Preparation method of high-temperature-resistant salt-resistant instant drag reducer polymerized by initiation of cellulose, gallium-based liquid metal and fluorine-containing ionic liquid

Abstract

The invention discloses a preparation method of a high-temperature-resistant salt-resistant instant drag reducer polymerized by initiation of cellulose, gallium-based liquid metal and fluorine-containing ionic liquid, and belongs to the technical field of oil drag reducer preparation. According to the drag reducer (PAAAF), gallium-based liquid metal (GLM (at) BCNF) coated with bacterial cellulose nanofiber (BCNF) serves as a low-temperature rapid initiator, acrylamide (AM), acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) serve as comonomers, and meanwhile fluorine-containing imidazole ionic liquid (FIL) is introduced to enhance the high temperature resistance of the material. By introducing the BCNF, liquid metal gallium can be better dispersed, meanwhile, a continuous heat conduction network is provided, and the initiation efficiency is accelerated. The AMPS endows the drag reducer with excellent salt resistance, and the fluorine-containing imidazole ionic liquid significantly improves the thermal stability of the drag reducer. The drag reducer prepared by the invention has the characteristics of rapid initiation, high temperature resistance, high salt resistance and efficient drag reduction, and has wide application prospects in high-temperature and high-salt systems such as oil and gas exploitation and geothermal exploitation.

Description

Technical Field

[0001] This invention relates to the field of oil drag-reducing agent preparation technology, specifically to a high-performance salt- and temperature-resistant drag-reducing agent dry powder formed by copolymerizing acrylamide (AM), acrylic acid (AA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) with gallium-based liquid metal modified with cellulose (including bacterial cellulose and cellulose nanofibers) as a low-temperature free radical initiator, and fluorinated imidazole zwitterionic liquid (FIL) to impart excellent high-temperature stability and rapid dissolution performance to the drag-reducing agent. Background Technology

[0002] In fields such as oil extraction, hydraulic transportation, and heating systems, the flow resistance of fluids in pipelines is one of the main sources of energy consumption. Polymer drag-reducing agents effectively reduce fluid turbulence resistance by altering the fluid boundary layer structure, thereby significantly improving transportation efficiency and saving energy.

[0003] However, existing polymer drag reducers generally have some limitations. First, many drag reducers have poor stability at high temperatures and are prone to degradation, leading to a rapid decline in drag reduction effect and making it difficult to meet the needs of high-temperature oil and gas fields or geothermal fluid transportation. Second, in formation water or industrial wastewater with high salinity, the polymer chains of traditional drag reducers are prone to coiling or aggregation, resulting in decreased water solubility, significantly reduced drag reduction performance, and insufficient salt resistance. Furthermore, most polymer drag reducers are typically present in the field as liquid concentrates or solid particles, which dissolve slowly and require prolonged stirring to dissolve completely, affecting on-site operational efficiency. In addition, traditional polymer synthesis often requires external heating, ultraviolet light irradiation, or the use of initiators such as persulfates or azo dyes, which may have problems such as toxicity, inconvenient storage, or demanding initiation conditions.

[0004] Liquid gallium (Ga) and its alloys, due to their unique physicochemical properties such as high thermal conductivity, low melting point, and easy oxidation to form an active oxide layer, have been found in recent years to be effective initiators for the free radical polymerization of vinyl monomers. Their polymerization process can typically be carried out at room temperature or even lower, without the need for additional light or heating, offering advantages such as being green and efficient. However, due to its large surface and cohesive energy, liquid metal is difficult to stably disperse into nanoscale droplets in an aqueous phase, easily agglomerating, thus affecting its initiation efficiency and uniform distribution in the polymer matrix. Furthermore, after liquid metal-initiated polymerization, further post-processing is required to prepare a dry powder product.

[0005] Therefore, developing a polymer drag-reducing agent dry powder that can overcome the above-mentioned defects, integrate high temperature resistance, salt resistance, and rapid solubility, and can be prepared through an efficient and green initiation method has important theoretical significance and practical application value. Summary of the Invention

[0006] Given that existing high-temperature and salt-resistant drag-reducing agents suffer from problems such as complex preparation, poor solubility, demanding polymerization initiation conditions (e.g., requiring ultraviolet light or high temperatures), and performance degradation in high-temperature and high-salt environments, this invention aims to provide a dry powder drag-reducing agent and its preparation method that is easy to prepare, can rapidly initiate polymerization at room temperature, has excellent high-temperature and salt-resistant properties, and rapid solubility.

[0007] To solve the above problems, the technical solution of the present invention is as follows: This invention provides a method for preparing a high-temperature resistant, salt-resistant, and fast-dissolving drag-reducing agent initiated by polymerization of cellulose, gallium-based liquid metal, and fluorinated ionic liquid. The drag-reducing agent uses cellulose-modified gallium-based liquid metal (GLM@BCNF) as a low-temperature initiator, acrylamide (AM), acrylic acid (AA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as monomers, and a fluorinated imidazole ionic liquid (FIL) as a high-temperature resistant and fast-dissolving aid or comonomer. The monomers are rapidly polymerized at room temperature using GLM@BCNF, and the resulting copolymer is obtained by washing with ethanol, drying, and pulverizing, resulting in a fast-dissolving dry powder drag-reducing agent.

[0008] The preparation method of the high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent of this invention is characterized by comprising the following steps: S1. Gallium-based liquid metal (GLM) and deionized water are mixed and ultrasonicated to obtain a GLM suspension; S2. The cellulose and GLM suspension are mixed and sonicated to obtain a cellulose-modified gallium-based liquid metal suspension (GLM@BCNF). S3. Mix acrylamide (AM), acrylic acid (AA), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), fluorinated imidazole ionic liquid (FIL) with deionized water and stir to obtain a homogeneous monomer mixture solution. S4. Mix the monomer mixture obtained in step S3 with the GLM@BCNF suspension obtained in step S2 and stir to rapidly initiate the polymerization reaction at room temperature or low temperature to obtain a polymer gel. S5. Wash the polymer gel obtained in step S4 with ethanol to remove unreacted monomers and byproducts and to precipitate the polymer. S6. The washed polymer is dried under normal pressure to remove the solvent; the dried polymer is then pulverized to obtain a high-temperature resistant, salt-resistant, fast-dissolving dry powder drag-reducing agent.

[0009] As a further improvement of the present invention, the mass ratio of gallium-based liquid metal to deionized water in step S1 is 1:20 to 1:100; the ultrasonic power is 400 W to 800 W; the pulse mode is 0.1s on / 0.3s off; the temperature is 0℃ to 10℃; and the time is 20 min to 60 min.

[0010] As a further improvement of the present invention, in step S2, the cellulose is bacterial cellulose (BCNF) or carboxylated cellulose nanofibers (CCNF) with a concentration of 0.5 wt% to 10 wt% dispersion; the mass ratio of gallium-based liquid metal to cellulose (based on solid content) is 1:0.5 to 1:5; the ultrasonic power is 400 W to 800 W, the pulse mode is 0.1 s on / 0.3 s off, the temperature is 0℃ to 10℃, and the time is 20 min to 60 min.

[0011] As a further improvement of the present invention, in step S3, the mass fraction of AM is 10 wt% to 30 wt%; the ratio of the total mass of AM, AA and AMPS to the total mass of deionized water and fluorinated imidazole ionic liquid is 1:2 to 1:5; the mass ratio of AM, AA and AMPS is (20 to 80):(5 to 30):(10 to 50); and the fluorinated imidazole ionic liquid accounts for 1 wt% to 10 wt% of the total mass of the monomers.

[0012] As a further improvement of the present invention, in step S4, the ratio of the mass of GLM to the total mass of monomers in the GLM@BCNF suspension is 1:500 to 1:100; the stirring and mixing temperature is 5℃ to 30℃, and the time is 1 min to 10 min.

[0013] As a further improvement of the present invention, in step S5, an ethanol-water solution with a volume ratio of 1:1 to 1:5 is used for washing, and the number of washing cycles is 2 to 5.

[0014] As a further improvement of the present invention, in step S6, the drying temperature is 40℃~80℃, the drying time is 12h~48h, the pulverizing speed is 2000r / min~5000r / min, the pulverizing time is 10min~30min, and the particle size of the drag-reducing agent after pulverization is 80 mesh~200 mesh.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses cellulose-modified gallium-based liquid metal (GLM@BCNF) as a low-temperature initiator. The abundant hydroxyl and carboxyl groups on the surface of cellulose (such as bacterial cellulose or carboxylated cellulose nanofibers) can form hydrogen bonds and coordination bonds with gallium-based liquid metal (especially its surface oxide layer), significantly improving the dispersibility and colloidal stability of gallium-based liquid metal and effectively solving the problem of difficult dispersion of liquid metal. At the same time, the GLM@BCNF initiator can rapidly initiate the free radical polymerization of vinyl monomers such as acrylamide, acrylic acid and AMPS at room temperature or even lower temperatures, shortening the polymerization time to a few minutes, reducing energy consumption, and overcoming the requirement of traditional initiators for ultraviolet light or high temperature.

[0016] (2) Introducing 2-acrylamido-2-methylpropanesulfonic acid (AMPS) monomer, utilizing the strong ionization of its sulfonic acid group, endows the polymer with excellent salt resistance properties, and can still maintain good drag reduction effect and stability in high-mineralization fluids (such as seawater and formation water).

[0017] (3) Fluorinated imidazole ionic liquids (FILs) are used as comonomers or additives. Their unique fluorinated structure and ionic properties endow drag reducers with excellent high-temperature resistance and rapid solubility. FILs can improve the rigidity and thermal stability of polymer chains, making them less prone to degradation in high-temperature environments. At the same time, their hydrophilic ionic properties help polymer powders to disperse and dissolve rapidly in water, avoiding the problem of clumping and insolubility of traditional dry powder drag reducers, and greatly improving on-site preparation efficiency.

[0018] (4) The drag-reducing agent prepared by this invention is in dry powder form, which is easy to store, transport and prepare on-site, thus improving its convenience. It has excellent comprehensive performance and can play a highly efficient drag-reducing role in high-temperature and high-salinity oil reservoir environments, and has broad application prospects. Attached Figure Description

[0019] Figure 1 A flowchart for the preparation of a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent, which is polymerized from cellulose, gallium-based liquid metal and fluorine-containing ionic liquid, is provided for this invention. Figure 2 The images (ab) show a comparison of the dispersion stability of the cellulose-modified gallium-based liquid metal suspension (GLM@BCNF) prepared in Example 1 of this invention with that of the comparative example (without BCNF). Figure 3 The fluorescence spectra of the drag-reducing agent prepared in Example 1 of this invention at different polymer concentrations and the curves showing the change of intensity ratio with concentration are shown. Figure 4 The molecular weight distribution curve of the high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent prepared in Example 1 of this invention is shown. Figure 5 The graphs show the changes in shear stress versus shear rate at different concentrations for Comparative Example 5(a) and Example 1(b) of the present invention; Figure 6 The drag reduction rate versus viscosity curves of the drag-reducing agent prepared in Example 1 of this invention under different NaCl concentrations are shown. Figure 7 The image shows the actual dissolution process of the drag-reducing agent powder prepared in Example 1 of the present invention in water (ab). Figure 8 This is a schematic diagram of the polymer structure of the high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent described in this invention, as well as a diagram of its high-temperature resistance, salt resistance, and fast-dissolving mechanism. Detailed Implementation

[0020] This invention provides a method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid. Figure 1 The preparation process of the present invention has been disclosed. In order to make the purpose, technical solution and advantages of the present invention clearer and more explicit, the present invention will be further described in conjunction with specific embodiments and accompanying drawings.

[0021] Example 1: In this example, bacterial cellulose (BC) was used to modify gallium-based liquid metal and a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent was prepared.

[0022] Step 1: Mix 1 g of gallium-based liquid metal (Ga, purity 99.999%) with 50 g of deionized water, and sonicate at 5 ℃ using a 600 W ultrasonic instrument in pulse mode (0.1s on / 0.3s off) for 30 min to obtain a uniformly dispersed GLM suspension.

[0023] Step 2: Add 10 g of 2 wt% bacterial cellulose dispersion (commercially available, average diameter approximately 50 nm, length 1–3 μm) to the GLM suspension obtained in step S1, and continue sonicating at 5 ℃ using a 600 W sonicator in pulse mode (0.1 s on / 0.3 s off) for 15 min to obtain a stable GLM@BC suspension. Figure 2 As shown in a.

[0024] Step 3: Add 10 g acrylamide (AM, 20 wt%), 2.5 g acrylic acid (AA, 5 wt%), 5 g 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 10 wt%) and 0.5 g fluorinated imidazole ionic liquid (e.g., 1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4]) to 30 g deionized water and stir at room temperature (25°C) for 30 min to obtain a homogeneous and transparent monomer mixture solution.

[0025] Step 4: Mix the monomer mixture obtained in step S3 with the GLM@BC suspension obtained in step S2 (where the mass of GLM is 1 g), and stir rapidly at room temperature (25°C) for 1 min. The solution was observed to become turbid and gradually gel, forming a stable polymer gel within 5 min.

[0026] Step 5: Cut the polymer gel obtained in step S4 into small pieces and soak it in an ethanol-water solution (ethanol:water volume ratio of 3:1). Stir for 30 minutes and then pour out the washing solution. Repeat the washing process 3 times until there is no obvious monomer residue in the washing solution. The washed polymer becomes a gray, opaque solid.

[0027] Step 6: Place the washed polymer solid in a vacuum oven at 60°C and dry for 48 hours to obtain a brittle polymer block. The dried polymer block is then crushed by a high-speed pulverizer and passed through a 100-mesh sieve to obtain a gray, fast-dissolving dry powder drag-reducing agent.

[0028] Comparative Example 1: This comparative example aims to investigate the effect of bacterial cellulose (BC) on the initiation performance of gallium-based liquid metal (GLM).

[0029] Step 1: Mix 1 g of gallium-based liquid metal (Ga, purity 99.999%) with 50 g of deionized water, and sonicate at 5 ℃ using a 600 W ultrasonic instrument in pulse mode (0.1s on / 0.3s off) for 30 min to obtain a uniformly dispersed GLM suspension.

[0030] Step 2: The bacterial cellulose addition and sonication steps in Example 1 are omitted.

[0031] Step 3: Add 10 g acrylamide (AM, 20 wt%), 2.5 g acrylic acid (AA, 5 wt%), 5 g 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 10 wt%) and 0.5 g fluorinated imidazole ionic liquid (e.g., 1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4]) to 30 g deionized water and stir at room temperature (25°C) for 30 min to obtain a homogeneous and transparent monomer mixture solution.

[0032] Step 4: Mix the monomer mixture obtained in step S3 with the GLM suspension obtained in step S1 (where the mass of GLM is 1 g), and stir rapidly at room temperature (25°C) for 1 min. The solution was observed to become slightly turbid, but a stable polymer gel was not formed within 5 min. The polymerization rate was significantly reduced, and the final gel strength was weak.

[0033] Steps 5-6: Since a stable gel has not been formed, the subsequent washing, drying and pulverizing steps cannot be carried out effectively.

[0034] Comparative Example 2: This comparative example aims to examine the necessity of liquid gallium (GLM) as an initiator.

[0035] Steps 1-2: The steps of adding gallium-based liquid metal (GLM) and bacterial cellulose (BC) and sonication in Example 1 are omitted.

[0036] Step 3: Add 10 g acrylamide (AM, 20 wt%), 2.5 g acrylic acid (AA, 5 wt%), 5 g 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 10 wt%) and 0.5 g fluorinated imidazole ionic liquid (e.g., 1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4]) to 30 g deionized water and stir at room temperature (25°C) for 30 min to obtain a homogeneous and transparent monomer mixture solution.

[0037] Step 4: The monomer mixture obtained in step S3 was stirred at room temperature (25°C) for 1 min. No color change or gelation was observed. No polymerization reaction occurred even after prolonged standing (several hours).

[0038] Steps 5-6: Since no polymerization reaction has occurred, the subsequent washing, drying and pulverizing steps cannot be carried out.

[0039] Comparative Example 3: This comparative example is intended to be compared with the room temperature rapid initiation system of the present invention.

[0040] Steps 1-2: The steps of adding gallium-based liquid metal (GLM) and bacterial cellulose (BC) and sonication in Example 1 are omitted.

[0041] Step 3: Add 10 g acrylamide (AM, 20 wt%), 2.5 g acrylic acid (AA, 5 wt%), 5 g 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 10 wt%), and 0.5 g fluorinated imidazole ionic liquid (e.g., 1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4]) to 30 g deionized water, then add 0.05 g potassium persulfate (KPS) and 0.05 mL tetramethylethylenediamine (TEMED). Stir at room temperature (25°C) for 30 min to obtain a homogeneous and transparent monomer mixture solution.

[0042] Step 4: The monomer mixture obtained in step S3 was rapidly stirred and mixed at room temperature (25°C) for 1 min. It was observed that the solution began to gel after about 10–15 min and formed a stable polymer gel within 30 min.

[0043] Steps 5-6: The polymer gel obtained in step S4 was cut into small pieces and soaked in an ethanol-water solution (ethanol:water volume ratio of 3:1). After stirring for 30 min, the washing solution was poured off. Washing was repeated 3 times until no obvious monomer residue remained in the washing solution. The washed polymer became a gray, opaque solid. The washed polymer solid was placed in a vacuum oven at 60°C and dried for 48 h to obtain a brittle polymer block. The dried polymer block was pulverized using a high-speed pulverizer and passed through a 100-mesh sieve to obtain a gray, fast-dissolving dry powder drag-reducing agent. Although it can still form polymers, the polymerization initiation rate is significantly slower than in Example 1, and the traditional initiator system may introduce other impurities.

[0044] Comparative Example 4: Without the addition of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), this comparative example aims to investigate the effect of AMPS on the salt resistance of drag-reducing agents.

[0045] Step 1: Mix 1 g of gallium-based liquid metal (Ga, purity 99.999%) with 50 g of deionized water, and sonicate at 5 ℃ using a 600 W ultrasonic instrument in pulse mode (0.1 seconds on / 0.3 seconds off) for 30 min to obtain a uniformly dispersed GLM suspension.

[0046] Step 2: Add 10 g of 2 wt% bacterial cellulose dispersion to the GLM suspension obtained in step S1, and continue to sonicate at 5 ℃ using a 600 W ultrasonic instrument in pulse mode (0.1 seconds on / 0.3 seconds off) for 15 min to obtain a stable GLM@BC suspension.

[0047] Step 3: Add 10 g acrylamide (AM, 20 wt%), 2.5 g acrylic acid (AA, 5 wt%) and 0.5 g fluorinated imidazole ionic liquid to 35 g deionized water (adjust the water volume to maintain monomer concentration), and stir at room temperature (25℃) for 30 min to obtain a homogeneous and transparent monomer mixture solution.

[0048] Step 4: Mix the monomer mixture obtained in step S3 with the GLM@BC suspension obtained in step S2, and stir rapidly at room temperature (25°C) for 1 min. The solution was observed to become turbid and gradually gel, forming a stable polymer gel within 5 min.

[0049] Steps 5-6: The polymer gel obtained in step S4 is cut into small pieces and soaked in an ethanol-water solution (ethanol:water volume ratio of 3:1). After stirring for 30 min, the washing solution is poured off. This washing process is repeated three times until no obvious monomer residue remains in the washing solution. The washed polymer becomes a gray, opaque solid. The washed polymer solid is dried in a vacuum oven at 60℃ for 48 h to obtain brittle polymer blocks. The dried polymer blocks are then pulverized using a high-speed pulverizer and passed through a 100-mesh sieve to obtain a gray, fast-dissolving dry powder drag-reducing agent. The obtained drag-reducing agent exhibits drag-reducing properties in pure water, but its drag-reducing properties significantly decrease or fail under high-salt conditions (such as simulated formation water).

[0050] Comparative Example 5: Except for step 3 in Example 1, no fluorinated imidazole ionic liquid (FIL) was added to this comparative example.

[0051] Step 1: Mix 1 g of gallium-based liquid metal (Ga, purity 99.999%) with 50 g of deionized water, and sonicate at 5 ℃ using a 600 W ultrasonic instrument in pulse mode (0.1 seconds on / 0.3 seconds off) for 30 min to obtain a uniformly dispersed GLM suspension.

[0052] Step 2: Add 10 g of 2 wt% bacterial cellulose dispersion to the GLM suspension obtained in step S1, and continue to sonicate at 5 ℃ using a 600 W ultrasonic instrument in pulse mode (0.1 seconds on / 0.3 seconds off) for 15 min to obtain a stable GLM@BC suspension.

[0053] Step 3: Add 10 g acrylamide (AM, 20 wt%), 2.5 g acrylic acid (AA, 5 wt%) and 5 g 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 10 wt%) to 30.5 g deionized water (adjust the water volume to maintain an approximate total monomer concentration), and stir at room temperature (25°C) for 30 min to obtain a homogeneous and transparent monomer mixture solution.

[0054] Step 4: Mix the monomer mixture obtained in step S3 with the GLM@BC suspension obtained in step S2 (where the mass of GLM is 1 g), and stir rapidly at room temperature (25°C) for 1 min. The solution was observed to become turbid and gradually gel, forming a stable polymer gel within 5 min.

[0055] Step 5: Cut the polymer gel obtained in step S4 into small pieces and soak it in an ethanol-water solution (ethanol:water volume ratio of 3:1). Stir for 30 minutes and then pour out the washing solution. Repeat the washing process 3 times until there is no obvious monomer residue in the washing solution. The washed polymer becomes a gray, opaque solid.

[0056] Step 6: The washed polymer solid was dried in a vacuum oven at 60℃ for 48 h to obtain a brittle polymer block. The dried polymer block was then pulverized using a high-speed pulverizer and passed through a 100-mesh sieve to obtain a gray, fast-dissolving dry powder drag-reducing agent. The prepared drag-reducing agent exhibits significantly reduced stability at high temperatures, and its dissolution rate may slow down.

[0057] In summary, the comparative analysis of Example 1 and Comparative Examples 1-5 fully verifies the innovation and superiority of the high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent and its preparation method proposed in this invention. Comparative Example 2 clearly demonstrates that liquid gallium is the core element for achieving rapid polymerization of monomers at room temperature. Furthermore, Comparative Example 1 confirms that the effective modification of gallium-based liquid metal by bacterial cellulose is crucial, significantly improving the initiation efficiency of GLM and ensuring the rapid progress of the polymerization reaction and the stability of the resulting gel. Compared with Comparative Example 3, which uses a traditional initiator, the GLM@BC initiation system of this invention exhibits a faster polymerization rate at room temperature, significantly shortening the reaction time. In addition, Comparative Example 4 clearly reveals the decisive role of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) in imparting excellent salt resistance to the polymer. Comparative Example 5 emphasizes the key contribution of fluorinated imidazole ionic liquids in significantly improving the high-temperature resistance of polymers and accelerating their solubility. This invention, through ingenious component synergistic design, successfully achieves rapid and efficient preparation of high-performance drag-reducing agents with excellent high-temperature resistance, salt resistance, and rapid dissolution characteristics at room temperature, effectively overcoming many limitations of existing technologies.

Claims

1. A method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid, characterized in that, Specifically, the following steps are included: S1. Gallium-based liquid metal (GLM) and deionized water are mixed and subjected to ultrasonic treatment to obtain a GLM suspension; S2. The cellulose and GLM suspension are mixed and sonicated to obtain a cellulose-modified gallium-based liquid metal suspension (GLM@BCNF). S3. Mix acrylamide (AM), acrylic acid (AA), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), fluorinated imidazole ionic liquid (FIL) with deionized water and stir until homogeneous to obtain a homogeneous monomer mixture solution. S4. The homogeneous monomer mixture obtained in step S3 is mixed and stirred with the cellulose-modified gallium-based liquid metal suspension obtained in step S2, and the polymerization reaction is rapidly initiated at room temperature to obtain a polymer gel. S5. The polymer gel obtained in step S4 is washed with ethanol to remove unreacted monomers and byproducts from the system and to promote the full release of polymer. S6. The washed polymer is dried under normal pressure to remove the solvent; the dried polymer is then pulverized to obtain a high-temperature resistant, salt-resistant, fast-dissolving dry powder drag-reducing agent.

2. The method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 1, characterized in that, The mass ratio of gallium-based liquid metal to deionized water in step S1 is 1:20 to 1:

100. The specific conditions for ultrasonic treatment in step S1 are: ultrasonic power of 400 W to 800 W, pulse mode of 0.1 s on / 0.3 s off, temperature of 0℃ to 10℃, and time of 20 min to 60 min.

3. The method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 1, characterized in that, The cellulose mentioned in step S2 is bacterial cellulose or carboxylated cellulose nanofibers (CCNF) with a concentration of 0.5 wt% to 10 wt% dispersion; the cellulose and GLM suspension mentioned in step S2 are mixed and ultrasonically subjected to the following conditions: the mass ratio of gallium-based liquid metal to cellulose (based on solid content) is 1:0.5 to 1:5; the ultrasonic power is 400 W to 800 W; the pulse mode is 0.1 s on / 0.3 s off; the temperature is 0℃ to 10℃; and the time is 20 min to 60 min.

4. The method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 1, characterized in that, The specific conditions for mixing acrylamide (AM), acrylic acid (AA), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), fluorinated imidazole ionic liquid (FIL) with deionized water in step S3 are as follows: the mass fraction of AM is 10 wt% to 30 wt%; the ratio of the total mass of AM, AA, and AMPS to the total mass of deionized water and FIL is 1:2 to 1:5; the mass ratio of AM, AA, and AMPS is (20 to 80):(5 to 30):(10 to 50); FIL is 1 wt% to 10 wt% of the total monomer mass; the above components are mixed and stirred evenly to obtain a monomer mixed solution.

5. The method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 1, characterized in that, The specific conditions for the blending and stirring described in step S4 are as follows: the mass ratio of GLM to the total mass of monomers in the GLM@BCNF suspension is 1:500 to 1:100, the stirring and mixing temperature is 5℃ to 30℃, and the time is 1 min to 10 min.

6. The method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 1, characterized in that, The ethanol washing described in step S5 is specifically performed using an ethanol-water solution with a volume ratio of 1:1 to 1:5, and the washing is repeated 2 to 5 times.

7. The method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 1, characterized in that, The drying process described in step S6 is specifically performed under the following conditions: a drying temperature of 40℃ to 80℃ and a drying time of 12 h to 48 h.

8. The method for preparing a high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 1, characterized in that, The specific conditions for the pulverization described in step S6 are: pulverization speed of 2000 r / min to 5000 r / min, pulverization time of 10 min to 30 min, and the particle size of the drag-reducing agent obtained after pulverization controlled at 80 mesh to 200 mesh.

9. A high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. A high-temperature resistant, salt-resistant, fast-dissolving drag-reducing agent polymerized from cellulose, gallium-based liquid metal, and fluorine-containing ionic liquid according to claim 9, characterized in that, The drag-reducing agent is a copolymer dry powder formed by polymerization of cellulose-modified gallium-based liquid metal (GLM@BCNF) as a low-temperature initiator, acrylamide (AM), acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as monomers, and fluorinated imidazole ionic liquid (FIL) as a high-temperature resistant and fast-dissolving aid.

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