CN-121991303-A - Carbon dioxide trapping absorbent and preparation method and application thereof

Abstract

The invention belongs to the field of petroleum and natural gas exploration, and discloses a carbon dioxide trapping and absorbing agent, a preparation method and application thereof, which are used for relieving and preventing pollution and damage caused by invasion of CO 2 to water-based drilling fluid. The method comprises the steps of crushing plant straws, placing the crushed plant straws into a reaction container containing a strong alkali solution for reaction to obtain a liquid material, adding lignite into the liquid material, uniformly stirring the lignite to obtain a first mixed material, adding acrylamide and dimethyl diallyl ammonium chloride into the first mixed material, stirring the acrylamide and dimethyl diallyl ammonium chloride to obtain a second mixed material, and adding an initiator into the second mixed material for copolymerization reaction to obtain the carbon dioxide trapping absorbent. The functional group contained in the carbon dioxide trapping absorbent prepared by the method can rapidly trap carbon dioxide invaded into slurry to form a denser mud cake, so that more carbon dioxide is prevented from invading, and pollution and damage of water-based drilling fluid caused by CO 2 invasion are relieved.

Inventors

• LIU HONGGUO
• BAI XIANGSHUANG
• YANG ZHENKE
• HOU BING
• ZHAO YUNFEI
• SUN WEIXU
• ZHANG QING
• LI WEIHAN
• CHEN XUSHENG

Assignees

• 中国石油天然气股份有限公司

Dates

Publication Date

20260508

Application Date

20241104

Claims (16)

1. 1. A method for preparing a carbon dioxide trapping absorbent, which is characterized by comprising the following steps: crushing plant straws, and putting the crushed plant straws into a reaction container containing a strong alkali solution for reaction to obtain a liquid material; Adding lignite into the liquid material and uniformly stirring to obtain a first mixed material; Adding acrylamide and dimethyl diallyl ammonium chloride into the first mixed material, and stirring to obtain a second mixed material; And adding an initiator into the second mixed material to carry out copolymerization reaction to obtain the carbon dioxide trapping absorbent.
2. 2. The method for producing a carbon dioxide capturing absorbent according to claim 1, wherein the plant straw contains at least one of cellulose, hemicellulose, and lignin.
3. 3. The method for preparing a carbon dioxide trapping absorbent according to claim 1, wherein the humic acid content of the lignite is 20% -80%.
4. 4. The method for producing a carbon dioxide capturing absorbent according to claim 1, wherein the strong alkali solution is at least one selected from a potassium hydroxide solution and a sodium hydroxide solution.
5. 5. The method for producing a carbon dioxide trapping absorber according to claim 4, wherein the potassium hydroxide solution contains 1% to 10% of potassium hydroxide and the sodium hydroxide solution contains 1% to 10% of sodium hydroxide.
6. 6. The method for preparing a carbon dioxide trapping absorbent according to claim 1, wherein the weight ratio of the strong alkali solution to the plant straw is 2-7:1.
7. 7. The method for preparing a carbon dioxide trapping absorbent according to claim 1, wherein the reaction temperature of the strong alkali solution and the plant straw is 100-150 ℃, the reaction pressure is 1-3 mpa, and the reaction time is 3-5 hours.
8. 8. The method for preparing a carbon dioxide trapping absorbent according to claim 1, wherein the addition amount of the lignite is 10% -15% by weight of the liquid material.
9. 9. The method for producing a carbon dioxide capturing absorbent according to claim 8, wherein the lignite is added while stirring, and stirring is performed for 20 to 40 minutes after completion of the addition.
10. 10. The method for producing a carbon dioxide trapping absorbent according to claim 1, wherein the amount of acrylamide added is 2 to 3% by weight of the liquid material, and the amount of dimethyl diallyl ammonium chloride added is 4 to 6% by weight of the liquid material.
11. 11. The method for producing a carbon dioxide capturing absorbent according to claim 1, wherein the temperature of the second mixed material is controlled to 35 to 50 ℃ before the initiator is added to the second mixed material.
12. 12. The method for preparing the carbon dioxide trapping absorbent according to claim 1, wherein the initiator is an ammonium persulfate solution with a mass fraction of 4% -6%, and the addition amount of the initiator is 0.1% -0.3% of the weight of the second mixed material.
13. 13. The method for producing a carbon dioxide trapping absorbent according to claim 1, wherein the temperature of the copolymerization reaction is controlled to be 35-50 ℃ and the reaction time is 1-3 hours.
14. 14. The method for producing a carbon dioxide capturing absorbent according to claim 1, further comprising placing the product after the copolymerization reaction in a drying tower to spray-dry.
15. 15. A carbon dioxide trap absorbent, characterized in that it is prepared by the method according to any one of the preceding claims 1-14.
16. 16. Use of a carbon dioxide trap absorbent in drilling mud according to claim 15, wherein the carbon dioxide trap absorbent is added to the drilling mud in an amount of 2% -3%.

Description

Carbon dioxide trapping absorbent and preparation method and application thereof Technical Field The invention relates to the field of petroleum and natural gas exploration, in particular to a carbon dioxide trapping and absorbing agent and a preparation method and application thereof. Background Drilling fluids (also known as muds) are a general term for various circulating fluids used in the drilling engineering process of petroleum and gas drilling engineering to meet the needs of the drilling engineering. With the continuous progress of the related technology and the technological level of the drilling fluid at home and abroad, the types of the drilling fluid become more abundant. Drilling fluids can be broadly classified into water-based drilling fluids, oil-based drilling fluids, gas drilling fluids, and synthetic-based drilling fluids. The water-based drilling fluid is the most widely applied drilling fluid system in various drilling fluid systems. The solid phase particles of the water-based drilling fluid are suspended in water or brine, into which the oil may be emulsified, in which case the water is the continuous phase. The basic composition of water-based drilling fluids is mainly water (disperse medium continuous phase), clay (disperse phase solid phase), treatments or weighting materials. The water-based drilling fluid has the advantages of low cost, simple treatment, wide source of treating agent, suitability for deep wells and ultra-deep wells (especially when drilling out the surface layer), easy formation of compact mud cakes on the well wall, low filtration loss, easy control of performance, high anti-pollution capability and the like. During the drilling construction process, when different stratum are drilled, some pollutants invade the drilling fluid to influence the performance of the drilling fluid. When the water-based drilling fluid is used for drilling a stratum containing CO 2, the drilling fluid is polluted by CO 2, so that the problems of poor rheological property, out-of-control of fluid loss and the like of the drilling fluid are easily caused. The rheological property of drilling fluid is one of the most important properties, and mainly comprises rheological parameters such as plastic viscosity, apparent viscosity, static shear force, dynamic shear force and the like. The rheological property of the drilling fluid is closely related to drilling operations such as cuttings carrying, well wall stability, improvement of mechanical rotation speed, calculation of annulus hydrodynamic parameters and the like, so that the rheological property of the drilling fluid is very important in drilling operations. In addition, because of the pressure differential between the formation fluid pressure and the wellbore effective fluid column pressure, the drilling fluid may penetrate the formation, a property known as fluid loss of the drilling fluid. The fluid loss performance of drilling fluids is also one of the most important properties of drilling fluids. When the drilling fluid is polluted by CO 2, the rheological property and the fluid loss property of the drilling fluid are greatly damaged, and the drilling fluid has the characteristics that (1) the pH value of the drilling fluid is reduced and the color is changed, (2) the drilling fluid contains tiny bubbles, (3) the viscosity and the shear force are far higher than the normal value, (4) the mud cake is thickened and the fluid loss is suddenly increased, so that the complex conditions of slumping and blocking of a well wall, sticking of the well, scrapping of a well hole and the like are easily caused, and huge loss is caused to drilling operation, and meanwhile, huge environmental protection pressure is brought. Therefore, how to alleviate and prevent pollution and damage to water-based drilling fluids caused by CO 2 invasion is a major problem in the art. Disclosure of Invention The invention provides a carbon dioxide trapping absorbent, a preparation method and application thereof. The functional group contained in the carbon dioxide trapping absorbent can rapidly trap carbon dioxide invaded into slurry to form a denser mud cake, so that more carbon dioxide is prevented from invading, and pollution and damage caused by CO 2 invading of water-based drilling fluid are relieved. According to an aspect of the present invention, there is provided a method for producing a carbon dioxide capture absorbent, the method comprising the steps of: crushing plant straws, and putting the crushed plant straws into a reaction container containing a strong alkali solution for reaction to obtain a liquid material; Adding lignite into the liquid material and uniformly stirring to obtain a first mixed material; Adding acrylamide and dimethyl diallyl ammonium chloride into the first mixed material, and stirring to obtain a second mixed material; And adding an initiator into the second mixed material to carry out copolymerization reaction to obtain the