An efficient viscosity reducer with a branched structure, its preparation method and application

Abstract

The present invention relates to an efficient viscosity reducer with a branched structure, a preparation method thereof and an application. The viscosity reducer is prepared by an addition reaction of a (meth)acrylate with a branched structure and a hydrosilyl siloxane with a symmetric Si-O-Si structure centered on a silicon-hydrogen bond. The viscosity reducer can efficiently reduce the viscosity of crude oil at room temperature, and when used for reducing the viscosity of crude oil, it does not need to be compounded with other substances such as emulsifiers. At the same time, the viscosity reducer can be used for reducing the viscosity of an aqueous emulsion system.

Description

Technical Field

[0001] The present invention specifically relates to a highly efficient branched viscosity reducer and a preparation method and application thereof. Background Art

[0002] As an important product in the petroleum industry, crude oil plays a vital role in my country's economy. However, due to its complex composition and the presence of a large amount of colloids and other sediments, crude oil often exhibits higher viscosity at lower temperatures, which poses a challenge to the oil recovery efficiency of oil wells. At present, there is no large-scale low-temperature viscosity reducer for crude oil that has been widely used. Usually, emulsification viscosity reduction has to be used to deal with high-viscosity crude oil. However, this method not only wastes water resources, but also increases oil recovery costs. In addition, high-viscosity crude oil will also bring resistance to pipeline transportation and refining processes, easily causing problems such as equipment blockage and incomplete refining, resulting in a waste of resources.

[0003] There are many types of crude oil viscosity reducers in the prior art, with different performances. However, traditional crude oil viscosity reducers usually need to be used under the condition of crude oil heating to be effective, which brings great inconvenience to use, and is also limited by the conditions of use, increasing the cost of use. In addition, these traditional crude oil viscosity reducers usually need to be compounded with other substances such as emulsifiers, and the material selection process is very cumbersome. In the compounding process, not only is it necessary to select a suitable solvent, but also to ensure that the activity of the active ingredient will not be reduced. Summary of the invention

[0004] The purpose of the present invention is to provide an efficient branched viscosity reducer, which can effectively reduce the viscosity of crude oil at room temperature, and when used for reducing the viscosity of crude oil, it does not need to be compounded with other substances such as emulsifiers, and the viscosity reducer can be used for reducing the viscosity of aqueous emulsion systems.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A branched viscosity reducer having a structure shown in Formula I, Formula II or Formula III:

[0007]

[0008]

[0009] in,

[0010] R1 is independently H or methyl;

[0011] R2 is independently C1-C6 alkyl;

[0012] And in Formula I, each R1 is the same, each R2 is the same;

[0013] In Formula II, each R1 is the same, and each R2 is the same;

[0014] In Formula III, each R1 is the same, and each R2 is the same.

[0015] In some embodiments, R1 is H or methyl, and R2 is methyl or ethyl. In some embodiments, R1 is H and R2 is methyl.

[0016] In some embodiments, the viscosity reducer is selected from the following structural formulas:

[0017]

[0018]

[0019] In the prior art, crude oil viscosity reducers, such as acrylate or acrylamide copolymers containing both hydrophilic monomer units and lipophilic monomer units, usually need to be used effectively under the condition of heating crude oil, and usually need to be compounded with other components such as emulsifiers, resulting in inconvenience and high cost. The inventors of the present application have found through research that by using the organosiloxane substances with a branched structure shown in the above Formulas I - III, the viscosity of crude oil can be effectively reduced at room temperature, and effective viscosity reduction can be achieved by using it alone without compounding with other substances such as emulsifiers. The structure of each branched chain segment of the above viscosity reducer is the same, and in each branched chain segment, the siloxane structure is also symmetric. By adopting this specific symmetric structure, the viscosity reducer has high symmetry and isotropy. Furthermore, when the viscosity reducer is fully mixed with the system to be viscosity-reduced, such as crude oil or water-containing emulsion, the intermolecular force between the two has isotropy at the hydrophobic end of the viscosity reducer, and there will be no situation where the internal structure of the system to be viscosity-reduced cannot be uniformly destroyed due to too strong hydrophobicity at one end of the viscosity reducer. Therefore, this specific symmetric structure is beneficial to further improving the viscosity reduction effect of the viscosity reducer.

[0020] The present invention also provides a preparation method of the viscosity reducer with the above-mentioned branched structure. The preparation method uses (meth)acrylate shown in Formula I-1, Formula II-1 or Formula III-1 and siloxane shown in Formula I-2 as raw materials, and carries out an addition reaction in the presence of a catalyst;

[0021]

[0022] Among them, in Formula I-1, R1 is H or methyl;

[0023] In Formula II-1, R1 is H or methyl;

[0024] In Formula III-1, R1 is H or methyl;

[0025] In Formula I-2, R2 is a C1-C6 alkyl group.

[0026] The carbon-carbon double bond on the aforementioned (meth)acrylate reacts with the silicon-hydrogen bond in the siloxane shown in Formula I-2 to form a viscosity reducer with a target branched structure. The siloxane shown in Formula I-2 has a symmetric Si-O-Si structure centered on the silicon-hydrogen bond. Using the siloxane with this structure as a raw material can make the target product of the viscosity reducer with a branched structure have a symmetric structure, which is beneficial to its effective use as a crude oil viscosity reducer.

[0027] In some embodiments, R1 is H or methyl; R2 is methyl or ethyl.

[0028] In some embodiments, R1 is H and R2 is methyl.

[0029] In some embodiments, the (meth)acrylate is selected from one or a combination of more than one of dipentaerythritol hexa(meth)acrylate, bis-trimethylolpropane tetra(meth)acrylate, and trimethylolpropane tri(meth)acrylate. Among them, dipentaerythritol hexa(meth)acrylate corresponds to Formula I-1, where R1 is H or methyl; bis-trimethylolpropane tetra(meth)acrylate corresponds to Formula II-1, where R1 is H or methyl; trimethylolpropane tri(meth)acrylate corresponds to Formula III-1, where R1 is H or methyl.

[0030] In some embodiments, the catalyst is a platinum-based catalyst, preferably chloroplatinic acid.

[0031] In some embodiments, the molar ratio of the (meth)acrylate to the siloxane is 1:3.3 to 6.6.

[0032] In some embodiments, the molar ratio of the total molar amount of the (meth)acrylate and the siloxane to the molar amount of the catalyst is 1:0.02 to 0.06.

[0033] In some embodiments, the addition reaction is carried out under the protection of an inert gas.

[0034] In some embodiments, the temperature of the addition reaction is 100 to 105 °C.

[0035] In some embodiments, the time of the addition reaction is 6 to 8 h.

[0036] In some embodiments, the preparation method includes the following steps:

[0037] (1) Disperse the (meth)acrylate shown in Formula I-1, Formula II-1, or Formula III-1 in the siloxane shown in Formula I-2 to obtain a dispersion;

[0038] (2) Heat the dispersion to 45 - 55 °C and mix it evenly under stirring;

[0039] (3) Introduce an inert gas into the dispersion, and then add the catalyst;

[0040] (4) Heat the dispersion to 100 - 105 °C to carry out the addition reaction.

[0041] The (meth)acrylate esters represented by Formula I-1, Formula II-1 or Formula III-1 all contain unsaturated carbon-carbon double bonds. Before the reaction starts, a catalyst such as chloroplatinic acid first coordinates with a siloxane such as bis(trimethylsilyloxy)methylsilane represented by Formula I-2 to form an active metal-silicon compound complex. The π-electrons of the olefin form an electrophilic addition reaction with the silicon-hydrogen bond in the metal-silicon compound complex, generating a new carbon-silicon bond and a new carbon-carbon bond. The mechanism of the addition reaction between the unsaturated carbon-carbon double bond and the silicon-hydrogen bond is a metal-catalyzed electrophilic addition process.

[0042] In some embodiments, the preparation method further includes separating the reaction system after the addition reaction to obtain the target product.

[0043] In some embodiments, the separation is rotary evaporation under reduced pressure.

[0044] The present invention also provides a use of the viscosity reducer with the foregoing branched structure for reducing the viscosity of crude oil or the viscosity of water-containing emulsions.

[0045] In some embodiments, the water-containing emulsion includes a polyether surfactant and water.

[0046] In some embodiments, the polyether surfactant is selected from one or more combinations of polyoxyethylene ether, polyoxypropylene ether, and polyoxyethylene-block-polyoxypropylene ether. For example, it can be an L-64 type block polyether surfactant.

[0047] In some embodiments, the mass ratio of the polyether surfactant to water is 2 - 4:1.

[0048] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0049] (1) The organosiloxane substance with a branched structure of the present invention has a viscosity-reducing effect, can be used as a viscosity reducer, and can effectively reduce the viscosity of crude oil at room temperature, and can achieve effective viscosity reduction by itself without compounding other substances such as emulsifiers. It overcomes the defects of traditional crude oil viscosity reducers that require heating and compounding with emulsifiers.

[0050] (2) The structures of each branched chain segment of the viscosity reducer of the present invention are the same, and in each branched chain segment, the siloxane structure is also symmetric. With this specific symmetric structure, the viscosity reducer has high symmetry and isotropy. Furthermore, when the viscosity reducer is fully mixed with the system to be viscosity-reduced, such as crude oil or water-containing emulsion, the intermolecular forces between the two are isotropic at the hydrophobic end of the viscosity reducer, and there will be no situation where the internal structure of the system to be viscosity-reduced cannot be uniformly disrupted due to the overly strong hydrophobicity at one end of the viscosity reducer. That is, the viscosity-reducing effect of this viscosity reducer can be further improved.

[0051] (3) The viscosity reducer of the present invention can also be used for reducing the viscosity of an emulsion system containing surfactants and water, and has a wide range of applications.

[0052] (4) The viscosity reducer with a branched structure of the present invention can achieve viscosity reduction for different crude oil systems relying on its large branched structure and extremely strong hydrophobicity, and has a wide range of applications. Description of the Drawings

[0053] Figure 1 : Infrared spectrum of the viscosity reducer prepared in Example 1, where TSO refers to bis(trimethylsilyloxy)methylsilane, T1 refers to dipentaerythritol hexaacrylate, and T1-TSO refers to the reaction product viscosity reducer.

[0054] Figure 2 : NMR spectrum of the viscosity reducer prepared in Example 1.

[0055] Figure 3 : Effect diagram of the viscosity reducer prepared in Examples 1-3 for reducing the viscosity of crude oil.

[0056] Figure 4 : Effect diagram of the viscosity reducer prepared in Examples 1-3 for reducing the viscosity of water-containing emulsion. Detailed Embodiments

[0057] The technical solutions of the present invention will be described in detail below in conjunction with specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention, but the present invention is not limited to the scope of the described examples.

[0058] Example 1

[0059] This example provides a viscosity reducer material prepared based on dipentaerythritol hexaacrylate and bis(trimethylsilyloxy)methylsilane, and its preparation method is as follows:

[0060] The whole reaction is carried out under the conditions of normal pressure and 105 °C. An oil bath is used for heating. Nitrogen is introduced into the right end of the three-necked flask to exhaust the air in the system and protect the reaction system. Condensed water is connected to the upper end, and a thermometer is inserted into the left end.

[0061] (1) Weigh 2 g of dipentaerythritol hexaacrylate accurately and place it in a round-bottom flask. Then add 12 g of bis(trimethylsiloxy)methylsilane and put in a magnetic rotor.

[0062] (2) Assemble the device according to the aforementioned structure, then immediately introduce nitrogen, start magnetic stirring and heat to 105 °C over 40 min.

[0063] (3) After introducing nitrogen for 10 min, use a pipette to add 110 μL of chloroplatinic acid catalyst to the round-bottom flask. Under the action of the catalyst, this reaction process can stop after 6 h.

[0064] (4) Collect the product by rotary evaporation under reduced pressure: Rotary evaporate the mixture after the reaction for 2 h under reduced pressure. The water bath temperature during rotary evaporation is 80 °C, and the viscosity reducer of formula I, labeled as T1-TSO, can be obtained.

[0065] The reaction formula is as follows:

[0066]

[0067] The infrared spectrum of the viscosity reducer prepared above is as Figure 1 shown. Among them, TSO refers to the raw material bis(trimethylsiloxy)methylsilane, T1 refers to the raw material dipentaerythritol hexaacrylate, and T1-TSO refers to the reaction product viscosity reducer. It can be seen that for the viscosity reducer product T1-TSO compared with the T1 raw material, the stretching vibration peak of the carbon-carbon double bond at 1650 cm -1 completely disappears, indicating that the double bond reaction is complete. And for T1-TSO compared with the TSO raw material, the peak of the silicon-hydrogen bond at 2160 cm -1 disappears, indicating that the bis(trimethylsiloxy)methylsilane raw material with an excessive stoichiometric ratio has been completely removed by rotary evaporation.

[0068] The NMR spectrum of the viscosity reducer prepared above is as Figure 2 shown. Among them, for the hydrogen on the Si-methyl, the chemical shift is generally around 0, corresponding to Figure 2 the two peaks ab in. For the hydrogen on the Si-methylene, the chemical shift is generally a little larger than that of the Si-methyl, around 1. Figure 2 The methylene in the d peak in

[0069] Example 2

[0070] This embodiment provides a viscosity reducer material prepared from ditrimethylolpropane tetraacrylate and bis(trimethylsilyloxy)methylsilane, and its preparation method is as follows:

[0071] The whole reaction is carried out under the conditions of normal pressure and 105 °C. An oil bath is used for heating. Nitrogen is introduced at the right end of the three-necked flask to exhaust the air in the system and protect the reaction system. Condensed water is connected at the upper end, and a thermometer is inserted at the left end.

[0072] (1) Accurately weigh 2 g of ditrimethylolpropane tetraacrylate and place it in a round-bottom flask. Then add 8 g of bis(trimethylsilyloxy)methylsilane and put in a magnetic rotor.

[0073] (2) Set up the device according to the aforementioned structure. Then immediately introduce nitrogen, turn on the magnetic stirring and heat to 105 °C in 40 min.

[0074] (3) After nitrogen is introduced for 10 min, use a pipette to add 110 μL of chloroplatinic acid catalyst to the round-bottom flask. Under the action of the catalyst, the reaction process can be stopped after 6 h.

[0075] (4) Collect the product by rotary evaporation under reduced pressure: Rotary evaporate the mixture after the reaction for 2 h under reduced pressure. The water bath temperature during rotary evaporation is 80 °C, and the viscosity reducer of formula II, marked as T2-TSO, can be obtained.

[0076] The reaction formula is as follows:

[0077]

[0078] Example 3

[0079] This embodiment provides a viscosity reducer material prepared from trimethylolpropane triacrylate and bis(trimethylsilyloxy)methylsilane, and its preparation method is as follows:

[0080] The whole reaction is carried out under the conditions of normal pressure and 105 °C. An oil bath is used for heating. Nitrogen is introduced at the right end of the three-necked flask to exhaust the air in the system and protect the reaction system. Condensed water is connected at the upper end, and a thermometer is inserted at the left end.

[0081] (1) Accurately weigh 2 g of trimethylolpropane triacrylate and place it in a round-bottom flask. Then add 6 g of bis(trimethylsilyloxy)methylsilane and put in a magnetic rotor.

[0082] (2) Set up the device according to the aforementioned structure. Then immediately introduce nitrogen, turn on the magnetic stirring and heat to 105 °C in 40 min.

[0083] (3) After nitrogen is introduced for 10 min, use a pipette to add 110 μL of chloroplatinic acid catalyst to the round-bottom flask. Under the action of the catalyst, the reaction process can be stopped after 6 h.

[0084] (4) Collecting the product by vacuum rotary evaporation: The mixed solution after the reaction was completed was subjected to vacuum rotary evaporation for 2 h at a water bath temperature of 80° C. to obtain a viscosity reducer of formula II, which was labeled as T3-TSO.

[0085] The reaction formula is as follows:

[0086]

[0087] Example 4

[0088] This example provides an example of using the viscosity reducer prepared in Examples 1-3 for reducing the viscosity of crude oil:

[0089] Taking Ecuadorian crude oil as an example, the viscosity reducers prepared in Examples 1, 2, and 3 were added to the Ecuadorian crude oil for viscosity reduction test. The test method was to use a rheometer to measure the change in viscosity with shear rate under fixed temperature conditions. At the same time, under the same conditions, the viscosity of the crude oil to which the viscosity reducers in Examples 1, 2, and 3 were not added was compared.

[0090] First, the crude oil was placed at room temperature, and the initial viscosity of the crude oil without any viscosity reducer was tested. Then, 100 mL of crude oil was taken, and the viscosity reducers of Examples 1-3 were added respectively, and the amount thereof was 1000 ppm relative to the crude oil. The above viscosity reducers were added at one time, and a mechanical stirring paddle was used to stir for ten minutes to mix them evenly, and then a rheometer was used to test the change of viscosity with shear rate. The viscosity was measured three times for each test, and the average value was taken. The interval between the three tests was less than 30 seconds to improve the accuracy.

[0091] The results are as follows Figure 3 As shown, it can be seen that the viscosity reducers of Examples 1-3 have excellent viscosity reducing performance for crude oil systems.

[0092] Example 5

[0093] This example provides an example of using the viscosity reducer prepared in Examples 1-3 to reduce the viscosity of an aqueous emulsion:

[0094] Taking polyether surfactant as an example, the viscosity reducer prepared in Examples 1, 2, and 3 was added to a mixture of polyether surfactant propylene glycol block polyether L-64 and water (the mass ratio of the two was 3:1) to carry out viscosity reduction test. The test method was to compare the viscosity of the same polyether surfactant and water mixture without adding the viscosity reducer in Examples 1-3 under the same conditions at a fixed temperature, fixed viscometer rotor and speed. First, the mixture was placed in a 30°C oil bath, stirred and heated to 30°C, and its initial viscosity was tested after stirring evenly. Then, 100 ml of the viscosity reducer in Examples 1-3 was added respectively (the amount added each time was the same as Figure 4As shown in the figure, the viscosity reduction effect was tested according to the quality gradient. After each addition of the viscosity reducer, a mechanical stirring paddle was used to stir for ten minutes to make it evenly mixed, and then it was taken to the viscosity instrument to test the viscosity change. Each test measured the viscosity three times and took the average value. The interval between the three tests was less than 30 s to improve the accuracy.

[0095] The results are as Figure 4 shown. It can be seen that the viscosity reducers in Examples 1-3 have good viscosity reduction performance for the viscous system of the polyether surfactant mixed with water.

[0096] The above embodiments are only for illustrating the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A branched viscosity reducer, characterized in that: It has the structure shown in the following formula I or formula II: in, R1 is independently H or methyl; R2 is independently C1-C6 alkyl; And in Formula I, each R1 is the same, each R2 is the same; In Formula II, each R1 is the same, and each R2 is the same.

2. The viscosity reducer according to claim 1, characterized in that: R1 is H or methyl, and R2 is methyl or ethyl.

3. The viscosity reducer according to claim 1, characterized in that: The viscosity reducing agent is selected from the following structural formula:

4. The method for preparing the branched viscosity reducer according to any one of claims 1 to 3, characterized in that: The preparation method uses the (meth)acrylate represented by formula I-1 or formula II-1 and the siloxane represented by formula I-2 as raw materials, and performs an addition reaction in the presence of a catalyst; Wherein, in formula I-1, R1 is H or methyl; In formula II-1, R1 is H or methyl; In formula I-2, R2 is a C1-C6 alkyl group.

5. The preparation method according to claim 4, characterized in that: In formula I-1 or II-1, R1 is H or methyl; in formula I-2, R2 is methyl or ethyl; and / or, the (meth)acrylate is selected from dipentaerythritol hexa(meth)acrylate.

6. The preparation method according to claim 4, characterized in that: The catalyst is a platinum catalyst.

7. The preparation method according to claim 4, characterized in that: The catalyst is chloroplatinic acid.

8. The preparation method according to claim 4, characterized in that: The molar ratio of the (meth)acrylate to the siloxane is 1:3.3-6.6; and / or the ratio of the total molar amount of the (meth)acrylate and the siloxane to the molar amount of the catalyst is 1:0.02-0.

06.

9. The preparation method according to claim 4, characterized in that: The addition reaction is carried out under the protection of an inert gas; and / or, the temperature of the addition reaction is 100 to 105° C.; and / or, the time of the addition reaction is 6 to 8 hours.

10. The preparation method according to claim 4, characterized in that: The preparation method comprises the following steps: (1) dispersing the (meth)acrylate represented by formula I-1 or formula II-1 in the siloxane represented by formula I-2 to obtain a dispersion; (2) heating the dispersion to 45-55° C. and mixing uniformly under stirring; (3) introducing an inert gas into the dispersion and then adding the catalyst; (4) The dispersion is heated to 100-105° C. to carry out the addition reaction.

11. A use of the branched viscosity reducer according to any one of claims 1 to 3, characterized in that: Used for reducing the viscosity of crude oil or aqueous emulsion.

12. Use of a branched viscosity reducer, characterized in that: Used for reducing the viscosity of crude oil or aqueous emulsion, the branched viscosity reducer has a structure shown in the following formula III: in, R1 is independently H or methyl; R2 is independently C1-C6 alkyl; In Formula III, each R1 is the same, and each R2 is the same.

13. The use according to claim 12, characterized in that: R1 is H or methyl, and R2 is methyl or ethyl.

14. The use according to claim 12, characterized in that: The viscosity reducing agent has the following structural formula:

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