Powder polymer online filling system and method for oil and gas well fracturing transformation

Abstract

The invention relates to the technical field of oil and gas well fracturing transformation, and discloses a powder polymer online filling system and method for oil and gas well fracturing transformation, and the powder polymer online filling system comprises a vehicle-mounted mixing device, a transfer tank and a PLC control system, the PLC control system is connected with the vehicle-mounted mixing device and the transfer tank; the vehicle-mounted mixing equipment mixes powder polymer and chemical mixing liquid into thickening agent suspension liquid capable of being added on line, the vehicle-mounted mixing equipment comprises a dispersion tank and a liquid tank, the powder tank and the transfer tank are connected with the dispersion tank, the transfer tank is connected with the upper portion of the dispersion tank, a negative pressure feeding valve is arranged on a second branch pipeline, the upper portion of the liquid tank is connected with a liquid barrel tank, and the liquid barrel tank is connected with a second branch pipeline. The transfer tank is connected with the lower part of the liquid tank through a centrifugal pump II; the variable-frequency rotor pump is connected with the transfer tank through a pipeline; the variable-frequency rotor pump is connected with the fracturing blender truck through a pipeline IV; the method comprises a preparation stage and a matching stage. The construction process can be optimized, the liquid performance can be improved, the project cost can be saved, safety and environmental protection are realized, the powder polymer dispersion uniformity is good, and the hydration efficiency is high.

Description

Technical Field

[0001] The present invention relates to the field of wellbore engineering technology in oil and natural gas, especially shale oil and gas exploration and development, and in particular to an online powder polymer filling system and method for oil and gas well fracturing transformation. It is used to mix and add the required powder polymer online during the on-site operation of oil and gas well fracturing, so as to optimize the construction process, improve the liquid performance, save the project cost, and achieve safety and environmental protection. Background Art

[0002] Oil and gas well fracturing is a wellbore engineering technology frequently used in the process of oil and gas exploration and development. The purpose of increasing oil and gas well production is achieved by fracturing oil and gas reservoirs. In the process of oil and gas well fracturing, three aspects of science and engineering technology are usually involved: mechanics, chemistry, and mathematical models. The mechanics include high-pressure pumping equipment, sand mixing vehicles, instrumentation vehicles, etc., the chemistry includes fracturing fluids, additives and proppants, and the mathematical models include fracturing design software. Powder polymers are often used in the fracturing process to achieve the purpose of increasing viscosity, reducing drag and carrying sand for the working fluid. Oil and gas well fracturing refers to a method of increasing oil and gas production by transforming oil and gas reservoirs through fracturing process engineering technology. Mixing and adding refers to the engineering process method of continuously delivering fracturing fluid additives and proppants into the wellbore through special mechanical equipment and processes at the fracturing construction site.

[0003] Polymer is the main additive in the fracturing fluid system. By adding polymer to the fracturing fluid, the viscosity of the fracturing fluid at well temperature can be maintained, the fracturing fluid can be diverted, the resistance of the pumping process can be reduced, and the sand carrying performance of the liquid can be improved.

[0004] How to mix and add polymers during the on-site construction process has a great impact on the economy and transformation effect of the oil and gas well fracturing transformation process. At present, there are mainly two ways to mix and add polymers in on-site construction, namely batch mixing and continuous methods. In the batch mixing method, before the fracturing construction, the powder is first hydrated in the fracturing fluid tank and other additives are added. Then, during the fracturing construction, the prepared fracturing fluid in the fracturing fluid tank is sucked in by a low-pressure pump truck and transferred to the sand mixing truck. The continuous method refers to the real-time mixing of powder or liquid polymers, water and other additives through special or conventional transfer equipment during the fracturing construction process and adding them to the sand mixing truck. At present, these two mixing and adding methods have the following problems, which can be seen in CN 108659809A, 2018.10.16 "A method for preparing concentrated liquid based on continuous fracturing": The batch mixing method divides the entire fracturing construction process into two parts. On the one hand, it requires additional equipment, personnel and other logistical support measures. On the other hand, it will greatly extend the construction time, which increases the cost of the entire oil and gas reservoir fracturing transformation and reduces the efficiency. Especially in the fracturing transformation of shale oil and gas reservoirs in recent years, the scale of single well transformation (horizontal well staged fracturing) is dozens of times the scale of traditional fracturing transformation (vertical well single layer). Such fracturing transformation process is almost impossible to use traditional liquid batch mixing due to the complex process procedures and low construction efficiency, see CN 108659809 A.

[0005] There are two main types of continuous mixing and transfer methods at present. The most common method is to form a liquefied product from polymer additives, such as an inverse (water-in-oil) polymer emulsion produced by emulsion polymerization, or a thickener suspension formed by suspending a powder polymer in an oil phase or other liquid solvent. During the fracturing operation, the liquefied polymer is directly transferred to a sand blender using a corresponding transfer pump, see CN 108659809 A.

[0006] Oil-in-water inverse emulsion polymers contain a large number of other additives (such as oil phase and surfactants). Although these additives help maintain the stability of the emulsion to a certain extent, they result in relatively low effective ingredients (generally 30%). In addition, the molecular weight of the polymer obtained by inverse emulsion polymerization is usually low, which means that in practical applications, the amount of thickener added is large, especially when using high-mineralized water to prepare the fluid, the performance of the prepared fracturing fluid is poor, see CN 116179180 A, 2023.05.30 "A clean concentrated fracturing fluid based on water-soluble polymer".

[0007] For oil-based suspensions, the main components contain a large amount of mineral oil, stabilizers, and surfactants. Stabilizers are usually water-insoluble organic bentonites, nanomaterials, etc. Surfactants are usually non-ionic surfactants, such as Span and Tween series. The presence of mineral oil not only increases the cost, but also causes potential damage to storage equipment and formations. Insoluble stabilizers such as organic bentonites are difficult to dissolve in water, which will affect the uniformity and stability of the fracturing fluid. These insoluble substances may also remain in the formation, reduce the effective permeability of the formation, affect the output efficiency of oil and gas, and seriously limit the promotion and large-scale application of this technology. In addition, whether it is an inverse polymer emulsion or an oil-based suspension polymer product, because it contains a large amount of oil phase, not only does it greatly increase the cost of the liquid, it also has a very negative impact on environmental protection, and it will cause potential damage to the reservoir and affect the effective permeability of the reservoir, see CN 116179180 A.

[0008] In recent years, aqueous solvent-based suspensions have begun to attract people's attention. However, similar to oil-based suspensions or inverse emulsion polymers, in the design of aqueous solvent-based products, a large number of solvents such as polyethylene glycol, methanol, and ethanol are used to replace the oil phase of the oil-based suspension. See CN 111394085 A, 2020.07.10, "A high-content aqueous drag reducer and its preparation method". The addition of a large amount of solvent not only has a negative impact on environmental protection, but also causes other technical and economic problems. From the perspective of stability, particles in the suspension are prone to sedimentation and agglomeration. This is because the interaction between the particles and the dispersion medium is not strong enough to effectively resist gravity and the attraction between particles. In some solvent-based thickener suspensions, polymer particles may gradually sink after standing for a period of time due to their own high density or surface properties, resulting in uneven concentration of the suspension above and below, affecting the consistency of its performance. Moreover, the particles may aggregate together due to interactions such as van der Waals forces to form larger aggregates, further destroying the stability of the suspension and reducing the dispersion of its effective ingredients, thereby affecting its effect in the oil and gas production process. In terms of solubility, some components in solvent-based suspensions may have poor solubility. For example, some additives or polymers dissolve slowly in water and require a long period of stirring or special treatment to completely dissolve. This not only increases the complexity and time cost of the operation, but may also result in the failure to achieve the expected performance effect in time in practical applications. In the application scenario of fracturing fluid, if the key thickener or drag reducer components cannot be dissolved quickly, it will affect the immediate performance of the fracturing fluid, such as the increase in viscosity and the effect of drag reduction, which will in turn have an adverse effect on the efficiency of oil and gas production. In terms of cost, the preparation and use costs of solvent-based suspensions are relatively high. On the one hand, in order to maintain the stability of the suspension, some expensive stabilizers or surfactants may need to be added, and the use of these additives increases the cost of raw materials. On the other hand, due to the above-mentioned solubility and stability issues, more complex production processes and equipment may be required to ensure the quality of the suspension, which will also lead to an increase in production costs. In large-scale oil and gas production operations, these cost increases will have a significant impact on economic benefits, limiting the widespread application and promotion of solvent-based suspensions.

[0009] A new mixing and transfer process technology has also been reported, which uses special equipment to directly mix powder polymers and water at the construction site (usually prepared into a prefabricated glue solution with a concentration of about 2%) and transfer it to a sand mixer. This process technology idea not only achieves continuous mixing in theory to improve work efficiency, but also avoids the problems of rising costs and environmental impact during the use of liquid emulsions or suspensions, becoming a new type of continuous mixing and transfer method that has attracted much attention. However, fatal defects were also found during the on-site implementation process. On the one hand, when the powder polymer is prefabricated as a 2% solution in water, it is easy to form fish eyes, and the product efficiency is greatly reduced. On the other hand, the polymer aqueous solution dissolved in water quickly forms a highly viscous colloidal substance. When these semi-solid colloids are transferred to the sand mixer for further hydration and mixed with other additives, they not only have poor dispersion and solubility, but also have the risk of clogging pipelines, downhole tools and reservoirs. Summary of the invention

[0010] The present invention is to overcome the shortcomings of the above-mentioned prior art and provide an online powder polymer injection system for oil and gas well fracturing transformation. The present invention mixes, adds and transfers the required powder polymer online, achieving the purpose of optimizing the construction process, improving liquid performance, saving project costs, and achieving safety and environmental protection, and solves the problems of poor powder dispersion uniformity and low hydration efficiency in the prior art.

[0011] The invention also provides an online powder polymer injection method for oil and gas well fracturing transformation.

[0012] The technical solution adopted by the present invention to solve the technical problem is: A powder polymer online filling system for oil and gas well fracturing transformation, comprising a mixing device, the mixing device comprising a vehicle-mounted mixing device, a transfer tank, and a PLC control system, the PLC control system being connected to the vehicle-mounted mixing device and the transfer tank, the vehicle-mounted mixing device mixing the powder polymer with a chemical mixing liquid into a thickener suspension that can be added online, the vehicle-mounted mixing device comprising a dispersion tank, a liquid tank, and a powder tank, the transfer tank being connected to the dispersion tank through a main pipeline, a branch pipeline 1, and a centrifugal pump 1, the transfer tank being connected to the upper part of the dispersion tank through a main pipeline and a branch pipeline 2, a negative pressure feed valve being provided on the branch pipeline 2, the upper part of the liquid tank being connected to a liquid barrel tank through a delivery pump and a pipeline, the transfer tank being connected to the lower part of the liquid tank through a main pipeline, a branch pipeline 3, and a centrifugal pump 2, a flow control valve being provided on the branch pipeline 3, a variable frequency rotor pump being connected to the transfer tank through a pipeline, a variable frequency rotor pump being connected to a sand mixing vehicle through a pipeline 4, and a flow meter being provided on the pipeline 4; The powder tank is used to store powder polymer; The liquid tank is used to store the chemical mixed liquid pumped from the liquid barrel tank; The chemical mixing liquid and the powder polymer are mixed in the dispersion tank to form a thickener suspension; The transfer tank serves as an intermediate storage device, providing the thickener suspension transfer and temporary storage functions.

[0013] The dispersion tank is provided with a stirrer 2, and a negative pressure feed valve is provided on the dispersion tank. During the mixing process, the chemical mixing liquid and the powder polymer are fully mixed in the dispersion tank to form a uniform thickener suspension; A centrifugal pump is connected to the lower part of the dispersion tank.

[0014] A stirrer is installed in the liquid tank, and the chemical mixed liquid is added into the liquid tank and stirred by the stirrer to ensure that the chemical mixed liquid has uniform composition; The liquid tank is provided with a liquid level display device.

[0015] The powder tank is provided with an automatic bag breaking device, and the powder tank is provided with an arch breaking device. The automatic bag breaking device completes the bag breaking operation, so that the powder polymer falls into the tank smoothly; the arch breaking device prevents the powder from agglomerating and bridging in the tank, and ensures that the powder flows out stably and smoothly; a screw conveying device is provided at the lower part of the powder tank, and the screw conveying device is connected to the compressed air pipeline. The screw conveying device conveys the powder polymer to the dispersion tank through the negative pressure feed valve through compressed air. The negative pressure feed valve uses the pressure difference principle of the Venturi effect to realize the negative pressure feeding function, and the screw conveying device adopts a screw quantitative conveyor.

[0016] The weight ratio of the powder polymer to the chemical mixed liquid is 20:80 to 60:40.

[0017] The powder polymer is a synthetic polymer, or a natural polymer and its derivatives.

[0018] The chemical mixed fluid is mainly composed of additives associated with the fracturing fluid, and the additives include one or more of a clay stabilizer, a bactericide, and a drainage aid; The clay stabilizer is a quaternary ammonium compound.

[0019] According to different types of powder polymers, water-based inhibitors are added to the chemical mixture; The aqueous inhibitor is water-soluble salts, cationic polymers and cationic surfactants and organic solvents or a combination thereof.

[0020] A method for online filling of powder polymer for oil and gas well fracturing and reconstruction, using the powder polymer online filling system for oil and gas well fracturing and reconstruction, mixing the powder polymer with a chemical mixed liquid in a dispersion tank through a negative pressure feed valve, and dispersing through a stirrer in the dispersion tank to form a uniformly dispersed thickener suspension, and then directly transferring the suspension to a sand mixing truck through a variable frequency rotor pump of a transfer tank to mix with water and other additives to form a fracturing fluid, comprising the following steps: 1) Preparation The preparation stage includes liquid material storage and powder polymer storage; 2) Mixing stage The mixing stage includes starting the circulation and forming negative pressure, premixing and conveying of powder polymer, continuous mixing and material replenishment, preliminary dispersion and storage of thickener suspension, completion of operation preparation, and pumping and use of thickener suspension.

[0021] The liquid material storage and powder polymer storage specifically include the following steps: Liquid material storage: Use a delivery pump to deliver the chemical mixed liquid in the on-site liquid barrel tank to the liquid tank; during the delivery process, pay attention to the liquid level display device on the liquid tank, and stop delivering the chemical mixed liquid when the liquid level reaches the pre-set specified position; after the delivery is completed, if other additives need to be added according to the process requirements, start the agitator 1, add the additives according to the specified addition order and dosage, and continue to stir for a period of time to fully mix the additives and liquid materials; Powder polymer storage: hoist a suitable number of powder polymer bags to the bag breaking device on the top of the powder tank for automatic bag breaking; the bag breaking device starts to accurately break the powder polymer bag, allowing the powder polymer to fall naturally into the powder tank; during the powder storage process, the arch breaking device of the powder tank remains in the open state, and the arch breaking device continuously acts on the powder to prevent the powder from agglomerating or bridging due to moisture and static electricity, ensuring that the powder is always in a loose state and can flow out smoothly for subsequent mixing; The starting cycle and forming of negative pressure, powder polymer premixing and conveying, continuous mixing and material replenishment, preliminary dispersion and storage of thickener suspension, completion of operation preparation, and pumping and use of thickener suspension specifically include the following steps: Start the circulation and form negative pressure, pump an appropriate amount of chemical mixed liquid from the liquid tank into the dispersion tank, and start the circulation system of the dispersion tank; after the circulation system is running, the negative pressure feed valve will generate a negative pressure environment due to the high-speed flow of the chemical mixed liquid, creating conditions for the subsequent inhalation of powder polymers; Powder polymer premixing conveying: start the screw conveying device to convey the powder polymer in the powder tank to the dispersion tank; monitor the weight of the conveyed powder polymer in real time during the conveying process, and stop the screw conveying device when the weight of the powder polymer required for premixing is reached; Continuous mixing and material replenishment: According to the designed displacement, continuously pump or self-circulate the chemical mixing liquid from the liquid tank to the dispersion tank, so that the chemical mixing liquid and the powder polymer are fully mixed in the dispersion tank to achieve continuous mixing; during the mixing process, pay attention to the material levels in the liquid tank and the powder tank; when the liquid level in the liquid tank is close to the lower limit or the powder remaining in the powder tank is insufficient, replenish it; when replenishing the liquid, repeat the operation of storing the chemical mixing liquid material in the preparation stage; when replenishing the powder, lift the powder polymer bag again to the bag breaking device of the powder tank for bag breaking and material addition; Initial dispersion and storage of thickener suspension: After continuous mixing begins, the thickener suspension in the dispersion tank is continuously pumped to the transfer tank through a pipeline, where the thickener suspension continues to be dispersed to improve its uniformity and stability; Operation preparation is completed: when the liquid level in the transfer tank reaches the specified position, it indicates that the thickener suspension required for the on-site operation has been prepared in sufficient quantity. At this time, the status of all equipment and materials meet the operation requirements, and the on-site operation can begin; Pumping and use of thickener suspension: turn on the variable frequency rotor pump, accurately control the flow rate according to the designed displacement, and pump the thickener suspension in the transfer tank into the sand mixing truck; during the pumping process, continuously monitor the operating parameters of the variable frequency rotor pump to ensure stable operation, ensure that the flow rate and pressure of the transported thickener suspension meet the use requirements of the sand mixing truck, and provide a stable material supply for subsequent construction operations.

[0022] The beneficial effects of the present invention are: 1. The powder polymer online mixing, adding equipment and method for oil and gas well fracturing transformation of the present invention utilizes the structure and working principle of the negative pressure feed valve mixing and the rapid dispersion agitator to fully mix the powder polymer with the chemical mixing liquid (rather than water) in a short time to form a uniformly dispersed pure water-based low-viscosity thickener suspension, thereby ensuring the high efficiency and uniformity of the mixing, and achieving the effect of uniform dispersion and rapid hydration that is difficult to achieve with the traditional mixing method. The present invention mixes, adds and transfers the required powder polymer online, which can optimize the construction process, improve the liquid performance, save project costs, and achieve safety and environmental protection. At the same time, it solves the problems of poor powder dispersion uniformity and low hydration efficiency in the prior art: that is, in the prior art, whether it is the traditional batch mixing or the on-site continuous powder mixing technology, when mixing the powder polymer with water and additives, it is difficult to achieve rapid and uniform dispersion and hydration, resulting in low product use efficiency, the need for additional special equipment assistance, increased overall operating costs, and potential operating risks and formation damage.

[0023] 2. The chemical mixed liquid of the present invention comprises a quaternary ammonium compound and a water-based inhibitor. The quaternary ammonium compound may play an important role in the mixed system, and it helps to improve the chemical properties of the system, such as enhancing the compatibility with other substances or promoting specific chemical reactions. The water-based inhibitor can inhibit the occurrence of some unnecessary reactions or phenomena in the system, such as preventing the hydrolysis or precipitation of certain substances, thereby ensuring the stability and effectiveness of the entire mixed system in terms of physical and chemical properties, and solving the problems of poor uniformity of the mixed dispersion and poor rapid hydration performance in the prior art.

[0024] 3. The present invention can accurately control the ratio of powder polymer to chemical mixed liquid through precise design and flow control of negative pressure feed valve and rapid dispersion agitator, ensuring that the performance of the suspension formed by each mixing is stable and meets technical and design requirements. It solves the problem that the existing online powder mixing and transfer technology has large errors in ratio control and stability, and is prone to affect the final performance of the fracturing fluid due to fluctuations in the mixing ratio, ensuring the reliability and stability of the fracturing operation.

[0025] 4. The present invention utilizes a simple negative pressure feed valve mixer and a rapid dispersion agitator to achieve online addition and instant mixing. After the powder is mixed with the chemical mixed liquid mentioned in the present invention at the construction site, it is pumped to a sand mixer through a variable frequency rotor pump in a transfer tank and mixed with clean water to form a fracturing fluid. There is no need for large-scale premixing operations in advance, and no additional special equipment is required. This greatly simplifies the equipment and operating procedures, reduces construction costs, improves operating efficiency, reduces construction risks, and improves the convenience and efficiency of on-site operations. It solves the problem that the traditional powder batch mixing method of the prior art requires additional complex premixing equipment and a long mixing time, and cannot meet the needs of on-site rapid construction, especially in shale oil and gas development fracturing operations in recent years.

[0026] 5. The present invention eliminates the expensive oil and solvent used to realize the liquefaction of powder polymers, greatly reducing the cost of the fracturing liquid system. At the same time, the supporting chemical mixed liquid used in the present invention is pure water-based and environmentally friendly, with excellent environmental performance, further reducing the cost of the fracturing liquid system, and has no side effects on environmental protection. It solves the problem that most of the liquid polymer products used in the fracturing operation of the prior art are liquid polymer products, including reverse emulsions, oil-based or solvent-based suspensions. Although these products and technologies have solved the problems of difficult dispersion and hydration and complex equipment and process of powder polymer products to a certain extent, they also have the defects and shortcomings of greatly increasing the cost of liquids and negative effects on environmental protection. The present invention solves the problems of high cost and environmental pollution of the currently widely used liquid polymer product technology.

[0027] 6. In the field of oil and gas reservoir fracturing and wellbore engineering technology, the present invention innovatively proposes a new powder polymer online injection system and method. It cleverly combines chemical and mechanical technical means, breaking the limitation of using only a single method (mechanical or chemical) in this field, thereby solving various technical, economic and environmental problems caused by the current use of a single method.

[0028] In terms of chemical mechanism, the present invention involves the analysis and utilization of the chemical properties of polymer dry powder and chemical mixing liquid, ensuring that appropriate physical and chemical reactions can occur between the components during the mixing and adding process, thereby improving the technical, economic and environmental performance of the final product.

[0029] In terms of mechanical equipment and process, the present invention uses a carefully designed negative pressure feeding device and a high-speed dispersing agitator to utilize their unique fluid mechanics principles to achieve efficient mixing, dispersing, transferring and adding of polymer dry powder and chemical mixed liquid.

[0030] The present invention effectively combines chemical and mechanical technologies to achieve accurate and efficient online mixing and addition of polymer dry powder during fracturing operations, which not only improves the convenience and efficiency of operations, accurately controls additive mixing and final product performance, but also provides a reliable technical approach for on-site operations of oil and gas reservoir fracturing and transformation, with superior fracturing fluid performance, low operating costs, low construction risks, and greater environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the powder polymer online filling system of the present invention; Figure 2 This is a stability picture of Preparation Example 3 of the present invention; Figure 3 The hydration curves of Preparation Example 3 and Comparative Examples 1 and 2 of the present invention are shown in FIG. Figure 4 This is a picture of the heat and shear resistance of the cross-linked fracturing fluid prepared in Preparation Example 3 and Comparative Example 1 of the present invention; Figure 5 This is a picture of the clay stability performance of Preparation Example 4 of the present invention.

[0032] In the figure, transfer tank 1, dispersion tank 2, liquid tank 3, powder tank 4, centrifugal pump 1 5, negative pressure feed valve 6, flow control valve 7, centrifugal pump 2 8, screw conveyor 9, liquid barrel tank 10, bag breaking device 11, arch breaking device 12, agitator 1 13, agitator 2 14, main pipeline 15, branch pipeline 1 16, branch pipeline 2 17, branch pipeline 3 18, variable frequency rotor pump 19, conveying pump 20, compressed air pipeline 21, powder polymer ton bag 22, flow meter 23. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0034] Example 1 like Figure 1-5As shown, an online filling system for powder polymer for oil and gas well fracturing transformation includes a mixing device, the mixing device includes a vehicle-mounted mixing device, a transfer tank 1, and a PLC control system. The PLC control system is connected to the vehicle-mounted mixing device and the transfer tank 1. The vehicle-mounted mixing device mixes the powder polymer with the chemical mixing liquid into a thickener suspension that can be added online. The vehicle-mounted mixing device includes a dispersion tank 2, a liquid tank 3, and a powder tank 4. The transfer tank 1 is connected to the dispersion tank 2 through a main pipeline 15, a branch pipeline 16, and a centrifugal pump 15. The transfer tank 1 is connected to the upper part of the dispersion tank 2 through the main pipeline 15 and the branch pipeline 17. The branch pipeline 17 is provided with a negative pressure feed valve 6. The upper part of the liquid tank 3 is connected to the liquid barrel tank 10 through a delivery pump 20 and a pipeline. The transfer tank 1 is connected to the lower part of the liquid tank 3 through a main pipeline 15, a branch pipeline three 18, and a centrifugal pump two 8. A flow control valve 7 is provided on the branch pipeline three 18. The variable frequency rotor pump 19 is connected to the transfer tank 1 through a pipeline; the variable frequency rotor pump 19 is connected to the sand mixing truck through a pipeline four, and a flow meter 23 is provided on the pipeline four; the negative pressure feed valve 6 realizes the negative pressure feeding function by utilizing the pressure difference principle of the Venturi effect.

[0035] The powder tank 4 is used to store powder polymers. The powder tank 4 is provided with an automatic bag breaking device 11 and an arch breaking device 12. The automatic bag breaking device 11 can automatically complete the bag breaking operation after the powder polymer ton bag 22 is lifted to the designated position by the crane, so that the powder polymer can fall into the tank smoothly; the arch breaking device 12 can effectively prevent the powder from agglomerating and bridging in the tank, and ensure that the powder flows out stably and smoothly. A screw conveying device 9 is provided at the bottom of the powder tank 4. The screw conveying device 9 adopts a screw quantitative conveyor. The screw quantitative conveyor is connected to the compressed air pipeline 21. The screw quantitative conveyor conveys the powder polymer to the dispersion tank 2 through the negative pressure feed valve 6 by compressed air.

[0036] The liquid tank 3 is used to store the chemical mixed liquid pumped from the on-site liquid barrel tank 10. A stirrer 13 is installed in the liquid tank 3. The stirring function of the stirrer 13 ensures that the liquid material composition is uniform.

[0037] The liquid tank 3 is provided with a liquid level display device.

[0038] The dispersion tank 2 is provided with an agitator 14, and the dispersion tank 2 is provided with a negative pressure feed valve 6, which is a key place for mixing. During the mixing process, a series of operations are performed to fully mix the chemical mixing liquid and the powder polymer to form a uniform thickener suspension. The agitator 13 is a paddle agitator, the agitator 14 is a dispersion disc agitator, and the lower part of the dispersion tank 2 is connected to a centrifugal pump 5.

[0039] The transfer tank 1 serves as an intermediate storage device and can be flexibly arranged according to actual on-site needs, providing a more convenient material transfer and temporary storage function for the entire mixing process.

[0040] The weight ratio of the powder polymer to the chemical mixed liquid is 20:80 to 60:40.

[0041] Preferably, the weight ratio of the powder polymer to the chemical mixing liquid is 30:70 to 50:50.

[0042] The powder polymer is a synthetic polymer, or a natural polymer and its derivatives. For example, the powder polymer is an artificially synthesized polymer, such as polyacrylamide homopolymers and copolymers, or a natural plant gum and its derivatives, such as guar gum and its derivatives, starch and its derivatives, or a polymer prepared by biological methods, such as xanthan gum or vinblastine gum.

[0043] The chemical mixed liquid is mainly composed of additives related to fracturing fluid, and the additives include one or more of clay stabilizers, bactericides, and drainage aids; the chemical mixed liquid is added to the liquid tank 3 according to demand, and the stirring function of the stirrer 13 is used to ensure that the chemical mixed liquid with the additives is uniform in composition.

[0044] The clay stabilizer is a quaternary ammonium compound, such as ammonium chloride, choline chloride, tetramethylammonium chloride, etc. A high concentration of quaternary ammonium compound solution can inhibit the hydration of the polymer. The powder polymer is mixed with the high concentration of the quaternary ammonium compound at the well site to form a uniform thickener suspension. When the suspension is mixed with a large amount of water, the quaternary ammonium compound is fully diluted, and the polymer will be completely and quickly hydrated.

[0045] The weight fraction of the quaternary ammonium compound is 40%-100%. Preferably, the weight fraction of the quaternary ammonium compound can be 50%-70%.

[0046] The quaternary ammonium compound is a monoquaternary ammonium compound, a diquaternary ammonium compound, a polymeric quaternary ammonium compound or a combination thereof.

[0047] The quaternary ammonium compound is preferably a salt comprising a quaternary ammonium cation and an anion portion.

[0048] The anion portion is a halide, such as fluoride, chloride, bromide or iodide; salicylate; oxalate; bicarbonate; bitartrate; citrate; carbonate; dihydrogen citrate; nitrate; nitrite; phosphate; sulfate; sulfonate.

[0049] The anionic moiety is preferably selected from halides, such as chloride.

[0050] Preferably, the cation of the quaternary ammonium compound is selected from choline, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium and imidazolinium; The quaternary ammonium compound is choline chloride, tetramethylammonium chloride, tetraethylammonium chloride and tetrapropylammonium chloride. Preferably, the quaternary ammonium compound is choline chloride and tetramethylammonium chloride.

[0051] The quaternary ammonium compound is usually a choline chloride solution or a tetramethylammonium chloride solution. The choline chloride solution is usually a 75wt.% aqueous solution. The tetramethylammonium chloride solution is usually a 50wt.% aqueous solution.

[0052] Depending on the type of powder polymer, a water-based inhibitor is added to the chemical mixing liquid.

[0053] The weight fraction of the water-based inhibitor is 1-40%. Preferably, the weight fraction of the water-based inhibitor is 1-10%.

[0054] The aqueous inhibitor is water-soluble salts, cationic polymers and cationic surfactants and organic solvents or a combination thereof.

[0055] The water-soluble salts include water-soluble metal salts and ammonium salts, such as barium chloride, sodium chloride, sodium acetate, potassium chloride, calcium nitrate, calcium acetate, calcium chloride, magnesium sulfate, magnesium nitrate, ammonium sulfate, and the like.

[0056] The cationic polymer and surfactant are cationic polyacrylamide, polydimethyldiallylammonium chloride, hexadecyltrimethylammonium bromide, etc. The organic solvent is methanol, ethanol, dimethylformamide, dimethylacetamide, acetone, etc.

[0057] Example 2 A method for online filling of powder polymer for oil and gas well fracturing and reconstruction, using an online filling system for powder polymer for oil and gas well fracturing and reconstruction, mixing powder polymer with chemical mixed liquid in a dispersion tank 2 through a negative pressure feed valve, and dispersing through a high-speed dispersion disk to form a uniformly dispersed thickener suspension, and then directly transferring the suspension to a sand mixing truck to mix with water and other additives to form a fracturing fluid. The weight ratio of the powder polymer to the chemical mixed liquid is 20:80. The following steps are included: 1) Preparation The preparation stage includes liquid material storage and powder polymer storage; specifically includes the following steps: Liquid material storage: Use the delivery pump 20 to deliver the chemical mixed liquid in the on-site liquid barrel tank 10 to the liquid tank 3. During the delivery process, pay close attention to the liquid level display device on the liquid tank 3. When the liquid level reaches the pre-set specified position, stop the delivery of the chemical mixed liquid; after the delivery is completed, according to the process requirements, if other additives need to be added, start the stirrer 13, add additives according to the specified addition order and dosage, and continue stirring for a period of time to fully mix the additives with the chemical mixed liquid.

[0058] Powder polymer storage: Use a crane to stably lift a suitable number of powder polymer bags to the bag breaking device 11 on the upper part of the powder tank 4 for automatic bag breaking; the bag breaking device is started to accurately cut the powder polymer bag, so that the powder polymer naturally falls into the powder tank 4; during the powder storage process, the arch breaking device 12 remains in the open state, and the arch breaking device 12 continuously acts on the powder through mechanical vibration, air flow disturbance and other means to prevent the powder from agglomerating or bridging due to moisture, static electricity and other factors, ensuring that the powder is always in a loose state and can flow out smoothly at any time to participate in subsequent mixing.

[0059] 2) Mixing stage The mixing stage includes starting the cycle and forming negative pressure, premixing and conveying of powder polymer, continuous mixing and material replenishment, initial dispersion and storage of thickener suspension, completion of operation preparation, and pumping and use of thickener suspension, specifically including: Start the circulation and form negative pressure: Pump an appropriate amount of liquid from the liquid tank 3 into the dispersion tank 2 to start the circulation system of the dispersion tank; after the circulation system is running, a negative pressure environment will be generated at the negative pressure feed valve due to the high-speed flow of the chemical mixing liquid, creating conditions for the subsequent absorption of the powder polymer.

[0060] Powder polymer premixing and conveying: Turn on the screw conveying device 9 to slowly and evenly convey the powder polymer in the powder tank 4 to the dispersion tank 2; during the conveying process, the weight of the polymer being conveyed is monitored in real time by an electronic scale or other measuring equipment, and when the weight of the polymer required for premixing is reached, stop the screw conveying device 9.

[0061] Continuous mixing and material replenishment: According to the designed displacement, liquid or self-circulating liquid is continuously pumped from liquid tank 3 to dispersion tank 2, so that the chemical mixing liquid and powder polymer are fully mixed in the dispersion tank to achieve continuous mixing. The liquid can be pumped to transfer tank 1; during the mixing process, due to the continuous consumption of materials, it is necessary to pay close attention to the material level in liquid tank 3 and powder tank 4; when the liquid level in liquid tank 3 is close to the lower limit or the powder remaining in powder tank 4 is insufficient, replenish it in time. When replenishing liquid, repeat the operation of liquid material storage in the preparation stage; when replenishing powder, use the crane again to lift the powder polymer bag to the bag breaking device 11 of powder tank 4 for bag breaking and material addition.

[0062] Initial dispersion and storage of thickener suspension: After the continuous mixing starts, the thickener suspension in the dispersion tank is continuously pumped to the transfer tank 1 through the pipeline. In the transfer tank 1, the thickener suspension continues to be dispersed to further improve its uniformity and stability.

[0063] Operation preparation is completed: When the liquid level in the transfer tank 1 reaches the specified position, it indicates that the thickener suspension required for the on-site operation has been prepared in sufficient quantity. At this time, the status of all equipment and materials meets the operation requirements, and the on-site operation can begin.

[0064] Pumping and use of thickener suspension: turn on the variable frequency rotor pump 19, accurately control the flow rate according to the designed displacement, and pump the thickener suspension in the transfer tank 1 into the sand blending truck; during the pumping process, continuously monitor the operating parameters of the variable frequency rotor pump to ensure its stable operation, ensure that the flow rate and pressure of the transported thickener suspension meet the use requirements of the sand blending truck, and provide a stable material supply for subsequent construction operations.

[0065] This equipment integrates all the above operations into the PLC control system, and realizes automatic continuous production through pre-written programs. The PLC control system can monitor the operating status of each device, material level, flow, pressure and other parameters in real time. Once an abnormal situation occurs, it can issue an alarm in time and take corresponding measures, which greatly improves production efficiency and the safety and stability of the production process.

[0066] The present invention mixes the powder polymer with the chemical mixing liquid through a negative pressure feed valve to form a uniformly dispersed thickener suspension, and then directly transfers the suspension to a sand mixing truck to mix with water and other additives to form a fracturing fluid. The present invention mixes the chemical mixing liquid with the powder polymer to form a thickener suspension system with high chemical and physical stability.

[0067] The following are examples and comparative examples of the present invention prepared in the laboratory by simulating the procedure of Example 2: Example 3 53 parts by weight of 75% choline chloride solution, 5 parts by weight of dimethylformamide and 2 parts by weight of calcium acetate were added to a Wu Yin stirrer and mixed evenly, and then 40 parts by weight of anionic polyacrylamide was added and mixed evenly to obtain a water-based thickener suspension with a polyacrylamide content of 40 wt.%. The weight ratio of the powder polymer to the chemical mixed liquid was 40:60.

[0068] Example 4 30 parts by weight of 75% choline chloride solution, 7 parts by weight of anhydrous ethanol and 3 parts by weight of magnesium sulfate were added to a Wu Yin stirrer and mixed evenly, and then 60 parts by weight of anionic polyacrylamide was added and mixed evenly to obtain a water-based thickener suspension with a polyacrylamide content of 60 wt.%. The weight ratio of the powder polymer to the chemical mixed liquid was 60:40.

[0069] Comparative Example 1 Add 57 parts by weight of the oil phase (No. 5 white oil) into Wu Yin's mixer, start stirring, add 2 parts by weight of the suspending agent (organic clay) and 1 part by weight of the emulsifier (Span 80) in sequence and mix evenly, then add 40 parts by weight of anionic polyacrylamide and mix evenly to obtain an oil-based thickener suspension with a polyacrylamide content of 40wt.%.

[0070] Comparative Example 2 Add 98 parts by weight of tap water into Wu Yin's mixer, start stirring and slowly add 2 parts by weight of anionic polyacrylamide, and mix well to obtain a thickener concentrate with a polyacrylamide content of 2 wt.%.

[0071] The following are experimental examples of the present invention.

[0072] 1. Experimental methods (1) Bulk viscosity of thickener suspension Test method: Preheat the thickener suspension prepared in the example to 25°C, and then measure the apparent viscosity of the sample according to the method in SY / T 7627.

[0073] (2) Thickener suspension stability Test method: The thickener suspension prepared in the example was placed in a 100 mL stoppered measuring cylinder, and whether there was free liquid precipitation was observed at 5 / 20 / 60 minutes respectively.

[0074] (3) Hydration curve Test method: Weigh a certain amount of deionized water and add it to the Wu Yin stirrer, turn on the speed of 1000RPM, and then quickly (within 1s) add a certain amount of the example or comparative example sample to make the content of anionic polyacrylamide in this solution 0.12wt.%. After adding the sample, stir for 10 seconds and then stop stirring. In the next 10 seconds, transfer the liquid in the stirring cup to the slurry cup of the rotational viscometer, and install the slurry cup. The rotational viscometer speed is set to 300rpm. Start timing after adding the sample, read the reading of the rotational viscometer from the 20th second, and then read it every 5s until the reading stabilizes. Draw the hydration curve with time as the horizontal axis and the rotational viscometer reading as the vertical axis.

[0075] (4) Temperature and shear resistance of cross-linked fracturing fluid Test method: 98.9 parts by weight of tap water was added to the Wu Yin mixer, and 0.8 parts by weight of the sample of Example 3 or Comparative Example 1 was added after stirring for 5 minutes. After mixing for 2 minutes, 0.3 parts by weight of the organic zirconium crosslinking agent was added. The crosslinked fracturing fluid was obtained by stopping stirring. The fracturing fluid was measured at a temperature of 145°C and a shear rate of 100s according to the method in SY / T 7627. -1 , viscosity value after shearing for 60 minutes.

[0076] (5) Drag reduction rate Test method: The drag reduction rate of the solution with a concentration of 0.1 wt.% of Example 3 and Comparative Example 1 was tested according to NB / T 14003.1.

[0077] (6) Clay stability Test method: Take 99.9 parts by weight of deionized water and add it to Wu Yin's agitator, add 0.1 parts by weight of the sample of the embodiment or 0.1 parts by weight of a 50% tetramethylammonium chloride solution, and mix well to obtain the liquid to be tested. Take 4 mL of the above liquid to be tested and add it to a 10 mL centrifuge tube, then add 0.5 g of bentonite powder to the centrifuge tube, and finally continue to add the liquid to be tested to the 10 mL scale. Cover the centrifuge tube lid and shake it vigorously 50 times continuously (one round trip counts). Let the centrifuge tube stand at room temperature for 2 hours. Then centrifuge it at 1500RPM for 15 minutes with an automatic balancing centrifuge. Read the volume of bentonite at the bottom after taking out the centrifuge tube.

[0078] 2. Experimental data Table 1 Bulk viscosity data of the examples

[0079] The bulk viscosity of the water-based thickener suspension prepared in Example 3 and Example 4 is moderate, which is conducive to mixing and pumping by pumping equipment.

[0080] Table 2 Drag reduction rate data of Example 3 and Comparative Example 1

[0081] The following is a specific combination Figure 2 , Figure 3 , Figure 4 , Figure 5 Specific instructions: Combination Figure 2 The water-based thickener suspension prepared in Example 3 had no sedimentation and no free liquid produced within 60 minutes, and had good stability.

[0082] Combination Figure 3 , as well as this Example 3, Comparative Example 1, and Comparative Example 2, it can be seen that the water-based thickener suspension prepared in Example 3 does not need to undergo a demulsification process, has a fast hydration rate, quickly disperses and hydrates after mixing with water, and has a short viscosity time. And there is no oil phase, organic clay, and surfactant contained in Comparative Example 1. Therefore, the sample in Example 3 has a high drag reduction rate and a short time to reach the maximum drag reduction rate.

[0083] The oil-based thickener suspension prepared in Comparative Example 1 is a suspension form of an oil external phase, and needs to go through the processes of dispersion, demulsification, and hydration after being mixed with water, so it takes a long time to build viscosity and has a slow hydration rate.

[0084] The 2 wt.% thickener concentrate prepared in Comparative Example 2 has a very high viscosity. It is difficult to disperse and hydrate evenly after mixing with water, and it is very easy to form "fish eyes". Therefore, its viscosity is low, and the unhydrated polymer will cause damage to the formation.

[0085] Combination Figure 4 Compared with Comparative Example 1, the water-based thickener suspension prepared in Example 3 does not contain the oil phase, suspending agent and surfactant that affect the viscosity, so the cross-linked fracturing fluid prepared by the sample of Example 3 has a higher viscosity.

[0086] Combination Figure 5 In Example 4, not only choline chloride, a clay stabilizer commonly used in fracturing construction, but also polyacrylamide and water-based inhibitors can effectively inhibit clay expansion, so it has good clay stability. At the same dosage, the clay stability is even slightly better than the commonly used clay stabilizer tetramethylammonium chloride.

[0087] The invention ensures that appropriate physical and chemical reactions can occur between the components during the mixing and adding process, thereby improving the technical, economic and environmental performance of the final product.

[0088] The invention realizes efficient mixing, dispersion and transfer addition of the powder polymer and the chemical liquid system of the invention through a negative pressure feed valve mixer and a high-speed dispersing stirrer.

[0089] The present invention realizes accurate and efficient online mixing and addition of powder polymers during fracturing operations, improves the convenience and efficiency of operations, accurately controls additive mixing and final product performance, and provides a reliable way for on-site operations of oil and gas reservoir fracturing transformation with superior fracturing fluid performance, low operating costs, low construction risks, and greater environmental protection.

[0090] In the description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the purpose of describing the present invention rather than requiring the present invention to be constructed or operated in a specific position, and therefore should not be construed as limiting the present invention. The terms "connected" and "connected" in the present invention should be understood in a broad sense, for example, it can be a connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0091] The above is a preferred embodiment of the present invention, and the description of the specific embodiment is only used to better understand the concept of the present invention. For those skilled in the art, several improvements or equivalent replacements can be made according to the principles of the present invention, and these improvements or equivalent replacements are also considered to fall within the protection scope of the present invention.

Claims

1. An online powder polymer filling system for oil and gas well fracturing reformation, comprising a mixing device, the mixing device comprising a vehicle-mounted mixing device, a transfer tank, and a PLC control system, the PLC control system is connected to the vehicle-mounted mixing device and the transfer tank, the vehicle-mounted mixing device mixes the powder polymer with a chemical mixing liquid into a thickener suspension that can be added online, characterized in that: The vehicle-mounted mixing equipment includes a dispersion tank, a liquid tank, and a powder tank. The transfer tank is connected to the dispersion tank through a main pipeline, a branch pipeline 1, and a centrifugal pump 1. The transfer tank is connected to the upper part of the dispersion tank through a main pipeline and a branch pipeline 2. A negative pressure feed valve is provided on the branch pipeline 2. The upper part of the liquid tank is connected to the liquid barrel tank through a delivery pump and a pipeline. The transfer tank is connected to the lower part of the liquid tank through a main pipeline, a branch pipeline 3, and a centrifugal pump 2. A flow control valve is provided on the branch pipeline 3. The variable frequency rotor pump is connected to the transfer tank through a pipeline; the variable frequency rotor pump is connected to the sand mixing vehicle through a pipeline 4, and a flow meter is provided on the pipeline 4; The powder tank is used to store powder polymer; The liquid tank is used to store the chemical mixed liquid pumped from the liquid barrel tank; The chemical mixing liquid and the powder polymer are mixed in the dispersion tank to form a thickener suspension; The transfer tank serves as an intermediate storage device, providing the thickener suspension transfer and temporary storage functions.

2. The powder polymer online injection system for oil and gas well fracturing reconstruction according to claim 1 is characterized in that: The dispersion tank is provided with a stirrer 2, and a negative pressure feed valve is provided on the dispersion tank. During the mixing process, the chemical mixing liquid and the powder polymer are fully mixed in the dispersion tank to form a uniform thickener suspension; A centrifugal pump is connected to the lower part of the dispersion tank.

3. The powder polymer online injection system for oil and gas well fracturing reconstruction according to claim 1 is characterized in that: A stirrer is installed in the liquid tank, and the chemical mixed liquid is added into the liquid tank and stirred by the stirrer to ensure that the chemical mixed liquid has uniform composition; The liquid tank is provided with a liquid level display device.

4. The powder polymer online injection system for oil and gas well fracturing reconstruction according to claim 1 is characterized in that: The powder tank is provided with an automatic bag breaking device, and the powder tank is provided with an arch breaking device. The automatic bag breaking device completes the bag breaking operation, so that the powder polymer falls into the tank smoothly; the arch breaking device prevents the powder from agglomerating and bridging in the tank, and ensures that the powder flows out stably and smoothly; a screw conveying device is provided at the lower part of the powder tank, and the screw conveying device is connected to the compressed air pipeline. The screw conveying device conveys the powder polymer to the dispersion tank through the negative pressure feed valve through compressed air. The negative pressure feed valve uses the pressure difference principle of the Venturi effect to realize the negative pressure feeding function, and the screw conveying device adopts a screw quantitative conveyor.

5. The powder polymer online injection system for oil and gas well fracturing reconstruction according to claim 1 is characterized in that: The weight ratio of the powder polymer to the chemical mixed liquid is 20:80 to 60:

40.

6. The powder polymer online injection system for oil and gas well fracturing reconstruction according to claim 5 is characterized in that: The powder polymer is a synthetic polymer, or a natural polymer and its derivatives.

7. The powder polymer online injection system for oil and gas well fracturing reconstruction according to claim 1 is characterized in that: The chemical mixed fluid is mainly composed of additives associated with fracturing fluid, and the additives include one or more of clay stabilizers, fungicides, and drainage aids; The clay stabilizer is a quaternary ammonium compound.

8. The powder polymer online injection system for oil and gas well fracturing reconstruction according to claim 6 is characterized in that: According to different types of powder polymers, water-based inhibitors are added to the chemical mixture; The aqueous inhibitor is water-soluble salts, cationic polymers and cationic surfactants and organic solvents or a combination thereof.

9. A method for online injection of powder polymer for oil and gas well fracturing transformation, characterized in that: The powder polymer online filling system for oil and gas well fracturing reconstruction according to claim 1 is used to mix the powder polymer with the chemical mixed liquid in a dispersion tank through a negative pressure feed valve, and dispersed by a stirrer in the dispersion tank to form a uniformly dispersed thickener suspension, and then the suspension is directly transferred to a sand mixing truck through a variable frequency rotor pump of a transfer tank to be mixed with water and other additives to form a fracturing fluid, comprising the following steps: 1) Preparation The preparation stage includes liquid material storage and powder polymer storage; 2) Mixing stage The mixing stage includes starting the circulation and forming negative pressure, premixing and conveying of powder polymer, continuous mixing and material replenishment, preliminary dispersion and storage of thickener suspension, completion of operation preparation, and pumping and use of thickener suspension.

10. The method for online injection of powder polymer for oil and gas well fracturing reconstruction according to claim 9, characterized in that: The liquid material storage and powder polymer storage specifically include the following steps: Liquid material storage: Use a delivery pump to deliver the chemical mixed liquid in the on-site liquid barrel tank to the liquid tank; during the delivery process, pay attention to the liquid level display device on the liquid tank, and stop delivering the chemical mixed liquid when the liquid level reaches the pre-set specified position; after the delivery is completed, if other additives need to be added according to the process requirements, start the agitator 1, add the additives according to the specified addition order and dosage, and continue to stir for a period of time to fully mix the additives and liquid materials; Powder polymer storage: hoist a suitable number of powder polymer bags to the bag breaking device on the top of the powder tank for automatic bag breaking; the bag breaking device starts to accurately break the powder polymer bag, allowing the powder polymer to fall naturally into the powder tank; during the powder storage process, the arch breaking device of the powder tank remains in the open state, and the arch breaking device continuously acts on the powder to prevent the powder from agglomerating or bridging due to moisture and static electricity, ensuring that the powder is always in a loose state and can flow out smoothly for subsequent mixing; The starting cycle and forming of negative pressure, powder polymer premixing and conveying, continuous mixing and material replenishment, preliminary dispersion and storage of thickener suspension, completion of operation preparation, and pumping and use of thickener suspension specifically include the following steps: Start the circulation and form negative pressure, pump an appropriate amount of chemical mixed liquid from the liquid tank into the dispersion tank, and start the circulation system of the dispersion tank; after the circulation system is running, the negative pressure feed valve will generate a negative pressure environment due to the high-speed flow of the chemical mixed liquid, creating conditions for the subsequent inhalation of powder polymers; Powder polymer premixing conveying: start the screw conveying device to convey the powder polymer in the powder tank to the dispersion tank; monitor the weight of the conveyed powder polymer in real time during the conveying process, and stop the screw conveying device when the weight of the powder polymer required for premixing is reached; Continuous mixing and material replenishment: According to the designed displacement, continuously pump or self-circulate the chemical mixing liquid from the liquid tank to the dispersion tank, so that the chemical mixing liquid and the powder polymer are fully mixed in the dispersion tank to achieve continuous mixing; during the mixing process, pay attention to the material levels in the liquid tank and the powder tank; when the liquid level in the liquid tank is close to the lower limit or the powder remaining in the powder tank is insufficient, replenish it; when replenishing the liquid, repeat the operation of storing the chemical mixing liquid material in the preparation stage; when replenishing the powder, lift the powder polymer bag again to the bag breaking device of the powder tank for bag breaking and material addition; Initial dispersion and storage of thickener suspension: After continuous mixing begins, the thickener suspension in the dispersion tank is continuously pumped to the transfer tank through a pipeline, where the thickener suspension continues to be dispersed to improve its uniformity and stability; Operation preparation is completed: when the liquid level in the transfer tank reaches the specified position, it indicates that the thickener suspension required for the on-site operation has been prepared in sufficient quantity. At this time, the status of all equipment and materials meet the operation requirements, and the on-site operation can begin; Pumping and use of thickener suspension: turn on the variable frequency rotor pump, accurately control the flow rate according to the designed displacement, and pump the thickener suspension in the transfer tank into the sand mixing truck; during the pumping process, continuously monitor the operating parameters of the variable frequency rotor pump to ensure stable operation, ensure that the flow rate and pressure of the transported thickener suspension meet the use requirements of the sand mixing truck, and provide a stable material supply for subsequent construction operations.

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