Full-automatic online fracturing fluid powder mixing device and mixing method

Abstract

The invention relates to the technical field of shale oil exploitation, in particular to a full-automatic fracturing fluid powder online mixing device and method, and the method comprises the steps: obtaining a target mixing parameter a with the maximum priority from a mixing parameter set; the mixing device carries out mixing work with a, a mother liquor uniformity change sequence A and the stability of a are obtained, the attention coefficient of a is adjusted according to the stability, and a target mixing parameter b is obtained from the mixing parameter set again according to the adjusted attention coefficient; a blending parameter of the blending device is changed from a to b by using a PID algorithm, a mother liquor uniformity change sequence B is recorded, and the attention coefficient of b is adjusted according to the difference between the mother liquor uniformity change sequences A and B and the priorities of a and b; and then deleting the mixing parameter with the minimum concern coefficient in the mixing parameter set, and carrying out mixing work by the mixing device according to b. When the mother liquor of the fracturing fluid is mixed on line, the mixing efficiency is improved, and the occurrence of non-uniform conditions such as fisheyes and adhesion is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of shale oil exploitation, and in particular to a fully automatic online fracturing fluid powder mixing device and a mixing method. Background Art

[0002] Hydraulic fracturing technology is currently one of the most commonly used methods for shale oil extraction. Hydraulic fracturing technology is currently one of the most commonly used methods for shale oil extraction. This technology uses the principle of high-pressure water injection, rock fracturing, and oil and gas discharge to inject fracturing fluid (water and chemical additives) into the rock cracks, forming high pressure, causing the rock to break and further develop along the rock layer. Hydraulic fracturing technology can release shale oil from the rock pores and easily recycle it. Hydraulic fracturing technology requires the use of polymer dry powder to mix and prepare fracturing fluid. In order to save the preparation cost of fracturing fluid, it is necessary to prepare the powder into a large-volume fracturing mother liquid online at the fracturing site; however, when using the existing production process to configure the mother liquid online, there is an inappropriate mixing ratio of powder and clean water, and the powder and clean water cannot be quickly, efficiently and evenly mixed, which leads to problems such as fish eyes (water-in-powder) and sticky lumps (powder-in-water). Summary of the invention

[0003] In order to solve the above problems, the present invention provides a fully automatic online fracturing fluid powder mixing device and a mixing method.

[0004] The fully automatic online fracturing fluid powder mixing device and mixing method of the present invention adopt the following technical solutions:

[0005] One embodiment of the present invention provides a fully automatic online fracturing fluid powder mixing device, which includes: a fracturing site water supply tank, a dry powder tank, and a sand mixing truck. The clean water output from the fracturing site water supply tank passes through a booster pump to form a jet in a high powder-water ratio ejector; the polymer dry powder in the dry powder tank is transported to a dry powder hopper through a spiral metering feeder; the negative pressure of the jet in the high powder-water ratio ejector lifts the polymer dry powder in the dry powder hopper into the high powder-water ratio ejector, and the polymer dry powder in the high powder-water ratio ejector collides and mixes with the water jet to obtain a mother liquid;

[0006] The mother liquid enters the buffer tank, and the mother liquid in the buffer tank is transported to the static mixing and dilution skid. The fracturing site water supply tank is connected to the static mixing and dilution skid. The mother liquid in the static mixing and dilution skid is mixed with the clean water provided by the fracturing site water supply tank, and then sucked into the sand mixing truck by the suction pump of the sand mixing truck, and then mixed with sand in the sand mixing tank, and finally transported to the fracturing pump and pressed into the formation;

[0007] An ultrasonic sensor is installed in the buffer tank to detect the uniformity of the mother liquor in the buffer tank.

[0008] One embodiment of the present invention further provides a fully automatic online fracturing fluid powder mixing method, using the above-mentioned fully automatic online fracturing fluid powder mixing device, the method comprises the following steps:

[0009] The feeding speed of the dry powder hopper, the water output of the water supply tank at the fracturing site, and the water pressure output by the booster pump are recorded as a set of mixing parameters of the mixing device;

[0010] The mixing parameter with the highest priority is obtained from the mixing parameter set as the target mixing parameter, which is recorded as a; the mixing parameter set includes a plurality of mixing parameters, and each group of mixing parameters corresponds to a preset attention coefficient, and the priority of each group of mixing parameters is positively correlated with the attention coefficient, the uniformity of the mother liquid, and the feeding speed in each group of mixing parameters;

[0011] According to the target mixing parameter a, the target mixing parameter is selected from the mixing parameter set to perform mixing work, including:

[0012] The mixing device performs mixing with a target mixing parameter a, obtains a mother liquid uniformity change sequence A during the mixing process, obtains the stability of the target mixing parameter a according to the mother liquid uniformity change sequence A, adjusts the attention coefficient of the target mixing parameter a according to the stability, and re-obtains the target mixing parameter from the mixing parameter set according to the adjusted attention coefficient, which is recorded as b;

[0013] The mixing parameter of the mixing device is changed from a to b by using a PID algorithm, and the mother liquid uniformity change sequence B is recorded, and the attention coefficient of b is adjusted according to the difference between the mother liquid uniformity change sequences A and B, and the priority of a and b; then the mixing parameter with the smallest attention coefficient in the mixing parameter set is deleted, and the mixing device performs mixing work with the target mixing parameter b;

[0014] The difference between the priority corresponding to b after the attention coefficient is adjusted and the priority corresponding to a after the attention coefficient is adjusted is positively correlated with the difference between A and B;

[0015] According to the target mixing parameter b, the target mixing parameter is selected again from the deleted mixing parameter set to perform mixing work.

[0016] Preferably, the specific steps of obtaining the mixing parameter set are as follows:

[0017] When the mixing device mixes the mother liquid, the mixing parameters used and the uniformity of the mother liquid in the buffer tank are recorded; and the mixing parameters whose uniformity of the mother liquid is greater than the first preset threshold are taken as the mixing parameter set.

[0018] Preferably, the specific calculation formula of the priority of each group of mixing parameters is as follows:

[0019] The priority is expressed as Q=w×F+V, wherein F represents the uniformity of the mother liquor corresponding to each group of mixing parameters, V represents the feeding speed in each mixing parameter, and w represents the attention coefficient of each group of mixing parameters.

[0020] Preferably, the stability of the target mixing parameter a is obtained according to the mother liquor uniformity variation sequence A, and the specific steps include the following:

[0021] The mother liquor uniformity in the mother liquor uniformity change sequence A is linearly normalized, and the variance of all mother liquor uniformities after linear normalization is recorded as x. exp(-x) is used as the stability of the target mixing parameter a, and exp() represents an exponential function with a natural constant as the base.

[0022] Preferably, the attention coefficient of adjusting the target mixing parameter a according to the stability comprises the following specific steps:

[0023] The attention coefficient after the target mixing parameter a is adjusted is (1+hq)×k; wherein k represents the attention coefficient before the target mixing parameter a is adjusted, q is a preset adjustment coefficient, and h represents the stability.

[0024] Preferably, the step of adjusting the attention coefficient of b according to the difference between the mother liquid uniformity change sequences A and B and the priorities of a and b comprises the following specific steps:

[0025] The average value of all the mother liquid uniformities in the mother liquid uniformity change sequence B is obtained and recorded as fb, and the average value of all the mother liquid uniformities in the mother liquid uniformity change sequence A is obtained and recorded as fa;

[0026] Let Fab = (fb-fa) / max(fb, fa), where max(fb, fa) represents the maximum value of fb and fa, and Fab represents the difference between the mother liquor uniformity change sequences A and B;

[0027] After the attention coefficient of the target mixing parameter a is adjusted, the priority of a is recorded as Qa; before the attention coefficient of the target mixing parameter b is adjusted, the priority of b is recorded as Qb; assuming that the adjusted attention coefficient of the target mixing parameter b is x, the priority of the target mixing parameter b obtained according to x is recorded as Qb1; Qb1=Qb+Fab×p×Qa, then x=(Qb1-Vb) / wb, Vb represents the feeding speed in the target mixing parameter b, wb represents the attention coefficient of the target mixing parameter b before adjustment; p represents the difference attention coefficient.

[0028] Preferably, the specific steps of obtaining the difference attention coefficient are as follows:

[0029] When the target mixing parameter b is different from the target mixing parameter a, the difference attention coefficient is negatively correlated with the stability of the target mixing parameter a;

[0030] When the target mixing parameter b is the same as the target mixing parameter a, the mixing device continues to perform mixing with the target mixing parameter a, obtains the mother liquor uniformity change sequence A during the mixing process again, obtains the stability of the target mixing parameter a again according to the mother liquor uniformity change sequence A, adjusts the attention coefficient of the target mixing parameter a again according to the stability, and obtains the target mixing parameter b from the mixing parameter set again according to the adjusted attention coefficient; when the target mixing parameter b is the same as the target mixing parameter a again, the mixing device continues to perform mixing with the target mixing parameter a, and so on, until the obtained target mixing parameter b is different from the target mixing parameter a; then the several stabilities obtained for the target mixing parameter a are summed up and recorded as Pa; the difference attention coefficient is negatively correlated with Pa.

[0031] Preferably, the step of reselecting the target mixing parameter from the deleted mixing parameter set according to the target mixing parameter b to perform the mixing operation comprises the following specific steps:

[0032] When the mixing device performs mixing with the target mixing parameter b, a mother liquid uniformity variation sequence A during the mixing process is obtained, and the stability of the target mixing parameter b is obtained according to the mother liquid uniformity variation sequence A;

[0033] When the stability of the target mixing parameter b and the stability of the target mixing parameter a are both greater than the second preset threshold, the average of a and b is added to the mixing parameter set as a new mixing parameter.

[0034] Preferably, in the mixing parameter set, if the number of mixing parameters whose attention coefficients have been adjusted is less than or equal to a preset number, no mixing parameter will be deleted.

[0035] The beneficial effects of the technical solution of the present invention are:

[0036] The high powder-water ratio ejector in the online mixing device of the present invention utilizes a high-speed water flow to lift dry powder, so that the dry powder flow and the high-speed water flow collide and mix, so that a uniform mother liquor can be continuously produced during online mixing of the mother liquor.

[0037] Furthermore, the present invention continuously adjusts the attention coefficient of the mixing parameters in the mixing parameter set when mixing the mother liquor, and deletes inappropriate mixing parameters to ensure that the mixing parameter set is continuously updated, so that the target mixing parameters selected in the mixing parameter set have a higher mixing efficiency (that is, the mother liquor is mixed more evenly and the mother liquor production is larger), and the occurrence of uneven conditions such as fish eyes and sticky lumps is prevented. At the same time, the target mixing parameters are adaptively changed according to the specific process of online mixing, so that the mixing parameters of the mixing device are not fixed in one process, but dynamically adjusted between different target mixing parameters, and the uniformity of the mother liquor will not be changed, so that the mixing device has better fault tolerance and stability when facing complex and changeable online mixing scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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 or the description of the prior art 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.

[0039] Figure 1 A schematic diagram of the structure of a fully automatic online fracturing fluid powder mixing device provided by an embodiment of the present invention;

[0040] Figure 2 The present invention is a flowchart of a fully automatic online fracturing fluid powder mixing method provided by an embodiment of the present invention.

[0041] In the figure: 1. Water supply tank at fracturing site; 2. Filter before pump; 3. Booster pump; 4. Pressure transmitter at outlet of booster pump; 5. Flowmeter of booster pump; 6. Electric ball valve at outlet of booster pump; 7. Ejector with high powder-water ratio; 8. Roots blower; 9. High level tuning fork of dry powder tank; 10. Low level tuning fork of dry powder tank; 11. Dry powder storage vehicle; 12. Dry powder tank; 13. Gate valve; 14. Weighing instrument; 15. Vibrator; 16. Cyclone dust collector; 17. Back-blowing filter element dust collector; 18. Air compressor; 19. Solenoid valve; 20. First dust removal discharge valve; 21. Second dust removal discharge valve; 22. Spiral metering feeder; 23. Dry powder hopper; 24. Sand mixing truck; 25. Sand mixing truck suction pump; 26. Static mixing and dilution skid; 27. Dry powder hopper level meter; 28. Mother liquor output pump; 29. ​​Mother liquor output flow meter; 30. Mother liquor output pressure transmitter; 31. Buffer tank level meter; 32. Buffer tank. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the fully automatic fracturing fluid powder online mixing device and mixing method proposed by the present invention, its specific implementation, structure, features and effects, in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0044] Hydraulic fracturing requires a large amount of fracturing fluid to be injected. Traditional fracturing stations prepare the fluid at a concentration of less than 0.4%, which is then transported to the fracturing site, greatly increasing costs. An existing method is to use an emulsion prepared with white oil and polymer dry powder, the concentration of which can reach about 40%, and transport it to the site. According to the different stages of fracturing, the amount of emulsion corresponding to the concentration required by the fracturing operation is input. After the emulsion meets water, it quickly forms a fracturing fluid with the same properties as traditional fracturing fluid, which greatly reduces costs.

[0045] White oil is a petroleum product with high cost, and white oil does not play any role in the whole process of fracturing. The fully automatic online fracturing fluid powder mixing device and mixing method provided by the present invention can use polymer dry powder to prepare the aqueous solution required for fracturing at the fracturing site, adopt online continuous preparation of fracturing fluid, and ensure that fracturing fluids of different concentrations and different displacements can be provided as the fracturing progresses in different stages. This not only solves the problem of fracturing fluid cost, but also makes on-site agent storage extremely convenient, and the fracturing fluid can be used as it is prepared, without waste.

[0046] The specific scheme of the fully automatic fracturing fluid powder online mixing device and mixing method provided by the present invention is described in detail below with reference to the accompanying drawings.

[0047] Embodiment 1:

[0048] See also Figure 1 , which shows a fully automatic online fracturing fluid powder mixing device provided by an embodiment of the present invention, in which a dry powder storage vehicle 11 in the mixing device is loaded with polymer dry powder, the outlet pipeline of the Roots blower 8 is connected to the air inlet of the dry powder storage vehicle 11, and the inlet of the dry powder tank 12 in the mixing device is connected to the discharge port of the dry powder storage vehicle 11. The dry powder tank 12 is installed with a dry powder tank low material level tuning fork 10, a weighing instrument 14 and a dry powder tank high material level tuning fork 9.

[0049] The mixing process of the online mixing device includes:

[0050] First, check whether the dry powder tank 12 has material. The specific method is: install the dry powder tank low material level tuning fork 10 and the weighing instrument 14 on the dry powder tank 12. The signal value output by the dry powder tank low material level tuning fork 10 and the weighing instrument 14 when the dry powder tank 12 has material (that is, when the dry powder just submerges the dry powder tank low material level tuning fork 10) is obtained in advance, and recorded as a reference signal. If the signal value output by the powder tank low material level tuning fork 10 and the weighing instrument 14 during the current mixing is not equal to or less than the reference signal, it is judged that the dry powder tank 12 is insufficient in polymer dry powder. Otherwise, it is judged that the dry powder tank 12 has enough polymer dry powder.

[0051] When it is detected that there is insufficient polymer dry powder in the dry powder tank 12, the Roots blower 8 is started to feed the dry powder tank 12 with positive pressure. This process requires a two-stage dust removal system to ensure that there is no dust pollution. The specific process is: the blown-in dry powder first passes through the cyclone dust collector 16 for primary dust removal treatment, and a large amount of dust enters the dust exhaust port of the cyclone dust collector 16, and the remaining dust enters the back-blowing filter element dust collector 17 through the airflow, and the dust removal process is completed.

[0052] In addition, it is determined in advance that the output signal value of the high material level tuning fork 9 of the dry powder tank and the weighing instrument 14 when the dry powder just submerges the high material level tuning fork 9 of the dry powder tank is recorded as the upper limit signal;

[0053] When the high material level tuning fork 9 of the dry powder tank and the feedback signal of the weighing instrument 14 are equal to the upper limit signal, the roots blower 8 is stopped, and the solenoid valve 19 is opened. The solenoid valve 19 is installed between the back-blowing filter element dust collector 17 and the air compressor 18; the back-blowing filter element dust collector 17 receives the compressed air of the air compressor 18, blows the filter element of the back-blowing filter element dust collector 17, and discharges the dust to the dust discharge port below. At the same time, the first dust removal discharge valve 20 and the second dust removal discharge valve 21 are opened to discharge the dust to the entrance of the spiral metering discharger 22 for reuse. The spiral metering discharger 22 is installed at the discharge port below the dry powder tank 12.

[0054] In order to ensure the feeding fluidity of the polymer dry powder, the vibrator 15 is started in real time.

[0055] The gate valve 13 is opened, and the spiral metering feeder 22 conveys the polymer dry powder in the dry powder tank 12 to the dry powder hopper 23 at a certain speed; a dry powder hopper level meter 27 is installed on the dry powder hopper 23 to detect the powder level of the dry powder in the dry powder hopper 23. When the powder level is higher than the set warning value (for example, 20 cm), the dry powder hopper level meter 27 generates an alarm and stops mixing to prevent blockage during the pneumatic conveying of dry powder and affect the mixing effect.

[0056] The clean water outlet of the fracturing site water supply tank 1 is connected to the pre-pump filter 2, the clean water is filtered by the pre-pump filter 2, and then pressurized by the booster pump 3; the booster pump 3 uses the booster pump outlet pressure transmitter 4 to change the pressure of the clean water, and the water flow of the pressurized clean water is obtained using the booster pump flowmeter 5.

[0057] While the spiral metering feeder 22 is working, the electric ball valve 6 at the outlet of the booster pump is opened, and then the booster pump 3 is started, and then the pressurized clean water enters the high powder-water ratio ejector 7, forming a jet in the high powder-water ratio ejector 7; the high powder-water ratio ejector 7 is connected to the dry powder hopper 23 through a gas pipeline.

[0058] The high-speed water flow generates a high negative pressure in the high-powder-water ratio ejector 7 to generate a lifting force, which can lift the dry powder in the dry powder hopper 23 into the high-powder-water ratio ejector 7 and make the lifted dry powder flow flow at a high speed. The high-speed dry powder flow and the high-speed water flow collide and mix in the high-powder-water ratio ejector 7 to obtain a mother liquor.

[0059] In this embodiment, clean water and dry powder collide and mix in the ejector, which ensures sufficient water-powder mixing (suitable for the preparation of high-concentration mother liquor 25000PPM, i.e., powder-water ratio 2.5%) and prevents the appearance of fish eyes and sticky lumps.

[0060] The mixed mother liquor enters the buffer tank 32; wherein the buffer tank level gauge 31 is installed on the buffer tank 32, and is used to detect the liquid level of the mother liquor in the buffer tank 32. When the liquid level reaches the set working liquid level, the mother liquor output pump 28 is started (using a variable frequency drive). In order to ensure that the liquid level of the mother liquor in the buffer tank 32 is always constant at the working liquid level, this embodiment controls the mother liquor output pump 28 through a PID algorithm (that is, the mother liquor output pump 28 and the buffer tank level gauge 31 form a closed-loop control).

[0061] In addition, an ultrasonic sensor is installed in the buffer tank 32, and the ultrasonic sensor emits ultrasonic waves toward the surface of the mother liquid and receives ultrasonic waves reflected at different positions.

[0062] When ultrasound encounters an interface in a medium (such as the interface between dry powder particles and water), reflection occurs. The intensity of the reflected wave can reflect the distribution of particles in the mixed liquid. The reflected wave of a uniform mixed liquid is weak and stable, while the reflected wave of an uneven mixed liquid is strong and fluctuating.

[0063] In this embodiment, the intensity of the reflected wave at all positions is linearly normalized, and the variance H of the reflected wave intensity at all positions after the linear normalization is obtained, and exp(-H) is used as the uniformity of the mother liquor in the buffer tank 32; exp() represents an exponential function with a natural constant as the base. The greater the uniformity of the mother liquor, the less fluctuation in the intensity of the reflected wave at all positions, and the more uniform the mother liquor is mixed.

[0064] The output port of the buffer tank 32 is connected to the static mixing and dilution skid 26 through the mother liquid output pump 28. In addition, the mother liquid output pump 28 is also connected to a mother liquid output flow meter 29 and a mother liquid output pressure transmitter 30, which are used to obtain the amount of mother liquid output from the buffer tank 32 and control the pressure of the mother liquid output.

[0065] The buffer tank 32 transports the mother liquor to the mother liquor inlet of the static mixing and dilution skid 26; in addition, the static mixing and dilution skid 26 is connected to the fracturing site water supply tank 1 through a water pipe, and the fracturing site water supply tank 1 provides clean water for the static mixing and dilution skid 26; the static mixing and dilution skid 26 mixes the high-concentration mother liquor and clean water, and converts them into low-concentration target liquid at its outlet, and the low-concentration target liquid is sucked into the sand mixing truck 24 by the sand mixing truck suction pump 25. In the sand mixing truck 24, the low-concentration target liquid is mixed with sand in the sand mixing tank, and then transported to the fracturing pump, and pressed into the formation for rock fracturing.

[0066] During the working process of the mixing device, the water and powder collide and mix in the ejector, which ensures sufficient mixing of the water and powder and prevents unevenness such as fish eyes and sticky lumps. However, the premise is that the flow rate of the high-speed water flow and the high-speed dry powder flow and the water-powder ratio must be appropriate, otherwise it is still impossible to ensure uniform mixing of the water and powder.

[0067] In this embodiment, the booster pump 3 is controlled (specifically, the booster pump flowmeter 5 of the booster pump 3 is controlled) to change the flow rate of the water flow. The water pressure is set within a set range (for example, 0.4 to 0.8 MPa) by detecting and setting the booster pump pressure transmitter 4. As the booster pump flowmeter 5 changes, the control system adjusts the feeding speed of the spiral metering feeder 22 in real time through PID control. When the pressure of the high-speed water flow in the high-powder-to-water ratio ejector 7 is constant, the greater the water flow rate, the faster the dry powder feeding speed, otherwise the smaller the speed.

[0068] In this embodiment, the flow rate of clean water, the pressure of the water flow, and the feeding speed of the dry powder are recorded as the mixing parameters of the mixing device. When the mixing parameters of the mixing device are set to different values, the flow rate and water pressure of the high-speed water flow in the high-powder-water ratio ejector 7, as well as the content of dry powder in the dry powder flow are all different. Only by setting appropriate mixing parameters can it be ensured that the mother liquor mixed in the high-powder-water ratio ejector 7 has the target concentration and is mixed evenly without fish eyes and sticky lumps.

[0069] Embodiment 2:

[0070] like Figure 2 As shown, this embodiment provides a fully automatic online fracturing fluid powder mixing method for setting appropriate mixing parameters for a mixing device to ensure that when the mixing device works online, it can efficiently produce a mother liquor of a target concentration that is uniformly mixed and free of fisheyes and sticky lumps.

[0071] Step S201, when the mixing device mixes the mother liquid, the mixing parameters used and the uniformity of the mother liquid in the buffer tank are recorded; the mixing parameters whose uniformity of the mother liquid is greater than a first preset threshold are taken as a mixing parameter set.

[0072] First of all, it should be noted that when using hydraulic fracturing technology to extract shale oil, different concentrations of fracturing fluid need to be provided as the fracturing progresses in different stages, and different concentrations of fracturing fluid require different concentrations of mother liquor to prepare. The concentration of the mother liquor required in each stage is recorded as the target concentration, and the value of the target concentration is determined in advance before the mixing device works.

[0073] When preparing a mother solution of target concentration, the mixing parameters used and the uniformity of the mother solution in the buffer tank 32 are recorded and stored in the MySQL database.

[0074] All mixing parameters for preparing target concentration mother liquor in the historical mixing process and the mother liquor uniformity corresponding to each set of mixing parameters are read from the database, and the mixing parameters with mother liquor uniformity greater than the first preset threshold th1 are taken as the mixing parameter set.

[0075] If the mixing device has not mixed a mother liquor of the target concentration, it is necessary to manually adjust the mixing parameters of the mixing device, obtain the mother liquor concentration under each mixing parameter, record the mixing parameters that can mix the mother liquor of the target concentration, and record these parameters in the MySQL database. If the mixing parameter set is empty, it is necessary to continue to manually adjust the mixing parameters of the mixing device, and obtain the mixing parameter set again until there are more than 5 mixing parameters in the mixing parameter set. In other embodiments, when manually adjusting the mixing parameters of the mixing device, if it is not possible to make more than 5 mixing parameters in the mixing parameter set, then th1 is expanded by 10% in sequence and the mixing parameter set is obtained again until there are more than 5 mixing parameters in the mixing parameter set.

[0076] This embodiment is described by taking th1=0.75 as an example. In other embodiments, th1 may be set to other values, which are not specifically limited in this embodiment.

[0077] Compared with other mixing parameters stored in the database, the mother liquor obtained under the mixing parameters in the mixing parameter set is relatively uniform. That is, by applying the mixing parameters in the mixing parameter set to the mixing device to perform the current mixing process, a relatively uniform mother liquor can be obtained.

[0078] This embodiment then uses the mixing parameter set obtained in the historical mixing process to further obtain the mixing parameters that can be used for the current mixing device.

[0079] Step S202, assigning a focus coefficient to each mixing parameter in the mixing parameter set; obtaining the priority of each group of mixing parameters according to the focus coefficient, the mother liquor uniformity corresponding to each mixing parameter, and the feeding speed in each mixing parameter, and taking the mixing parameter with the highest priority as the target mixing parameter a.

[0080] An initial attention coefficient w is assigned to each set of mixing parameters in the mixing parameter set. The attention coefficient is used to describe the attention paid to the uniformity of the mother liquor mixed under each set of mixing parameters.

[0081] Assume that the number of mixing parameters in the mixing parameter set is recorded as D, and 1 / D is used as the initial attention coefficient of each group of mixing parameters.

[0082] The priority of each group of mixing parameters is recorded as Q, and Q = w × F + V. Among them, w represents the attention coefficient of each group of mixing parameters; F represents the mother liquor uniformity corresponding to each group of mixing parameters (read from the database), and V represents the feeding speed in each mixing parameter.

[0083] The priority Q is used to describe the mixing efficiency of the mother liquor. The larger the Q, the more uniform the mother liquor obtained under the mixing parameters, and the faster the mother liquor is produced, which means that the mixing parameters can be efficiently mixed. When Q is smaller, the mother liquor obtained under the mixing parameters is more uneven and the mother liquor output is slower, which means that the mixing parameters cannot be efficiently mixed. The larger w is, the more attention is paid to the uniformity of the mother liquor when judging whether the mixing parameters can be efficiently mixed. The smaller w is, the less attention is paid to the uniformity of the mother liquor when judging whether the mixing parameters can be efficiently mixed.

[0084] In the mixing parameter set, the mixing parameter with the highest priority is used as the target mixing parameter a. The mixing device performs mixing with the target mixing parameter a. The target mixing parameter a is the most efficient mixing parameter in the historical mixing process. Using it in the current mixing process can ensure the efficient performance of the current mixing to a certain extent.

[0085] Step S203, obtaining a mother liquor uniformity change sequence A during the mixing process, obtaining the stability of a target mixing parameter a according to the mother liquor uniformity change sequence A, adjusting the attention coefficient of the target mixing parameter a according to the stability, and re-obtaining the target mixing parameter b according to the adjusted attention coefficient.

[0086] In the current mixing process, the mixing parameter of the mixing device is set to a and the mother liquor is mixed.

[0087] During the mixing process, the uniformity of the mother liquid in the buffer tank 32 is recorded in real time, and in this embodiment, the uniformity is recorded every 2 seconds. In other embodiments, the recording time interval can be set to other values, which are not specifically limited in this embodiment.

[0088] It should be noted that it takes a certain time interval for the mother liquor produced in the high powder-water ratio ejector 7 to flow into the buffer tank 32 and be detected by the ultrasonic sensor for the uniformity of the mother liquor. Therefore, in order to make the recorded mother liquor uniformity correspond to the set mixing parameters, it is necessary to calibrate the mother liquor uniformity and the mixing parameters in advance.

[0089] The mother liquor uniformity recorded in real time within a preset time period (e.g., within 14 seconds) constitutes a time series, which is recorded as the mother liquor uniformity change sequence A. The stability of the target mixing parameter a is obtained according to the mother liquor uniformity change sequence A. The stability represents the change in the uniformity of the mother liquor obtained when the target mixing parameter a is used for the current mixing. The larger the value, the less uniformity there is, which indicates that the uniformity of the mother liquor obtained by mixing has not changed significantly, and further indicates that the target mixing parameter a is suitable for the current mixing process and can ensure the stable operation of the mixing device. When the stability is smaller, it means that the uniformity of the mother liquor obtained by mixing has changed significantly (uneven conditions such as fish eyes and sticky lumps are prone to occur), which indicates that the target mixing parameter a is not suitable for the current mixing process and cannot ensure the stable operation of the mixing device (the stable operation refers to the continuous and stable output of uniform mother liquor).

[0090] As an example, the stability of the target mixing parameter a is obtained according to the mother liquid uniformity variation sequence A, including:

[0091] The mother liquor uniformity in the mother liquor uniformity variation sequence A is linearly normalized, the variance of all mother liquor uniformities after linear normalization is recorded as x, and exp(-x) is used as the stability h of the target mixing parameter a.

[0092] The purpose of adjusting the attention coefficient of the target mixing parameter a according to the stability is to adjust the attention coefficient of the target mixing parameter a according to the change in the uniformity of the mother liquor produced by the mixing device under the target mixing parameter a. When the uniformity of the produced mother liquor changes more obviously, it means that the target mixing parameter a is not conducive to the stable production of uniform mother liquor, and at this time, no more attention is paid to the uniformity of the mother liquor corresponding to the target mixing parameter a. When the uniformity of the produced mother liquor is more stable, it means that the target mixing parameter a can continuously and stably produce uniform mother liquor, and at this time, more attention needs to be paid to the uniformity of the mother liquor corresponding to the target mixing parameter a.

[0093] As an example, the attention coefficient of the target mixing parameter a is adjusted according to the stability, and the formula included is: the attention coefficient of the target mixing parameter a after adjustment is (1+hq)×k.

[0094] Wherein k represents the attention coefficient of the target mixing parameter a before adjustment, q is the preset adjustment coefficient, and this embodiment is described by taking q=0.35 as an example. In other embodiments, q can be set to other values, which are not specifically limited in this embodiment. In the above formula, when h is less than q, the attention coefficient of the target mixing parameter a after adjustment is reduced compared with the attention coefficient before adjustment; when h is greater than q, the attention coefficient of the target mixing parameter a after adjustment is expanded compared with the attention coefficient before adjustment.

[0095] After adjusting the attention coefficient of the target mixing parameter a, the target mixing parameter is obtained again in the mixing parameter set, which is recorded as b (the specific method is the same as above); that is, the priority of each mixing parameter in the mixing parameter set is recalculated, and then the mixing parameter with the largest priority is selected from them, which is recorded as b.

[0096] When the target mixing parameters b are different from a, it means that when the target mixing parameter a cannot enable the mixing device to stably mix a uniform mother liquor, there is a target mixing parameter b that can be used as a mixing parameter in the subsequent mixing process of the mixing device.

[0097] When the target mixing parameter b is the same as a, it means that even if there is a certain instability in the uniformity of the mother liquor mixed under the target mixing parameter a, it is impossible to obtain other mixing parameters that are more efficient than the target mixing parameter a, so the target mixing parameter a will continue to be used for mixing; at the same time, the time series consisting of the mother liquor uniformity recorded within the preset time period (for example, within 14 seconds) is still recorded as the mother liquor uniformity change sequence A, and the stability of the target mixing parameter a is obtained again according to the mother liquor uniformity change sequence A, and the attention coefficient of the target mixing parameter a is adjusted again, and then the target mixing parameter b is obtained again, and so on, until the obtained target mixing parameter b is different from a, or the mixing process is ended; the stability of a obtained for the last time in this process is used as the stability h in the above formula.

[0098] Step S204, using the PID algorithm to change the mixing parameter of the mixing device from a to b, recording the mother liquor uniformity change sequence B in the process of changing from a to b, adjusting the attention coefficient of b according to the difference between the mother liquor uniformity change sequences A and B, and the priority of a and b, and deleting the mixing parameter with the smallest attention coefficient in the mixing parameter set.

[0099] When the attention coefficient of a is adjusted to a small value, the target mixing parameter b in the mixing parameter set becomes the most efficient mixing parameter. In this embodiment, the PID algorithm is used to control the booster pump pressure transmitter 4, the booster pump flow meter 5, and the spiral metering feeder 22 to adjust the mixing parameter of the mixing device from a to b. In the process of adjusting the mixing parameter from a to b, the time series of the mother liquid uniformity is recorded as the mother liquid uniformity change sequence B.

[0100] It should be noted that, from the PID algorithm, the PID algorithm continuously adjusts the mixing parameters of the mixing device so that the mixing parameters gradually approach b from a and then stabilize to b (in this embodiment, the mixing parameters are equal to b after the PID algorithm adjusts the mixing parameters three times in a row, then it is judged that the mixing parameters are stably equal to b); in this embodiment, the time interval for the PID algorithm to adjust the mixing parameters is also set to 2 seconds (equal to the interval for sampling the uniformity of the mother liquor). The above-mentioned process is a well-known technology in the PID algorithm, and this embodiment will not be described in detail. The purpose of obtaining the mother liquor uniformity change sequence B is to obtain the change in the uniformity of the mother liquor when different mixing parameters are changed.

[0101] The mean value of the uniformity of all mother liquids in the mother liquid uniformity change sequence B is obtained and recorded as fb, and the mean value of the uniformity of all mother liquids in the mother liquid uniformity change sequence A is obtained and recorded as fa.

[0102] According to the difference between the mother liquor uniformity change sequences A and B, and the priority of a and b, the attention coefficient of b is adjusted. This process can ensure that when the target mixing parameter a cannot ensure the uniform and stable mixing of the mother liquor, there are still other mixing parameters that can efficiently mix the mother liquor. It can also describe the fault tolerance and stability of the mixing device when the mixing parameters change dynamically.

[0103] As an example, according to the difference between the mother liquid uniformity change sequences A and B and the priority of a and b, the attention coefficient of b is adjusted, and the specific steps included are as follows:

[0104] Let Fab = (fb-fa) / max(fb, fa), where max(fb, fa) represents the maximum value of fb and fa, and Fab represents the difference between the mother liquor uniformity change sequences A and B.

[0105] After the attention coefficient of the target mixing parameter a is adjusted, the priority of a is recorded as Qa; before the attention coefficient of the target mixing parameter b is adjusted, the priority of b is recorded as Qb; assuming that the adjusted attention coefficient of the target mixing parameter b is x, the priority of the target mixing parameter b obtained according to x is recorded as Qb1 (the calculation method is described in step S202); then let Qb1=Qb+Fab×Qa, then x=(Qb1-Vb) / wb, Vb represents the feeding speed in the target mixing parameter b, and wb represents the attention coefficient of the target mixing parameter b before adjustment.

[0106] In the above formula, when fb is larger than fa (fb-fa is greater than 0), it means that during the adjustment process of the mixing parameters of the mixing device, as the mixing parameters change, the uniformity of the mother liquor does not decrease. At this time, it means that it is more appropriate to adjust the mixing parameters from a to b, which can avoid the instability of the uniformity of the mother liquor mixed under a and increase the efficiency of the mother liquor. At the same time, the mixing parameters have a certain dynamic adjustment range, so that the mixing device has better fault tolerance and stability to cope with complex and changeable online mixing scenarios, including abnormal vibration of the mixing device, equipment failure or unstable operation, residue or blockage in the equipment, inaccurate instruments and other complex and changeable situations; at this time, increasing the attention coefficient of b means that the uniformity of the mother liquor mixed by the mixing parameter b is paid more attention. Compared with fa, the larger fb is, the higher the priority of b after the attention coefficient is adjusted compared with a.

[0107] When fb is smaller than fa (fb-fa is less than 0), it means that during the adjustment process of the mixing parameters of the mixing device, as the mixing parameters change, the uniformity of the mother liquor becomes significantly lower. At this time, it means that it is inappropriate to adjust the mixing parameter from a to b. Although the instability of the mother liquor uniformity under the mixing parameter a is avoided to a certain extent, the mixing parameters cannot maintain a stable and uniform mixing of the mother liquor during dynamic adjustment, and uneven conditions such as fish eyes and sticky lumps are prone to occur. The mixing device does not have good fault tolerance and stability and cannot cope with complex and changeable online mixing scenarios. At this time, reduce the attention coefficient of b. Compared with fa, the smaller fb is, the less difference will be made in the priority of b after the adjustment of the attention coefficient compared with a.

[0108] When Qb1 is less than Qa, Qb1=1.01×Qa. The purpose is: because the above adjustment process of the attention coefficient of b is performed when the mixing parameter is adjusted from a to b, it is necessary to ensure that the priority of b is still greater than that of a.

[0109] In the mixing parameter set, the mixing parameter with the smallest interest coefficient is deleted.

[0110] It should be noted that, in the hybrid parameter set, if the number of hybrid parameters whose attention coefficients have been adjusted is less than or equal to 5, no hybrid parameter will be deleted.

[0111] Step S205 : selecting target mixing parameters again from the deleted mixing parameter set to perform mixing.

[0112] In the above steps, when the mixing parameter of the mixing device is changed from a to b, the attention coefficient of b is adjusted, and then the mixing device mixes with the target mixing parameter b, and then steps S202 to S204 are repeated, specifically:

[0113] During the mixing process, the uniformity of the mother liquid in the buffer tank 32 is recorded in real time. Within a preset time period, the real-time recorded uniformity of the mother liquid constitutes a time series, which is again recorded as the mother liquid uniformity change sequence A. The stability of the target mixing parameter b is obtained based on the mother liquid uniformity change sequence A.

[0114] It should be noted that when the stabilities of a and b are both greater than the second preset threshold th2, the average of a and b is added to the mixing parameter set as a new mixing parameter.

[0115] The average of a and b refers to the average of the water volume, water pressure and feeding speed in a and b respectively.

[0116] The attention coefficient of the target mixing parameter b is adjusted according to the stability, and the target mixing parameter c is obtained again according to the adjusted attention coefficient. Then, the mixing parameter of the mixing device is changed from b to c using the PID algorithm, and the mother liquid uniformity change sequence is recorded during the change from b to c, and is re-recorded as B. The attention coefficient of c is adjusted according to the difference between the mother liquid uniformity change sequences A and B, and the priority of b and c, and the mixing parameter with the smallest attention coefficient in the mixing parameter set is deleted.

[0117] It should be noted that when the stabilities of b and c are both greater than the second preset threshold th2, the average of b and c is added to the mixing parameter set as a new mixing parameter.

[0118] Then the mixing device mixes with the target mixing parameter c, and similarly obtains the stability of the target mixing parameter c, adjusts the attention coefficient of the target mixing parameter c according to the stability, and re-obtains the target mixing parameter d according to the adjusted attention coefficient. Then the mixing parameter of the mixing device is changed from c to d using the PID algorithm, and the mother liquid uniformity change sequence B is recorded during the change from c to d. The attention coefficient of d is adjusted according to the difference between the mother liquid uniformity change sequences A and B, and the priority of c and d, and the mixing parameter with the smallest attention coefficient in the mixing parameter set is deleted.

[0119] It should be noted that when the stabilities of c and d are both greater than the second preset threshold th2, the average of c and d is added to the mixing parameter set as a new mixing parameter.

[0120] And so on, until the mixing process is finished (that is, the mixing is finished after the mother liquid of the required flow rate is obtained). When the number of mixing parameters in the mixing parameter set is less than or equal to 5, no mixing parameters in the mixing parameter set are deleted.

[0121] This embodiment is described by taking th2=0.5 as an example. In other embodiments, th2 may be set to other values, which are not specifically limited in this example.

[0122] In the above process, the attention coefficients of the mixing parameters in the mixing parameter set are continuously adjusted, and inappropriate mixing parameters are deleted to ensure that the mixing parameter set is continuously updated, so that the target mixing parameters selected in the mixing parameter set have higher mixing efficiency (that is, the mother liquor is mixed more evenly and the amount of mother liquor produced is larger). At the same time, the target mixing parameters are adaptively changed according to the specific process of online mixing, so that the mixing parameters of the mixing device are not fixed. At the same time, when different target mixing parameters are dynamically adjusted, the uniformity of the mother liquor will not be changed, so that the mixing device has better fault tolerance and stability when facing complex and changeable online mixing scenarios.

[0123] Finally, after the mother liquor of the current target concentration is mixed, the mixing parameters used in the process and the corresponding mother liquor uniformity are stored in the database.

[0124] When a mother solution of another target concentration needs to be prepared next time, the mixing is performed again according to the method of steps S201 to S205. With multiple mixing, more mixing parameters are stored in the database, and with the continuous updating of the mixing parameter set, the mixing device can operate more and more efficiently.

[0125] Embodiment three:

[0126] This embodiment differs from the second embodiment in that: when calculating the difference between the mother liquor uniformity change sequences A and B and adjusting the attention coefficient of b according to the priority of a and b, the mother liquor uniformity during mixing under the target mixing parameter a is further combined.

[0127] In this embodiment, the calculation is performed based on the difference between the mother liquid uniformity change sequences A and B, and the priority of a and b to adjust the attention coefficient of b, including the steps of:

[0128] It can be seen from step S203 in the first embodiment that after the target mixing parameter a is obtained, the mixing parameter of the mixing device is set to a and the mixing work is performed. The stability of a is obtained according to the mother liquid uniformity change sequence A, and the attention coefficient of a is adjusted according to the stability, and then the target mixing parameter b is obtained. The obtained b may be the same mixing parameter as a. If it is the same mixing parameter, then the target mixing parameter b is re-obtained according to the method in step S203 so that it is not the same mixing parameter as a, and then the mixing parameter of the mixing device is adjusted from a to b.

[0129] From this process, it can be seen that another target mixing parameter b is obtained according to the target mixing parameter a. In this process, the stability of a has one or more values. The sum of all the stabilities of a is obtained, which is recorded as Pa.

[0130] Assume that the adjusted attention coefficient of the target mixing parameter b is x, and the priority of the target mixing parameter b obtained according to x is recorded as Qb1; then let Qb1 = Qb + Fab × exp(-Pa) × Qa, then x = (Qb1-Vb) / wb, Vb represents the feeding speed in the target mixing parameter b, and wb represents the attention coefficient of the target mixing parameter b before adjustment.

[0131] exp(-Pa) represents the difference attention coefficient p. The larger the Pa, that is, the smaller the exp(-Pa), the more stable the uniformity of the mother liquor mixed under the target mixing parameter a. At this time, when adjusting the attention coefficient of the target mixing parameter b, do not pay too much attention to the change in the uniformity of the mother liquor during the adjustment of the mixing parameter from a to b (that is, do not pay too much attention to the size of Fab), and avoid adjusting the attention coefficient of b too large. For example, when Fab is greater than 0, avoid adjusting the attention coefficient of b too large, resulting in the target mixing parameter a being deleted from the mixing parameter set too early; for another example, when Fab is less than 0, the attention coefficient of b will be smaller, so that when the uniformity of the mother liquor decreases during the adjustment from a to b, the target mixing parameter b may also be deleted.

[0132] When Pa is smaller, that is, exp(-Pa) is larger, it means that the uniformity of the mother liquor mixed under the target mixing parameter a is unstable, and it is easy to have uneven conditions such as fisheyes and sticky clumps. At this time, when adjusting the attention coefficient of the target mixing parameter b, it is necessary to pay more attention to the change in the uniformity of the mother liquor in the process of adjusting the mixing parameter from a to b (that is, pay more attention to the size of Fab), and avoid adjusting the attention coefficient of b too small. For example, when Fab is less than 0, avoid adjusting the attention coefficient of b too small, which will result in the target mixing parameter a not being deleted from the mixing parameter set in time.

[0133] The above method for obtaining the adjusted attention coefficient of b further realizes the effective update of the attention coefficient, so that the mixing parameters in the mixing parameter set are also reasonably updated, thereby ensuring that the mixing device further increases the uniformity and avoids the occurrence of uneven conditions such as fish eyes and sticky clumps when mixing the mother liquor using the mixing parameters in the mixing parameter set.

[0134] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Fully automatic fracturing fluid powder online mixing device, the device includes: A fracturing site water supply tank (1), a dry powder tank (12), and a sand mixing truck (24), characterized in that the clean water output from the fracturing site water supply tank (1) passes through a booster pump (3) and forms a jet in a high powder-water ratio ejector (7); the polymer dry powder in the dry powder tank (12) is transported to a dry powder hopper (23) through a spiral metering feeder (22); the negative pressure of the jet in the high powder-water ratio ejector (7) lifts the polymer dry powder in the dry powder hopper (23) into the high powder-water ratio ejector (7), and the polymer dry powder in the high powder-water ratio ejector (7) collides and mixes with the jet to obtain a mother liquor; The mother liquid enters the buffer tank (32), and the mother liquid in the buffer tank (32) is transported to the static mixing and dilution skid (26). The fracturing site water supply tank (1) is connected to the static mixing and dilution skid (26). The mother liquid in the static mixing and dilution skid (26) is mixed with the clean water in the fracturing site water supply tank (1), and then sucked into the sand mixing truck (24) by the sand mixing truck suction pump (25), and then mixed with sand in the sand mixing tank, and finally transported to the fracturing pump and pressed into the formation. An ultrasonic sensor is installed in the buffer tank (32) to detect the uniformity of the mother liquid in the buffer tank (32).

2. A fully automatic online fracturing fluid powder mixing method, using the fully automatic online fracturing fluid powder mixing device according to any one of claim 1, characterized in that: The method comprises the following steps: The feeding speed of the dry powder hopper (23), the water volume outputted by the water supply tank (1) at the fracturing site, and the water pressure outputted by the booster pump (3) are recorded as a set of mixing parameters of the mixing device; The mixing parameter with the highest priority is obtained from the mixing parameter set as the target mixing parameter, which is recorded as a; the mixing parameter set includes a plurality of mixing parameters, and each group of mixing parameters corresponds to a preset attention coefficient, and the priority of each group of mixing parameters is positively correlated with the attention coefficient, the uniformity of the mother liquid, and the feeding speed in each group of mixing parameters; According to the target mixing parameter a, the target mixing parameter is selected from the mixing parameter set to perform mixing work, including: The mixing device performs mixing with a target mixing parameter a, obtains a mother liquid uniformity change sequence A during the mixing process, obtains the stability of the target mixing parameter a according to the mother liquid uniformity change sequence A, adjusts the attention coefficient of the target mixing parameter a according to the stability, and re-obtains the target mixing parameter from the mixing parameter set according to the adjusted attention coefficient, which is recorded as b; The mixing parameter of the mixing device is changed from a to b by using a PID algorithm, and the mother liquid uniformity change sequence B is recorded, and the attention coefficient of b is adjusted according to the difference between the mother liquid uniformity change sequences A and B, and the priority of a and b; then the mixing parameter with the smallest attention coefficient in the mixing parameter set is deleted, and the mixing device performs mixing work with the target mixing parameter b; The difference between the priority corresponding to b after the attention coefficient is adjusted and the priority corresponding to a after the attention coefficient is adjusted is positively correlated with the difference between A and B; According to the target mixing parameter b, the target mixing parameter is selected again from the deleted mixing parameter set to perform mixing work.

3. The fully automatic online fracturing fluid powder mixing method according to claim 2, characterized in that: The specific steps for obtaining the mixing parameter set are as follows: When the mixing device mixes the mother liquid, the mixing parameters used and the uniformity of the mother liquid in the buffer tank (32) are recorded; and the mixing parameters whose uniformity of the mother liquid is greater than a first preset threshold are taken as a mixing parameter set.

4. The fully automatic online fracturing fluid powder mixing method according to claim 2, characterized in that: The specific calculation formula of the priority of each group of mixing parameters is as follows: The priority is expressed as Q=w×F+V, wherein F represents the uniformity of the mother liquor corresponding to each group of mixing parameters, V represents the feeding speed in each mixing parameter, and w represents the attention coefficient of each group of mixing parameters.

5. The fully automatic online fracturing fluid powder mixing method according to claim 2, characterized in that: The method of obtaining the stability of the target mixing parameter a according to the mother liquor uniformity variation sequence A comprises the following specific steps: The mother liquor uniformity in the mother liquor uniformity change sequence A is linearly normalized, and the variance of all mother liquor uniformities after linear normalization is recorded as x. exp(-x) is used as the stability of the target mixing parameter a, and exp() represents an exponential function with a natural constant as the base.

6. The fully automatic online fracturing fluid powder mixing method according to claim 2, characterized in that: The specific steps of adjusting the attention coefficient of the target mixing parameter a according to the stability are as follows: The attention coefficient after the target mixing parameter a is adjusted is (1+hq)×k; wherein k represents the attention coefficient before the target mixing parameter a is adjusted, q is a preset adjustment coefficient, and h represents the stability.

7. The fully automatic online fracturing fluid powder mixing method according to claim 2, characterized in that: The specific steps of adjusting the attention coefficient of b according to the difference between the mother liquid uniformity change sequences A and B and the priority of a and b are as follows: The average value of all the mother liquid uniformities in the mother liquid uniformity change sequence B is obtained and recorded as fb, and the average value of all the mother liquid uniformities in the mother liquid uniformity change sequence A is obtained and recorded as fa; Let Fab = (fb-fa) / max(fb, fa), where max(fb, fa) represents the maximum value of fb and fa, and Fab represents the difference between the mother liquor uniformity change sequences A and B; After the attention coefficient of the target mixing parameter a is adjusted, the priority of a is recorded as Qa; before the attention coefficient of the target mixing parameter b is adjusted, the priority of b is recorded as Qb; assuming that the adjusted attention coefficient of the target mixing parameter b is x, the priority of the target mixing parameter b obtained according to x is recorded as Qb1; Qb1=Qb+Fab×p×Qa, then x=(Qb1-Vb) / wb, Vb represents the feeding speed in the target mixing parameter b, wb represents the attention coefficient of the target mixing parameter b before adjustment; p represents the difference attention coefficient.

8. The fully automatic online fracturing fluid powder mixing method according to claim 7, characterized in that: The specific steps for obtaining the difference attention coefficient are as follows: When the target mixing parameter b is different from the target mixing parameter a, the difference attention coefficient is negatively correlated with the stability of the target mixing parameter a; When the target mixing parameter b is the same as the target mixing parameter a, the mixing device continues to perform mixing with the target mixing parameter a, obtains the mother liquor uniformity change sequence A during the mixing process again, obtains the stability of the target mixing parameter a again according to the mother liquor uniformity change sequence A, adjusts the attention coefficient of the target mixing parameter a again according to the stability, and obtains the target mixing parameter b from the mixing parameter set again according to the adjusted attention coefficient; when the target mixing parameter b is the same as the target mixing parameter a again, the mixing device continues to perform mixing with the target mixing parameter a, and so on, until the obtained target mixing parameter b is different from the target mixing parameter a; then the several stabilities obtained for the target mixing parameter a are summed up and recorded as Pa; the difference attention coefficient is negatively correlated with Pa.

9. The fully automatic online fracturing fluid powder mixing method according to claim 2, characterized in that: The specific steps of selecting the target mixing parameter again from the deleted mixing parameter set according to the target mixing parameter b to perform the mixing work include the following: When the mixing device performs mixing with the target mixing parameter b, a mother liquid uniformity variation sequence A during the mixing process is obtained, and the stability of the target mixing parameter b is obtained according to the mother liquid uniformity variation sequence A; When the stability of the target mixing parameter b and the stability of the target mixing parameter a are both greater than the second preset threshold, the average of a and b is added to the mixing parameter set as a new mixing parameter.

10. The fully automatic online fracturing fluid powder mixing method according to claim 2, characterized in that: In the mixing parameter set, if the number of mixing parameters whose attention coefficients have been adjusted is less than or equal to a preset number, no mixing parameter will be deleted.

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