Preparation method and application of a high-temperature acidification demulsifier

Abstract

The present invention provides a preparation method and application of a high-temperature acidification demulsifier. The demulsifier is prepared by compounding demulsifier SP169, a non-ionic surfactant, polyoxyethylene alkyl ether, a quaternary ammonium salt cationic fluorocarbon surfactant and water. Preparation method of the non-ionic surfactant: (1) Mix dodecylphenol polyoxyethylene ether, sodium hydroxide and formaldehyde, heat up to 55-60 °C, and keep the temperature for reaction for 7-9 h to obtain mixture 1; (2) Add octylphenol polyoxyethylene ether to mixture 1, add p-toluenesulfonic acid, and heat up to 125-130 °C for reaction for 5-7 h to obtain mixture 2; (3) Add sodium hydroxide and toluene to mixture 2, heat up to 115-120 °C and keep the temperature for 5-7 h; cool down to 65-70 °C, add sodium chloroacetate, keep the temperature for 9-10 h, add ethanol, filter, and carry out rotary evaporation under reduced pressure to obtain the non-ionic surfactant. The demulsifier has good high-temperature resistance effect and good storage performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of demulsifiers, and particularly relates to a preparation method and application of a high-temperature acidizing demulsifier. Background Art

[0002] The acid fracturing measure is an essential technical means in oilfield development. Well acid fracturing is an enhanced oil recovery measure to improve the productivity of low-permeability or blocked reservoirs. It combines the advantages of acidizing technology and fracturing technology, aiming to improve the permeability of wells and increase the conductivity of fractures, thereby enhancing the oil recovery rate. During the fracturing process, the working fluid (including acid fluid and fracturing fluid) used for acid fracturing injected into the formation contains a large amount of surfactants, which easily form stable emulsions when contacting with crude oil. Such emulsions will reduce the oil recovery efficiency and may also block the formation pores, affecting the flow channels of oil and gas. When the emulsion flows in the pipeline, the frictional resistance is relatively high. If the emulsion formed during the acid fracturing process cannot be well demulsified, it will bring great difficulties to the flowback after acid fracturing, resulting in the long-term retention of fracturing fluid or acid fluid in the formation, causing serious damage to the formation and affecting the stimulation effect.

[0003] The demulsifier in the fracturing fluid is a specially designed chemical additive, mainly used in the hydraulic fracturing operations of shale gas and tight oil reservoirs. The demulsifier can effectively reduce the viscosity of the oil-water mixture, facilitate pumping and treatment, improve the treatment efficiency and reduce costs. After the fracturing operation is completed, the returned formation fluid (flowback fluid) usually contains a large amount of emulsified oil droplets. The demulsifier can destroy the stability of these emulsified oil droplets, promote oil-water stratification, and accelerate the oil-water separation process. The fracturing operation is usually carried out at a depth of several thousand meters underground. With the increasing number of ultra-deep (>6000m) and ultra-high-temperature (>200°C) wells, higher requirements are put forward for the performance of fracturing fluid due to the reservoir characteristics and fracturing process characteristics. In a high-temperature environment, ordinary chemical substances may lose stability, decompose or fail, and conventional demulsifiers are difficult to meet the construction requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of a high-temperature acidizing demulsifier. The demulsifier has good high-temperature resistance and can be applicable to the oil well environment above 200°C. At the same time, it has good storage performance and has extremely high market value and application prospects.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A preparation method of a high-temperature acidizing demulsifier, wherein the preparation method of the demulsifier is as follows: by mass parts, mix 4 - 10 parts of demulsifier SP169, 2 - 8 parts of non-ionic surfactant, 1 - 5 parts of polyoxyethylene alkyl ether, 0.8 - 1.5 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 5 - 10 parts of water, and stir evenly to obtain the high-temperature acidizing demulsifier.

[0007] Furthermore, the preparation method of the non-ionic surfactant is as follows:

[0008] (1) Mix 1 mol of dodecylphenol polyoxyethylene ether, 0.6 - 0.9 mol of sodium hydroxide, and 2 - 3 mol of formaldehyde, heat up to 55 - 60 °C, stir evenly, and then keep the temperature for reaction for 7 - 9 h to obtain mixture 1;

[0009] (2) Add 2 mol of octylphenol polyoxyethylene ether to mixture 1, adjust the pH to neutral with hydrochloric acid, add 6 - 8 g of p-toluenesulfonic acid, heat up to 70 - 80 °C to remove water by vacuum pumping, and continue to heat up to 125 - 130 °C for reaction for 5 - 7 h; obtain mixture 2;

[0010] (3) Add 4 - 5 mol of sodium hydroxide and 550 - 600 mL of toluene to mixture 2, mix evenly, heat up to 115 - 120 °C and keep the temperature for 5 - 7 h; cool down to 65 - 70 °C, add 3.5 - 3.8 mol of sodium chloroacetate, keep the temperature for 9 - 10 h, add hydrochloric acid to adjust the pH to neutral, remove toluene and water under reduced pressure, add 500 - 600 mL of ethanol, filter while it is hot, and remove ethanol by rotary evaporation under reduced pressure to obtain the non-ionic surfactant.

[0011] Furthermore, the structural formula of the non-ionic surfactant is:

[0012]

[0013] The main component of the demulsifier SP169 (brand: Haishihua) produced by Hai'an Petrochemical Factory in Jiangsu Province is polyoxypropylene polyoxyethylene octadecanol ether, which is a demulsifier with good temperature resistance. However, its high-temperature resistance is not good above 200 °C, resulting in low demulsification and long time. By compounding the demulsifier SP169 with the non-ionic surfactant and polyoxyethylene alkyl ether, the high-temperature resistance of the demulsifier can be improved, and good demulsification performance can still be maintained under the condition above 200 °C. The analysis is that after compounding, the rigid and planar structure of the benzene ring has high thermal stability, which can resist thermal degradation at high temperatures, thereby maintaining the overall structure and performance of the surfactant. Complementary enhancement is formed between the structures of the three surfactants, which can produce a synergistic effect and maintain stable interfacial activity in a wide temperature range.

[0014] Furthermore, the polyoxyethylene alkyl ether is a mixture of three kinds of polyoxyethylene alkyl ethers compounded, and the molecular formulas of the three kinds of polyoxyethylene alkyl ethers are successively: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2)10 OH and C 13 H 27 (OCH2CH2) 12 OH.

[0015] Polyoxyethylene (10) tridecyl ether, C 13 H 27 (OCH2CH2) 10 OH, CAS: 78330-21-9.

[0016] Polyoxyethylene (10) cetyl ether, C 16 H 33 (OCH2CH2) 10 OH, CAS: 9004-95-9.

[0017] Polyoxyethylene (12) tridecyl ether, C 13 H 27 (OCH2CH2) 12 OH, CAS: 78330-21-9.

[0018] Furthermore, C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 The mass ratio of OH is 1:1.4 - 1.8:0.2 - 0.6.

[0019] The inventors found that when the three polyoxyethylene alkyl ethers are compounded in a specific ratio, the surface tension of the demulsified liquid and the interfacial tension of the demulsified liquid of the demulsifier can be improved. The analysis is that the combination of different chain lengths can more comprehensively cover the oil-water interface and form a denser and more ordered interfacial layer, thereby more effectively reducing the interfacial tension.

[0020] Quaternary ammonium salt cationic fluorocarbon surfactant, CAS: 84166-37-0.

[0021] Furthermore, the mass ratio of the demulsifier SP169 to the sum of the non-ionic surfactant and the polyoxyethylene alkyl ether is 1 - 1.5:1.

[0022] Furthermore, the mass ratio of the demulsifier SP169 to the sum of the non-ionic surfactant and the polyoxyethylene alkyl ether is 1 - 1.3:1.

[0023] Furthermore, the mass ratio of the demulsifier SP169 to the sum of the non-ionic surfactant and the polyoxyethylene alkyl ether is 1.2:1.

[0024] In the actual use process, it is found that the demulsifier of the present invention is prone to phase separation during long-term storage. After analysis, it is because different surfactants may undergo phase separation during storage due to chemical property differences, resulting in unstable active ingredients of the demulsifier and affecting the use effect. Through a large number of experiments, it is found that when the mass ratio of the demulsifier SP169 to the sum of the non-ionic surfactant and polyoxyethylene alkyl ether is 1 to 1.5:1, the demulsifier has high storage stability.

[0025] Furthermore, the molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

[0026] Furthermore, the molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

[0027] The present invention provides the application of the high-temperature acidification demulsifier in the preparation of fracturing fluid.

[0028] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0029] 1. The present invention provides a preparation method and application of a high-temperature acidification demulsifier. The demulsifier has good high-temperature resistance and can be added to fracturing fluid for use. It is suitable for oil well environments above 200 °C. At the same time, it has good storage performance and has extremely high market value and application prospects.

[0030] 2. By compounding the demulsifier SP169 with non-ionic surfactants and polyoxyethylene alkyl ethers, the present invention can improve the high-temperature resistance of the demulsifier and still maintain good demulsification performance under conditions above 200 °C.

[0031] 3. When three polyoxyethylene alkyl ethers are compounded in a specific ratio, the surface tension of the gel-breaking liquid and the interfacial tension of the gel-breaking liquid of the demulsifier can be improved.

[0032] 4. When the mass ratio of the demulsifier SP169 to the sum of the non-ionic surfactant and polyoxyethylene alkyl ether is 1 to 1.5:1, the demulsifier has high storage stability. Specific Embodiments

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Example 1

[0035] This embodiment provides a high-temperature acidification demulsifier, and the preparation method is as follows: by mass, 8.4 parts of demulsifier SP169, 5 parts of non-ionic surfactant, 2 parts of polyoxyethylene alkyl ether, 1.2 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 7 parts of water are mixed and stirred evenly to obtain the demulsifier.

[0036] The preparation method of the non-ionic surfactant is as follows:

[0037] (1) Mix 1 mol of dodecylphenol polyoxyethylene ether, 0.7 mol of sodium hydroxide, and 2.5 mol of formaldehyde, heat up to 57 °C, stir evenly, and keep the reaction for 8 h to obtain mixture 1;

[0038] (2) Add 2 mol of octylphenol polyoxyethylene ether to mixture 1, adjust the pH to neutral with hydrochloric acid, add 7 g of p-toluenesulfonic acid, heat up to 75 °C to vacuum-remove water, and continue to heat up to 127 °C for reaction for 6 h; obtain mixture 2;

[0039] (3) Add 4.4 mol of sodium hydroxide and 570 mL of toluene to mixture 2, mix evenly, heat up to 118 °C and keep warm for 6 h; cool down to 67 °C, add 3.6 mol of sodium chloroacetate, keep warm for 9.5 h, add hydrochloric acid to adjust the pH to neutral, remove toluene and water under reduced pressure, add 550 mL of ethanol, filter while it is hot, and remove ethanol by rotary evaporation under reduced pressure to obtain the non-ionic surfactant.

[0040] The molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

[0041] The molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

[0042] The structural formula of the non-ionic surfactant is:

[0043]

[0044] The polyoxyethylene alkyl ether is a mixture of three kinds of polyoxyethylene alkyl ethers compounded, and the molecular formulas of the three kinds of polyoxyethylene alkyl ethers are successively: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH.

[0045] Polyoxyethylene(10) tridecyl ether, C 13 H 27 (OCH2CH2) 10 OH, CAS: 78330 - 21 - 9.

[0046] Polyoxyethylene(10) cetyl ether, C 16 H 33 (OCH2CH2) 10 OH, CAS: 9004 - 95 - 9.

[0047] Polyoxyethylene(12) tridecyl ether, C 13 H 27 (OCH2CH2) 12 OH, CAS: 78330 - 21 - 9.

[0048] C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 The mass ratio of OH is 1:1.6:0.4.

[0049] Quaternary ammonium salt cationic fluorocarbon surfactant, CAS: 84166 - 37 - 0.

[0050] Example 2

[0051] This example provides a high - temperature acidification demulsifier, and the preparation method is as follows: By mass, 6.5 parts of demulsifier SP169, 4 parts of non - ionic surfactant, 1 part of polyoxyethylene alkyl ether, 0.8 part of quaternary ammonium salt cationic fluorocarbon surfactant and 8 parts of water are mixed and stirred evenly to obtain the demulsifier.

[0052] The preparation method of the non - ionic surfactant:

[0053] (1) 1 mol of dodecylphenol polyoxyethylene ether, 0.6 mol of sodium hydroxide and 3 mol of formaldehyde are mixed, heated to 55 °C, stirred evenly, and then kept for reaction for 7 h to obtain mixture 1;

[0054] (2) 2 mol of octylphenol polyoxyethylene ether is added to mixture 1, the pH is adjusted to neutral with hydrochloric acid, 6 g of p - toluenesulfonic acid is added, heated to 70 °C to vacuum - remove water, and then heated to 125 °C for reaction for 5 h; mixture 2 is obtained;

[0055] (3) Add 4 mol of sodium hydroxide and 550 mL of toluene to the mixed solution 2, mix evenly, heat up to 115 °C and keep warm for 5 h; cool down to 65 °C, add 3.5 mol of sodium chloroacetate, keep warm for 9 h, add hydrochloric acid to adjust the pH to neutral, remove toluene and water under reduced pressure, add 600 mL of ethanol, filter while hot, and remove ethanol by rotary evaporation under reduced pressure to obtain a non-ionic surfactant.

[0056] The molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

[0057] The molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

[0058] The structural formula of the non-ionic surfactant is:

[0059]

[0060] The polyoxyethylene alkyl ether is a mixture of three kinds of polyoxyethylene alkyl ethers compounded, and the molecular formulas of the three kinds of polyoxyethylene alkyl ethers are successively: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH.

[0061] Polyoxyethylene (10) tridecyl ether, C 13 H 27 (OCH2CH2) 10 OH, CAS: 78330-21-9.

[0062] Polyoxyethylene (10) cetyl ether, C 16 H 33 (OCH2CH2) 10 OH, CAS: 9004-95-9.

[0063] Polyoxyethylene (12) tridecyl ether, C 13 H 27 (OCH2CH2) 12 OH, CAS: 78330-21-9.

[0064] C 13 H 27 (OCH2CH2) 10 OH, C16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 The mass ratio of OH to C

[0065] Quaternary ammonium salt cationic fluorocarbon surfactant, CAS: 84166-37-0.

[0066] Example 3

[0067] This example provides a high-temperature acidification demulsifier, and the preparation method is as follows: By mass, 10 parts of demulsifier SP169, 2.7 parts of non-ionic surfactant, 4 parts of polyoxyethylene alkyl ether, 1.5 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 9 parts of water are mixed and stirred evenly to obtain the demulsifier.

[0068] The preparation method of the non-ionic surfactant is as follows:

[0069] (1) Mix 1 mol of dodecylphenol polyoxyethylene ether, 0.9 mol of sodium hydroxide, and 3 mol of formaldehyde, heat up to 60 °C, stir evenly, and keep the temperature for reaction for 9 h to obtain mixture 1;

[0070] (2) Add 2 mol of octylphenol polyoxyethylene ether to mixture 1, adjust the pH to neutral with hydrochloric acid, add 8 g of p-toluenesulfonic acid, heat up to 80 °C to remove water under vacuum, and continue to heat up to 130 °C for reaction for 7 h; obtain mixture 2;

[0071] (3) Add 5 mol of sodium hydroxide and 600 mL of toluene to mixture 2, mix evenly, heat up to 120 °C and keep the temperature for 6 h; cool down to 70 °C, add 3.8 mol of sodium chloroacetate, keep the temperature for 10 h, add hydrochloric acid to adjust the pH to neutral, remove toluene and water under reduced pressure, add 600 mL of ethanol, filter while it is hot, and remove ethanol by rotary evaporation under reduced pressure to obtain the non-ionic surfactant.

[0072] The molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

[0073] The molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

[0074] The structural formula of the non-ionic surfactant is:

[0075]

[0076] The polyoxyethylene alkyl ether is a mixture of three kinds of polyoxyethylene alkyl ethers compounded, and the molecular formulas of the three kinds of polyoxyethylene alkyl ethers are successively: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH.

[0077] Polyoxyethylene(10) tridecyl ether, C 13 H 27 (OCH2CH2) 10 OH, CAS: 78330-21-9.

[0078] Polyoxyethylene(10) hexadecyl ether, C 16 H 33 (OCH2CH2) 10 OH, CAS: 9004-95-9.

[0079] Polyoxyethylene(12) tridecyl ether, C 13 H 27 (OCH2CH2) 12 OH, CAS: 78330-21-9.

[0080] C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH have a mass ratio of 1:1.8:0.6.

[0081] Quaternary ammonium salt cationic fluorocarbon surfactant, CAS: 84166-37-0.

[0082] Example 4

[0083] This example provides a high-temperature acidification demulsifier, and the preparation method is: by mass, mix 8 parts of demulsifier SP169, 2 parts of non-ionic surfactant, 3.7 parts of polyoxyethylene alkyl ether, 1.1 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 10 parts of water, and stir evenly to obtain the demulsifier.

[0084] The preparation method of the non-ionic surfactant:

[0085] (1) Mix 1 mol of dodecylphenol polyoxyethylene ether, 0.8 mol of sodium hydroxide, and 2.2 mol of formaldehyde, heat up to 55 °C, stir evenly, and keep the reaction at this temperature for 7.5 h to obtain mixture 1;

[0086] (2) Add 2 mol of octylphenol polyoxyethylene ether to mixture 1, adjust the pH to neutral with hydrochloric acid, add 6.4 g of p-toluenesulfonic acid, heat up to 72 °C and evacuate to remove water, then continue to heat up to 127 °C and react for 5.2 h; obtain mixture 2;

[0087] (3) Add 4.2 mol of sodium hydroxide and 555 mL of toluene to mixture 2, mix evenly, heat up to 119 °C and keep the temperature for 6 h; cool down to 68 °C, add 3.7 mol of sodium chloroacetate, keep the temperature for 10 h, add hydrochloric acid to adjust the pH to neutral, remove toluene and water under reduced pressure, add 510 mL of ethanol, filter while it is hot, and remove ethanol by rotary evaporation under reduced pressure to obtain a non-ionic surfactant.

[0088] The molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

[0089] The molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

[0090] The structural formula of the said non-ionic surfactant is:

[0091]

[0092] The said polyoxyethylene alkyl ether is a mixture of three kinds of polyoxyethylene alkyl ethers compounded, and the molecular formulas of the three kinds of polyoxyethylene alkyl ethers are in turn: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH.

[0093] Polyoxyethylene(10) tridecyl ether, C 13 H 27 (OCH2CH2) 10 OH, CAS: 78330-21-9.

[0094] Polyoxyethylene(10) cetyl ether, C 16 H 33(OCH2CH2) 10 OH, CAS: 9004-95-9.

[0095] Polyoxyethylene (12) tridecyl ether, C 13 H 27 (OCH2CH2) 12 OH, CAS: 78330-21-9.

[0096] C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 The mass ratio of OH is 1:1.5:0.3.

[0097] Quaternary ammonium salt cationic fluorocarbon surfactant, CAS: 84166-37-0.

[0098] Example 5

[0099] This example provides a high-temperature acidification demulsifier, and the preparation method is as follows: by mass, 7.5 parts of demulsifier SP169, 3 parts of non-ionic surfactant, 3 parts of polyoxyethylene alkyl ether, 0.9 part of quaternary ammonium salt cationic fluorocarbon surfactant and 5 parts of water are mixed and stirred evenly to obtain the demulsifier.

[0100] The preparation method of the non-ionic surfactant:

[0101] (1) 1 mol of dodecylphenol polyoxyethylene ether, 0.8 mol of sodium hydroxide, and 3 mol of formaldehyde are mixed, heated to 59 °C, stirred evenly, and then kept at a constant temperature for reaction for 8.2 h to obtain mixture 1;

[0102] (2) 2 mol of octylphenol polyoxyethylene ether is added to mixture 1, the pH is adjusted to neutral with hydrochloric acid, 7 g of p-toluenesulfonic acid is added, heated to 79 °C to vacuum-remove water, and then heated to 129 °C for reaction for 6.7 h; to obtain mixture 2;

[0103] (3) 4.8 mol of sodium hydroxide and 557 mL of toluene are added to mixture 2, mixed evenly, heated to 117 °C and kept at a constant temperature for 6 h; cooled to 67 °C, 3.8 mol of sodium chloroacetate is added, kept at a constant temperature for 9 h, the pH is adjusted to neutral with hydrochloric acid, toluene and water are removed under reduced pressure, 600 mL of ethanol is added, filtered while hot, and ethanol is removed by rotary evaporation under reduced pressure to obtain the non-ionic surfactant.

[0104] The molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

[0105] The molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

[0106] The structural formula of the non-ionic surfactant is:

[0107]

[0108] The polyoxyethylene alkyl ether is a mixture of three polyoxyethylene alkyl ethers compounded, and the molecular formulas of the three polyoxyethylene alkyl ethers are successively: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH.

[0109] Polyoxyethylene(10) tridecyl ether, C 13 H 27 (OCH2CH2) 10 OH, CAS: 78330-21-9.

[0110] Polyoxyethylene(10) hexadecyl ether, C 16 H 33 (OCH2CH2) 10 OH, CAS: 9004-95-9.

[0111] Polyoxyethylene(12) tridecyl ether, C 13 H 27 (OCH2CH2) 12 OH, CAS: 78330-21-9.

[0112] C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH have a mass ratio of 1:1.7:0.5.

[0113] Quaternary ammonium salt cationic fluorocarbon surfactant, CAS: 84166-37-0.

[0114] Example 6

[0115] This example provides a high-temperature acidification demulsifier, and the preparation method is as follows: By mass, 6 parts of demulsifier SP169, 3 parts of non-ionic surfactant, 2 parts of polyoxyethylene alkyl ether, 1.5 parts of quaternary ammonium salt cationic fluorocarbon surfactant, and 6 parts of water are mixed and stirred evenly to obtain the demulsifier.

[0116] The preparation method of the non-ionic surfactant:

[0117] (1) 1 mol of dodecylphenol polyoxyethylene ether, 0.8 mol of sodium hydroxide, and 3 mol of formaldehyde are mixed, heated to 55 °C, stirred evenly, and then kept at a constant temperature for reaction for 9 h to obtain mixture 1;

[0118] (2) 2 mol of octylphenol polyoxyethylene ether is added to mixture 1, the pH is adjusted to neutral with hydrochloric acid, 6 g of p-toluenesulfonic acid is added, the temperature is raised to 80 °C to vacuum-remove water, and the temperature is further raised to 125 °C for reaction for 7 h; mixture 2 is obtained;

[0119] (3) 4.2 mol of sodium hydroxide and 550 mL of toluene are added to mixture 2, mixed evenly, heated to 120 °C and kept at a constant temperature for 5 h; cooled to 70 °C, 3.8 mol of sodium chloroacetate is added, kept at a constant temperature for 9 h, the pH is adjusted to neutral with hydrochloric acid, toluene and water are removed under reduced pressure, 600 mL of ethanol is added, filtered while hot, and ethanol is removed by rotary evaporation under reduced pressure to obtain the non-ionic surfactant.

[0120] The molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

[0121] The molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

[0122] The structural formula of the non-ionic surfactant is:

[0123]

[0124] The polyoxyethylene alkyl ether is a mixture of three polyoxyethylene alkyl ethers compounded, and the structural formulas of the three polyoxyethylene alkyl ethers are successively: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C13 H 27 (OCH2CH2) 12 OH.

[0125] Polyoxyethylene(10) tridecyl ether, C 13 H 27 (OCH2CH2) 10 OH, CAS: 78330-21-9.

[0126] Polyoxyethylene(10) cetyl ether, C 16 H 33 (OCH2CH2) 10 OH, CAS: 9004-95-9.

[0127] Polyoxyethylene(12) tridecyl ether, C 13 H 27 (OCH2CH2) 12 OH, CAS: 78330-21-9.

[0128] C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 The mass ratio of OH is 1:1.8:0.2.

[0129] Quaternary ammonium salt cationic fluorocarbon surfactant, CAS: 84166-37-0.

[0130] Comparative Example 1

[0131] The difference between this comparative example and Example 1 is: A high-temperature acidification demulsifier, the preparation method is: by mass, mix 8.4 parts of demulsifier SP169, 5 parts of polyethylene glycol octadecyl ether (CAS: 9005-00-9), 2 parts of polyoxyethylene alkyl ether, 1.2 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 7 parts of water, and stir evenly to obtain the demulsifier.

[0132] Comparative Example 2

[0133] The difference between this comparative example and Example 1 is: A high-temperature acidification demulsifier, the preparation method is: by mass, mix 8.4 parts of demulsifier SP169, 5 parts of non-ionic surfactant, 2 parts of dodecyl phosphate (CAS: 12751-23-4), 1.2 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 7 parts of water, and stir evenly to obtain the demulsifier.

[0134] Comparative Example 3

[0135] The difference between this comparative example and Example 1 is as follows: A high-temperature acidification demulsifier, and its preparation method is: by mass, mix 8.4 parts of demulsifier SP169, 5 parts of non-ionic surfactant, 2 parts of polyoxyethylene alkyl ether, 1.2 parts of n-hexadecanol and 7 parts of water, and stir evenly to obtain the demulsifier.

[0136] Comparative Example 4

[0137] The difference between this comparative example and Example 1 is as follows: A high-temperature acidification demulsifier, and its preparation method is: by mass, mix 13.4 parts of demulsifier SP169, 4 parts of non-ionic surfactant, 2 parts of polyoxyethylene alkyl ether, 0.2 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 7 parts of water, and stir evenly to obtain the demulsifier.

[0138] Comparative Example 5

[0139] The difference between this comparative example and Example 1 is as follows: A high-temperature acidification demulsifier, and its preparation method is: by mass, mix 3.4 parts of demulsifier SP169, 1 part of non-ionic surfactant, 7 parts of polyoxyethylene alkyl ether, 5.2 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 7 parts of water, and stir evenly to obtain the demulsifier.

[0140] Comparative Example 6

[0141] The difference between this comparative example and Example 1 is: C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 The mass ratio of O is 1:1:1.

[0142] Comparative Example 7

[0143] The difference between this comparative example and Example 1 is: The polyoxyethylene alkyl ether is a mixture of three kinds of polyoxyethylene alkyl ethers compounded, and the molecular formulas of the three kinds of polyoxyethylene alkyl ethers are in turn: C 12 H 25 (OCH2CH2)8OH, C 13 H 27 (OCH2CH2)8OH and C 12 H 25 (OCH2CH2) 10 OH.

[0144] C 12 H25 (OCH2CH2)8OH, C 13 H 27 (OCH2CH2)8OH and C 12 H 25 (OCH2CH2) 10 The mass ratio of OH is 1:1.6:0.4.

[0145] Performance Test

[0146] I. Preparation of fracturing fluid: (1) Weigh 90 g of potassium formate, measure 60 mL of deionized water, add them to a 200 mL beaker, and stir evenly until the solid is completely dissolved to obtain a potassium formate solution. (2) Take 100 g of the potassium formate solution, add 2.0 g of a partially hydrolyzed polyacrylamide suspension with a polymer effective content of 30 wt% (molecular weight 25 million, hydrolysis degree 25%); after the polymer is completely dissolved, add 0.2 g of an organic zirconium crosslinking agent solution (solid content 25%), 0.05 g of polyethyleneimine, and 0.1 g of a demulsifier (prepared in Examples 1 - 6 and Comparative Examples 1 - 7) to obtain a fracturing fluid.

[0147] Test the performance of the fracturing fluid according to SY / T5107 - 2005 "Evaluation Method for Performance of Aqueous Fracturing Fluids". The results are shown in Table 1.

[0148] II. Stability of the demulsifier: Place the demulsifiers prepared in Examples 1 - 6 and Comparative Examples 1 - 7 at 25°C for 6 months, and observe the time of phase separation. The results are shown in Table 1.

[0149] Table 1 Performance Test Results

[0150]

[0151]

[0152] From the results, it can be seen that when the demulsifier of the present invention is added to the fracturing fluid, it has good demulsification performance under the condition of 220°C. From Examples 1 and 6, it can be known that when the mass ratio of the demulsifier SP169 to the sum of the non - ionic surfactant and polyoxyethylene alkyl ether is 1.2:1, the demulsifier has high storage stability.

[0153] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a high-temperature acidizing demulsifier with a gel-breaking effect, characterized in that, The preparation method of the high-temperature acidizing demulsifier with gel-breaking effect is as follows: by mass, mix 4-10 parts of demulsifier SP169, 2-8 parts of non-ionic surfactant, 1-5 parts of polyoxyethylene alkyl ether, 0.8-1.5 parts of quaternary ammonium salt cationic fluorocarbon surfactant and 6-10 parts of water, and stir evenly to obtain the high-temperature acidizing demulsifier with gel-breaking effect; The preparation method of the non-ionic surfactant: (1) Mix 1 mol of dodecylphenol polyoxyethylene ether, 0.6-0.9 mol of sodium hydroxide, and 2-3 mol of formaldehyde, heat up to 55-60 °C, stir evenly, and keep the reaction for 7-9 h to obtain mixture 1; (2) Add 2 mol of octylphenol polyoxyethylene ether to mixture 1, adjust the pH to neutral with hydrochloric acid, add 6-8 g of p-toluenesulfonic acid, heat up to 70-80 °C to remove water under vacuum, and continue to heat up to 125-130 °C for reaction for 5-7 h; obtain mixture 2; (3) Add 4-5 mol of sodium hydroxide and 550-600 mL of toluene to mixture 2, mix evenly, heat up to 115-120 °C and keep warm for 5-7 h; cool down to 65-70 °C, add 3.5-3.8 mol of sodium chloroacetate, keep warm for 9-10 h, add hydrochloric acid to adjust the pH to neutral, remove toluene and water under reduced pressure, add 500-600 mL of ethanol, filter while it is hot, and remove ethanol by rotary evaporation under reduced pressure to obtain the non-ionic surfactant; The structural formula of the non-ionic surfactant is: ； Polyoxyethylene alkyl ether is composed of C 13 H 27 (OCH2CH2) 10 OH, C 16 H 33 (OCH2CH2) 10 OH and C 13 H 27 (OCH2CH2) 12 OH in a mass ratio of 1:1.4 - 1.8:0.2 - 0.6; the CAS number of the quaternary ammonium salt cationic fluorocarbon surfactant is 84166 - 37 - 0.

2. The preparation method according to claim 1, wherein The mass ratio of demulsifier SP169 to the sum of the non-ionic surfactant and polyoxyethylene alkyl ether is 1-1.5:

1.

3. The preparation method according to claim 1, characterized in that, The molecular formula of dodecylphenol polyoxyethylene ether is C 12 H 25 C6H4O(CH2CH2O)6H.

4. The preparation method according to claim 1, characterized in that, The molecular formula of octylphenol polyoxyethylene ether is C8H 17 C6H4O(CH2CH2O)8H.

5. The preparation method according to claim 1, wherein, The mass ratio of demulsifier SP169 to the sum of the non-ionic surfactant and polyoxyethylene alkyl ether is 1-1.3:

1.

6. The preparation method according to claim 1, characterized in that, The mass ratio of demulsifier SP169 to the sum of the non-ionic surfactant and polyoxyethylene alkyl ether is 1.2:

1.

7. The application of a high-temperature acidizing demulsifier with gel-breaking effect prepared by the preparation method according to any one of claims 1-6 in the preparation of fracturing fluid.

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