A suspended sand dragging wire for efficient placement of proppant in fracturing wells and preparation method thereof

Abstract

The invention discloses a suspended sand dragging wire for efficient laying of a fracturing well proppant and a preparation method thereof, and belongs to the technical field of oil and gas field reservoir exploitation. First, nanoparticles are dispersed in solvent A, and then a coating agent and a flexibilizer are added, stirred for 0.5-1h and aged for 24h to obtain a surface treatment agent; the coating agent is selected from one or more of silane coupling agent, polyurethane emulsion, epoxy resin emulsion, etc.; the flexibilizer is selected from one or more of polyethylene glycol 600, azelaic acid, and octanoic acid; the cationic surfactant is dissolved in solvent B, and then an alkyl polyether siloxane is added to obtain a finishing agent; the surface treatment agent is transferred to the sizing machine slurry tank, and the polyester fiber is double-dipped and double-rolled by the sizing machine, and then dried and solidified to obtain a surface-modified fiber; the surface-modified fiber is further treated with a finishing agent solution diluted with water to obtain a suspended sand dragging wire. The suspended sand dragging wire can overcome the problems of poor dispersibility of the fiber in the fracturing fluid and weak binding ability of the fiber and the proppant.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field reservoir exploitation, in particular to a suspended sand dragging wire for efficient paving of a fracturing well proppant and a preparation method thereof. Background Art

[0002] Through a large number of shale post-fracturing fracture simulation analysis, the fracture width is mostly 2.5-4.0 mm. Coring data shows that in the existing technology, proppant is only laid in the main fracture and branch fracture, and the proppant laying distance is too short, mainly laid at the bottom of the fracture, and the cross-section distribution is uneven, and effective support for each level of fracture is not achieved. Moreover, while the volume fracturing process greatly increases the production of a single well, proppant reflux inevitably occurs during the test backflow and production process, resulting in sand burying the production layer, severely eroding and damaging the test and production processes, increasing downhole operation costs, and seriously affecting the production and safety of a single well.

[0003] Fiber fracturing technology can effectively improve the suspension performance of proppants in the fracturing fluid system by adding different types of fiber materials to the fracturing fluid system, while also reducing proppant spitting. However, in the actual application of fiber in fracturing construction, its dispersibility becomes a key problem. In order to achieve the best effect of efficient proppant laying technology in fracturing construction wells, it is necessary to develop fiber surface modification materials with strong sand suspension ability, good dispersibility, and control of proppant spitting, to ensure that they can be evenly distributed in the fracturing fluid, form an effective network structure, enhance the proppant laying effect, and reduce proppant spitting.

[0004] The fiber surface modification methods are mainly divided into chemical treatment (such as redox, coupling agent treatment, chemical grafting, etc.), plasma, corona modification, surface heat treatment (heating, melting or thermal curing), etc. The coating method is to cover the fiber surface with a layer of polymer, nanomaterial, metal particles or inorganic non-metal and its composite coating through physical or chemical deposition and coating, sol-gel method and other coating processes. After the coating is modified, the wettability of the fiber surface is changed and the compatibility of the fiber and the matrix is ​​increased. For example, patent CN112778508A discloses a water-soluble polyester slurry for short fiber sizing and a preparation method thereof, which has the effect of strong adhesion to polyester fiber and easy desizing, and the mechanical properties of the fiber are improved after sizing. However, the slurry needs to be melted at 90°C before it can be used, which is not easy to produce and operate; and the fiber after coating treatment has too strong tow force, poor dispersibility, reduced flexibility and elasticity, and affects the network structure performance of the fiber, which shows that only the coating modification of the fiber surface will greatly reduce the suspension and laying effect of the fiber on the proppant in the fracturing fluid system.

[0005] Therefore, although the fiber modification methods in the prior art can improve its dispersibility to a certain extent, they do not completely solve the problems of proppant suspension and efficient laying. Summary of the invention

[0006] In view of the problems existing in fiber fracturing technology, such as poor fiber dispersion, weak fiber-proppant bonding, and inability to achieve efficient proppant placement, the present invention provides a suspended sand dragging wire for efficient proppant placement in fracturing wells. The surface treatment agent is used to improve the interaction between polyester fiber and proppant, and the finishing agent is used to improve the dispersion and mechanical properties of the fiber. The prepared suspended sand dragging wire plays a key role in the proppant placement process.

[0007] The preparation method of the suspended sand dragging wire for efficient laying of proppant in fracturing wells provided by the present invention comprises the following steps:

[0008] S1. Disperse the nanoparticles in solvent A, then add a coating agent and a softening agent, stir at a stirring speed of 40-60 r / min for 0.5-1 h and age for 24 h to obtain a surface treatment agent.

[0009] The coating agent is selected from one or more of silane coupling agent, polyurethane emulsion, epoxy resin emulsion and styrene acrylic emulsion.

[0010] The softener is selected from one or more of polyethylene glycol 600, azelaic acid, and caprylic acid.

[0011] The nanoparticles are selected from one or more of nano-silicon dioxide, nano-titanium dioxide, nano-kaolin, and graphene.

[0012] The solvent A is selected from one or more of ethylene glycol butyl ether, glycerol and water.

[0013] The amounts of each raw material component are as follows by mass percentage:

[0014] Coating agent 0.1%-10.0%, softening agent 0.1%-3.0%, nanoparticles 0.1%-2.0%, and the balance is solvent A, totaling 100%.

[0015] S2. Add the cationic surfactant to solvent B, add alkyl polyether siloxane after it is completely dissolved, and stir at a stirring speed of 40-60 r / min for 5-30 min to obtain a finishing agent.

[0016] The cationic surfactant is selected from one or more of dodecylbenzylammonium chloride, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, dodecyldimethylamine oxide, ethylenebis(hexadecyldimethylammonium chloride), and alkyl polyetheramine.

[0017] The solvent B is selected from one or more of acetone, ethanol or deionized water.

[0018] The amounts of each raw material component are as follows by mass percentage:

[0019] Cationic surfactant 5%-15.0%, alkyl polyether siloxane 5%-15.0%, and the balance is solvent B, totaling 100%.

[0020] S3, transferring the surface treatment agent to the sizing tank of the sizing machine, and drying and curing the polyester fiber after double dipping and double rolling in the sizing machine, with the drying temperature being 80-120°C, to obtain surface modified fiber.

[0021] S4, further treating the surface modified fiber with a finishing agent solution diluted with water to obtain suspended sand dragging fibers. Specifically, one of the following two methods is used:

[0022] Method 1: Cut the surface modified fiber into short fibers with a length of 3 mm to 9 mm, mix the short fibers with a finishing agent solution diluted with water, stir evenly, and obtain suspended sand-drag fibers.

[0023] Method 2: Transfer the finishing agent solution diluted with water to the impregnation mill tank, connect the surface modified fiber to the impregnation mill tank, roller and wire cutter in sequence, and cut it into short fibers with a length of 3mm-9mm after being squeezed by two rollers to obtain suspended sand dragging wire.

[0024] Preferably, the mass proportion of the finishing agent in the finishing agent solution is 10%-30%.

[0025] Preferably, in method 1, the short fibers and the finishing agent solution are mixed in a mass ratio of 6:4-8:2.

[0026] Compared with the prior art, the present invention is beneficial in that:

[0027] (1) The present invention uses a surface treatment agent to modify the surface of polyester fibers, thereby increasing the proportion of hydrophilic groups on the fiber surface and improving the roughness, making it easier for the finishing agent to adsorb on the fiber.

[0028] (2) During the research process, it was found that the nanoparticle material in the surface treatment agent can be solidified on the fiber surface at the same time as the coating agent, changing the fiber surface structure and thus changing the hydrophilicity of the fiber surface; at the same time, the nanoparticle material has many adsorption points on the surface and can produce a strong adsorption effect on the proppant surface. The strong adsorption and adhesion of the nanomaterial act on the proppant at the same time, making the polyester fiber and the proppant more tightly combined, thereby preventing the fiber from escaping.

[0029] (3) The cationic surfactant in the finishing agent can not only improve the dispersibility of the fiber and enhance the hydrophilicity of the fiber, but also produce a strong adsorption effect with anionic groups such as carboxyl groups of polymers in the fracturing fluid, thereby enhancing the strength of the network structure of the fiber, proppant, and fracturing fluid, and improving the laying effect. In addition, the adsorption layer formed by the alkyl polyether siloxane in the finishing agent on the fiber surface has good stability, providing a lasting effect on the modification of the fiber.

[0030] (4) The suspended sand dragging fiber of the present invention solves the problems of poor fiber dispersion in the fracturing fluid (especially slick water), weak proppant suspension performance, and proppant spitting during current volume fracturing.

[0031] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a comparison of the microstructure of the fiber before and after treatment.

[0033] Figure 2 This is a comparison chart of the macroscopic dispersion of fibers before and after treatment. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0035] Example 1

[0036] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0037] (1) Add 0.1 kg of nano-silica to 70 kg of propylene glycol, add 17.9 kg of water while stirring, then add 10 kg of γ-glycidyloxypropyltrimethoxysilane coupling agent and 2 kg of polyethylene glycol 600 in sequence, stir at a speed of 50 r / min for 1 hour and age for 24 hours to obtain a surface treatment agent.

[0038] (2) Add 15 kg of dodecylbenzyl ammonium chloride into 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 5 minutes to obtain the finishing agent.

[0039] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 120°C. It is dried for 10 minutes and then cooled to room temperature to obtain surface-modified fiber.

[0040] (4) The surface modified fibers are stranded by a pulling machine and then cut into 3-9 mm short fibers by a shredder.

[0041] (5) Take 10 kg of finishing agent and add 40 kg of water to prepare a finishing agent solution; the short fibers and the finishing agent solution are mixed in a mass ratio of 6:4 and put into a sealed bag to obtain suspended sand-drag silk.

[0042] Example 2

[0043] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0044] (1) Add 0.5 kg of nano-kaolin to 92.5 kg of water and stir for 10 min. Then add 5 kg of non-ionic waterborne polyurethane emulsion and 2 kg of polyethylene glycol 600 in sequence. Stir at a speed of 50 r / min for 1 h and age for 24 h to obtain a surface treatment agent.

[0045] (2) Add 15 kg of dodecylbenzyl ammonium chloride into 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 10 minutes to obtain the finishing agent.

[0046] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 100°C. It is dried for 20 minutes and cooled to room temperature to obtain surface-modified fiber.

[0047] (4) Take 1 kg of finishing agent, add 4 kg of water to prepare a finishing agent solution, and transfer it to the padding tank. The surface-modified fiber is connected to the padding tank, rollers and shredder in sequence, and is squeezed by two rollers and cut to 3-9 mm to obtain suspended sand filaments.

[0048] Example 3

[0049] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0050] (1) Add 0.5 kg of nano titanium dioxide to 87.5 kg of ethylene glycol butyl ether, stir for 10 min, then add 10 kg of styrene acrylic emulsion and 2 kg of polyethylene glycol 600 in sequence, stir at a speed of 50 r / min for 1 h and age for 24 h to obtain the surface treatment agent.

[0051] (2) Add 15 kg of ethylene bis(hexadecyldimethylammonium chloride) into 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 20 min to obtain the finishing agent.

[0052] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 100°C. It is dried for 30 minutes and cooled to room temperature to obtain surface-modified fiber.

[0053] (4) Take 1 kg of finishing agent, add 4 kg of water to prepare a finishing agent solution, and transfer it to the padding tank. The surface-modified fiber is connected to the padding tank, rollers and shredder in sequence, and is squeezed by two rollers and cut to 3-9 mm to obtain suspended sand filaments.

[0054] Example 4

[0055] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0056] (1) Add 0.1 kg of nano-silicon dioxide to 10 kg of propylene glycol, add 77.9 kg of water while stirring, then add 10 kg of styrene acrylic emulsion and 2 kg of sebacic acid in sequence, stir at a speed of 50 r / min for 1 hour and age for 24 hours to obtain a surface treatment agent.

[0057] (2) Add 15 kg of dodecylbenzyl ammonium chloride into 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 30 minutes to obtain the finishing agent.

[0058] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 100°C. It is dried for 30 minutes and cooled to room temperature to obtain surface-modified fiber.

[0059] (4) Take 1 kg of finishing agent, add 4 kg of water to prepare a finishing agent solution, and transfer it to the padding tank. The surface-modified fiber is connected to the padding tank, rollers and shredder in sequence, and is squeezed by two rollers and cut to 3-9 mm to obtain suspended sand filaments.

[0060] Example 5

[0061] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0062] (1) Add 0.1 kg of nano-alumina to 10 kg of propylene glycol, add 77.9 kg of water while stirring, then add 10 kg of styrene acrylic emulsion and 2 kg of octanoic acid in sequence, stir at 50 r / min for 1 hour and age for 24 hours to obtain the surface treatment agent.

[0063] (2) Add 15 kg of dodecylbenzyl ammonium chloride into 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 30 minutes to obtain the finishing agent.

[0064] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 100°C. It is dried for 30 minutes and cooled to room temperature to obtain surface-modified fiber.

[0065] (4) Take 1 kg of finishing agent, add 4 kg of water to prepare a finishing agent solution, and transfer it to the padding tank. The surface-modified fiber is connected to the padding tank, rollers and shredder in sequence, and is squeezed by two rollers and cut to 3-9 mm to obtain suspended sand filaments.

[0066] Example 6

[0067] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0068] (1) Add 0.1 kg of nano-silica to 70 kg of propylene glycol, add 17.9 kg of water while stirring, then add 10 kg of γ-glycidyloxypropyltrimethoxysilane coupling agent and 2 kg of polyethylene glycol 600 in sequence, stir at a speed of 50 r / min for 1 hour and age for 24 hours to obtain a surface treatment agent.

[0069] (2) Add 15 kg of hexadecyltrimethylammonium chloride into 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 30 minutes to obtain the finishing agent.

[0070] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 100°C. It is dried for 30 minutes and cooled to room temperature to obtain surface-modified fiber.

[0071] (4) Take 1 kg of finishing agent, add 4 kg of water to prepare a finishing agent solution, and transfer it to the padding tank. The surface-modified fiber is connected to the padding tank, rollers and shredder in sequence, and is squeezed by two rollers and cut to 3-9 mm to obtain suspended sand filaments.

[0072] Example 7

[0073] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0074] (1) Add 0.1 kg of nano-silica to 70 kg of propylene glycol, add 17.9 kg of water while stirring, then add 10 kg of γ-glycidyloxypropyltrimethoxysilane coupling agent and 2 kg of polyethylene glycol 600 in sequence, stir at a speed of 50 r / min for 1 hour and age for 24 hours to obtain a surface treatment agent.

[0075] (2) Add 15 kg of dodecyl dimethyl amine oxide to 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 30 minutes to obtain the finishing agent.

[0076] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 100°C. It is dried for 30 minutes and cooled to room temperature to obtain surface-modified fiber.

[0077] (4) Take 1 kg of finishing agent, add 4 kg of water to prepare a finishing agent solution, and transfer it to the padding tank. The surface-modified fiber is connected to the padding tank, rollers and shredder in sequence, and is squeezed by two rollers and cut to 3-9 mm to obtain suspended sand filaments.

[0078] Example 8

[0079] A suspended sand dragging wire for efficient placement of proppant in fracturing wells, the preparation method is as follows:

[0080] (1) Add 0.1 kg of nano-silica to 70 kg of propylene glycol, add 17.9 kg of water while stirring, then add 10 kg of γ-glycidyloxypropyltrimethoxysilane coupling agent and 2 kg of polyethylene glycol 600 in sequence, stir at a speed of 50 r / min for 1 hour and age for 24 hours to obtain a surface treatment agent.

[0081] (2) Add 15 kg of dodecyl polyether amine to 70 kg of water and start stirring at a speed of 50 r / min. After complete dissolution, add 15 kg of PEG-12 polydimethylsiloxane and stir for 30 minutes to obtain the finishing agent.

[0082] (3) The surface treatment agent is transferred to the sizing tank of the sizing machine. The polyester fiber is dragged into the sizing tank by the yarn guide roller. After being dipped and rolled twice, it is introduced into the drying room. The drying room temperature is 100°C. It is dried for 30 minutes and cooled to room temperature to obtain surface-modified fiber.

[0083] (4) Take 1 kg of finishing agent, add 4 kg of water to prepare a finishing agent solution, and transfer it to the padding tank. The surface-modified fiber is connected to the padding tank, rollers and shredder in sequence, and is squeezed by two rollers and cut to 3-9 mm to obtain suspended sand filaments.

[0084] Comparative Example 1

[0085] The preparation method of the suspended sand-drawn silk is basically the same as that of Example 1, except that no finishing agent is used, that is, steps (2) and (5) are omitted. The surface-modified fiber is directly cut into 6 mm short fibers as the suspended sand-drawn silk.

[0086] Comparative Example 2

[0087] The preparation method of suspended sand dragging silk is basically the same as that of Example 1, except that no surface treatment agent is used: that is, steps (1) and (3) are omitted. The polyester fiber is directly cut into 6 mm short fibers, and then the short fibers and the finishing agent solution are mixed in a mass ratio of 6:4 and packed into a sealed bag to obtain suspended sand dragging silk.

[0088] Comparative Example 3

[0089] The preparation method of the suspended sand-drawn silk is basically the same as that of Example 1, except that the polyester fiber is directly cut into 6 mm short fibers as the suspended sand-drawn silk without using a surface treatment agent and a finishing agent.

[0090] The following performance test experiments were conducted on the suspended sand dragging wires prepared in the above embodiments and comparative examples:

[0091] 1. Microscopic experiment: The suspended sand dragging silk prepared in Example 1 and Comparative Examples 1-3 was observed under a high-power microscope for its microstructure. The experimental results are shown in Figure 1 The fiber surfaces of Example 1 and Comparative Example 1 are covered with a layer of film, while the fiber surfaces of Comparative Examples 2 and 3 do not have such a structure, indicating that the fibers of Example 1 and Comparative Example 1 are successfully loaded with coating materials.

[0092] 2. Macroscopic experiment: 0.1 g of the 6 mm suspended sand-drawn silk prepared in Example 1 and Comparative Examples 1-3 was added to a square glass dish containing 100 mL of clean water, stirred with a glass rod for 3 circles, and the fiber dispersion was observed. The experimental results are shown in Figure 2 As shown in the dispersibility test results, it can be seen that the dispersibility of the suspended sand dragging silk of Example 1 is significantly better than that of Comparative Examples 1-3.

[0093] 3. Laying experiment: The suspended sand-drawing fibers prepared in Examples 1-8 and Comparative Examples 1-3 were applied to the implementation of the proppant efficient laying technology to determine the effect of the suspended sand-drawing fibers on the proppant laying volume and fiber escape rate in the slippery water medium. The test method is as follows:

[0094] (1) Take two dry 100mL measuring cylinders and record them as 1# and 2#. Take another measuring cylinder and measure 100mL of slippery water into two 250mL beakers and record them as 1# and 2#.

[0095] (2) Experiment 1: Transfer beaker #1 to a vertical stirrer (speed 700 r / min) and start stirring. At the same time, weigh 15.00 g of proppant and add it to beaker #1. Stir for 2 min to evenly distribute the proppant in the slippery water. After stopping stirring, quickly remove beaker #1 and use a glass rod to stir the slippery water in beaker #1 into measuring cylinder #1. Place measuring cylinder #1 on a water platform and start timing. After 5 min, when the proppant is completely settled, read the laying volume of the proppant as the control group.

[0096] (3) Weigh 0.075 g of suspended sand filaments and place them in beaker #2. The mass is recorded as m0. Transfer beaker #2 to a vertical stirrer (speed 700 r / min) and start stirring. At the same time, weigh 15.00 g of proppant and add it to beaker #2. Stir for a total of 2 min to ensure that the proppant and suspended sand filaments are evenly distributed in the slippery water. After stopping stirring, quickly remove beaker #2 and use a glass rod to stir the slippery water in beaker #2 into measuring cylinder #2. Place measuring cylinder #2 on a water platform and start timing. After 5 min, when the proppant is completely settled, read the laying volume of the proppant.

[0097] (4) Pour the supernatant and the floating suspended sand fibers in the No. 2 measuring cylinder into a 20-mesh filter, wash the suspended sand fibers with clean water, dry and weigh them. The recorded mass is m2, and the suspended sand fiber escape rate η is calculated according to formula (1); formula (1): η = (m2 / m0) × 100%.

[0098] According to the methods of steps (3) and (4), the suspended sand dragging experiments of Examples 1-8 and Comparative Examples 1-3 were carried out in sequence, and the corresponding experiments were numbered as Experiments 2-12.

[0099] The experimental conditions are as follows: slick water viscosity 6mPa·s, sand ratio 20%, 6mm long suspended sand wire, 0.5% usage, quartz sand 70-140 mesh as proppant. The test results are shown in Table 1.

[0100] Table 1 Experimental results of applying suspended sand dragging simulation to efficient proppant placement of Examples 1-8 and Comparative Examples 1-3

[0101]

[0102] It can be seen from the data in Table 1 that when the suspended sand-drawing silk prepared in Examples 1-8 is used in combination with a proppant, the effective laying volume of the proppant is significantly greater than that of the three comparative examples and the blank test group, and the fiber escape rate is significantly lower than that of the three comparative examples, which shows that the performance of the suspended sand-drawing silk prepared by the method of the present invention is significantly better than that of the three comparative examples. It can be seen from the three comparative examples that the use of a surface treatment agent or a finishing agent alone to treat polyester fibers can only slightly improve the performance of the fibers. Only when the surface treatment agent and the finishing agent are used to treat polyester fibers at the same time, the obtained suspended sand-drawing silk can achieve the best performance, which can significantly increase the laying volume of the proppant and significantly reduce the escape rate of the suspended sand-drawing silk.

[0103] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a suspended sand dragging wire for efficient placement of proppant in a fracturing well, characterized in that: Here are the steps: S1, dispersing the nanoparticles into solvent A, then adding a coating agent and a flexibilizer, stirring for 0.5-1h and aging for 24h to obtain a surface treatment agent; the coating agent is selected from one or more of a silane coupling agent, a polyurethane emulsion, and a styrene-acrylic emulsion; the flexibilizer is selected from one or more of polyethylene glycol 600, azelaic acid, and octanoic acid; the nanoparticles are selected from one or more of nano-silicon dioxide, nano-titanium dioxide, nano-kaolin, and nano-alumina; the solvent A is selected from one or more of ethylene glycol butyl ether, glycerol, and water; The amounts of each raw material component are as follows by mass percentage: Coating agent 0.1%-10.0%, flexible agent 0.1%-3.0%, nanoparticles 0.1%-2.0%, the balance is solvent A, totaling 100%; S2, adding a cationic surfactant to solvent B, adding an alkyl polyether siloxane after it is completely dissolved, and stirring for 5-30 minutes to obtain a finishing agent; the cationic surfactant is selected from one or more of dodecyl benzyl ammonium chloride, hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, dodecyl dimethyl amine oxide, ethylene bis (hexadecyl dimethyl ammonium chloride), and alkyl polyether amine; the solvent B is selected from one or more of acetone, ethanol, or deionized water; The amounts of each raw material component are as follows by mass percentage: Cationic surfactant 5%-15.0%, alkyl polyether siloxane 5%-15.0%, the balance is solvent B, totaling 100%; S3, transferring the surface treatment agent to the sizing tank of the sizing machine, and the polyester fiber is double-dipped and double-rolled by the sizing machine, and then dried and solidified to obtain surface-modified fiber; S4. The surface-modified fibers are further treated with a finishing agent solution diluted with water to obtain suspended sand-dragged fibers.

2. The method for preparing the suspended sand-drawing wire for efficient placement of proppant in fracturing wells according to claim 1, characterized in that: In step S3, the drying temperature is 80-120°C.

3. The method for preparing the suspended sand-drawing wire for efficient placement of proppant in fracturing wells according to claim 1, characterized in that: Step S4 specifically adopts one of the following two methods: Method 1: Cut the surface modified fiber into short fibers with a length of 3mm-9mm, mix the short fibers with a finishing agent solution diluted with water, and stir evenly to obtain suspended sand dragging fibers; Method 2: Transfer the finishing agent solution diluted with water to the impregnation mill tank, connect the surface modified fiber to the impregnation mill tank, roller and wire cutter in sequence, and cut it into short fibers with a length of 3mm-9mm after being squeezed by two rollers to obtain suspended sand dragging wire.

4. The method for preparing the suspended sand dragging wire for efficient placement of proppant in fracturing wells according to claim 3, characterized in that: In step S4, method 1, the short fibers and the finishing agent solution are mixed in a mass ratio of 6:4-8:

2.

5. A suspended sand dragging wire for efficient placement of proppant in fracturing wells, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 4.

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