rate of 10L / min based on the simulated deep oil and gas reservoir fracturing conditions. The screw pump extracts the mixed proppant from the surface manifold through the feed port and delivers it to the inlet of the proppant transport simulation system through the discharge port at a stable pressure and flow rate. This allows the mixed proppant to enter the channel of the simulation system, simulating the delivery scenario of proppant in underground fractures during actual hydraulic fracturing. During the delivery process, the data acquisition system records the delivery pressure and flow rate data of the screw pump in real time.

[0058] S207: The distribution profile of the mixed proppant in the proppant migration simulation system is scanned in real time by a laser particle size sensor to capture the migration difference data of proppant with different particle sizes and generate the sedimentation velocity curve of the mixed proppant.

[0059] The migration difference data includes first migration difference data and second migration difference data.

[0060] Specifically, the distribution profile of the mixed proppant within the proppant migration simulation system is scanned in real time using a laser particle size sensor to capture the migration differences of proppant particles of different sizes, generating a sedimentation velocity curve of the mixed proppant, including steps Sa1~Sa5:

[0061] Sa1: The laser particle size sensor is activated at a preset frequency to continuously scan the distribution profile of the mixed proppant in the proppant transport simulation system and record the mixed proppant particle size distribution data at different times at each laser particle size sensor monitoring point.

[0062] Specifically, the experimenters first activated the laser particle size sensor according to the preset scanning frequency; each sensor probe was fixed by the mounting bracket of the corresponding monitoring point and vertically aligned with the cross-section of the channel of the proppant transport simulation system to ensure that the scanning range completely covered the distribution area of ​​the mixed proppant in the channel; during the scanning process, the laser particle size sensor captured the mixed proppant particle size distribution data of each monitoring point, such as the monitoring points at the channel inlet, middle and outlet sections, at different times, including the proportion of proppant of each particle size, spatial coordinates, etc., and transmitted this data to the data acquisition system for storage in real time.

[0063] Sa2: By comparing the particle size distribution data of mixed proppant at different times at the same laser particle size sensor monitoring point, the first migration difference data of proppant of different particle sizes at the laser particle size sensor monitoring point is captured. The first migration difference data indicates the change in the distribution ratio or the shift in the profile position of proppant of different particle sizes at the laser particle size sensor monitoring point.

[0064] Specifically, the data acquisition system uses a built-in data comparison module to compare the particle size distribution data of the mixed proppant at the same monitoring point at two adjacent scanning times, such as t1 and t2. If the distribution ratio of a certain particle size proppant at the monitoring point at time t2 is significantly higher than that at time t1, or if its spatial position shifts to the outside / inside of the channel within the profile, then this change in distribution ratio or shift in profile position is recorded as the first migration difference data of that particle size proppant.

[0065] Sa3: By comparing the mixed proppant particle size distribution data at different laser particle size sensor monitoring points at the same time, the second migration difference data of proppant with different particle sizes is captured. The second migration difference data indicates the difference in the migration progress of proppant with different particle sizes along the channel of the proppant migration simulation system from the inlet to the outlet.

[0066] Specifically, researchers used a data acquisition system to extract mixed proppant particle size distribution data from all monitoring points at a fixed time and compared the data across monitoring points. For example, comparing the data from the inlet and outlet monitoring points at the same time, if the proportion of large-diameter proppant in the inlet monitoring point is significantly higher than that in the outlet monitoring point, while the proportion of small-diameter proppant in the outlet monitoring point is significantly higher than that in the inlet monitoring point, it indicates that there is a difference in the migration progress of proppant of different particle sizes along the channel from the inlet to the outlet. Large-diameter proppant migrates more slowly and lingers near the inlet, while small-diameter proppant migrates more quickly and reaches the far outlet. This difference in migration progress along the channel direction is the second migration difference data.

[0067] Sa4: Based on the first and second migration difference data, and the preset scanning time interval of the laser particle size sensor, the sedimentation velocity data of proppant with different particle sizes are calculated.

[0068] Specifically, combining the acquired first transport difference data, the acquired second transport difference data, and the pre-set laser particle size sensor scanning time interval, the data acquisition system processes the data using a preset velocity calculation algorithm. For the first transport difference data, if the profile position offset distance of a certain particle size proppant at adjacent times at the same monitoring point is... The scan time interval is The settling velocity of the proppant with this particle size For the second transport difference data, if the transport distance of a certain size proppant from the inlet monitoring point to the middle monitoring point at the same time is... The proppant transport time between the two monitoring points is Then its migration speed Subsequently and Weighted integration was performed to obtain sedimentation velocity data for proppants of different particle sizes.

[0069] Sa5: By fitting the settling velocity data of proppants with different particle sizes, a settling velocity curve of the mixed proppant is generated.

[0070] Specifically, the data acquisition system categorizes and organizes the calculated settling velocity data of proppant with different particle sizes, classifying the settling velocity values ​​corresponding to each particle size according to particle size. Then, it calls the built-in data fitting algorithm to plot the settling velocity data points of each particle size into a coordinate system with proppant particle size as the abscissa and settling velocity as the ordinate, and generates a smooth settling velocity curve through the fitting algorithm. The curve needs to clearly mark the settling velocity values ​​corresponding to different particle sizes, intuitively presenting the correlation between particle size and settling velocity.

[0071] S208: The data acquisition system outputs the proppant migration and deposition parameters corresponding to the mixed proppant in the proppant migration simulation system based on the sedimentation velocity curve, the opening data of the flow control valve, and the delivery pressure and flow data of the screw pump. It completes the migration analysis experiment corresponding to the preset particle size combination. The proppant migration and deposition parameters are used to compare the migration and deposition effects of proppant with different particle size combinations in order to screen the target mixed particle size combination.

[0072] Among them, proppant migration and deposition parameters include sandbank equilibrium height and heterogeneity index.

[0073] Specifically, based on the settling velocity curve, the opening data of the flow control valve, and the delivery pressure and flow rate data of the screw pump, the data acquisition system outputs the proppant migration and deposition parameters corresponding to the mixed proppant in the proppant migration simulation system, including steps Sb1~Sb5:

[0074] Sb1: The data acquisition system receives the settling velocity curve, the opening data of the flow control valve, and the delivery pressure and flow data of the screw pump. It then timestamps the settling velocity curve, the opening data of the flow control valve, and the delivery pressure and flow data of the screw pump to obtain an experimental dataset with consistent time dimensions.

[0075] Specifically, the data acquisition system first synchronously receives three types of core experimental data, including the mixed proppant settling velocity curve data generated by the laser particle size sensor, the real-time opening data of the flow control valves at the outlets of each independent sand tank, and the delivery pressure and flow data during the operation of the screw pump. Based on the system timestamp at the time of data acquisition, the acquisition time of the three types of data is matched and aligned to eliminate the time deviation caused by the data acquisition delay, and finally form an experimental dataset with completely consistent time dimensions.

[0076] Sb2: Input the experimental dataset with consistent time dimension and the channel size parameters of the proppant migration simulation system into the preset algorithm model, and output the difference in deposition height of the mixed proppant in the channel of the proppant migration simulation system. The channel size parameters are used to characterize the simulated fracture space characteristics of actual oil and gas wells in the proppant migration simulation system.

[0077] Specifically, the channel size parameters of the proppant migration simulation system are first retrieved from the preset parameter library of the device. These parameters need to accurately match the real characteristics of artificial fractures in deep oil and gas reservoirs, including the width, height, length, and cross-sectional shape of the channel, to characterize the actual spatial environment of proppant migration. Next, the obtained time-consistent experimental dataset and the aforementioned channel size parameters are input into the preset algorithm model, such as the CFD-DEM coupled algorithm model (Computational FluidDynamics - Discrete Element Method Coupled Algorithm Model). The model simulates the motion state of proppant particles of different sizes using the discrete element method, and combines it with computational fluid dynamics to simulate the fracturing fluid flow field. The two are coupled to analyze the deposition process of the mixed proppant in the channel, and finally output the difference in deposition height of the mixed proppant at different positions in the channel. This difference reflects the difference in the deposition distribution of the proppant in the channel.

[0078] Sb3: When the difference in sedimentation height output for a consecutive preset number of times is within the first preset range, the average value of the difference in sedimentation height output for a consecutive preset number of times is determined as the sandbank equilibrium height.

[0079] Specifically, based on the difference in deposition height at different locations in the output channel, the data acquisition system tracks and analyzes the trend of deposition height changes over time at each location. As the experiment progresses, the mixed proppant continues to deposit in the channel, and the deposition height gradually increases. When the difference in deposition height at multiple consecutive time points, such as five consecutive scan cycles, is less than a preset stability threshold, such as 0.1 cm, it is determined that the sand embankment deposition has reached a stable state. At this time, the average value of the deposition height at each location in the channel is the sand embankment equilibrium height. This parameter directly reflects the final deposition scale of the proppant in the channel. If the equilibrium height is low, it indicates that the sand embankment accumulates slowly in the near-well section, and the proppant is more likely to migrate to the far-well section.

[0080] Sb4: Based on the sedimentation velocity curves in the experimental dataset with consistent time dimension and the migration difference data of proppant of different particle sizes, the actual proportion of proppant of each particle size at different locations in the proppant migration simulation system was calculated.

[0081] Specifically, based on the difference in deposition height at different locations in the output channel and the obtained equilibrium height of the sand embankment, the data acquisition system uses preset dispersion calculation methods such as the variance method and the coefficient of variation method for processing. First, the deviation between the deposition height and the equilibrium height of the sand embankment at each monitoring point in the channel is calculated. Then, the dispersion of the deposition height is quantified by the sum of the squares and the mean of the deviations or the ratio of the deviation to the equilibrium height. The greater the dispersion, the more uneven the proppant is spread in the channel, and the higher the corresponding non-uniformity index. Conversely, the more uniform the spread, the lower the non-uniformity index. This index can intuitively reflect the spatial distribution quality of the mixed proppant.

[0082] Sb5: The non-uniformity index is obtained based on the deviation between the actual proportion of each particle size proppant and the preset mixing ratio.

[0083] Specifically, the data acquisition system integrates the calculated sand embankment equilibrium height with the calculated heterogeneity index as the final proppant migration and deposition parameters, and stores them in association with the preset grain size combination corresponding to this experiment. These parameters provide a quantitative basis for subsequent comparisons of the effects of different grain size combinations. By comparing the sand embankment equilibrium height and heterogeneity index of different combinations, researchers can screen out the target mixed grain size combination that can achieve slow sand embankment deposition near the wellbore and sufficient proppant migration in the far-wellbore section.

[0084] In summary, from proppant pretreatment to experimental setup debugging, mixing ratio control, dynamic transport simulation, and then to the acquisition of migration data and calculation of deposition parameters throughout the entire process, a closed-loop analysis system adapted to multi-stage pumping conditions in the field has been formed. This system not only realistically recreates the migration and deposition process of proppants of different particle sizes in a simulated fracture environment, but also captures the differences in migration across multiple particle sizes using laser particle size sensors and quantifies parameters such as sandbank equilibrium height and non-uniformity index using a pre-set algorithm model. Finally, the optimal mixing particle size combination is selected through parameter comparison. This process solves the problem that single-particle-size analysis cannot adapt to actual construction and compensates for the shortcomings of traditional devices in dynamic ratio control, real-time accurate monitoring, and quantitative analysis capabilities. It provides reliable experimental data support for optimizing hydraulic fracturing schemes in the field, and helps to extend the proppant fracture length and improve fracture conductivity.

[0085] Figure 3 A schematic flowchart of the experimental method for multi-component proppant transport analysis provided in the embodiments of this application. Figure 2After completing the transport analysis experiments corresponding to the preset particle size combinations, the process also includes screening the target mixed particle size combinations, which includes:

[0086] S301: Conduct experiments on proppant corresponding to at least two different particle size combinations to obtain proppant migration and deposition parameters for each particle size combination.

[0087] Specifically, at least two groups of proppant particle size combinations with significant differences were selected. For each particle size combination, migration analysis experiments were carried out strictly in accordance with the experimental procedures of S201 to S208, from proppant drying, device debugging, ratio control to data acquisition and analysis. Finally, the proppant migration and deposition parameters corresponding to each particle size combination were obtained, and the proppant migration and deposition parameters were associated and stored with the corresponding particle size combination.

[0088] S302: Compare the sandbank equilibrium heights obtained from at least two sets of experiments, and screen out the particle size combinations with lower sandbank equilibrium heights.

[0089] Specifically, from the acquired parameters, the sand embankment balance height values ​​corresponding to each particle size combination are extracted; these values ​​are sorted by size through a data acquisition system or manual calculation, and particle size combinations with lower sand embankment balance heights are selected, while combinations with excessively high balance heights that are prone to near-wellbore accumulation are excluded.

[0090] S303: If the particle size combination obtained by screening is a set, then the particle size combination obtained by screening shall be determined as the target mixed particle size combination.

[0091] Specifically, if, after screening, there is only one particle size combination with the lowest sandbank equilibrium height, then that particle size combination is directly determined as the target mixed particle size combination.

[0092] S304: If there are at least two particle size combinations obtained from screening, then the particle size combination with the higher non-uniformity index shall be eliminated.

[0093] Specifically, if at least two groups of sand embankment balance heights still exist after screening, the non-uniformity index corresponding to these two groups is further retrieved, the group with the higher non-uniformity index is eliminated, and the group with more uniform laying is retained.

[0094] S305: If the remaining particle size combinations after elimination form a group, then the remaining particle size combinations are determined as the target mixed particle size combinations.

[0095] Specifically, if after eliminating combinations with high non-uniformity indices, there is only one remaining particle size combination, then the remaining combination is directly determined as the target mixed particle size combination. At this time, the combination satisfies both the low sand embankment balance height and the low non-uniformity index, that is, the near-well section has slow deposition and more uniform distribution.

[0096] S306: If there are at least two remaining grain size combinations after elimination, the sandbank laying distance improvement rate corresponding to each grain size combination is calculated based on the proppant migration and deposition parameters.

[0097] Specifically, the improvement rate of sandbank laying distance corresponding to each grain size combination was calculated based on proppant migration and deposition parameters, including:

[0098] Sc1: Obtain the deposition length data of the sand embankment along the channel of the proppant transport simulation system corresponding to each grain size combination, where the deposition length data is the straight-line distance from the end deposition point of the sand embankment to the entrance of the channel.

[0099] Specifically, for at least two remaining particle size combinations after elimination, the sand embankment deposition length data corresponding to each combination is extracted from the monitoring data of the proppant transport simulation system. This data is defined as the straight-line distance from the end deposition point of the sand embankment to the channel entrance, which can be determined by scanning the entire channel length using a laser particle size sensor. For example, if the sensor detects proppant deposition at 10m in the channel and no deposition beyond 10m, then the deposition length is 10m.

[0100] Sc2: Based on the deposition length data and baseline laying distance corresponding to each particle size combination, the sand dike laying distance improvement rate corresponding to each particle size combination is calculated. The baseline laying distance is the deposition length data of a preset single particle size proppant under the same experimental conditions as each particle size combination.

[0101] Specifically, the baseline proppant distance is first retrieved from the experimental preset parameter library. This baseline proppant distance is the deposition length data of a single-size proppant, such as 40 / 70 mesh, under experimental conditions that are exactly the same as the current multiple particle size combinations. According to the formula Sandbank Propagation Distance Improvement Rate = (Deposition Length of a Certain Combination - Baseline Propagation Distance) / Baseline Propagation Distance × 100%, the improvement rate of each remaining combination is calculated.

[0102] S307: The particle size combination with the highest increase in sandbank laying distance is determined as the target mixed particle size combination.

[0103] Specifically, the calculated improvement rates of sand embankment laying distance for each particle size combination are compared, and the combination with the highest improvement rate is selected as the final target mixed particle size combination.

[0104] In summary, by first obtaining core sedimentation parameters for different particle size combinations through multiple sets of experiments, then narrowing down the selection range based on low sand dam equilibrium height as the primary screening condition, further optimizing by low heterogeneity index, and finally determining the final target combination based on high sand dam laying distance improvement rate, a closed-loop screening system is formed, from obtaining basic parameters to multi-dimensional comparison and then to quantitative verification. This not only ensures that the selected target combination can meet the core requirements of in-situ fracturing, namely slow sand dam deposition near the wellbore, sufficient migration in the distant wellbore, and uniform laying, but also intuitively demonstrates the migration advantages of multi-component combinations compared to single particle sizes through quantitative data, providing a reliable basis for determining proppant combinations in in-situ hydraulic fracturing schemes.

[0105] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for analyzing the transport of multi-component proppant, characterized in that, include: Select proppant with different particle sizes corresponding to a preset particle size combination, and dry the proppant with different particle sizes. Check whether the connections of each component of the multi-component proppant transport analysis device are normal; If all components of the multi-component proppant transport analysis device are properly connected, then the dried proppant of different particle sizes will be loaded into their respective independent sand containers. Start the data acquisition system, and adjust the laser particle size sensor to the monitoring state, the flow control valve to the initial closed state, and the screw pump to the standby state. According to the preset mixing ratio, adjust the opening of the flow control valve corresponding to the outlet of each independent sand tank so that the proppant of different particle sizes can be mixed into proppant through the ground manifold; The screw pump is started to deliver the mixed proppant to the proppant transport simulation system at a preset pressure and flow rate; The distribution profile of the mixed proppant within the proppant migration simulation system is scanned in real time using the laser particle size sensor, capturing the migration difference data of proppants with different particle sizes, and generating the sedimentation velocity curve of the mixed proppant. The data acquisition system timestamps the sedimentation velocity curve, the opening data of the flow control valve, and the delivery pressure and flow data of the screw pump to obtain an experimental dataset with consistent time dimensions. The experimental dataset with consistent time dimension and the channel size parameters of the proppant migration simulation system are input into the preset algorithm model, and the deposition height difference of the mixed proppant in the channel of the proppant migration simulation system is output. The channel size parameters are used to characterize the simulated fracture space characteristics of actual oil and gas wells in the proppant migration simulation system. When the sedimentation height difference output for a consecutive preset number of times is within a first preset range, the average value of the sedimentation height difference output for the consecutive preset number of times is determined as the sand embankment equilibrium height. Based on the sedimentation velocity curves in the experimental dataset with consistent time dimension and the migration difference data of proppant of different particle sizes, the actual proportion of proppant of each particle size at different locations in the proppant migration simulation system is calculated. Based on the deviation between the actual proportion of each particle size proppant and the preset mixing ratio, the non-uniformity index is obtained, and the transport analysis experiment corresponding to the preset particle size combination is completed. Experiments were conducted on proppants corresponding to at least two different particle size combinations to obtain proppant migration and deposition parameters for each particle size combination; the proppant migration and deposition parameters include sandbank equilibrium height and non-uniformity index; By comparing the sand embankment equilibrium heights obtained from the at least two sets of experiments, a particle size combination with a lower sand embankment equilibrium height is selected. If the particle size combination obtained by screening is a set, then the particle size combination obtained by screening is determined as the target mixed particle size combination; If there are at least two particle size combinations obtained from screening, then the particle size combination with the higher non-uniformity index is eliminated. If the remaining particle size combinations after elimination form a group, then the remaining particle size combinations are determined as the target mixed particle size combination; If at least two sets of particle size combinations remain after elimination, the sandbank laying distance improvement rate corresponding to each set of particle size combinations is calculated based on the proppant migration and deposition parameters. The particle size combination that achieves the highest increase in sandbank laying distance is determined as the target mixed particle size combination.

2. The experimental method according to claim 1, characterized in that, The process of using the laser particle size sensor to scan the distribution profile of the mixed proppant within the proppant migration simulation system in real time, capturing the migration differences of proppant particles of different sizes, and generating the sedimentation velocity curve of the mixed proppant includes: The laser particle size sensor is activated at a preset frequency to continuously scan the distribution profile of the mixed proppant within the proppant transport simulation system, and the particle size distribution data of the mixed proppant at different times at each laser particle size sensor monitoring point are recorded. By comparing the particle size distribution data of the mixed proppant at different times at the same laser particle size sensor monitoring point, the first migration difference data of the proppant with different particle sizes at the laser particle size sensor monitoring point is captured, wherein the first migration difference data indicates the change in the distribution ratio or the shift in the profile position of the proppant with different particle sizes at the laser particle size sensor monitoring point. By comparing the mixed proppant particle size distribution data at different laser particle size sensor monitoring points at the same time, a second migration difference data of the proppant with different particle sizes is captured, wherein the second migration difference data indicates the difference in the migration progress of the proppant with different particle sizes along the channel of the proppant migration simulation system from the inlet to the outlet. Based on the first and second transport difference data, and the preset scanning time interval of the laser particle size sensor, the sedimentation velocity data of the proppant with different particle sizes are calculated. The settling velocity curve of the mixed proppant is generated by fitting the settling velocity data of the proppant with different particle sizes.

3. The experimental method according to claim 1, characterized in that, The calculation of the sandbank laying distance improvement rate corresponding to each grain size combination based on the proppant migration and deposition parameters includes: Obtain the deposition length data of the sand embankment corresponding to each group of particle size combinations along the channel of the proppant transport simulation system, wherein the deposition length data is the straight-line distance from the end deposition point of the sand embankment to the entrance of the channel; Based on the deposition length data and benchmark laying distance corresponding to each group of particle size combinations, the sandbank laying distance improvement rate corresponding to each group of particle size combinations is calculated, wherein the benchmark laying distance is the deposition length data of a preset single particle size proppant under the same experimental conditions as each group of particle size combinations.

4. The experimental method according to claim 2, characterized in that, The drying process for the proppant with different particle sizes includes: The proppant of different particle sizes is loaded into an independent constant temperature drying oven, and the drying temperature of each constant temperature drying oven is set, and the drying program of each constant temperature drying oven is started. During the drying process, proppant samples are extracted from each of the constant temperature drying ovens at preset intervals, and the mass of the proppant samples is recorded. If the mass difference between two consecutive samples of proppant of the same particle size is within the second preset range, it is determined that the proppant of the particle size has reached the drying endpoint and the heating of the corresponding constant temperature drying oven is stopped. At room temperature, the dried proppant is transferred to a moisture-proof sealed container for cooling, and after cooling, proppants of different particle sizes after the drying treatment are obtained.

5. A multi-component proppant transport analysis apparatus, used to implement the multi-component proppant transport analysis experimental method as described in any one of claims 1-4, characterized in that, include: Multiple independent sand tanks, multiple flow control valves, surface manifolds, screw pumps, proppant transport simulation system, laser particle size sensor and data acquisition system; Each independent sand tank has a corresponding flow control valve connected to its outlet. Each independent sand tank is used to store proppant of a single particle size. Each flow control valve is used to control the start and stop of the outflow of proppant in the corresponding independent sand tank. The outlet end of each flow control valve is connected to the inlet end of the ground manifold, which is used to collect the proppant of different particle sizes flowing out of each flow control valve to form a mixed proppant. The outlet end of the ground manifold is connected to the inlet of the screw pump, and the outlet of the screw pump is connected to the inlet of the proppant transport simulation system. The screw pump is used to deliver the mixed proppant to the proppant transport simulation system. The laser particle size sensor is fixed to the outside of the proppant transport simulation system and is used to scan the distribution profile of the mixed proppant in the proppant transport simulation system in real time to capture the distribution differences of proppant with different particle sizes. The data acquisition system is connected to the laser particle size sensor, the plurality of flow control valves, and the screw pump, respectively. It is used to output the proppant migration and deposition parameters of the mixed proppant in the proppant migration simulation system based on the mixed proppant distribution profile data output by the laser particle size sensor, the opening data of the flow control valves, and the delivery pressure and flow data of the screw pump. The proppant migration and deposition parameters are used to compare the migration and deposition effects of proppants with different particle size combinations in order to screen the target mixed particle size combination.

6. The apparatus according to claim 5, characterized in that, Each independent sand tank is equipped with a feed inlet with a filter screen and a pressure balancing valve at the top; each independent sand tank is equipped with a liquid level observation window on the outside. The pressure balancing valve is connected to the inside of the corresponding independent sand tank to maintain the air pressure inside each independent sand tank consistent with atmospheric pressure. The filter screen at the feed inlet is used to filter impurities when the corresponding proppant is loaded. The liquid level observation window is connected to the inside of the corresponding independent sand tank, and is used to view the remaining amount of proppant in the corresponding independent sand tank in real time. The inner walls of each individual sand tank are polished to reduce the residue of the corresponding proppant on the inner wall of the tank.

7. The apparatus according to claim 5, characterized in that, The proppant migration simulation system is equipped with channels that simulate the spatial characteristics of fractures in actual oil and gas wells; The inner wall of the channel is smooth and free of scratches, which is used to simulate the proppant migration environment in the fracture in actual hydraulic fracturing scenarios. The proppant transport simulation system has multiple laser particle size sensor monitoring points set along the length of the channel. Each laser particle size sensor monitoring point is equipped with a mounting bracket adapted to the laser particle size sensor. Each laser particle size sensor monitoring point is used to cooperate with the laser particle size sensor to collect the distribution profile data of the mixed proppant from the inlet to the outlet of the channel. The proppant migration simulation system is made of transparent resin and is used to observe the migration trajectory, deposition location, and sorting phenomenon of proppant of different particle sizes within the channel.

8. The apparatus according to claim 5, characterized in that, The laser particle size sensor includes multiple sensor probes; The plurality of sensor probes correspond one-to-one with the plurality of laser particle size sensor monitoring points of the proppant transport simulation system. Each sensor probe is fixed by a mounting bracket corresponding to the laser particle size sensor monitoring point, and each sensor probe is vertically aligned with the channel cross-section of the proppant transport simulation system. Each sensor probe is used to collect the distribution profile data of the mixed proppant at the corresponding laser particle size sensor monitoring point in real time. The signal output terminal of the laser particle size sensor is connected to the signal input terminal of the data acquisition system, and is used to send the distribution profile data to the data acquisition system.

Images