Solid thickening agent for fracturing and preparation method thereof

Abstract

The invention discloses a solid thickening agent for fracturing and a preparation method thereof, and relates to the technical field of chemical treatment agents. The water-based adhesive is prepared from the following components in parts by weight: 30 to 35 parts of N-hydroxyethyl acrylamide, 18 to 24 parts of N-(3-methoxypropyl) acrylamide, 14 to 16 parts of vinyl sulfonate, 8 to 10 parts of vinyl benzoate, 6 to 8 parts of diacetone acrylamide, 4 to 6 parts of dimethyl itaconate, 2 to 4 parts of dodecyl benzene sulfonic acid isopropylamine salt, 120 to 140 parts of deionized water and 1 to 2 parts of azodiisobutylimidazoline hydrochloride. The materials are put into a blending tank to be uniformly mixed. According to the solid thickening agent for fracturing and the preparation method thereof, the shearing resistance, the temperature resistance, the salt resistance and the sand suspending property of the solid thickening agent are obviously superior to those of an existing thickening agent.

Description

A solid thickener for fracturing and its preparation method Technical Field

[0001] This invention relates to the field of chemical treatment agent technology, specifically to a solid thickener for fracturing and its preparation method. Background Technology

[0002] Oilfield fracturing thickeners are polymeric additives used to increase the viscosity and improve the rheological properties of aqueous systems, and are one of the main components of fracturing fluids. As oil and gas extraction increasingly relies on hydraulic fracturing technology, the performance of cleaning and thickening agents directly affects the rheological properties, stability, and suspension capacity of solid particles in oil and gas wells, thereby improving oil and gas extraction efficiency. Traditional oilfield fracturing thickeners are typically composed of natural or synthetic polymers and surfactants. Synthetic polymers provide excellent thickening effects in water, exhibiting good temperature and shear resistance, strong thickening ability, good sand-suspending capacity and gel-breaking properties, and are insensitive to bacteria, outperforming natural polymers in all aspects.

[0003] Existing solid fracturing fluid thickeners suffer from various technical shortcomings, including insufficient temperature resistance, and the need for further improvement in salt resistance and shear resistance. These limitations hinder their development in petrochemical and oilfield extraction fields. Developing more efficient, stable, environmentally friendly, and cost-effective thickeners has become an urgent technical challenge. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a solid thickener for fracturing and its preparation method. The thickener prepared by this method has significantly better shear resistance, temperature resistance, salt resistance and sand suspension properties than existing thickeners.

[0005] To address the problems existing in the background technology, the present invention adopts the following technical solution: comprising N-hydroxyethyl acrylamide, N-(3-methoxypropyl)acrylamide, vinyl sulfonate, vinyl benzoate, diacetone acrylamide, itaconic acid dimethyl ester, isopropylamine dodecylbenzenesulfonate, deionized water, and azobisisobutyrazoline hydrochloride, wherein the content of each component is as follows: 30-35 parts of N-hydroxyethyl acrylamide, 18-24 parts of N-(3-methoxypropyl)acrylamide, 14-16 parts of vinyl sulfonate, 8-10 parts of vinyl benzoate, 6-8 parts of diacetone acrylamide, 4-6 parts of itaconic acid dimethyl ester, 2-4 parts of isopropylamine dodecylbenzenesulfonate, 120-140 parts of deionized water, and 1-2 parts of azobisisobutyrazoline hydrochloride.

[0006] The preparation method of solid thickener for fracturing is as follows: Step 1, N-hydroxyethyl acrylamide, N-(3-methoxypropyl)acrylamide, vinyl sulfonate, vinyl benzoate, diacetone acrylamide, dimethyl itaconic acid, isopropylamine dodecylbenzenesulfonate, deionized water, and azobisisobutyrazoline hydrochloride are added to a mixing tank and mixed and stirred until a homogeneous material is obtained; Step 2, the homogeneous material is transferred to a reaction vessel, and the motor speed of the reaction vessel is adjusted to 100-150 rpm; Step 3, nitrogen gas is introduced into the reaction vessel for 30 minutes. Next, heat the reaction vessel to 50℃~55℃ and stir for 2~3 hours; Step four, after stirring for 2~3 hours, stop stirring and maintain the temperature at 50℃~55℃ for 6~8 hours, then let it cool naturally to room temperature; Step five, after cooling to room temperature, transfer it to a cutting machine for cutting, and then transfer it to a drying oven for drying. The drying temperature is adjusted to 105℃ and dried for 12 hours; Step six, after drying for 12 hours, let it cool naturally to room temperature, remove the material, and transfer it to a pulverizer for pulverization. The pulverizer pulverizes the material into a size of 0.5~1mm to obtain a solid thickener.

[0007] The beneficial effects of this invention are: the dissolution and dispersion time, shear resistance, temperature resistance, salt resistance, and sand suspension are all superior to existing solid thickeners. The dissolution and dispersion time is less than 6 minutes, the shear resistance viscosity is above 81 mPa·s, the temperature resistance viscosity is above 65 mPa·s, the salt resistance viscosity is above 90 mPa·s, the sand suspension is above 390 mL, and the sand suspension rate is above 97.50%. Detailed Implementation

[0008] The present invention specifically adopts the following embodiments: including N-hydroxyethyl acrylamide, N-(3-methoxypropyl)acrylamide, vinyl sulfonate, vinyl benzoate, diacetone acrylamide, itaconic acid dimethyl ester, isopropylamine dodecylbenzenesulfonate, deionized water and azobisisobutyrazoline hydrochloride, the content of each component is as follows: N-hydroxyethyl acrylamide 30-35 parts, N-(3-methoxypropyl)acrylamide 18-24 parts, vinyl sulfonate 14-16 parts, vinyl benzoate 8-10 parts, diacetone acrylamide 6-8 parts, itaconic acid dimethyl ester 4-6 parts, isopropylamine dodecylbenzenesulfonate 2-4 parts, deionized water 120-140 parts and azobisisobutyrazoline hydrochloride 1-2 parts.

[0009] The preparation method of solid thickener for fracturing is as follows: Step 1, N-hydroxyethyl acrylamide, N-(3-methoxypropyl)acrylamide, vinyl sulfonate, vinyl benzoate, diacetone acrylamide, dimethyl itaconic acid, isopropylamine dodecylbenzenesulfonate, deionized water, and azobisisobutyrazoline hydrochloride are added to a mixing tank and mixed and stirred until a homogeneous material is obtained; Step 2, the homogeneous material is transferred to a reaction vessel, and the motor speed of the reaction vessel is adjusted to 100-150 rpm; Step 3, nitrogen gas is introduced into the reaction vessel for 30 minutes. Then, heat the reaction vessel to 50℃~55℃ and stir for 2~3 hours; Step four, after stirring for 2~3 hours, stop stirring and maintain the temperature at 50℃~55℃ for 6~8 hours, then allow it to cool naturally to room temperature; Step five, after cooling to room temperature, transfer it to a cutting machine for cutting, and then transfer it to a drying oven for drying at 105℃ for 12 hours; Step six, after drying for 12 hours, allow it to cool naturally to room temperature, remove the material, and transfer it to a pulverizer for pulverization. The pulverizer pulverizes the material into a size of 0.5~1mm, thereby obtaining a solid thickener. Example

[0010] 30 parts of N-hydroxyethyl acrylamide, 24 parts of N-(3-methoxypropyl)acrylamide, 14 parts of vinyl sulfonate, 8 parts of vinyl benzoate, 6 parts of diacetone acrylamide, 4 parts of itaconic acid dimethyl ester, 2 parts of isopropylamine dodecylbenzenesulfonate, 120 parts of deionized water, and 1 part of azobisisobutyrazoline hydrochloride were added to a mixing tank and mixed thoroughly. The material was transferred to a reaction vessel, the motor speed was adjusted to 100-150 rpm, and nitrogen gas was introduced for 30 minutes. The mixture was then heated to 50℃-55℃ and stirred for 2-3 hours. The mixture was then maintained at 50℃-55℃ for 6-8 hours. After natural cooling to room temperature, the mixture was cut using a cutting machine and transferred to a dryer. The drying temperature was adjusted to 105℃ and dried for 12 hours. After cooling to room temperature, the material was removed and pulverized to 0.5-1 mm using a pulverizer to obtain a solid thickener. Example

[0011] The preparation method of solid thickener for oil fracturing includes the following steps: 32.5 parts of N-hydroxyethyl acrylamide, 21 parts of N-(3-methoxypropyl)acrylamide, 15 parts of vinyl sulfonate, 9 parts of vinyl benzoate, 7 parts of diacetone acrylamide, 5 parts of itaconic acid dimethyl ester, 3 parts of isopropylamine dodecylbenzenesulfonate, 130 parts of deionized water, and 1.5 parts of azobisisobutyrazoline hydrochloride are added to a mixing tank and mixed evenly. The material is transferred to a reaction vessel, the motor speed is adjusted to 100-150 rpm, nitrogen gas is introduced for 30 minutes, then heated to 50℃-55℃, stirred for 2-3 hours, and then kept at 50℃-55℃ for 6-8 hours. After natural cooling to room temperature, the material is cut by a cutting machine and transferred to a dryer. The drying temperature is adjusted to 105℃ and dried for 12 hours. After cooling to room temperature, the material is removed and pulverized to 0.5-1 mm using a pulverizer to obtain the solid thickener. Example

[0012] The preparation method of solid thickener for oil fracturing includes the following steps: 35 parts of N-hydroxyethyl acrylamide, 18 parts of N-(3-methoxypropyl)acrylamide, 16 parts of vinyl sulfonate, 10 parts of vinyl benzoate, 8 parts of diacetone acrylamide, 6 parts of itaconic acid dimethyl ester, 4 parts of isopropylamine dodecylbenzenesulfonate, 140 parts of deionized water, and 2 parts of azobisisobutyrazoline hydrochloride are added to a mixing tank and mixed evenly. The material is transferred to a reaction vessel, the motor speed is adjusted to 100-150 rpm, nitrogen gas is introduced for 30 minutes, then heated to 50℃-55℃, stirred for 2-3 hours, and then kept at 50℃-55℃ for 6-8 hours. After natural cooling to room temperature, the material is cut by a cutting machine and transferred to a dryer. The drying temperature is adjusted to 105℃ and dried for 12 hours. After cooling to room temperature, the material is removed and pulverized to 0.5-1 mm using a pulverizer to obtain the solid thickener. Example

[0013] The performance of the solid thickener was tested as follows: 1. The thickeners of each example (Examples 1-3) were prepared into aqueous solutions with a mass fraction of 0.20%, and the dispersion time was tested at room temperature for 510 s. -1 1. The viscosity of the fracturing fluid was tested at a rate shear of 600 s to evaluate its shear resistance. 2. The thickeners of each embodiment were prepared into a 0.20% (w / w) thickener solution, and after being heated at 140°C for 12 h, the solution was cooled to room temperature, and the viscosity of the fracturing fluid was measured to evaluate its temperature resistance. 3. The viscosity of the fracturing fluid gel after salt treatment with 10 g / L sodium chloride was tested to evaluate its salt resistance. 4. The thickeners of each embodiment were prepared into a 0.20% (w / w) thickener solution, and 400 mL of the solution was added to a 500 mL graduated cylinder. 20% 60-mesh quartz sand was added, and after stirring for 20 min, the volume of the suspended sand was measured.

[0014] The results are shown in Table 1: Table 1

[0015] In summary, the solid thickener for fracturing and its preparation method, in all embodiments, are superior to existing solid thickeners in terms of dissolution and dispersion time, shear resistance, temperature resistance, salt resistance, and sand suspension. The dissolution and dispersion time is less than 6 minutes, the shear resistance viscosity is above 81 mPa·s, the temperature resistance viscosity is above 65 mPa·s, the salt resistance viscosity is above 90 mPa·s, the sand suspension is above 390 mL, and the sand suspension rate is above 97.50%.

Claims

1. A solid thickener for fracturing, characterized in that: It includes N-hydroxyethyl acrylamide, N-(3-methoxypropyl)acrylamide, vinyl sulfonate, vinyl benzoate, diacetone acrylamide, itaconic acid dimethyl ester, isopropylamine dodecylbenzenesulfonate, deionized water, and azobisisobutyrazoline hydrochloride. The content of each component is as follows: N-hydroxyethyl acrylamide 30-35 parts, N-(3-methoxypropyl)acrylamide 18-24 parts, vinyl sulfonate 14-16 parts, vinyl benzoate 8-10 parts, diacetone acrylamide 6-8 parts, itaconic acid dimethyl ester 4-6 parts, isopropylamine dodecylbenzenesulfonate 2-4 parts, deionized water 120-140 parts, and azobisisobutyrazoline hydrochloride 1-2 parts.

2. The method for preparing a solid thickener for fracturing according to claim 1, characterized in that: The preparation method is as follows: Step 1, N-hydroxyethyl acrylamide, N-(3-methoxypropyl)acrylamide, vinyl sulfonate, vinyl benzoate, diacetone acrylamide, dimethyl itaconic acid, isopropylamine dodecylbenzenesulfonate, deionized water, and azobisisobutyrazoline hydrochloride are added to a mixing tank and mixed and stirred until a homogeneous material is obtained; Step 2, the homogeneous material is transferred to a reaction vessel, and the motor speed of the reaction vessel is adjusted to 100-150 rpm; Step 3, nitrogen gas is introduced into the reaction vessel, and after 30 minutes of nitrogen gas introduction, the mixture is heated. Step 4: Heat the mixture in a reactor to 50℃~55℃ and stir for 2~3 hours. Step 5: After stirring for 2~3 hours, stop stirring and maintain the temperature at 50℃~55℃ for 6~8 hours, then allow it to cool naturally to room temperature. Step 6: After cooling to room temperature, transfer the mixture to a cutting machine for cutting, and then transfer it to a drying oven for drying. Adjust the drying temperature to 105℃ and dry for 12 hours. Step 7: After drying for 12 hours, allow it to cool naturally to room temperature, remove the material, and transfer it to a pulverizer for pulverization. The pulverizer pulverizes the material into a size of 0.5~1mm to obtain a solid thickener.

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