CN107868658B - Hydrophobic association type guanidine gum for fracturing fluid and preparation method thereof - Google Patents

Abstract

The invention relates to a hydrophobic association modified guanidine gum, which mainly solves the technical problems of lower viscosity and poorer shearing resistance of a conventional guanidine gum solution in the prior art, and is obtained by adopting the hydrophobic association type guanidine gum for fracturing fluid and reacting a reaction system comprising the following components in parts by weight: (1)30-50 parts of hydroxypropyl guar gum; (2)0.05-0.5 parts of hydrophobic monomer; (3)0.1-5 parts of ionic monomer; (4)0.1-5 parts of nonionic monomer, can be used in the oil field fracturing process.

Description

Hydrophobic association type guanidine gum for fracturing fluid and preparation method thereof

Technical Field

The invention relates to a hydrophobic modification method of guar gum, in particular to hydrophobic modification of guar gum to obtain hydrophobic association type guar gum for fracturing construction of oil fields.

Background

The fracturing is an important means for improving the oil recovery ratio of the oil field, and with the further development of the oil field, most of the oil fields in China need to be subjected to fracturing modification, but the fracturing in the exploitation process of an unconventional oil and gas field is one of the core technologies.

Fracturing fluids are an important component of fracturing technology, and galactomannan, commonly known as guar gum, is one of the important components in fracturing fluids. However, as oil and gas exploration and development develop to a deep level, the currently used guanidine gum does not meet the actual use requirements. For example, even the first-grade product of hydroxypropyl guar gum has a water-insoluble content of 8% or more, and the document reports that the so-called super guar gum has a water-insoluble content of 2%. The residues have obvious damage to the stratum and seriously affect the actual use effect of the guar gum. The price fluctuation of the guar gum is another reason influencing the application and popularization of the guar gum. In 2012, the price of the guanidine gum exceeds 15 ten thousand per ton once, and then the guanidine gum falls greatly, which causes serious influence on oil field application.

For the above reasons, much research has been conducted on modifying guar gum. For example, low-damage low-molecular-weight guanidine gum is developed for reducing damage, the content of water-insoluble substances is obviously reduced due to the fact that the molecular weight of the low-molecular-weight guanidine gum is reduced to one tenth to one twentieth of that of the conventional guanidine gum, and meanwhile, the molecular weight of the gel breaking liquid is also obviously reduced, and damage to a stratum is reduced. However, the viscosity of the low molecular weight guar gum solution is obviously reduced compared with the conventional guar gum due to the reduction of the molecular weight, so the low molecular weight guar gum solution is not suitable for high-temperature operation. By combining the reasons, if a stronger tackifying mechanism can be introduced into the guar gum, the viscosity of the guar gum solution under the same concentration can be greatly improved, the use concentration of the guar gum in the solution can be effectively reduced on the basis of meeting the viscosity standard, the reduction of the use concentration is beneficial to reducing the relative residue content in the solution, and meanwhile, the method has an obvious effect on reducing the system application cost.

The research of the hydrophobic association type polymer is mainly focused on the polyacrylamide polymer, a hydrophobic association micro-area can be formed in aqueous solution by introducing a hydrophobic group into a molecular chain, and the association micro-area can be used as a physical crosslinking point to play an effective tackifying role. The hydrophobic association type polyacrylamide has higher viscosity than the conventional polyacrylamide. Meanwhile, the hydrophobic association network is a reversible crosslinking network, can be recovered after being damaged under high-speed shearing, and can effectively improve the shearing stability of the system. The hydrophobic association structure is introduced into the guar gum, so that the use concentration of the guar gum can be effectively reduced on the premise of meeting the viscosity index, the effects of reducing the relative use amount of residues in a system and reducing the use cost are further achieved, and the introduction of the physical crosslinking network further improves the anti-shearing performance of the guar gum solution.

Disclosure of Invention

One of the technical problems to be solved by the invention is the problems of low viscosity and poor anti-shearing performance of the conventional guanidine gum solution in the prior art, and the hydrophobic association type guanidine gum for the fracturing fluid is provided.

The second technical problem to be solved by the invention is to provide a preparation method of hydrophobic association type guanidine gum for fracturing fluid, which solves one of the technical problems.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows: the hydrophobic association type guanidine gum for the fracturing fluid is obtained by reacting a reaction system comprising the following components in parts by weight:

(1)30-50 parts of hydroxypropyl guar gum;

(2)0.05-0.5 parts of hydrophobic monomer;

(3)0.1-5 parts of ionic monomer;

(4)0.1-5 parts of nonionic monomer.

In the above technical scheme, the ionic monomer is preferably at least one selected from acrylic acid, methacrylic acid, sodium vinylsulfonate, p-vinylbenzenesulfonic acid, sodium allylsulfonate, sodium 2-acrylamido-2-methylpropanesulfonate, methacryloyloxyethyl trimethyl ammonium chloride, 2-acrylamido-2-methylpropyltrimethyl ammonium chloride, dimethylethyl allyl ammonium chloride, dimethyldiallyl ammonium chloride and acryloyloxyethyl trimethyl ammonium chloride.

In the above technical solution, the nonionic monomer is preferably at least one selected from acrylamide, methacrylamide, dimethylacrylamide, diethylacrylamide, methylolacrylamide, dimethylaminoethyl methacrylate, and vinylpyrrolidone.

In the above technical solution, the hydrophobic monomer is selected from at least one of the following general formulas:

in the formula, R₀、R₅Is H or methyl, R₁、R₂、R₆Is C₁～C₂₂Alkyl chain of carbon atoms, A being-COOH, -SO₃H、-SO₃Na, amido, -CONHRSO₃H、-CONHRSO₃Na；R₃And R₄Is independently selected from C₁～C₄X is halogen.

In the above technical solution, the reaction system further preferably includes:

(5)100-200 parts of an oil solvent;

(6)0.002-0.1 part of initiator;

(7)30-50 parts of deionized water;

(8)1-5 parts of an emulsifier.

In the above technical solution, the emulsifier is preferably at least one selected from sorbitan trioleate, sorbitan tripurate, sorbitan monooleate, sorbitan monostearate, sorbitan monopalmitate, sorbitan monolaurate, polyethylene glycol oleate, polyethylene glycol laurate, polyoxyethylene sorbitan ester shown in formula (i), fatty alcohol polyoxyethylene ether shown in formula (ii), and alkylphenol polyoxyethylene ether shown in formula (iii):

wherein a + b + c + d is equal to 20, 40, 60, 80; r₁、R₂Each independently selected from C₁-C₁₆Linear or branched alkyl of (a); e. f is respectively and independently 5-80.

In the above technical solution, the oil solvent is preferably at least one selected from aliphatic hydrocarbon, mineral oil or vegetable oil; the aliphatic hydrocarbon is at least one of n-hexane, cyclohexane, heptane and octane. The mineral oil is selected from at least one of white oil (3#, 5#, 7#, 11#, 15#, 18#), diesel oil, kerosene and liquid paraffin. The vegetable oil is at least one of peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil and olive oil.

In the above technical solution, the initiator is preferably at least one selected from the group consisting of cerium ammonium nitrate, persulfate, potassium persulfate, sodium persulfate and hydrogen peroxide, and more preferably at least one selected from the group consisting of cerium ammonium nitrate and potassium persulfate.

In order to solve the second problem, the invention adopts the following technical scheme: a preparation method of hydrophobic association type guanidine gum for fracturing fluid comprises the following steps:

1) dispersing the required amount of guar gum powder in an oil solvent, adding the dispersion into a reaction kettle, stirring and dispersing at a stirring speed of 300-500r/min, and introducing inert gas for protection;

2) dissolving a hydrophobic monomer, an ionic monomer, a nonionic monomer and an emulsifier in deionized water to prepare an aqueous solution, and adjusting the pH value to be between 7 and 11;

3) slowly dripping the monomer aqueous solution into a reaction kettle while stirring, and controlling the temperature of a jacket of the reaction kettle to be 30-40 ℃;

4) preparing an initiator into an aqueous solution, slowly dripping the aqueous solution into a reaction kettle at a dripping speed of not more than 0.5 mL/min;

5) introducing inert gas for protection at 30-40 ℃, stirring for not less than 0.5 hour, heating to 60-70 ℃, and continuing to react for not less than 0.5 hour;

6) and taking out the reaction product, separating, drying and crushing to obtain the hydrophobic association type guanidine gum for the fracturing fluid.

In the technical scheme, the acceleration of the drop of the monomer aqueous solution in the step 3) is preferably not more than 1 mL/min; after the monomer aqueous solution is added in the step 3), controlling the temperature of a jacket of the reaction kettle to be 30-40 ℃, and preferably continuously stirring for not less than 2 hours; introducing inert gas for protection and stirring for not less than 1 hour at the temperature of 30-40 ℃ in the step 5); the temperature is raised to 60-70 ℃ to continue the reaction for preferably not less than 1 hour.

In the above technical solution, the inert gas may be various inert gases commonly used in the art, such as nitrogen.

The key point of the invention is that the guar gum powder is dispersed in the oil phase to form a dispersion system, and the comonomer solution to be grafted is slowly added, so that the guar gum powder can uniformly absorb the monomer aqueous solution, thereby ensuring the uniformity of the grafting reaction, and simultaneously reducing the amount of water added in the guar gum powder as low as possible to reduce the energy consumption of post-treatment and improve the efficiency. The initiator can form free radical active points on a guanidine gum molecular chain, and further initiates the polymerization of the comonomer to form a side chain, and a hydrophobic side group is formed on the guanidine gum molecular chain.

Compared with unmodified guar gum and modified guar gum modified under the same condition but without hydrophobic chains, the hydrophobically modified hydroxypropyl guar gum for the fracturing fluid in the technical scheme of the invention has obviously increased viscosity, and the viscosity is increased by more than 60% under the same concentration, thereby obtaining better technical effect.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

Dispersing 40 parts of hydroxypropyl guar gum in 100 parts of cyclohexane, stirring and dispersing at 500r/min, and introducing inert gas for protection. 5 parts of acrylamide, 0.4 part of 2-acrylamide dodecyl sodium sulfonate, 0.5 part of 2-acrylamide-2-methylpropanesulfonic acid, 2 parts of span 80 and 0.05 part of tween 60 are dissolved in 40 parts of water to prepare an aqueous solution, and the pH value is adjusted to be 9.0. The aqueous monomer solution is slowly added dropwise into the reaction vessel at a rate of 1 mL/min. Stirring was continued for 2 hours with the reactor jacket temperature controlled at 30 ℃. 0.05 part of ammonium ceric nitrate is prepared into an aqueous solution in 10 parts of deionized water, and the aqueous solution is slowly dripped into the reaction kettle at the dripping speed of 0.5 mL/min. Introducing inert gas for protection and stirring at the temperature of 30 ℃, reacting for 60min, then heating to 60 ℃, and continuing to react for 60 min. Taking out the reaction product, centrifugally separating, drying and crushing for later use.

The product obtained in example 1, KCl solution with the mass percentage concentration of 2% is used as a solvent to prepare solution with the concentration of 6000mg/L, and when the solution is kept stand and aged for 24 hours, the shear viscosity at 140 ℃ and 1701/s shear rate under a Haake rotational rheometer is shown as # 1 in Table 1. It can be seen that the viscosity of the hydrophobically modified hydroxypropyl guar is obviously increased compared with the unmodified guar and the modified guar modified under the same conditions but without hydrophobic chains, and the viscosity is increased by 60% under the same concentration, which proves that the hydrophobic association structure effectively increases the viscosity of the aqueous solution.

[ example 2 ]

Dispersing 40 parts of hydroxypropyl guar gum in 100 parts of cyclohexane, stirring and dispersing at 500r/min, and introducing inert gas for protection. 5 parts of acrylamide, 0.4 part of dodecyl dimethyl allyl ammonium chloride, 0.5 part of 2-acrylamide-2-methyl propanesulfonic acid, 2 parts of span 80 and 0.05 part of tween 60 are dissolved in 40 parts of water to prepare an aqueous solution, and the pH value is adjusted to 9.0. The monomer aqueous solution is slowly added dropwise into a reaction kettle at a rate of 1 ml/min. Stirring was continued for 2 hours with the reactor jacket temperature controlled at 30 ℃. 0.05 part of ammonium ceric nitrate is prepared into an aqueous solution in 10 parts of deionized water, and the aqueous solution is slowly dripped into the reaction kettle at the dripping speed of 0.5 ml/min. Introducing inert gas for protection and stirring at the temperature of 30 ℃, reacting for 60min, then heating to 60 ℃, and continuing to react for 60 min. Taking out the reaction product, centrifugally separating, drying and crushing for later use.

The product obtained in example 2, KCl solution with the mass percentage concentration of 2% is used as a solvent to prepare solution with the concentration of 6000mg/L, and when the solution is kept stand and aged for 24 hours, the shear viscosity at 140 ℃ and 1701/S shear rate under a Haake rotational rheometer is shown as # 2 in Table 1. It can be seen that the viscosity of the hydrophobically modified hydroxypropyl guar is obviously increased compared with the unmodified guar and the modified guar modified under the same conditions but without hydrophobic chains, and the viscosity is increased by 50% under the same concentration, which proves that the hydrophobic association structure effectively increases the viscosity of the aqueous solution.

[ example 3 ]

Dispersing 40 parts of hydroxypropyl guar gum in 100 parts of cyclohexane, stirring and dispersing at 500r/min, and introducing inert gas for protection. 5 parts of acrylamide, 0.4 part of N-dodecyl acrylamide, 0.5 part of 2-acrylamide-2-methylpropanesulfonic acid, 2 parts of span 80 and 0.05 part of Tween 60 are dissolved in 40 parts of water to prepare an aqueous solution, and the pH value is adjusted to 9.0. The monomer aqueous solution is slowly added dropwise into a reaction kettle at a rate of 1 ml/min. Stirring was continued for 2 hours with the reactor jacket temperature controlled at 30 ℃. 0.05 part of ammonium ceric nitrate is prepared into an aqueous solution in 10 parts of deionized water, and the aqueous solution is slowly dripped into the reaction kettle at the dripping speed of 0.5 ml/min. Introducing inert gas for protection and stirring at the temperature of 30 ℃, reacting for 60min, then heating to 60 ℃, and continuing to react for 60 min. Taking out the reaction product, centrifugally separating, drying and crushing for later use.

The product obtained in example 3, KCl solution with the mass percentage concentration of 2% is used as a solvent to prepare solution with the concentration of 6000mg/L, and when the solution is kept stand and cured for 24 hours, the shear viscosity at 140 ℃ and 1701/S shear rate under a Haake rotational rheometer is shown as # 3 in Table 1. It can be seen that the viscosity of the hydrophobically modified hydroxypropyl guar is obviously increased compared with unmodified guar and modified guar which does not contain hydrophobic chains under the same modification conditions, and the viscosity is increased by 50% under the same concentration, thus proving that the viscosity of the aqueous solution is effectively increased by the hydrophobic association structure.

[ COMPARATIVE EXAMPLE 1 ]

Dispersing 40 parts of hydroxypropyl guar gum in 100 parts of cyclohexane, stirring and dispersing at 500r/min, and introducing inert gas for protection. 5 parts of acrylamide, 0.9 part of 2-acrylamide-2-methylpropanesulfonic acid, 2 parts of span 80 and 0.05 part of tween 60 are dissolved in 40 parts of water to prepare an aqueous solution, and the pH value is adjusted to 9.0. The monomer aqueous solution is slowly added dropwise into a reaction kettle at a rate of 1 ml/min. Stirring was continued for 2 hours with the reactor jacket temperature controlled at 30 ℃. 0.05 part of ammonium ceric nitrate is prepared into an aqueous solution in 10 parts of deionized water, and the aqueous solution is slowly dripped into the reaction kettle at the dripping speed of 0.5 ml/min. Introducing inert gas for protection and stirring at the temperature of 30 ℃, reacting for 60min, then heating to 60 ℃, and continuing to react for 60 min. Taking out the reaction product, centrifugally separating, drying and crushing for later use.

The product obtained in comparative example 1 was dissolved in 2% by mass KCl to prepare a solution of 6000mg/L, and the solution was left to stand for aging for 24 hours, and the shear viscosity at 140 ℃ and 1701/S shear rate was measured by Haake rotational rheometer and is shown as # 4 in Table 1. It can be seen that under the same modification conditions, the modified guar gum containing no hydrophobic chain has no obvious viscosity change because hydrophobic association micro-domains can not be formed in aqueous solution.

[ COMPARATIVE EXAMPLE 2 ]

Untreated hydroxypropyl guar was formulated in a 2% KCl solution at a concentration of 6000mg/L and left to stand for 24 hours to age, and the shear viscosity at 1701/S shear rate was as shown in # 5 in Table 1 at 140 ℃ as measured on a Haake rotational rheometer. The viscosity of the aqueous solution of unmodified guar gum is smaller than that of the hydrophobically associating modified guar gum, and the viscosity requirement can be met only by using larger concentration.

[ COMPARATIVE EXAMPLE 3 ]

Dispersing 40 parts of hydroxypropyl guar gum in 100 parts of cyclohexane, stirring and dispersing at 500r/min, and introducing inert gas for protection. 5.9 parts of acrylamide, 2 parts of span 80 and 0.05 part of Tween 60 are dissolved in 40 parts of water to prepare an aqueous solution, and the pH value is adjusted to 9.0. The monomer aqueous solution is slowly added dropwise into a reaction kettle at a rate of 1 ml/min. Stirring was continued for more than 2 hours and the reactor jacket temperature was controlled at 30 ℃. 0.05 part of ammonium ceric nitrate is prepared into an aqueous solution in 10 parts of deionized water, and the aqueous solution is slowly dripped into the reaction kettle at the dripping speed of 0.5 ml/min. Introducing inert gas for protection and stirring at the temperature of 30 ℃, reacting for 60min, then heating to 60 ℃, and continuing to react for 60 min. Taking out the reaction product, centrifugally separating, drying and crushing for later use.

The product obtained in comparative example 3 was dissolved in 2% by mass KCl to prepare a solution of 6000mg/L, and the solution was left to stand for aging for 24 hours, and the shear viscosity at 140 ℃ and 1701/S shear rate was measured by Haake rotational rheometer and is shown as # 4 in Table 1. Under the same modification condition, the viscosity of the product is obviously reduced due to the lack of the salt-resistant monomer 2-acrylamide-2-methylpropanesulfonic acid in the formula, because the 2-acrylamide-2-methylpropanesulfonic acid has large side groups, the rigidity of a molecular chain can be increased, the shrinkage of the molecular chain in saline is inhibited, and meanwhile, the sulfonate can effectively improve the salt resistance of the polymer, so the viscosity of the product after the lack of the salt is obviously reduced.

[ COMPARATIVE EXAMPLE 4 ]

Dispersing 40 parts of hydroxypropyl guar gum in 100 parts of cyclohexane, stirring and dispersing at 500r/min, and introducing inert gas for protection. 5.9 parts of 2-acrylamide sodium dodecyl sulfate, 2 parts of span 80 and 0.05 part of Tween 60 are dissolved in 40 parts of water to prepare an aqueous solution, and the pH value is adjusted to 9.0. The monomer aqueous solution is slowly added dropwise into a reaction kettle at a rate of 1 ml/min. Stirring was continued for 2 hours with the reactor jacket temperature controlled at 30 ℃. 0.05 part of ammonium ceric nitrate is prepared into an aqueous solution in 10 parts of deionized water, and the aqueous solution is slowly dripped into the reaction kettle at the dripping speed of 0.5 ml/min. Introducing inert gas for protection and stirring at the temperature of 30 ℃, reacting for 60min, then heating to 60 ℃, and continuing to react for 60 min. Taking out the reaction product, centrifugally separating, drying and crushing for later use.

The product obtained in comparative example 4 was dissolved in 2% by mass KCl to prepare a solution of 6000mg/L, and the solution was left to stand for aging for 24 hours, and the shear viscosity at 140 ℃ and 1701/S shear rate was measured by Haake rotational rheometer and is shown as # 7 in Table 1. Under the same modification condition, if no acrylamide exists in the polymerization, the pure 2-acrylamide-2-methylpropanesulfonic acid is used as a main comonomer, and as the molecular side group is larger and the steric hindrance is larger, a longer graft chain cannot be formed, and the polymer chain generated by polymerization is shorter, the performance of the guanidine gum cannot be obviously improved, so that the viscosity value is close to that of unmodified guanidine gum. Compared with comparative examples 1, 3 and 4, the modified formula has the advantages that the nonionic monomer acrylamide, the ionic monomer 2-acrylamide-2-methylpropanesulfonic acid and the hydrophobic monomer are not available, and the performance of the guar gum can be obviously improved only through the synergistic effect of the nonionic monomer acrylamide, the ionic monomer 2-acrylamide-2-methylpropanesulfonic acid and the hydrophobic monomer.

TABLE 1 sample Performance List of examples and comparative examples

Numbering	1#	2#	3#	4#	5#	6#	7#
								Viscosity mPaS	82.2	79.7	78.2	55.1	53.3	65.5	56.3

Claims (9)

1. The hydrophobic association type guanidine gum for the fracturing fluid is obtained by reacting a reaction system comprising the following components in parts by weight:

(1)30-50 parts of hydroxypropyl guar gum;

(2)0.05-0.5 parts of hydrophobic monomer;

(3)0.1-5 parts of ionic monomer;

(4)0.1-5 parts of a nonionic monomer;

the hydrophobic monomer is selected from at least one of the following formulas:

，（Ⅰ）；

，（Ⅱ）；

，（Ⅲ）；

in the formula, R₀、R₅Is H or methyl, R₁、R₂、R₆Is C₁~C₂₂Alkyl chain of carbon atoms, A being-COOH, -SO₃H、-SO₃Na, amido, -CONHRSO₃H、-CONHRSO₃Na；R₃And R₄Is independently selected from C₁~C₄X is halogen;

the ionic monomer is selected from anionic monomers or cationic monomers; the anionic monomer is at least one selected from acrylic acid, methacrylic acid, sodium vinylsulfonate, p-vinylbenzenesulfonic acid, sodium allylsulfonate and sodium 2-acrylamido-2-methylpropanesulfonate; the cationic monomer is selected from at least one of methacryloxyethyl trimethyl ammonium chloride, 2-acrylamide-2-methylpropyl trimethyl ammonium chloride, dimethyl ethyl allyl ammonium chloride, dimethyl diallyl ammonium chloride and acryloxyethyl trimethyl ammonium chloride;

the hydrophobic association type guanidine gum for the fracturing fluid is prepared by the following steps:

1) dispersing guanidine gum powder in an oil solvent, adding the oil solvent into a reaction kettle, stirring and dispersing, and introducing inert gas for protection;

2) dissolving a hydrophobic monomer, an ionic monomer, a nonionic monomer and an emulsifier in deionized water to prepare an aqueous solution, and adjusting the pH value to be between 7 and 11;

3) slowly dripping the monomer aqueous solution into a reaction kettle while stirring, and controlling the temperature of a jacket of the reaction kettle at 30-40 ℃;

4) preparing an initiator into an aqueous solution, slowly dripping the aqueous solution into a reaction kettle at a dripping speed of not more than 0.5 mL/min;

5) introducing inert gas for protection at 30-40 ℃, stirring for not less than 0.5 hour, heating to 60-70 ℃, and continuing to react for not less than 0.5 hour;

6) and taking out the reaction product, separating, drying and crushing to obtain the hydrophobic association type guanidine gum for the fracturing fluid.

2. The hydrophobic association type guanidine gum for fracturing fluid of claim 1, wherein the nonionic monomer is at least one selected from acrylamide, methacrylamide, dimethylacrylamide, diethylacrylamide, methylolacrylamide, dimethylaminoethyl methacrylate, and vinyl pyrrolidone.

3. The hydrophobic association type guanidine gum for fracturing fluid according to any one of claims 1 to 2, wherein the reaction system further comprises:

(5)100-200 parts of an oil solvent;

(6)0.002-0.1 part of initiator;

(7)30-50 parts of deionized water;

(8)1-5 parts of an emulsifier.

4. The hydrophobic association type guanidine gum for fracturing fluid of claim 3, wherein the oil solvent is at least one selected from aliphatic hydrocarbon, mineral oil or vegetable oil.

5. The hydrophobically associating type guanidine gum for fracturing fluids according to claim 3, wherein the initiator is at least one selected from the group consisting of ammonium cerium nitrate, persulfate, and hydrogen peroxide.

6. The hydrophobically associating type guanidine gum for fracturing fluids of claim 3, wherein the initiator is at least one selected from the group consisting of ammonium cerium nitrate and potassium persulfate.

7. The hydrophobically associative guanidine gum for fracturing fluids according to claim 3, wherein the emulsifier is at least one selected from sorbitan trioleate, sorbitan tristearate, sorbitan monooleate, sorbitan monostearate, sorbitan monopalmitate, sorbitan monolaurate, polyethylene glycol oleate, polyethylene glycol laurate, polyoxyethylene sorbitan ester represented by formula (I), fatty alcohol polyoxyethylene ether represented by formula (II), and alkylphenol polyoxyethylene ether represented by formula (III):

， (Ⅰ)；

， (Ⅱ)；

， (Ⅲ)；

wherein a + b + c + d is equal to 20, 40, 60, 80; r₁、R₂Each independently selected from C₁-C₁₆Linear or branched alkyl of (a); e. f is respectively and independently 5-80.

8. The hydrophobically associative guanidine gum for fracturing fluids according to claim 5, wherein:

the persulfate is at least one of potassium persulfate and sodium persulfate.

9. A preparation method of the hydrophobic association type guanidine gum for the fracturing fluid as claimed in any one of claims 1 to 8, comprising the following steps:

1) dispersing the required amount of guar gum powder in an oil solvent, adding the dispersion into a reaction kettle, stirring and dispersing at a stirring speed of 300-500r/min, and introducing inert gas for protection;

2) dissolving a hydrophobic monomer, an ionic monomer, a nonionic monomer and an emulsifier in deionized water to prepare an aqueous solution, and adjusting the pH value to be between 7 and 11;

3) slowly dripping the monomer aqueous solution into a reaction kettle while stirring, and controlling the temperature of a jacket of the reaction kettle at 30-40 ℃;

4) preparing an initiator into an aqueous solution, slowly dripping the aqueous solution into a reaction kettle at a dripping speed of not more than 0.5 mL/min;

5) introducing inert gas for protection at 30-40 ℃, stirring for not less than 0.5 hour, heating to 60-70 ℃, and continuing to react for not less than 0.5 hour;

6) and taking out the reaction product, separating, drying and crushing to obtain the hydrophobic association type guanidine gum for the fracturing fluid.