Efficient fluid loss additive, preparation method thereof and application of the additive in water-based drilling fluid for shale gas horizontal well
Patent Information
- Application Number
- CN202611260592.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-19
- Publication Date
- 2026-11-03
AI Technical Summary
现有的纤维素类、腐殖酸类和改性淀粉降滤失剂在抗高温性和抗盐抗钙性方面表现不佳，限制了其应用范围。
Using nanocellulose as a base, a highly efficient filtration loss reducer was prepared by modifying it with 3-chloropropyltrimethoxysilane and vinyltrimethoxysilane, and by combining it with a catalyst and specific reaction conditions, thereby enhancing its resistance to high temperature, salt and calcium.
In high-temperature, high-salt, and high-calcium environments, high-efficiency filtration loss reducers can effectively form low-permeability filter cakes, meeting the drilling needs of shale gas horizontal wells, and have broad application prospects.
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Figure CN123026728A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of water-based drilling fluid technology for shale gas horizontal wells, and particularly to a highly efficient filtration loss reducer, its preparation method, and its application in water-based drilling fluids for shale gas horizontal wells. Background Technology
[0002] Water-based drilling fluid for shale gas horizontal wells is a water-based circulating fluid specifically designed for shale gas horizontal well drilling. It ensures safe and efficient drilling by inhibiting shale hydration, stabilizing the wellbore, lubricating drill strings, and carrying cuttings. Among its components, the filtration loss reducer, a key element of the water-based drilling fluid, forms a low-permeability, flexible, and dense filter cake on the wellbore during operation. This physically prevents the liquid phase from permeating into the formation, thereby reducing filtration loss.
[0003] Currently, existing filtration loss reducers mainly include cellulose-based, humic acid-based, resin-based, modified starch, and acrylamide-based agents. Among them, cellulose-based, humic acid-based, and modified starch-based agents are environmentally friendly, have low cost, and good compatibility. However, their high-temperature resistance, salt resistance, and calcium resistance are not as good as those of resin-based and acrylamide-based agents, which limits their application range. Therefore, improving the high-temperature resistance, salt resistance, and calcium resistance of cellulose-based, humic acid-based, or modified starch-based agents is of great significance.
[0004] To address the aforementioned issues, engineers have explored several approaches, such as molecular structure modification, nanomaterial compositing, surface functionalization, and the introduction of functional groups, achieving some success. Based on this, developing a new modification method to provide a highly efficient filtration reducer has significant practical implications for the shale gas industry. Summary of the Invention
[0005] In view of this, the present invention provides a high-efficiency filtration loss reducer, its preparation method, and its application in water-based drilling fluids for shale gas horizontal wells. The high-efficiency filtration loss reducer provided by the present invention is suitable for use in water-based drilling fluids for shale gas horizontal wells and has good resistance to high temperatures, salt, and calcium.
[0006] This invention provides a highly efficient filtration loss reducer, comprising, by weight, the following raw materials: 100 parts of nanocellulose, 45-75 parts of 3-chloropropyltrimethoxysilane, 20-25 parts of vinyltrimethoxysilane, 40-60 parts of inorganic base, 1-5 parts of catalyst, and 180-300 parts of continuous phase.
[0007] Preferably, the nanocellulose includes a first nanocellulose and a second nanocellulose; the diameter of the first nanocellulose is 5-10 nanometers; the diameter of the second nanocellulose is 15-20 nanometers; and the mass ratio of the first nanocellulose to the second nanocellulose is 100:75-85.
[0008] Preferably, the catalyst includes a basic catalyst and an acidic catalyst; the basic catalyst is triethylamine; the acidic catalyst is acetic acid or hydrochloric acid; and the mass ratio of the basic catalyst to the acidic catalyst is 2~3:1~2.
[0009] Preferably, the continuous phase comprises isopropanol and ethanol; the volume ratio of isopropanol to ethanol is 100:50~65.
[0010] Preferably, the particle size of the high-efficiency filtration loss reducer is 30~60 nanometers.
[0011] This invention also provides a method for preparing the highly efficient filtration loss reducing agent described above, comprising the following steps: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated to obtain activated cellulose; (2) Activated cellulose, 3-chloropropyltrimethoxysilane, alkaline catalyst and part of ethanol are mixed and subjected to condensation reaction to obtain modified cellulose; (3) The modified cellulose, vinyltrimethoxysilane, acid catalyst and residual ethanol are mixed and etherified to obtain a highly efficient filtration loss reducer.
[0012] Preferably, the activation reaction is carried out at a temperature of 40-55 degrees Celsius for 1-5 hours; the activation reaction is carried out under stirring conditions at a speed of 100-200 rpm.
[0013] Preferably, the condensation reaction is carried out at a temperature of 75-95 degrees Celsius for 2-12 hours.
[0014] Preferably, the etherification reaction is carried out at a temperature of 45-70 degrees Celsius, a pH value of 4-6, and a time of 1-8 hours; the etherification reaction is carried out under stirring conditions, with a stirring speed of 80-150 rpm.
[0015] This invention also provides the application of the above-described high-efficiency filtration loss reducer in the field of water-based drilling fluids for shale gas horizontal wells.
[0016] Compared with the prior art, the present invention has achieved the following beneficial effects: This invention provides a highly efficient filtration loss reducer, which uses nanocellulose and is modified with 3-chloropropyltrimethoxysilane and vinyltrimethoxysilane respectively. The degree of reaction is controlled by catalyst and reaction conditions, resulting in good high-temperature resistance, salt resistance and calcium resistance. It can better meet the needs of various application scenarios, especially in high-temperature, high-salt and high-calcium environments, where it still maintains good high-temperature resistance, salt resistance and calcium resistance. It can be added to water-based drilling fluids for applications such as shale gas horizontal wells, and has broad application prospects. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of this invention, the accompanying drawings used in the embodiments of this invention or in the prior art are briefly described below. For those skilled in the art, other drawings can be derived from the following drawings without creative effort, and all such drawings are within the protection scope of this invention.
[0018] Figure 1 The results show the test results of the high temperature resistance, salt resistance and calcium resistance of the high-efficiency filtration reduction agents of Examples 1-5 and Comparative Examples 1-4. Detailed Implementation
[0019] This invention provides a highly efficient filtration loss reducer, comprising, by weight, the following raw materials: 100 parts of nanocellulose, 45-75 parts of 3-chloropropyltrimethoxysilane, 20-25 parts of vinyltrimethoxysilane, 40-60 parts of inorganic base, 1-5 parts of catalyst, and 180-300 parts of continuous phase.
[0020] The raw material of the high-efficiency filtration loss reducer provided by the present invention includes 100 parts of nanocellulose; the nanocellulose may include first nanocellulose and second nanocellulose; the diameter of the first nanocellulose may be 5~10 nanometers and the length may be 100~300 nanometers; the diameter of the second nanocellulose may be 15~20 nanometers and the length may be 150~300 nanometers.
[0021] In this invention, the mass ratio of the first nanocellulose and the second nanocellulose can be 100:75~85, specifically 100:78, 100:80 or 100:83.
[0022] The raw materials of the high-efficiency filtration loss reducer provided by the present invention include 45 to 75 parts of 3-chloropropyltrimethoxysilane, specifically 50 parts, 55 parts, 60 parts, 65 parts or 70 parts.
[0023] The raw materials of the high-efficiency filtration loss reducer provided by the present invention include 20-25 parts of vinyltrimethoxysilane, specifically 21 parts, 22 parts, 23 parts or 24 parts.
[0024] The raw materials for the high-efficiency filtration loss reducer provided by the present invention include 40 to 60 parts of inorganic alkali, specifically 45 parts, 50 parts or 55 parts.
[0025] In this invention, the inorganic base can be sodium hydroxide.
[0026] The raw materials for the high-efficiency filtration loss reducer provided by the present invention include 1 to 5 parts of catalyst, specifically 2, 3 or 4 parts.
[0027] In this invention, the catalyst may include a basic catalyst and an acidic catalyst; the basic catalyst may be triethylamine; the acidic catalyst may be acetic acid or hydrochloric acid; the mass ratio of the basic catalyst to the acidic catalyst may be 2~3:1~2, specifically 2.5:1.5.
[0028] The raw materials for the high-efficiency filtration loss reducer provided by the present invention include 180 to 300 parts of continuous phase, specifically 200 parts, 220 parts, 240 parts, 260 parts or 280 parts.
[0029] In this invention, the continuous phase may include isopropanol and ethanol; the volume ratio of isopropanol to ethanol may be 100:50~65, specifically 100:55 or 100:60.
[0030] This invention also provides a method for preparing the highly efficient filtration loss reducing agent described above, comprising the following steps: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated to obtain activated cellulose; (2) Activated cellulose, 3-chloropropyltrimethoxysilane, alkaline catalyst and part of ethanol are mixed and subjected to condensation reaction to obtain modified cellulose; (3) The modified cellulose, vinyltrimethoxysilane, acid catalyst and residual ethanol are mixed and etherified to obtain a highly efficient filtration loss reducer.
[0031] This invention involves mixing nanocellulose, inorganic alkali, and isopropanol to conduct an activation reaction, thereby obtaining activated cellulose. In this invention, the activation reaction temperature can be 40-55 degrees Celsius, specifically 45 degrees Celsius or 50 degrees Celsius, and the time can be 1-5 hours, specifically 2 hours, 3 hours, or 4 hours. The activation reaction can be carried out under stirring conditions, with a stirring speed of 100-200 rpm, specifically 150 rpm.
[0032] After obtaining activated cellulose, the present invention mixes the activated cellulose, 3-chloropropyltrimethoxysilane, an alkaline catalyst, and a portion of ethanol for a condensation reaction to obtain modified cellulose. In the present invention, the volume fraction of the ethanol portion can be 55-65%, specifically 60%.
[0033] In this invention, the temperature of the condensation reaction can be 75 to 95 degrees Celsius, specifically 80 degrees Celsius, 85 degrees Celsius or 90 degrees Celsius, and the time can be 2 to 12 hours, specifically 3 hours, 4 hours, 5 hours, 8 hours or 10 hours.
[0034] In this invention, after the condensation reaction, the product may be subjected to centrifugation, washing, drying and pulverization in sequence; washing may be with ethanol; the number of washing cycles may be more than two; the drying temperature may be 30-40 degrees Celsius and the drying time may be more than one hour; the target particle size of the pulverized product may be 50-80 nanometers.
[0035] After obtaining modified cellulose, the present invention mixes the modified cellulose, vinyltrimethoxysilane, acidic catalyst, and residual ethanol for etherification to obtain a highly efficient filtrate loss reducer. In the present invention, the etherification reaction temperature can be 45~70 degrees Celsius, specifically 50 degrees Celsius, 55 degrees Celsius, 60 degrees Celsius, or 65 degrees Celsius; the pH value can be 4~6, specifically 5; the time can be 1~8 hours, specifically 3 hours or 5 hours; the etherification reaction can be carried out under stirring conditions, and the stirring speed can be 80~150 rpm, specifically 100 rpm or 120 rpm.
[0036] In this invention, after the etherification reaction, the product may be subjected to neutralization, centrifugation, washing, drying and pulverization in sequence; the neutralizing agent may be sodium hydroxide; washing may be water washing; the number of washings may be more than 2; the drying temperature may be 50-60 degrees Celsius and the time may be more than 30 minutes; the target particle size of pulverization may be 30-60 nanometers.
[0037] This invention also provides the application of the above-described high-efficiency filtration loss reducer in the field of water-based drilling fluids for shale gas horizontal wells.
[0038] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments.
[0039] Example 1: This embodiment prepares a highly efficient filtration loss reducer. The specific formulation and preparation steps are as follows: Formula: 100 parts nanocellulose, 61 parts 3-chloropropyltrimethoxysilane, 20 parts vinyltrimethoxysilane, 55 parts inorganic base (sodium hydroxide), 5 parts catalyst (triethylamine and hydrochloric acid in a mass ratio of 2.5:1.5), and 230 parts continuous phase; wherein, the nanocellulose specifically consists of first nanocellulose (diameter distribution of 5~10 nm, length distribution of 100~300 nm) and second nanocellulose (diameter distribution of 15~20 nm, length distribution of 150~300 nm), with a mass ratio of first nanocellulose to second nanocellulose of 100:78; the continuous phase is isopropanol and ethanol, with a volume ratio of isopropanol to ethanol of 100:55.
[0040] Preparation method: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated for 3 hours under stirring conditions of 45 degrees Celsius and 150 rpm to obtain activated cellulose.
[0041] (2) The prepared activated cellulose, alkaline catalyst and ethanol (60%) were mixed, and then 3-chloropropyltrimethoxysilane was added to the mixture. The mixture was condensed at 85 degrees Celsius for 5 hours. After the reaction was completed, the mixture was centrifuged, washed three times with ethanol, dried at 35 degrees Celsius for 2 hours, and pulverized to 50~80 nanometers (sieved) to obtain modified cellulose.
[0042] (3) Mix vinyltrimethoxysilane and the remaining ethanol (40%), then mix the resulting premix with the obtained modified cellulose and acid catalyst, and etherify the mixture for 5 hours at 60 degrees Celsius, pH 5 and stirring speed 100 rpm. After the reaction is completed, neutralize with sodium hydroxide, centrifuge, wash with water 3 times, dry at 50 degrees Celsius for 30 minutes, and pulverize to 30~60 nanometers (sieve) to obtain a highly efficient filtration loss reducer.
[0043] Example 2: This embodiment prepares a highly efficient filtration loss reducer. The specific formulation and preparation steps are as follows: Formula: 100 parts nanocellulose, 55 parts 3-chloropropyltrimethoxysilane, 25 parts vinyltrimethoxysilane, 43 parts inorganic base (sodium hydroxide), 4.5 parts catalyst (triethylamine and hydrochloric acid in a mass ratio of 3:1.5), and 250 parts continuous phase; wherein, the nanocellulose specifically consists of first nanocellulose (diameter distribution of 5-10 nm, length distribution of 100-300 nm) and second nanocellulose (diameter distribution of 15-20 nm, length distribution of 150-300 nm), with a mass ratio of first nanocellulose to second nanocellulose of 100:80; the continuous phase is isopropanol and ethanol, with a volume ratio of isopropanol to ethanol of 100:60.
[0044] Preparation method: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated for 3 hours under stirring conditions of 45 degrees Celsius and 150 rpm to obtain activated cellulose.
[0045] (2) The prepared activated cellulose, alkaline catalyst and ethanol (60%) were mixed, and then 3-chloropropyltrimethoxysilane was added to the mixture. The mixture was condensed at 85 degrees Celsius for 4 hours. After the reaction was completed, the mixture was centrifuged, washed three times with ethanol, dried at 35 degrees Celsius for 2 hours, and pulverized to 50~80 nanometers (sieved) to obtain modified cellulose.
[0046] (3) Mix vinyltrimethoxysilane and the remaining ethanol (40%), then mix the resulting premix with the obtained modified cellulose and acid catalyst, and etherify the mixture for 5 hours at 60 degrees Celsius, pH 5 and stirring speed 100 rpm. After the reaction is completed, neutralize with sodium hydroxide, centrifuge, wash with water 3 times, dry at 50 degrees Celsius for 30 minutes, and pulverize to 30~60 nanometers (sieve) to obtain a highly efficient filtration loss reducer.
[0047] Example 3: This embodiment prepares a highly efficient filtration loss reducer. The specific formulation and preparation steps are as follows: Formula: 100 parts nanocellulose, 73 parts 3-chloropropyltrimethoxysilane, 22 parts vinyltrimethoxysilane, 47 parts inorganic base (sodium hydroxide), 5 parts catalyst (triethylamine and hydrochloric acid in a mass ratio of 3:2), and 260 parts continuous phase; wherein, the nanocellulose specifically consists of first nanocellulose (diameter distribution of 5-10 nm, length distribution of 100-300 nm) and second nanocellulose (diameter distribution of 15-20 nm, length distribution of 150-300 nm), with a mass ratio of first nanocellulose to second nanocellulose of 100:75; the continuous phase is isopropanol and ethanol, with a volume ratio of isopropanol to ethanol of 100:55.
[0048] Preparation method: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated for 3 hours under stirring conditions of 45 degrees Celsius and 150 rpm to obtain activated cellulose.
[0049] (2) The prepared activated cellulose, alkaline catalyst and ethanol (60%) were mixed, and then 3-chloropropyltrimethoxysilane was added to the mixture. The mixture was condensed at 85 degrees Celsius for 3 hours. After the reaction was completed, the mixture was centrifuged, washed 3 times with ethanol, dried at 35 degrees Celsius for 2 hours, and pulverized to 50~80 nanometers (sieved) to obtain modified cellulose.
[0050] (3) Mix vinyltrimethoxysilane and the remaining ethanol (40%), then mix the resulting premix with the obtained modified cellulose and acid catalyst, and etherify the mixture for 5 hours at 60 degrees Celsius, pH 5 and stirring speed 100 rpm. After the reaction is completed, neutralize with sodium hydroxide, centrifuge, wash with water 3 times, dry at 50 degrees Celsius for 30 minutes, and pulverize to 30~60 nanometers (sieve) to obtain a highly efficient filtration loss reducer.
[0051] Example 4: This embodiment prepares a highly efficient filtration loss reducer. The specific formulation and preparation steps are as follows: Formula: 100 parts nanocellulose, 58 parts 3-chloropropyltrimethoxysilane, 23 parts vinyltrimethoxysilane, 53 parts inorganic base (sodium hydroxide), 4 parts catalyst (triethylamine and hydrochloric acid in a mass ratio of 2.5:1.5), and 240 parts continuous phase; wherein, the nanocellulose specifically consists of first nanocellulose (diameter distribution of 5~10 nm, length distribution of 100~300 nm) and second nanocellulose (diameter distribution of 15~20 nm, length distribution of 150~300 nm), with a mass ratio of first nanocellulose to second nanocellulose of 100:85; the continuous phase is isopropanol and ethanol, with a volume ratio of isopropanol to ethanol of 100:65.
[0052] Preparation method: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated for 3 hours under stirring conditions of 45 degrees Celsius and 150 rpm to obtain activated cellulose.
[0053] (2) The prepared activated cellulose, alkaline catalyst and ethanol (60%) were mixed, and then 3-chloropropyltrimethoxysilane was added to the mixture. The mixture was condensed at 85 degrees Celsius for 7 hours. After the reaction was completed, the mixture was centrifuged, washed 3 times with ethanol, dried at 35 degrees Celsius for 2 hours, and pulverized to 50~80 nanometers (sieved) to obtain modified cellulose.
[0054] (3) Mix vinyltrimethoxysilane and the remaining ethanol (40%), then mix the resulting premix with the obtained modified cellulose and acid catalyst, and etherify the mixture for 5 hours at 60 degrees Celsius, pH 5 and stirring speed 100 rpm. After the reaction is completed, neutralize with sodium hydroxide, centrifuge, wash with water 3 times, dry at 50 degrees Celsius for 30 minutes, and pulverize to 30~60 nanometers (sieve) to obtain a highly efficient filtration loss reducer.
[0055] Example 5: This embodiment prepares a highly efficient filtration loss reducer. The specific formulation and preparation steps are as follows: Formula: 100 parts nanocellulose, 60 parts 3-chloropropyltrimethoxysilane, 22 parts vinyltrimethoxysilane, 57 parts inorganic base (sodium hydroxide), 4 parts catalyst (triethylamine and hydrochloric acid in a mass ratio of 2.5:1.5), and 220 parts continuous phase; wherein, the nanocellulose specifically consists of first nanocellulose (diameter distribution of 5~10 nm, length distribution of 100~300 nm) and second nanocellulose (diameter distribution of 15~20 nm, length distribution of 150~300 nm), with a mass ratio of first nanocellulose to second nanocellulose of 100:80; the continuous phase is isopropanol and ethanol, with a volume ratio of isopropanol to ethanol of 100:55.
[0056] Preparation method: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated for 3 hours under stirring conditions of 45 degrees Celsius and 150 rpm to obtain activated cellulose.
[0057] (2) The prepared activated cellulose, alkaline catalyst and ethanol (60%) were mixed, and then 3-chloropropyltrimethoxysilane was added to the mixture. The mixture was condensed at 85 degrees Celsius for 4 hours. After the reaction was completed, the mixture was centrifuged, washed three times with ethanol, dried at 35 degrees Celsius for 2 hours, and pulverized to 50~80 nanometers (sieved) to obtain modified cellulose.
[0058] (3) Mix vinyltrimethoxysilane and the remaining ethanol (40%), then mix the resulting premix with the obtained modified cellulose and acid catalyst, and etherify the mixture for 5 hours at 60 degrees Celsius, pH 5 and stirring speed 100 rpm. After the reaction is completed, neutralize with sodium hydroxide, centrifuge, wash with water 3 times, dry at 50 degrees Celsius for 30 minutes, and pulverize to 30~60 nanometers (sieve) to obtain a highly efficient filtration loss reducer.
[0059] Comparative Example 1: The preparation method of this comparative example is the same as that of Example 1, except that step (2) is omitted.
[0060] Comparative Example 2: The preparation method of this comparative example is the same as that of Example 1, except that step (3) is omitted.
[0061] Comparative Example 3: The preparation method of this comparative example is the same as that of Example 1, except that no alkaline catalyst is added in step (2).
[0062] Comparative Example 4: The preparation method of this comparative example is the same as that of Example 1, except that no acidic catalyst is added in step (3).
[0063] Test Example 1: The performance of the high-efficiency filtration loss reducers in Examples 1-5 and Comparative Examples 1-4 was tested. The test method was as follows: 1000 mL of water, 12 g of bentonite, 80 g of sodium chloride, 50 g of high-efficiency filtration loss reducer, 35 g of sodium carbonate, 3 g of potassium formate, 10 g of sodium hydroxide and 255 g of white oil were stirred evenly, sealed and cured for 24 hours to prepare the first water-based drilling fluid.
[0064] Mix 1000mL of water, 12g of bentonite, 330g of sodium chloride, 15g of calcium chloride, 50g of high-efficiency filtration reducer, 35g of sodium carbonate, 3g of potassium formate, 10g of sodium hydroxide, and 255g of white oil until well combined. Seal and cure for 24 hours to prepare the second water-based drilling fluid.
[0065] The first or second water-based drilling fluid was loaded into a high-temperature aging tank and placed in a roller furnace for rolling thermal aging at 160 degrees Celsius for 16 hours. After aging, it was cooled to room temperature. Referring to GB / T16783.1-2025 standard, a high-temperature, high-pressure filtration loss meter was used to measure the high-temperature, high-pressure filtration loss over 30 minutes at 160 degrees Celsius and a pressure difference of 3.5 MPa. The test results are shown in Table 1 and... Figure 1 As shown.
[0066] Table 1. Performance test results of the high-efficiency filtration loss reducers in Examples 1-5 and Comparative Examples 1-4:
[0067] According to Table 1 and Figure 1 It can be seen that the high-efficiency filtration reducer provided by this invention can effectively reduce the filtration loss of water-based drilling fluid in high-temperature, high-salt and high-calcium environments, keeping it within the range of 8~10mL / 30 minutes. The effect is quite ideal and meets the relevant performance requirements of shale gas horizontal wells.
[0068] The embodiments of the present invention have been described above; however, these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the above embodiments of the present invention without inventive effort are within the protection scope of the present invention.
Claims
1. A highly efficient filtration loss reducing agent, characterized in that, By weight, the raw materials include: 100 parts of nanocellulose, 45-75 parts of 3-chloropropyltrimethoxysilane, 20-25 parts of vinyltrimethoxysilane, 40-60 parts of inorganic base, 1-5 parts of catalyst, and 180-300 parts of continuous phase.
2. The high-efficiency filtration loss reducer according to claim 1, characterized in that, Nanocellulose includes first nanocellulose and second nanocellulose; The diameter of the first nanocellulose is 5-10 nanometers; The diameter of the second nanocellulose is 15-20 nanometers; The mass ratio of the first nanocellulose to the second nanocellulose is 100:75~85.
3. The high-efficiency filtration loss reducer according to claim 1, characterized in that, Catalysts include basic catalysts and acidic catalysts; The alkaline catalyst is triethylamine; The acidic catalyst is acetic acid or hydrochloric acid; The mass ratio of alkaline catalyst to acidic catalyst is 2~3:1~2.
4. The high-efficiency filtration loss reducer according to claim 1, characterized in that, The continuous phase includes isopropanol and ethanol; The volume ratio of isopropanol to ethanol is 100:50~65.
5. The high-efficiency filtration loss reducer according to claim 1, characterized in that, The particle size of the high-efficiency filtration loss reducer is 30~60 nanometers.
6. A method for preparing a highly efficient filtration loss reducing agent, characterized in that, The high-efficiency filtration reduction agent is any one of the high-efficiency filtration reduction agents according to claims 1 to 5, comprising the following steps: (1) Nanocellulose, inorganic base and isopropanol are mixed and activated to obtain activated cellulose; (2) Activated cellulose, 3-chloropropyltrimethoxysilane, alkaline catalyst and part of ethanol are mixed and subjected to condensation reaction to obtain modified cellulose; (3) The modified cellulose, vinyltrimethoxysilane, acid catalyst and residual ethanol are mixed and etherified to obtain a highly efficient filtration loss reducer.
7. The preparation method according to claim 6, characterized in that, The activation reaction is carried out at a temperature of 40-55 degrees Celsius for 1-5 hours, and the activation reaction is carried out under stirring conditions at a speed of 100-200 rpm.
8. The preparation method according to claim 6, characterized in that, The condensation reaction takes place at a temperature of 75-95 degrees Celsius for 2-12 hours.
9. The preparation method according to claim 6, characterized in that, The etherification reaction is carried out at a temperature of 45-70 degrees Celsius, a pH of 4-6, and a time of 1-8 hours. The etherification reaction was carried out under stirring conditions, with a stirring speed of 80~150 rpm.
10. The application of a high-efficiency filtration loss reducer in water-based drilling fluids for shale gas horizontal wells, characterized in that, The high-efficiency filtration reduction agent is any one of the high-efficiency filtration reduction agents according to claims 1 to 5.