Preparation method of double-drop drag reducer and double-drop drag reducer
By using modified silica nanoparticles and sulfonic acid functional monomer copolymers in the drag reducer and combining with deionized water reaction medium, the problems of poor temperature resistance and process pollution in traditional drag reducer at high temperature are solved, and a high-temperature stable and environmentally friendly double drag reducer preparation is achieved.
Patent Information
- Application Number
- CN202510238103.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-03
- Publication Date
- 2025-06-03
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Traditional drag reducing agents have poor temperature resistance at high temperatures, experience process pollution, and have a large amount of VOCs emissions.
Using the preparation method of double-drag reducing agent, by mixing hydrophobic nanosilica with silane coupling agent, combining copolymers of styrene-maleic anhydride-sulfonic acid functional monomers, a rigid interface film is formed using modified silica nanoparticles to inhibit layering, and deionized water is used as the reaction medium to eliminate VOCs emissions.
The temperature resistance of the double-reducing drag reducer is improved, and can be stable in a high temperature environment of 120℃, inhibit stratification, eliminate VOCs emissions, reduce process energy consumption, and shorten production cycles.
Smart Images
Figure CN120082335A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of petrochemical engineering, and particularly to a preparation method of a double-reducing drag reducer and a double-reducing drag reducer. Background Art
[0002] Traditional drag reducers are centered around the compounding of high-molecular surfactants (such as polyethylene oxide ethers and alkylbenzene sulfonates), and reduce the viscosity and pour point of crude oil through emulsification. For existing drag reducers, the following main deficiencies exist:
[0003] 1. Poor heat resistance. When the temperature is higher than 80°C, the polymer chains are prone to breakage, resulting in a decline in emulsion stability and stratification.
[0004] 2. There is process pollution. The preparation process relies on organic solvents (such as toluene and acetone), resulting in environmental pollution. Summary of the Invention
[0005] The object of the present invention is to address the problems in the background art and propose a preparation method of a double-reducing drag reducer and a double-reducing drag reducer, which can improve heat resistance, is not prone to dehydration at high temperatures, has high emulsion stability, inhibits stratification, eliminates VOCs emissions, and is more environmentally friendly.
[0006] On the one hand, the present invention proposes a preparation method of a double-reducing drag reducer, including the following steps:
[0007] S1. Ultrasonically disperse hydrophobic nano-silica and a silane coupling agent in ethanol at a mass ratio of 1:3 for 1 hour, then centrifuge and dry to obtain modified silica.
[0008] S2. Mix styrene, maleic anhydride, and a sulfonic acid functional monomer in a molar ratio of 3:2:1, add 0.5% sorbitan monooleate, and stir until transparent to obtain an oil phase; heat a 2% polyvinyl alcohol solution until dissolved to obtain an aqueous phase; drop the oil phase into the aqueous phase and shear-emulsify to obtain a pre-emulsion.
[0009] S3. Dissolve 0.5% potassium persulfate in the aqueous phase, purge with nitrogen to remove oxygen, drop the pre-emulsion, and control the reaction temperature at 74 - 76°C for 4 - 6 hours.
[0010] S4. Add the modified silica in three batches at intervals while maintaining stirring.
[0011] S5. Demulsify the reaction solution with ethanol, centrifuge and wash, and dry to obtain a powdery semi-finished product.
[0012] S6. Disperse the powdery semi-finished product in deionized water containing polyethylene glycol, and homogenize under high pressure until the particle size is ≤200 nm to obtain the double-reducing drag reducer.
[0013] Preferably, in S2, the oil phase is added dropwise to the aqueous phase at a rate of 1 mL / min, sheared and emulsified at a speed of 5000 rpm for 10 min to form a nano-scale pre-emulsion.
[0014] Preferably, after the reaction in S3, the pH is adjusted to 6-9 with 10% NaOH solution.
[0015] Preferably, in S4, three batches of modified silica are added at intervals of 30 min, stirred at 200 rpm, and the particle size is maintained at ≤200 nm.
[0016] Preferably, after S4, 0.1% polyether-modified silicone defoamer is added, stirred at a speed of 2000 r / min for 10-15 min, and filtered through a 5-μm filter membrane to remove unreacted impurities.
[0017] Preferably, in S5, centrifugation is carried out at a speed of 8000 rpm for 15-20 min, washed three times with deionized water, and vacuum dried at 50-55 °C for 20-24 h.
[0018] Preferably, in S6, the powdered semi-finished product is added to deionized water, mechanically stirred at 1000 rpm, dispersed using a high-pressure homogenizer at a pressure of 50 MPa, and circulated 3 times.
[0019] On the other hand, the present invention provides a double drag reducer prepared by the above preparation method of the double drag reducer.
[0020] Compared with the prior art, the present invention has the following beneficial technical effects:
[0021] This double drag reducer can withstand a high-temperature environment of 120 °C. The rigid interfacial film formed by modified silica nanoparticles inhibits delamination. Traditional organic solvents such as toluene and acetone are abandoned, and deionized water is used as the reaction medium to eliminate VOC emissions from the source. The preparation steps are few, reducing the energy consumption of multi-step separation and purification in the traditional process. The sulfonated copolymer is directly generated in the aqueous phase without subsequent sulfonation treatment, shortening the production cycle. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a schematic structural diagram of an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] Example 1
[0024] As Figure 1 shown, a preparation method of a double drag reducer proposed in this embodiment includes the following steps:
[0025] S1. Hydrophobic nano-silica and a silane coupling agent are ultrasonically dispersed in ethanol at a mass ratio of 1:3 for 1 hour, centrifuged and dried to obtain modified silica.
[0026] S2. Styrene, maleic anhydride and sulfonic acid functional monomers are mixed in a molar ratio of 3:2:1, 0.5% dehydrated sorbitan monooleate is added, and the mixture is stirred until transparent to obtain an oil phase; 2% Wanwei polyvinyl alcohol solution is heated until dissolved to obtain an aqueous phase; the oil phase is added dropwise to the aqueous phase at a rate of 1 mL / min, and sheared and emulsified at a speed of 5000 rpm for 10 minutes to form a nano-scale pre-emulsion. By introducing styrene-maleic anhydride copolymers with sulfonic acid groups (strong hydration), the copolymers can still maintain a stable hydration layer in a high-salt environment. The sulfonic acid groups are not easily dehydrated at high temperatures (120°C), ensuring the stability of the emulsion.
[0027] S3. Dissolve 0.5% potassium persulfate in the aqueous phase, introduce nitrogen to deoxygenate, add the pre-emulsion dropwise, control the reaction temperature at 76°C, and react for 4 hours.
[0028] S3.1. Adjust the pH to 6 with 10% NaOH solution.
[0029] S4. Add modified silica once every 30 minutes in three batches, keep stirring at 200rpm, and maintain the particle size ≤200nm. The hydrophobically modified nano-silica particles are grafted with long-chain alkyl groups through a silane coupling agent (KH-550) to form a dense physical barrier at the oil-water interface. The rigid structure of the nanoparticles can inhibit the merging of droplets (Ostwald ripening), while enhancing the mechanical strength of the interfacial film, resisting high-temperature shear and salt ion penetration, and reducing the interfacial tension from 4.2mN / m to 2.5mN / m. Each addition of modified silica is 30 minutes apart to ensure that the nanoparticles are gradually adsorbed on the liquid surface to form a multi-layer interfacial protective film. Compared with traditional one-time addition, the risk of stratification is reduced by 40%. Centrifugal stability: no phase separation under the condition of 4000rpm and centrifugation for 30 minutes. The viscosity change rate is <5% when stored at high temperature at 80°C for 7 days.
[0030] S4.1, add 0.1% polyether modified siloxane defoamer, stir at 2000r / min for 10min, filter through 5μm filter membrane to remove unreacted impurities. The long-term stability of the emulsion is improved through the synergistic effect of pH adjustment in S3.1 and the siloxane defoamer in S4.1, and there is no stratification after standing for 30 days.
[0031] S5. The reaction solution was demulsified with ethanol, centrifuged at 8000 rpm for 18 min, washed three times with deionized water, and vacuum dried at 53° C. for 23 h to obtain a powdery semi-finished product.
[0032] S6. Disperse the powdered semi-finished product in deionized water containing polyethylene glycol, stir mechanically at 1000 rpm, disperse using a high-pressure homogenizer, pressure 50 MPa, cycle 3 times, homogenize, particle size 198 nm, and obtain a double-reduction drag reducer with a density (20°C) of 1.0 g / cm 3 , drag reduction rate (20℃, water content 20%) ≥50%. Polyethylene glycol in deionized water can prevent particle sedimentation. The obtained double drag reducing agent is packaged in clean and dry plastic barrels. Store in a dry and ventilated place, avoid exposure to sunlight and rain, and store at room temperature. Avoid violent collision during transportation to prevent damage.
[0033] Embodiment 2
[0034] like Figure 1 As shown, a method for preparing a dual-reduction drag reducing agent proposed in this embodiment comprises the following steps:
[0035] S1. Ultrasonic dispersion of hydrophobic nano-silica and silane coupling agent in ethanol at a mass ratio of 1:3 for 1 hour, centrifugal drying, and obtaining modified silica.
[0036] S2. Styrene, maleic anhydride and sulfonic acid functional monomers are mixed in a molar ratio of 3:2:1, 0.5% dehydrated sorbitan monooleate is added, and the mixture is stirred until transparent to obtain an oil phase; 2% Wanwei polyvinyl alcohol solution is heated until dissolved to obtain an aqueous phase; the oil phase is added dropwise to the aqueous phase at a rate of 1 mL / min, and sheared and emulsified at a speed of 5000 rpm for 10 minutes to form a nano-scale pre-emulsion. By introducing styrene-maleic anhydride copolymers with sulfonic acid groups (strong hydration), the copolymers can still maintain a stable hydration layer in a high-salt environment. The sulfonic acid groups are not easily dehydrated at high temperatures (120°C), ensuring the stability of the emulsion.
[0037] S3. Dissolve 0.5% potassium persulfate in the aqueous phase, introduce nitrogen to deoxygenate, add the pre-emulsion dropwise, control the reaction temperature at 74°C, and react for 6 hours.
[0038] S3.1. Adjust the pH to 8.5 with 10% NaOH solution.
[0039] S4. Add modified silica once every 30 minutes in three batches, keep stirring at 200rpm, and maintain the particle size ≤200nm. The hydrophobically modified nano-silica particles are grafted with long-chain alkyl groups through a silane coupling agent (KH-550) to form a dense physical barrier at the oil-water interface. The rigid structure of the nanoparticles can inhibit the merging of droplets (Ostwald ripening), while enhancing the mechanical strength of the interfacial film, resisting high-temperature shear and salt ion penetration, and reducing the interfacial tension from 4.2mN / m to 2.5mN / m. Each addition of modified silica is 30 minutes apart to ensure that the nanoparticles are gradually adsorbed on the liquid surface to form a multi-layer interfacial protective film. Compared with traditional one-time addition, the risk of stratification is reduced by 40%. Centrifugal stability: no phase separation under the condition of 4000rpm and centrifugation for 30 minutes. The viscosity change rate is <5% when stored at high temperature at 80°C for 7 days.
[0040] S4.1, add 0.1% polyether modified siloxane defoamer, stir at 2000r / min for 12min, filter through 5μm filter membrane to remove unreacted impurities. The long-term stability of the emulsion is improved through the synergistic effect of pH adjustment in S3.1 and the siloxane defoamer in S4.1, and there is no stratification after standing for 30 days.
[0041] S5. The reaction solution was demulsified with ethanol, centrifuged at 8000 rpm for 17 min, washed three times with deionized water, and vacuum dried at 52° C. for 20 h to obtain a powdery semi-finished product.
[0042] S6. Disperse the powdered semi-finished product in deionized water containing polyethylene glycol, stir mechanically at 1000 rpm, disperse using a high-pressure homogenizer, pressure 50 MPa, cycle 3 times, homogenize, particle size 182 nm, and obtain a double-reduction drag reducer with a density (20°C) of 1.0 g / cm 3 , drag reduction rate (20℃, water content 20%) ≥50%. Polyethylene glycol in deionized water can prevent particle sedimentation. The obtained double drag reducing agent is packaged in clean and dry plastic barrels. Store in a dry and ventilated place, avoid exposure to sunlight and rain, and store at room temperature. Avoid violent collision during transportation to prevent damage.
[0043] Embodiment 3
[0044] like Figure 1 As shown, a method for preparing a dual-reduction drag reducing agent proposed in this embodiment comprises the following steps:
[0045] S1. Ultrasonic dispersion of hydrophobic nano-silica and silane coupling agent in ethanol at a mass ratio of 1:3 for 1 hour, centrifugal drying, and obtaining modified silica.
[0046] S2. Styrene, maleic anhydride and sulfonic acid functional monomers are mixed in a molar ratio of 3:2:1, 0.5% dehydrated sorbitan monooleate is added, and the mixture is stirred until transparent to obtain an oil phase; 2% Wanwei polyvinyl alcohol solution is heated until dissolved to obtain an aqueous phase; the oil phase is added dropwise to the aqueous phase at a rate of 1 mL / min, and sheared and emulsified at a speed of 5000 rpm for 10 minutes to form a nano-scale pre-emulsion. By introducing styrene-maleic anhydride copolymers with sulfonic acid groups (strong hydration), the copolymers can still maintain a stable hydration layer in a high-salt environment. The sulfonic acid groups are not easily dehydrated at high temperatures (120°C), ensuring the stability of the emulsion.
[0047] S3. Dissolve 0.5% potassium persulfate in the aqueous phase, introduce nitrogen to deoxygenate, add the pre-emulsion dropwise, control the reaction temperature at 74°C, and react for 5 hours.
[0048] S3.1. Adjust the pH to 8 with 10% NaOH solution.
[0049] S4. Add modified silica once every 30 minutes in three batches, keep stirring at 200rpm, and maintain the particle size ≤200nm. The hydrophobically modified nano-silica particles are grafted with long-chain alkyl groups through a silane coupling agent (KH-550) to form a dense physical barrier at the oil-water interface. The rigid structure of the nanoparticles can inhibit the merging of droplets (Ostwald ripening), while enhancing the mechanical strength of the interfacial film, resisting high-temperature shear and salt ion penetration, and reducing the interfacial tension from 4.2mN / m to 2.5mN / m. Each addition of modified silica is 30 minutes apart to ensure that the nanoparticles are gradually adsorbed on the liquid surface to form a multi-layer interfacial protective film. Compared with traditional one-time addition, the risk of stratification is reduced by 40%. Centrifugal stability: no phase separation under the condition of 4000rpm and centrifugation for 30 minutes. The viscosity change rate is <5% when stored at high temperature at 80°C for 7 days.
[0050] S4.1, add 0.1% polyether modified siloxane defoamer, stir at 2000r / min for 15min, filter through 5μm filter membrane to remove unreacted impurities. The long-term stability of the emulsion is improved through the synergistic effect of pH adjustment in S3.1 and the siloxane defoamer in S4.1, and there is no stratification after standing for 30 days.
[0051] S5. The reaction solution was demulsified with ethanol, centrifuged at 8000 rpm for 15 min, washed three times with deionized water, and vacuum dried at 55° C. for 22 h to obtain a powdery semi-finished product.
[0052] S6. Disperse the powdered semi-finished product in deionized water containing polyethylene glycol, stir mechanically at 1000 rpm, disperse using a high-pressure homogenizer, pressure 50 MPa, cycle 3 times, homogenize, particle size 190 nm, and obtain a double-reduction drag reducer with a density (20°C) of 1.0 g / cm 3, drag reduction rate (20℃, water content 20%) ≥50%. Polyethylene glycol in deionized water can prevent particle sedimentation. The obtained double drag reducing agent is packaged in clean and dry plastic barrels. Store in a dry and ventilated place, avoid exposure to sunlight and rain, and store at room temperature. Avoid violent collision during transportation to prevent damage.
[0053] Embodiment 4
[0054] like Figure 1 As shown, a method for preparing a dual-reduction drag reducing agent proposed in this embodiment comprises the following steps:
[0055] S1. Ultrasonic dispersion of hydrophobic nano-silica and silane coupling agent in ethanol at a mass ratio of 1:3 for 1 hour, centrifugal drying, and obtaining modified silica.
[0056] S2. Styrene, maleic anhydride and sulfonic acid functional monomers are mixed in a molar ratio of 3:2:1, 0.5% dehydrated sorbitan monooleate is added, and the mixture is stirred until transparent to obtain an oil phase; 2% Wanwei polyvinyl alcohol solution is heated until dissolved to obtain an aqueous phase; the oil phase is added dropwise to the aqueous phase at a rate of 1 mL / min, and sheared and emulsified at a speed of 5000 rpm for 10 minutes to form a nano-scale pre-emulsion. By introducing styrene-maleic anhydride copolymers with sulfonic acid groups (strong hydration), the copolymers can still maintain a stable hydration layer in a high-salt environment. The sulfonic acid groups are not easily dehydrated at high temperatures (120°C), ensuring the stability of the emulsion.
[0057] S3. Dissolve 0.5% potassium persulfate in the aqueous phase, introduce nitrogen to deoxygenate, add the pre-emulsion dropwise, control the reaction temperature at 75°C, and react for 5 hours.
[0058] S3.1. Adjust the pH to 9 with 10% NaOH solution.
[0059] S4. Add modified silica once every 30 minutes in three batches, keep stirring at 200rpm, and maintain the particle size ≤200nm. The hydrophobically modified nano-silica particles are grafted with long-chain alkyl groups through a silane coupling agent (KH-550) to form a dense physical barrier at the oil-water interface. The rigid structure of the nanoparticles can inhibit the merging of droplets (Ostwald ripening), while enhancing the mechanical strength of the interfacial film, resisting high-temperature shear and salt ion penetration, and reducing the interfacial tension from 4.2mN / m to 2.5mN / m. Each addition of modified silica is 30 minutes apart to ensure that the nanoparticles are gradually adsorbed on the liquid surface to form a multi-layer interfacial protective film. Compared with traditional one-time addition, the risk of stratification is reduced by 40%. Centrifugal stability: no phase separation under the condition of 4000rpm and centrifugation for 30 minutes. The viscosity change rate is <5% when stored at high temperature at 80°C for 7 days.
[0060] S4.1. Add 0.1% polyether-modified silicone defoamer, stir at a speed of 2000 r / min for 13 min, filter through a 5-μm filter membrane to remove unreacted impurities. Through the synergistic effect of pH adjustment in S3.1 and silicone defoamer in S4.1, the long-term stability of the emulsion is improved, and there is no layering after standing for 30 days.
[0061] S5. Demulsify the reaction solution with ethanol, centrifuge at a speed of 8000 rpm for 20 min, wash three times with deionized water, and vacuum dry at 50 °C for 24 h to obtain a powdery semi-finished product.
[0062] S6. Disperse the powdery semi-finished product in deionized water containing polyethylene glycol, stir mechanically at 1000 rpm, disperse with a high-pressure homogenizer at a pressure of 50 MPa for 3 cycles, homogenize to a particle size of 184 nm to prepare a double-reducing drag reducer with a density (20 °C) of 1.0 g / cm 3 , and the drag reduction rate (20 °C, containing 20% water) ≥ 50%. Polyethylene glycol in deionized water can prevent particle sedimentation. The prepared double-reducing drag reducer is packaged in a clean and dry plastic bucket. Store it in a dry and ventilated place, prevent exposure to the sun and rain, and store at room temperature. Avoid violent collision during transportation to prevent damage.
[0063] This double-reducing drag reducer is resistant to high-temperature environments of 120 °C. It forms a rigid interfacial film using modified silica nanoparticles to inhibit layering. Abandon traditional organic solvents such as toluene and acetone, and use deionized water as the reaction medium to eliminate VOCs (volatile organic compounds) emissions from the source. Control the temperature in the polymerization reaction stage at 75 °C ± 1 °C (traditional process ± 5 °C) to prevent too wide a molecular weight distribution caused by explosive polymerization. Regulate the shear rate in stages to ensure the uniformity of the emulsion particle size (PDI < 0.2). Use ethanol for demulsification in the post-treatment stage, which can be recycled and reused, reducing COD (chemical oxygen demand) emissions by 85%. The preparation steps are few, reducing the energy consumption of multi-step separation and purification in the traditional process, with an energy consumption reduction of 20%. The sulfonated copolymer is directly generated in the aqueous phase without subsequent sulfonation treatment, shortening the production cycle by 30%.
[0064] Example Five
[0065] This example presents a double-reducing drag reducer, which is prepared by the preparation method of the double-reducing drag reducer in the above example.
[0066] The usage methods of this double-reducing drag reducer are divided into two types: continuous dosing and intermittent dosing. The continuous dosing method is to add it at a concentration of 1‰ at the starting end of the gathering and transportation pipeline network; the intermittent dosing method is the dosing method adopted when continuous dosing is not possible. It is required to dilute the double-reducing drag reducer by 5 - 10 times and pump it into the oil casing annulus. The single-well dosing amount depends on the liquid production of the oil well. Generally, the dosing amount per time is 25 - 50 kg, and the dosing cycle depends on the back pressure.
[0067] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited thereto, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those skilled in the art.
Claims
1. A method for preparing a dual-reduction drag reducing agent, characterized in that: The following steps are involved: S1, ultrasonically dispersing hydrophobic nano-silica and silane coupling agent in ethanol at a mass ratio of 1:3 for 1 hour, centrifugally drying, to obtain modified silica; S2. Styrene, maleic anhydride and sulfonic acid functional monomers are mixed in a molar ratio of 3:2:1, 0.5% sorbitan monooleate is added, and the mixture is stirred until transparent to obtain an oil phase; 2% Wanwei polyvinyl alcohol solution is heated until dissolved to obtain a water phase; the oil phase is added dropwise to the water phase, and the pre-emulsion is obtained by shearing and emulsification; S3, dissolving 0.5% potassium persulfate in the aqueous phase, introducing nitrogen to deoxygenate, adding the pre-emulsion dropwise, controlling the reaction temperature at 74-76°C, and reacting for 4-6 hours; S4, adding modified silica in three batches at intervals, keeping stirring; S5, the reaction solution is demulsified with ethanol, washed by centrifugation, and dried into a powdery semi-finished product; S6. Disperse the powdered semi-finished product in deionized water containing polyethylene glycol, and homogenize it under high pressure until the particle size is ≤200nm to obtain a dual-reduction drag reducing agent.
2. The method for preparing the dual-reduction drag reducing agent according to claim 1, characterized in that: In S2, the oil phase was added dropwise to the water phase at a rate of 1 mL / min, and shear emulsified at a speed of 5000 rpm for 10 min to form a nanoscale pre-emulsion.
3. The method for preparing the dual-reduction drag reducing agent according to claim 1, characterized in that: After the reaction in S3 was completed, the pH was adjusted to 6-9 with 10% NaOH solution.
4. The method for preparing the dual-reduction drag reducing agent according to claim 1, characterized in that: In S4, three batches of modified silica were added every 30 min, stirring was maintained at 200 rpm, and the particle size was maintained at ≤ 200 nm.
5. The method for preparing the dual-reduction drag reducing agent according to claim 1, characterized in that: After S4 is completed, 0.1% polyether modified siloxane defoamer is added, stirred at a speed of 2000 r / min for 10-15 min, and filtered through a 5 μm filter membrane to remove unreacted impurities.
6. The method for preparing the dual-reduction drag reducing agent according to claim 1, characterized in that: In S5, centrifuge at 8000 rpm for 15-20 min, wash three times with deionized water, and vacuum dry at 50-55°C for 20-24 h.
7. The method for preparing the dual-reduction drag reducing agent according to claim 1, characterized in that: In S6, the powdered semi-finished product is added to deionized water, mechanically stirred at 1000 rpm, dispersed using a high-pressure homogenizer at a pressure of 50 MPa, and cycled three times.
8. A dual-reduction drag reducing agent, characterized in that: The double-reduction drag reducing agent is prepared by the preparation method of any one of claims 1 to 7.