Drilling fluid flow pattern regulator suitable for South Pole under-ice drilling as well as preparation method and application of drilling fluid flow pattern regulator

Abstract

The invention provides a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling and a preparation method and application thereof, and belongs to the technical field of polar region drilling. The flow pattern regulator is prepared from the following raw materials: 4-tert-butyl styrene, carboxylic acid, an acrylate monomer, oleyl alcohol, concentrated sulfuric acid and an initiator. The carboxylic acid is one of ricinoleic acid or phthalic acid; the acrylic ester monomer is one of acrylic acid-2-hydroxyethyl ester or 2-acrylic acid-2-hydroxy-3-phenoxy propyl ester, and the acrylic ester monomer is one of acrylic acid-2-hydroxyethyl ester and 2-acrylic acid-2-hydroxy-3-phenoxy propyl ester; and the initiator is one of azodiisobutyronitrile or benzoyl peroxide. The flow pattern regulator is simple in raw material composition and preparation method and low in cost. The flow pattern regulator can effectively improve the ultralow-temperature rheological property of the drilling fluid, enables the drilling fluid to have the advantages of low viscosity, high dynamic shearing force, chip carrying (ice chips and rock chips), excellent suspension performance and the like at the ultralow temperature, and is suitable for under-ice drilling in the Antarctic pole.

Description

Technical Field

[0001] The present invention relates to a drilling fluid flow pattern regulator suitable for Antarctic under-ice drilling, a preparation method and application thereof, and belongs to the technical field of polar drilling. Background Art

[0002] In recent years, humanity's increasing dependence on oil and gas resources has led countries to explore for oil and gas resources not only in deep layers but also in the polar regions. Antarctica boasts abundant oil and mineral resources, but its complex geological environment and ultra-low temperatures pose significant challenges to exploration and development, placing higher demands on drilling fluid performance. Currently, drilling fluids suitable for use in the Antarctic often exhibit poor rheological properties, primarily manifested by high viscosity, low dynamic shear force, and poor chip transport (ice and rock) performance. Therefore, developing a flow modifier for ultra-low-temperature drilling fluids suitable for Antarctic subglacial drilling to effectively control their rheological properties is crucial.

[0003] In the field of deepwater drilling, there have been numerous reports on drilling fluid flow pattern regulators. To address the problems of existing constant rheological drilling fluid flow pattern regulators, such as a narrow temperature adaptability range and poor salt tolerance, Chinese patent document CN117304426A discloses a hectorite-polymer large temperature gradient constant rheological flow pattern regulator, its preparation method, and application. This invention is prepared using nano-hectorite, a silane coupling agent, anionic and cationic monomers, and a temperature-sensitive monomer as raw materials. This flow pattern regulator exhibits good rheological properties in a high-temperature environment of 180°C and in a 15% salt water-based slurry, and has excellent low-temperature regulation capabilities and a wide temperature range of application. Chinese patent document CN114933673A discloses a constant rheological flow pattern regulator based on polyacrylamide-butyl acrylate-zwitterion and its preparation method. This invention primarily achieves constant rheological properties of drilling fluids through the hydrophobic association and electrostatic interaction of polymer chains. The selected monomers include acrylamide, butyl acrylate, and an emulsifier. Chinese patent document CN112194755A discloses a method for preparing a temperature-sensitive flow pattern modifier for deepwater water-based drilling fluids. Using temperature-sensitive monomers (N-isopropylacrylamide, N-vinylcaprolactam), acrylic monomers, and amide monomers as raw materials, this invention synthesizes a temperature-sensitive drilling fluid flow pattern modifier. This modifier stabilizes the rheological parameters of the drilling fluid within the temperature range of 4–65°C and reduces the dynamic shear force variation by over 30%, achieving rheological control of deepwater water-based drilling fluids under low-temperature conditions. However, this document only reports the application of various flow pattern modifiers in deepwater drilling, making their application in Antarctic subglacial drilling difficult. There are virtually no reports on ultra-low-temperature drilling fluid flow pattern modifiers suitable for Antarctic subglacial drilling.

[0004] Therefore, there is an urgent need to develop a drilling fluid flow regulator that can be used for Antarctic subglacial drilling, so as to effectively regulate the ultra-low temperature rheological properties of the drilling fluid to ensure safe and efficient drilling. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention provides a drilling fluid flow pattern modifier suitable for Antarctic subglacial drilling, as well as its preparation method and application. The present flow pattern modifier has simple raw material composition and preparation method, and is low-cost. The present flow pattern modifier can effectively improve the ultra-low-temperature rheological properties of drilling fluids, imparting advantages such as low viscosity, high dynamic shear force, and excellent chip carrying (ice and rock) and suspension properties at ultra-low temperatures, making it suitable for Antarctic subglacial drilling.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is prepared from the following raw materials: 4-tert-butylstyrene, carboxylic acid, acrylate monomer, oleyl alcohol, concentrated sulfuric acid, and an initiator; The carboxylic acid is one of ricinoleic acid and phthalic acid; the acrylic acid ester monomer is one of 2-hydroxyethyl acrylate and 2-hydroxy-3-phenoxypropyl 2-acrylate; the initiator is one of azobisisobutyronitrile and benzoyl peroxide; The molar ratio of the 4-tert-butylstyrene to the acrylate monomer is (1-1.2):1.05; the molar amount of the carboxylic acid is 0.5-1.0 times the molar amount of the acrylate monomer; the molar amount of the oleyl alcohol is 0.5-1.5 times the molar amount of the carboxylic acid; and the molar amount of the initiator is 0.2%-0.5% of the total molar amount of the 4-tert-butylstyrene and the acrylate monomer.

[0007] According to the present invention, preferably, the carboxylic acid is ricinoleic acid.

[0008] According to the present invention, preferably, the acrylic acid ester monomer is 2-hydroxyethyl acrylate.

[0009] According to the present invention, preferably, the initiator is benzoyl peroxide.

[0010] According to the preferred embodiment of the present invention, the molar ratio of 4-tert-butylstyrene to acrylate monomer is (1.1-1.2):1.05; the molar amount of carboxylic acid is 0.67-0.8 times the molar amount of acrylate monomer; the molar amount of oleyl alcohol is 0.98-1.2 times the molar amount of carboxylic acid; and the molar amount of initiator is 0.3%-0.4% of the total molar amount of 4-tert-butylstyrene and acrylate monomer.

[0011] According to the present invention, the concentration of concentrated sulfuric acid is preferably 15-18.4 mol / L; the molar amount of concentrated sulfuric acid is 0.2% to 0.8% of the total molar amount of 4-tert-butylstyrene, carboxylic acid, acrylate monomer, and oleyl alcohol, preferably 0.6% to 0.8%.

[0012] The method for preparing the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling comprises the following steps: (1) 4-tert-butylstyrene and acrylic ester monomers are fully mixed, an initiator is added, and a first reaction product is obtained by reaction; (2) Carboxylic acid and oleyl alcohol are added to the first reaction product, and concentrated sulfuric acid is added after being thoroughly mixed; and then, after the reaction, a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is obtained.

[0013] Preferably, in step (1), the reaction temperature is 60-80° C., the reaction time is 2-4 h, and the reaction is carried out under protective gas protection and stirring; the protective gas is nitrogen or argon.

[0014] Preferably, in step (2), the reaction temperature is 80°C to 100°C, the reaction time is 3 to 5 hours, and the reaction is carried out under protective gas protection and stirring conditions; the protective gas is nitrogen or argon.

[0015] The application of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling in the drilling fluid of Antarctic subglacial drilling.

[0016] According to the present invention, the preferred application temperature is -20 to -55°C.

[0017] The technical features and beneficial effects of the present invention are as follows: 1. The flow pattern regulator of the present invention has simple raw material composition and preparation method, low cost and is suitable for industrial production.

[0018] 2. The flow pattern modifier of the present invention is an optimal combination of specific raw materials in specific ratios, which work together to achieve the excellent effects of the present invention. The flow pattern modifier of the present invention can effectively improve the ultra-low temperature rheological properties of drilling fluids, imparting advantages such as low viscosity, high dynamic shear force, and excellent chip carrying (ice and rock) and suspension properties at ultra-low temperatures. It is suitable for ultra-low temperature drilling fluids used in Antarctic subglacial drilling.

[0019] 3. The present invention first uses 4-tert-butylstyrene and acrylic acid ester monomers as raw materials, undergoes a polymerization reaction under the action of an initiator to obtain a first reaction product, and then further reacts with carboxylic acid and oleyl alcohol under the catalysis of concentrated sulfuric acid to obtain a flow pattern modifier. The flow pattern modifier molecule contains strong polar groups such as carboxyl and ester groups, as well as long lipophilic carbon chains. The presence of this structure enables it to form a spatial grid structure in the drilling fluid, effectively improving the ultra-low temperature rheological properties of the drilling fluid, including dynamic shear force, viscosity under low shear rate conditions (10s -1 ) and the viscosity under high shear rate conditions (100s -1 ), debris carrying (ice and rock chips) and suspension performance, etc.

[0020] 4. The raw material types of the present invention must be appropriate. If the raw material types are inappropriate or some raw materials are omitted, the performance of the resulting flow pattern regulator will be reduced. The raw material ratios of the present invention must also be appropriate. If they are not appropriate, the performance of the resulting flow pattern regulator will also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the infrared spectrum of the drilling fluid flow pattern regulator prepared in Example 3. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to specific examples, but is not limited thereto.

[0023] The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials used are commercially available unless otherwise specified.

[0024] Example 1 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is prepared from the following raw materials: 4-tert-butylstyrene, ricinoleic acid, 2-hydroxyethyl acrylate, oleyl alcohol, 18.4 mol / L concentrated sulfuric acid, and an initiator, benzoyl peroxide; The molar ratio of 4-tert-butylstyrene to 2-hydroxyethyl acrylate is 1.1:1.05; the molar amount of ricinoleic acid is 0.67 times the molar amount of 2-hydroxyethyl acrylate; and the molar amount of oleyl alcohol is 0.98 times the molar amount of ricinoleic acid. The molar amount of benzoyl peroxide is 0.3% of the total molar amount of 4-tert-butylstyrene and 2-hydroxyethyl acrylate. The molar amount of concentrated sulfuric acid is 0.7% of the total molar amount of 4-tert-butylstyrene, ricinoleic acid, 2-hydroxyethyl acrylate, and oleyl alcohol.

[0025] The method for preparing the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling comprises the following steps: 1) Add 4-tert-butylstyrene and 2-hydroxyethyl acrylate into a three-necked flask and stir at a stirring rate of 270 r / min for 20 minutes until the mixture is uniformly mixed; 2) Purify with nitrogen for 20 minutes, heat to 75°C, add benzoyl peroxide, and react with stirring at 75°C in a nitrogen atmosphere for 3 hours to obtain the first reaction product; 3) Add ricinoleic acid and oleyl alcohol to the first reaction product at a stirring rate of 270 r / min, stir for 15 minutes, and flow nitrogen for 20 minutes. When the temperature reaches 90°C, add concentrated sulfuric acid; 4) stirring the reaction at 90° C. in a nitrogen atmosphere for 4 h, and cooling to room temperature to obtain a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling.

[0026] Example 2 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is prepared from the following raw materials: 4-tert-butylstyrene, ricinoleic acid, 2-hydroxyethyl acrylate, oleyl alcohol, 18.4 mol / L concentrated sulfuric acid, and an initiator, benzoyl peroxide; The molar ratio of 4-tert-butylstyrene to 2-hydroxyethyl acrylate is 1.2:1.05; the molar amount of ricinoleic acid is 0.67 times the molar amount of 2-hydroxyethyl acrylate; and the molar amount of oleyl alcohol is 0.98 times the molar amount of ricinoleic acid. The molar amount of benzoyl peroxide is 0.3% of the total molar amount of 4-tert-butylstyrene and 2-hydroxyethyl acrylate. The molar amount of concentrated sulfuric acid is 0.7% of the total molar amount of 4-tert-butylstyrene, ricinoleic acid, 2-hydroxyethyl acrylate, and oleyl alcohol.

[0027] The method for preparing the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling comprises the following steps: 1) Add 4-tert-butylstyrene and 2-hydroxyethyl acrylate into a three-necked flask and stir at a stirring rate of 270 r / min for 20 minutes until the mixture is uniformly mixed; 2) Purify with nitrogen for 20 minutes, heat to 75°C, add benzoyl peroxide, and react with stirring at 75°C in a nitrogen atmosphere for 3 hours to obtain the first reaction product; 3) Add ricinoleic acid and oleyl alcohol to the first reaction product at a stirring rate of 270 r / min, stir for 15 minutes, and flow nitrogen for 20 minutes. When the temperature reaches 90°C, add concentrated sulfuric acid; 4) stirring the reaction at 90° C. in a nitrogen atmosphere for 4 h, and cooling to room temperature to obtain a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling.

[0028] Example 3 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is prepared from the following raw materials: 4-tert-butylstyrene, ricinoleic acid, 2-hydroxyethyl acrylate, oleyl alcohol, 18.4 mol / L concentrated sulfuric acid, and an initiator, benzoyl peroxide; The molar ratio of 4-tert-butylstyrene to 2-hydroxyethyl acrylate is 1.1:1.05; the molar amount of ricinoleic acid is 0.67 times the molar amount of 2-hydroxyethyl acrylate; and the molar amount of oleyl alcohol is 0.98 times the molar amount of ricinoleic acid. The molar amount of benzoyl peroxide is 0.4% of the total molar amount of 4-tert-butylstyrene and 2-hydroxyethyl acrylate. The molar amount of concentrated sulfuric acid is 0.7% of the total molar amount of 4-tert-butylstyrene, ricinoleic acid, 2-hydroxyethyl acrylate, and oleyl alcohol.

[0029] The method for preparing the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling comprises the following steps: 1) Add 4-tert-butylstyrene and 2-hydroxyethyl acrylate into a three-necked flask and stir at a stirring rate of 270 r / min for 20 minutes until the mixture is uniformly mixed; 2) Purify with nitrogen for 20 minutes, heat to 75°C, add benzoyl peroxide, and react with stirring at 75°C in a nitrogen atmosphere for 3 hours to obtain the first reaction product; 3) Add ricinoleic acid and oleyl alcohol to the first reaction product at a stirring rate of 270 r / min, stir for 15 minutes, and flow nitrogen for 20 minutes. When the temperature reaches 90°C, add concentrated sulfuric acid; 4) stirring the reaction at 90° C. in a nitrogen atmosphere for 4 h, and cooling to room temperature to obtain a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling.

[0030] The infrared spectrum of the flow pattern regulator obtained in this example is as follows Figure 1 As shown, 2932 cm −1 and 2865 cm −1 The corresponding peaks near the center are the asymmetric stretching vibration peak and the symmetric stretching vibration peak of CH; 1720 cm −1 The corresponding peak near 1640 cm is the stretching vibration peak of C=O in ester; −1 The corresponding peak near 1500 cm is the stretching vibration peak of cis C=C in ricinoleic acid; −1 The corresponding peak near 1465cm is the stretching vibration peak of C=C in the benzene ring skeleton; −1 and 1365cm −1 The corresponding peaks nearby are the bending vibration peaks of the long-chain CH in ricinoleic acid and oleyl alcohol; 1270 cm −1 The corresponding peak near the 1200 cm −1The corresponding peak near 1050 cm is the asymmetric stretching vibration peak of the ester group COC; −1 The peak near 720 cm is the stretching vibration peak of CO of the primary hydroxyl group in oleyl alcohol; −1 The peaks near the bottom are the backbone vibrations of the long-chain methylene groups in ricinoleic acid and oleyl alcohol. IR spectroscopy confirmed the successful preparation of the target product.

[0031] Example 4 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, except that 2-hydroxyethyl acrylate is replaced by 2-hydroxy-3-phenoxypropyl 2-acrylate, and the other raw material compositions are the same as those in Example 3.

[0032] The preparation method of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, with the same differences as above.

[0033] Example 5 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, except that the molar addition amount of ricinoleic acid is changed from 0.67 times to 0.8 times that of 2-hydroxyethyl acrylate. The other raw material compositions are the same as those in Example 3.

[0034] The preparation method of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, with the same differences as above.

[0035] Example 6 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling, same as Example 3.

[0036] The preparation method of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, except that the reaction temperature in step 2) is changed from 75°C to 65°C. The other steps and conditions are the same as those in Example 3.

[0037] Example 7 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, except that ricinoleic acid is replaced by phthalic acid. The other raw material compositions are the same as those in Example 3.

[0038] The preparation method of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, with the same differences as above.

[0039] Example 8 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, except that the molar amount of oleyl alcohol is changed from 0.98 times the molar amount of ricinoleic acid to 1.2 times. The other raw material compositions are the same as those in Example 3.

[0040] The preparation method of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, with the same differences as above.

[0041] Example 9 A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, except that the initiator benzoyl peroxide is replaced by azobisisobutyronitrile, and the other raw material compositions are the same as those in Example 3.

[0042] The preparation method of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is as described in Example 3, with the same differences as above.

[0043] Comparative Example 1 A flow pattern regulator is as described in Example 3, except that the molar ratio of 4-tert-butylstyrene to 2-hydroxyethyl acrylate is changed from 1.1:1.05 to 2:1.05. The other raw material compositions are the same as those in Example 3.

[0044] The preparation method of the above flow pattern regulator is as described in Example 3, with the same differences as above.

[0045] Comparative Example 2 A flow pattern regulator is as described in Example 3, except that the molar amount of benzoyl peroxide is changed from 0.4% of the total molar amount of 4-tert-butylstyrene and 2-hydroxyethyl acrylate to 1%. The other raw material compositions are the same as those in Example 3.

[0046] The preparation method of the above flow pattern regulator is as described in Example 3, with the same differences as above.

[0047] Comparative Example 3 A flow pattern regulator is as described in Example 3, except that the molar amount of ricinoleic acid is changed from 0.67 times to 1.5 times that of 2-hydroxyethyl acrylate. The raw material composition is the same as that of Example 3.

[0048] The preparation method of the above flow pattern regulator is as described in Example 3, with the same differences as above.

[0049] Comparative Example 4 A flow pattern regulator, the raw material composition is the same as that in Example 3.

[0050] The preparation method of the above-mentioned flow pattern regulator comprises the steps of: 1) Add 4-tert-butylstyrene, 2-hydroxyethyl acrylate, ricinoleic acid and oleyl alcohol into a three-necked flask and stir at a stirring rate of 270 r / min for 20 min until the mixture is uniform; 2) Purify the mixture with nitrogen for 20 minutes, heat to 90°C, add benzoyl peroxide and 18.4 mol / L concentrated sulfuric acid, and react at 90°C under nitrogen for 4 hours with stirring. Cool to room temperature to obtain a flow pattern modifier.

[0051] Comparative Example 5 A flow pattern modifier, as described in Example 3, except that 4-tert-butylstyrene is omitted, the molar amount of benzoyl peroxide is 0.4% of the molar amount of 2-hydroxyethyl acrylate, and the molar amount of concentrated sulfuric acid is 0.7% of the total molar amount of ricinoleic acid, 2-hydroxyethyl acrylate, and oleyl alcohol. The other raw material compositions are the same as in Example 3.

[0052] The preparation method of the above flow pattern regulator is as described in Example 3, with the same differences as above.

[0053] Comparative Example 6 A flow pattern regulator is as described in Example 3, except that ricinoleic acid, oleyl alcohol, and concentrated sulfuric acid are not added. The other raw material compositions are the same as those in Example 3.

[0054] The preparation method of the above-mentioned flow pattern regulator comprises the steps of: 1) Add 4-tert-butylstyrene and 2-hydroxyethyl acrylate into a three-necked flask and stir at a stirring rate of 270 r / min for 20 minutes until the mixture is uniformly mixed; 2) Purify the mixture with nitrogen for 20 minutes, heat to 75°C, add benzoyl peroxide, and react with stirring at 75°C in a nitrogen atmosphere for 3 hours to obtain a flow pattern modifier.

[0055] Comparative Example 7 A flow pattern regulator, as described in Example 3, except that oleyl alcohol is replaced by hexadecanol, and the other raw material compositions are the same as those in Example 3.

[0056] The preparation method of the above flow pattern regulator is as described in Example 3, with the same differences as above.

[0057] Comparative Example 8 A flow pattern modifier, as described in Example 3, except that 4-tert-butylstyrene, 2-hydroxyethyl acrylate, and benzoyl peroxide were omitted, and the molar amount of concentrated sulfuric acid was 0.7% of the total molar amount of ricinoleic acid and oleyl alcohol. The other raw material compositions were the same as in Example 3.

[0058] The preparation method of the above-mentioned flow pattern regulator comprises the steps of: 1) Add ricinoleic acid and oleyl alcohol into a three-necked flask, stir at 270 rpm for 15 minutes, and flow nitrogen for 20 minutes. When the temperature reaches 90°C, add 18.4 mol / L concentrated sulfuric acid. 2) The mixture was stirred and reacted at 90° C. in a nitrogen atmosphere for 4 h, and then cooled to room temperature to obtain a flow pattern modifier.

[0059] Comparative Example 9 A flow pattern regulator, as described in Example 3, except that no oil alcohol is added, the molar amount of concentrated sulfuric acid is 0.7% of the total molar amount of 4-tert-butylstyrene, ricinoleic acid, and 2-hydroxyethyl acrylate, and the other raw material compositions are the same as in Example 3.

[0060] The preparation method of the above flow pattern regulator is as described in Example 3, with the same differences as above.

[0061] Test Example 1 The rheological properties of the flow pattern regulators in the examples and comparative examples were tested.

[0062] (1) Sample preparation: The drilling fluid base fluid was composed as follows: first, 4# aviation kerosene and 5# white oil were prepared into a base fluid in a volume ratio of 7:3, totaling 320 mL; the flow pattern modifiers described in the examples or comparative examples were added to the drilling fluid base fluid in an amount of 2% by mass of the base fluid, and the mixture was thoroughly stirred on a high-speed stirrer for 30 minutes to obtain a drilling fluid sample; and the performance of the flow pattern modifiers was tested at -55°C.

[0063] (2) Test method: Rheological test: 1) Viscosity, dynamic shear force and dynamic-plastic ratio test: Pour the prepared drilling fluid sample into the test slurry cup and use a low-temperature rheometer to measure the readings at 600r, 300r, 6r and 3r at -55°C. Then calculate the relevant rheological parameters such as apparent viscosity, plastic viscosity, dynamic shear force, dynamic-plastic ratio and shear lift rate.

[0064] 2) Low shear rate (10s -1 ) viscosity and high shear rate (100s -1 ) Viscosity ratio test: The prepared drilling fluid sample is placed in an ultra-low temperature constant temperature box and frozen (-55℃) for 16 hours. Then, the low shear rate viscosity and high shear rate viscosity are immediately tested using a Haake rheometer at 4℃, and the ratio is calculated.

[0065] The rheological properties were determined and the test results are shown in Table 1.

[0066] Table 1 Flow pattern modifier performance test data

[0067] The data in Table 1 show that the drilling fluid flow pattern modifier prepared by the present invention can significantly improve the ultra-low temperature rheological properties of drilling fluid. At -55°C, the dynamic shear force of the drilling fluid can reach a maximum of 3.25 Pa, with a dynamic shear force improvement rate of 550%, while the plastic viscosity is only 18 mPa·s. In addition, the flow pattern modifier can also increase the viscosity ratio of the drilling fluid (10s -1 / 100s -1 ) increased from 1.01 to 3.78, and the dynamic-plastic ratio increased from 0.03 to 0.18. This indicates that the drilling fluid also has good thixotropic properties and non-Newtonian characteristics of shear thinning, which can not only suspend rock and ice chips at the bottom of the well, but also carry them efficiently.

[0068] In summary, the flow pattern regulator of the present invention can meet the needs of Antarctic drilling.

[0069] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0070] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0071] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling, characterized in that: The method comprises the following raw materials: 4-tert-butylstyrene, carboxylic acid, acrylic acid ester monomer, oleyl alcohol, concentrated sulfuric acid, and initiator; The carboxylic acid is one of ricinoleic acid and phthalic acid; the acrylic acid ester monomer is one of 2-hydroxyethyl acrylate and 2-hydroxy-3-phenoxypropyl 2-acrylate; the initiator is one of azobisisobutyronitrile and benzoyl peroxide; The molar ratio of the 4-tert-butylstyrene to the acrylate monomer is (1-1.2):1.05; the molar amount of the carboxylic acid is 0.5-1.0 times the molar amount of the acrylate monomer; the molar amount of the oleyl alcohol is 0.5-1.5 times the molar amount of the carboxylic acid; and the molar amount of the initiator is 0.2%-0.5% of the total molar amount of the 4-tert-butylstyrene and the acrylate monomer.

2. The drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to claim 1, characterized in that: The carboxylic acid is ricinoleic acid.

3. The drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to claim 1, characterized in that: The acrylic acid ester monomer is 2-hydroxyethyl acrylate.

4. The drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to claim 1, characterized in that: The initiator is benzoyl peroxide.

5. The drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to claim 1, characterized in that: The molar ratio of 4-tert-butylstyrene to acrylate monomer is (1.1-1.2):1.05; the molar amount of carboxylic acid is 0.67-0.8 times the molar amount of acrylate monomer; the molar amount of oleyl alcohol is 0.98-1.2 times the molar amount of carboxylic acid; and the molar amount of initiator is 0.3%-0.4% of the total molar amount of 4-tert-butylstyrene and acrylate monomer.

6. The drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to claim 1, characterized in that: The concentration of concentrated sulfuric acid is 15-18.4 mol / L; the molar amount of concentrated sulfuric acid is 0.2%-0.8% of the total molar amount of 4-tert-butylstyrene, carboxylic acid, acrylic ester monomer, and oleyl alcohol.

7. The method for preparing a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to any one of claims 1 to 6, characterized in that: Including steps: (1) 4-tert-butylstyrene and acrylic ester monomers are fully mixed, an initiator is added, and a first reaction product is obtained by reaction; (2) Carboxylic acid and oleyl alcohol are added to the first reaction product, and concentrated sulfuric acid is added after being thoroughly mixed; and then, after the reaction, a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling is obtained.

8. The method for preparing a drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to claim 7, characterized in that: Include one or more of the following conditions: i. In step (1), the reaction temperature is 60-80°C, the reaction time is 2-4 hours, and the reaction is carried out under protective gas protection and stirring; the protective gas is nitrogen or argon; ii. In step (2), the reaction temperature is 80°C to 100°C, the reaction time is 3 to 5 hours, and the reaction is carried out under protective gas protection and stirring; the protective gas is nitrogen or argon.

9. Use of the drilling fluid flow pattern regulator suitable for Antarctic subglacial drilling according to any one of claims 1 to 6 in drilling fluid for Antarctic subglacial drilling.

10. The use according to claim 9, characterized in that The application temperature is -20 to -55°C.

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