Quaternary ammonium salt type efficient clay stabilizer and preparation method thereof

Abstract

The invention relates to the field of clay stabilizers, and particularly discloses a quaternary ammonium salt type efficient clay stabilizer and a preparation method thereof. The clay stabilizer comprises a clay stabilizer compound with the following structural formula: n is any integer from 9 to 17; the preparation method comprises the following steps: uniformly mixing anhydrous piperazine, a catalyst I and an organic solvent, reacting with bromoacetyl chloride, and carrying out rotary evaporation and recrystallization to obtain an intermediate S1; mixing and reacting the intermediate S1, 3-chloropropane and a catalyst II to obtain an intermediate S2; and adding the intermediate S2 and long-chain alkyl N, N-dimethyl tertiary amine into an organic solvent, carrying out stirring reaction, and carrying out rotary evaporation and recrystallization to obtain the clay stabilizer. The clay stabilizer disclosed by the invention has the advantages of excellent anti-swelling effect at low concentration and excellent temperature resistance and washing resistance.

Description

Technical Field

[0001] This application relates to the field of clay stabilizers, and more specifically, to a quaternary ammonium salt type high-efficiency clay stabilizer and its preparation method. Background Technology

[0002] Clay minerals in oil reservoirs are prone to hydration, swelling, dispersion, and migration. The reduction in formation pore throat diameter caused by swelling and the accumulation caused by migration work together to decrease formation permeability, leading to a decline in oilfield productivity. Therefore, clay stabilizers are often added in oilfield development to inhibit the hydration and dispersion of clay minerals and improve oil recovery.

[0003] Clay stabilizers mainly include inorganic salts, cationic surfactants, and organic cationic polymers. Inorganic salt clay stabilizers readily undergo cation exchange in solution, exhibiting poor stability and long-term effectiveness, and are unable to form multi-point adsorption, resulting in poor erosion resistance. Organic cationic polymer clay stabilizers have large molecular weights and are typically used at concentrations above 0.5 wt%. Long-term use can easily clog pores, reducing the permeability of low-permeability oil reservoirs, and they are difficult to decompose effectively, causing soil pollution and significant environmental damage.

[0004] In view of the above-mentioned technologies, developing a clay stabilizer that has excellent anti-swelling effect at low concentrations and good temperature and water washing resistance is an urgent problem to be solved. Summary of the Invention

[0005] In order to enable clay stabilizers to have excellent anti-swelling effects at low concentrations and good temperature and water washing resistance, this application provides a quaternary ammonium salt type high-efficiency clay stabilizer and its preparation method.

[0006] In a first aspect, this application provides a quaternary ammonium salt type high-efficiency clay stabilizer, which adopts the following technical solution:

[0007] A quaternary ammonium salt type high-efficiency clay stabilizer, comprising a clay stabilizer compound having the following structural formula:

[0008] n is any integer from 9 to 17.

[0009] By adopting the above technical solution, the quaternary ammonium salt type high-efficiency viscosity stabilizer compound disclosed in this application contains multiple positively charged quaternary ammonium groups, which can form multi-point adsorption with multiple clay particles. This allows the stabilizer to effectively neutralize the electronegativity of the clay particles at low usage concentrations and form an adsorption protective film on the surface of the clay particles, thus playing an excellent role in preventing swelling. At the same time, the long-chain alkyl groups in the stabilizer molecule are lipophilic groups. After the stabilizer molecule is adsorbed onto the clay surface, it changes the clay surface from hydrophilic to lipophilic, thereby preventing water molecules from wetting the clay particles and preventing the hydration and dispersion of the clay. Furthermore, the cyclic structure in the stabilizer molecule increases molecular rigidity and enhances the temperature resistance of the clay stabilizer.

[0010] Preferably, n = 11, 13 or 15.

[0011] By adopting the above technical solution, the inventors, through a great deal of creative work, have found that when the value of n is 11, 13, or 15, the clay stabilizer has better anti-swelling and water resistance properties.

[0012] Secondly, this application provides a method for preparing a quaternary ammonium salt type high-efficiency clay stabilizer, using the following technical solution:

[0013] A method for preparing a quaternary ammonium salt type high-efficiency clay stabilizer includes the following steps:

[0014] Step 1: Mix anhydrous piperazine, catalyst I and organic solvent, add bromoacetyl chloride-organic solvent mixture dropwise, stir the reaction in an ice-water bath, and obtain intermediate S1 by rotary evaporation and recrystallization;

[0015] Step 2: Mix intermediate S1, 3-chloropropane and catalyst II at 80-100℃, remove excess 3-chloropropane by vacuum distillation, filter, and dry to obtain intermediate S2;

[0016] Step 3: Add intermediate S2 and long-chain alkyl N,N-dimethyl tertiary amine to an organic solvent, stir and react at 75-100℃, and then purify by rotary evaporation and recrystallization to obtain a quaternary ammonium salt type high-efficiency clay stabilizer.

[0017] The long-chain alkyl N,N-dimethyl tertiary amine is CH3(CH2). n N(CH3)2, where n is any integer from 9 to 17.

[0018] By adopting the above technical solution, the synthetic reaction equation of the preparation method of this application is as follows:

[0019] Step 1:

[0020] Step 2:

[0021] Step 3:

[0022] This application demonstrates that a clay stabilizer with good temperature and water resistance, and excellent anti-swelling effect even at low concentrations, can be prepared using the above method. Furthermore, the preparation process is simple, easy to operate, and the raw materials are readily available, thus meeting a wide range of application needs.

[0023] Preferably, the molar ratio of anhydrous piperazine, bromoacetyl chloride and catalyst I is 1:(3.5-4.5):(2.0-3.0).

[0024] Preferably, the catalyst I is selected from pyridine and N,N-dimethylformamide.

[0025] Preferably, in step 1, the reaction time of the ice-water bath stirring reaction is 6-8 hours.

[0026] Preferably, the molar ratio of intermediate S1, 3-chloropropane, and catalyst II is 1:(2.5-3.0):(1.5-2.5).

[0027] Preferably, the catalyst II is selected from NaOH and K2CO3.

[0028] Preferably, in step 2, the reaction time is 3-5 hours.

[0029] Preferably, the long-chain alkyl N,N-dimethyl tertiary amine is selected from one of dodecyl N,N-dimethyl tertiary amine, tetradecyl N,N-dimethyl tertiary amine, and hexadecyl N,N-dimethyl tertiary amine.

[0030] Preferably, the molar ratio of intermediate S2 to long-chain alkyl N,N-dimethyl tertiary amine is 1:(2.0-2.5).

[0031] Preferably, in step 3, the reaction time of the stirring reaction is 3-5 hours.

[0032] Preferably, in step 1, the organic solvent is dichloromethane; in step 3, the organic solvent is acetonitrile.

[0033] In summary, this application has the following beneficial effects:

[0034] 1. The clay stabilizer in this application can form multi-point adsorption with multiple clay particles, so that the stabilizer can effectively neutralize the electronegativity of the clay particles at a low concentration and form an adsorption protective film on the surface of the clay particles, which plays an excellent role in preventing swelling; at the same time, it can change the clay surface from hydrophilic to oleophilic, effectively preventing water molecules from wetting the clay particles and preventing the hydration and dispersion of the clay; in addition, the clay stabilizer in this application has a stable molecular structure and excellent high-temperature aging resistance.

[0035] 2. The preparation method of this application is simple, easy to operate, and the raw materials are readily available, which can meet a wide range of application needs. Furthermore, by optimizing and limiting the preparation conditions, the clay stabilizer can have better performance. Detailed Implementation

[0036] To further aid in understanding the technical solution of this invention, several specific implementation examples are provided below to describe the technical solution of this invention in more detail. All of these described embodiments are only some embodiments of this invention, and not all of them.

[0037] The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments; and the reaction devices, monomer compounds, etc. involved in the following embodiments are all commercially available.

[0038] The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0039] The following examples further illustrate the present invention, but the invention is not limited thereto. Unless otherwise specified in the examples, all percentages (%) are mass percentages.

[0040] Example

[0041] Example 1

[0042] This embodiment discloses a quaternary ammonium salt type high-efficiency clay stabilizer, the preparation method of which is as follows:

[0043] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 7.91 g pyridine (0.10 mol), and 80 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 27.54 g bromoacetyl chloride (0.175 mol) was dissolved in 100 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 6 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0044] Step 2: Mix 9.72g of intermediate S1 (0.04mol), 7.85g of 3-chloropropane (0.10mol), and 8.3g of K2CO3 (0.06mol), stir and react at 80℃ for 3h, then distill under reduced pressure, filter and dry to obtain intermediate S2;

[0045] Step 3: 6.50 g of intermediate S2 (0.02 mol), 8.52 g of dodecyl N,N-dimethyl tertiary amine (0.04 mol), and 76.60 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 75 °C for 5 h. After the reaction was complete, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0046]

[0047] Example 2

[0048] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0049] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 9.49 g pyridine (0.12 mol), and 80 mL dichloromethane were added to a three-necked flask and stirred at 500 rpm. 31.48 g bromoacetyl chloride (0.20 mol) was dissolved in 100 mL dichloromethane, and the bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions and reacted for 6 h. After rotary evaporation, extraction, and recrystallization with ethyl acetate, intermediate S1 was obtained.

[0050] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 9.82g of 3-chloropropane (0.125mol), and 13.82g of K2CO3 (0.10mol), stir and react at 100℃ for 4h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0051] Step 3: 7.50 g of intermediate S2 (0.023 mol), 9.82 g of dodecyl N,N-dimethyl tertiary amine (0.046 mol), and 147.20 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 80 °C for 4 h. After the reaction was completed, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0052]

[0053] Example 3

[0054] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0055] Step 1: 6.90 g anhydrous piperazine (0.08 mol), 18.98 g pyridine (0.24 mol), and 150 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 44.07 g bromoacetyl chloride (0.28 mol) was dissolved in 120 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 7 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0056] Step 2: Mix 12.15g intermediate S1 (0.05mol), 11.78g 3-chloropropane (0.15mol), and 5.00g NaOH (0.125mol), stir and react at 100℃ for 4h, then distill under reduced pressure, filter and dry to obtain intermediate S2;

[0057] Step 3: 8.125 g of intermediate S2 (0.025 mol), 15.08 g of tetradecyl N,N-dimethyl tertiary amine (0.0625 mol), and 121.87 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 85 °C for 3 h. After the reaction was completed, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0058]

[0059] Example 4

[0060] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0061] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 10.96 g N,N-dimethylformamide (0.15 mol), and 150 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 31.48 g bromoacetyl chloride (0.20 mol) was dissolved in 120 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 8 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0062] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 10.21g of 3-chloropropane (0.13mol), and 3.00g of NaOH (0.075mol), stir and react at 100℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0063] Step 3: 6.50 g of intermediate S2 (0.02 mol), 12.07 g of tetradecyl N,N-dimethyl tertiary amine (0.05 mol), and 162.50 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 85 °C for 4 h. After the reaction was complete, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0064]

[0065] Example 5

[0066] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0067] Step 1: 5.00 g anhydrous piperazine (0.058 mol), 10.61 g N,N-dimethylformamide (0.145 mol), and 80 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 41.44 g bromoacetyl chloride (0.26 mol) was dissolved in 150 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 8 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0068] Step 2: Mix 14.58g of intermediate S1 (0.06mol), 13.19g of 3-chloropropane (0.17mol), and 16.58g of K2CO3 (0.12mol), stir and react at 90℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0069] Step 3: 9.75 g of intermediate S2 (0.03 mol), 16.16 g of hexadecyl N,N-dimethyl tertiary amine (0.06 mol), and 175.50 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 85 °C for 5 h. After the reaction was completed, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0070]

[0071] Example 6

[0072] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0073] Step 1: 5.00 g anhydrous piperazine (0.058 mol), 12.73 g N,N-dimethylformamide (0.174 mol), and 100 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 36.55 g bromoacetyl chloride (0.23 mol) was dissolved in 120 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 8 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0074] Step 2: Mix 14.58g of intermediate S1 (0.06mol), 14.14g of 3-chloropropane (0.18mol), and 16.58g of K2CO3 (0.12mol), stir and react at 80℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0075] Step 3: 9.75 g of intermediate S2 (0.03 mol), 20.21 g of hexadecyl N,N-dimethyl tertiary amine (0.075 mol), and 195.00 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 85 °C for 4 h. After the reaction was completed, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0076]

[0077] Example 7

[0078] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0079] Step 1: 5.60 g anhydrous piperazine (0.065 mol), 10.28 g pyridine (0.13 mol), and 100 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 35.81 g bromoacetyl chloride (0.23 mol) was dissolved in 150 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 6 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0080] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 9.82g of 3-chloropropane (0.125mol), and 10.36g of K2CO3 (0.075mol), stir and react at 80℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0081] Step 3: 6.50 g of intermediate S2 (0.02 mol), 10.77 g of hexadecyl N,N-dimethyl tertiary amine (0.04 mol), and 97.50 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 100 °C for 5 h. After the reaction was complete, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0082]

[0083] Example 8

[0084] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0085] Step 1: 5.60 g of anhydrous piperazine (0.065 mol), 14.25 g of N,N-dimethylformamide (0.195 mol), and 100 mL of dichloromethane were added to a three-necked flask and stirred at 500 r / min. 46.04 g of bromoacetyl chloride (0.29 mol) was dissolved in 150 mL of dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 8 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0086] Step 2: Mix 14.58g of intermediate S1 (0.06mol), 14.14g of 3-chloropropane (0.18mol), and 6.00g of NaOH (0.15mol), stir and react at 90℃ for 5h, then distill under reduced pressure, filter and dry to obtain intermediate S2;

[0087] Step 3: 6.50 g of intermediate S2 (0.02 mol), 12.07 g of tetradecyl N,N-dimethyl tertiary amine (0.05 mol), and 162.50 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 90 °C for 5 h. After the reaction, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0088]

[0089] Example 9

[0090] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0091] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 11.07 g pyridine (0.14 mol), and 100 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 35.41 g bromoacetyl chloride (0.225 mol) was dissolved in 150 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 8 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0092] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 11.00g of 3-chloropropane (0.14mol), and 16.58g of K2CO3 (0.12mol), stir and react at 80℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0093] Step 3: 6.50 g of intermediate S2 (0.02 mol), 13.47 g of hexadecyl N,N-dimethyl tertiary amine (0.05 mol), and 130.0 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 85 °C for 5 h. After the reaction, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0094]

[0095] Example 10

[0096] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0097] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 11.86 g pyridine (0.15 mol), and 150 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 31.48 g bromoacetyl chloride (0.20 mol) was dissolved in 120 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 6 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0098] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 11.00g of 3-chloropropane (0.14mol), and 3.00g of NaOH (0.075mol), stir and react at 100℃ for 5h, then distill under reduced pressure, filter and dry to obtain intermediate S2;

[0099] Step 3: 6.50 g of intermediate S2 (0.02 mol), 9.27 g of decyl dimethyl tertiary amine (0.05 mol), and 162.50 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 80 °C for 5 h. After the reaction was complete, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0100]

[0101] Example 11

[0102] The only difference between this embodiment and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0103] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 11.86 g pyridine (0.15 mol), and 150 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 35.41 g bromoacetyl chloride (0.225 mol) was dissolved in 150 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 6 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0104] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 11.00g of 3-chloropropane (0.14mol), and 16.58g of K2CO3 (0.12mol), stir and react at 85℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0105] Step 3: 6.50 g of intermediate S2 (0.02 mol), 14.88 g of octadecyl dimethyl tertiary amine (0.05 mol), and 195.00 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 85 °C for 4 h. After the reaction, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0106]

[0107] Comparative Example

[0108] Comparative Example 1

[0109] The only difference between this comparative example and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0110] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 11.07 g pyridine (0.14 mol), and 100 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 35.41 g bromoacetyl chloride (0.225 mol) was dissolved in 150 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 8 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0111] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 11.00g of 3-chloropropane (0.14mol), and 16.58g of K2CO3 (0.12mol), stir and react at 80℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0112] Step 3: 6.50 g of intermediate S2 (0.02 mol), 5.05 g of N,N-dimethylbutylamine (0.05 mol), and 130.0 g of acetonitrile were mixed and added to a flask. The mixture was stirred at 500 r / min and 85 °C for 5 h. After the reaction was complete, the acetonitrile was removed by rotary evaporation, and the mixture was recrystallized from ethyl acetate and dried to obtain a quaternary ammonium salt type high-efficiency clay stabilizer with the following structural formula:

[0113]

[0114] Comparative Example 2

[0115] The only difference between this comparative example and Example 1 is that the preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer is as follows:

[0116] Step 1: 4.30 g anhydrous piperazine (0.05 mol), 11.07 g pyridine (0.14 mol), and 100 mL dichloromethane were added to a three-necked flask and stirred at 500 r / min. 35.41 g bromoacetyl chloride (0.225 mol) was dissolved in 150 mL dichloromethane. The bromoacetyl chloride-dichloromethane mixture was added dropwise to the three-necked flask under ice-water bath conditions. After reacting for 8 h, the mixture was subjected to rotary evaporation, extraction, and recrystallization with ethyl acetate to obtain intermediate S1.

[0117] Step 2: Mix 12.15g of intermediate S1 (0.05mol), 11.00g of 3-chloropropane (0.14mol), and 16.58g of K2CO3 (0.12mol), stir and react at 80℃ for 5h, and then obtain intermediate S2 by vacuum distillation, filtration and drying.

[0118] Step 3: Take 6.50g of intermediate S2 (0.02mol), 13.47g of hexadecyl N,N-dimethyl tertiary amine (0.05mol), and 130.0g of acetonitrile and put them into a flask. Stir the mixture at 500r / min and 65℃ for 5h. After the reaction is completed, remove the acetonitrile by rotary evaporator, recrystallize it with ethyl acetate and dry it to obtain a quaternary ammonium salt type high-efficiency clay stabilizer.

[0119] Performance testing

[0120] Each example and comparative example yielded 0.3g of clay stabilizer sample, which was then dissolved in 300ml of deionized water to prepare a 0.1% clay stabilizer solution. The following tests were then conducted.

[0121] Test 1: Following the "SY / T5971-2016 Performance Evaluation Method for Clay Stabilizers Used in Fracturing, Acidizing, and Water Injection in Oil and Gas Fields" standard, the anti-swelling rate was tested. The steps were as follows: Weigh 0.50g of sodium bentonite, add it to a 10mL centrifuge tube, add deionized water to the 10mL mark, shake thoroughly, let stand at room temperature for 2 hours, then place it in a centrifuge and centrifuge at 1500r / min for 15 minutes. The volume V2 of the sodium bentonite in water was recorded. The same steps were used, but with a clay stabilizer solution of a certain concentration instead of water, to measure the volume V1 of the soil after centrifugation. The volume V0 of the soil was measured using kerosene instead of water. The anti-swelling rate calculation formula is as follows:

[0122]

[0123] Where: η—anti-swelling rate, %; V0—volume of sodium bentonite in kerosene, mL; V1—volume of sodium bentonite in clay stabilizer, mL; V2—volume of sodium bentonite in water, mL.

[0124] Test 2: Water Washability Test: Pour out the supernatant from the centrifuge tube after centrifugation in Test 1, add deionized water to 10 mL, stir thoroughly, let stand for 2 hours, and then centrifuge at 1500 r / min for 15 minutes. Finally, read the final volume V1 of the bentonite in the centrifuge tube. ′ The formula for calculating the wash resistance (N) is as follows:

[0125]

[0126] Where: V1 is the swelling volume of bentonite in clay stabilizer solution, mL; V 1′ V1 represents the volume of bentonite that has expanded after being washed with water, in mL; V2 represents the volume of bentonite that has expanded in water, in mL.

[0127] Test 3: High-Temperature Aging Anti-Swelling Rate Test: The high-temperature anti-swelling rate test was conducted according to "Q / SH125-2017 Technical Requirements for Clay Stabilizers". The steps are as follows: Weigh 5.00g of bentonite powder, accurate to 0.01g, and place it in a high-temperature, high-pressure sealed reactor; add 100mL of a 0.1% clay stabilizer solution, shake thoroughly to mix, and then heat in a rolling furnace for 24 hours, followed by cooling to room temperature; transfer the entire clay stabilizer mixture from the high-temperature, high-pressure sealed reactor to a 250mL beaker, shake thoroughly, quickly remove 10mL and add it to a glass centrifuge tube, place it in a centrifuge with an automatic balancing function, and centrifuge at 1500r / min for 15min. Read the swelling volume V1 of the bentonite. The anti-swelling rate (F) is calculated as follows:

[0128]

[0129] In the formula: V0 is the expansion volume of bentonite in kerosene; V1 is the expansion volume of bentonite in the clay stabilizer aqueous solution; V2 is the expansion volume of bentonite in water.

[0130] The results are summarized in Table 1.

[0131] Table 1

[0132]

[0133] As can be seen from Examples 1-11 and Table 1, the clay stabilizer prepared according to the method disclosed in this application has excellent performance. Even at a concentration of 0.1%, it still has excellent anti-swelling rate, water resistance, and high temperature resistance. Furthermore, when n in the structural formula is 11, 13, or 15, the anti-swelling rate at a concentration of 0.1% can reach more than 88%, the water washability can reach more than 95%, the anti-swelling rate remains basically unchanged after aging at 220℃ and 240℃, and the anti-swelling rate can still reach more than 85% after aging at 260℃, demonstrating excellent application effect.

[0134] As can be seen from Examples 1-11, Comparative Example 1, and Table 1, the long-chain alkyl N,N-dimethyl tertiary amine CH3(CH2) was selected. n N(CH3)2 can impart excellent anti-swelling properties to clay stabilizers, which may be due to the better lipophilicity of long-chain alkyl groups. After being adsorbed onto clay particles, it can more effectively prevent water molecules from wetting the clay particles and prevent clay hydration and dispersion. Furthermore, when n is 11, 13, or 15, the clay stabilizer can achieve excellent anti-swelling properties.

[0135] As can be seen from Examples 1-11, Comparative Example 2, and Table 1, adjusting the preparation conditions in the preparation method within the scope of this application can further ensure that the clay stabilizer can achieve better performance.

[0136] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A quaternary ammonium salt type high-efficiency clay stabilizer, characterized in that, Including clay stabilizer compounds having the following structural formulas: n is any integer from 9 to 17.

2. The quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, n = 11, 13 or 15.

3. A method for preparing a quaternary ammonium salt type high-efficiency clay stabilizer as described in any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Mix anhydrous piperazine, catalyst I and organic solvent, add bromoacetyl chloride-organic solvent mixture dropwise, stir the reaction in an ice-water bath, and obtain intermediate S1 by rotary evaporation and recrystallization; Step 2: Mix intermediate S1, 3-chloropropane and catalyst II at 80-100℃, remove excess 3-chloropropane by vacuum distillation, filter, and dry to obtain intermediate S2; Step 3: Add intermediate S2 and long-chain alkyl N,N-dimethyl tertiary amine to an organic solvent, stir and react at 75-100℃, and then purify by rotary evaporation and recrystallization to obtain a quaternary ammonium salt type high-efficiency clay stabilizer. The long-chain alkyl N,N-dimethyl tertiary amine is CH3(CH2). n N(CH3)2, where n is any integer from 9 to 17.

4. The preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, The molar ratio of anhydrous piperazine, bromoacetyl chloride and catalyst I is 1:(3.5-4.5):(2.0-3.0).

5. The preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, Catalyst I is selected from pyridine and N,N-dimethylformamide.

6. The preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, The molar ratio of intermediate S1, 3-chloropropane, and catalyst II is 1:(2.5-3.0):(1.5-2.5).

7. The preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, The catalyst II is selected from NaOH and K2CO3.

8. The preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, The long-chain alkyl N,N-dimethyl tertiary amine is selected from one of dodecyl N,N-dimethyl tertiary amine, tetradecyl N,N-dimethyl tertiary amine, and hexadecyl N,N-dimethyl tertiary amine.

9. The preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, The molar ratio of intermediate S2 to long-chain alkyl N,N-dimethyl tertiary amine is 1:(2.0-2.5).

10. The preparation method of the quaternary ammonium salt type high-efficiency clay stabilizer according to claim 1, characterized in that, In step 1, the organic solvent is dichloromethane; in step 3, the organic solvent is acetonitrile.

Images