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CN-121974855-A - Double Mannich base corrosion inhibitor and preparation method and application thereof

CN121974855ACN 121974855 ACN121974855 ACN 121974855ACN-121974855-A

Abstract

The invention relates to the technical field of CO 2 utilization and sealing and discloses a double Mannich base corrosion inhibitor and a preparation method and application thereof. The method is carried out under the condition of pH 3-4, and comprises the steps of (1) carrying out a first reaction on a compound shown in a formula (A) and 1,3, 5-trioxane in the presence of ethanol to obtain an intermediate product, wherein R in the formula (A) is- (CH 2 ) 7 CH=CH(CH 2 ) 7 CH 3 ), dropwise adding acetophenone into the intermediate product in the presence of ethanol to carry out a second reaction to obtain the double Mannich base corrosion inhibitor, and the dropwise adding rate of the acetophenone is 0.0125-0.05mL/s relative to 1mol of the compound shown in the formula (A), wherein the dosage mole ratio of the compound shown in the formula (A), the acetophenone and the 1,3, 5-trioxane is 1:2.0-2.3:2.0-2.3. Formula (A).

Inventors

  • LIU HUANRONG
  • WANG GANG
  • DU CHUNAN
  • LIU HUIFENG
  • SHI YUXIN
  • Ge Shunlin
  • YUAN MENG

Assignees

  • 山东石油化工学院
  • 中国石油大学(北京)
  • 克拉玛依中科恒信科技有限责任公司

Dates

Publication Date
20260505
Application Date
20260402

Claims (10)

  1. 1. A method for preparing a double Mannich base corrosion inhibitor is characterized in that the method is carried out under the condition of pH value of 3-4, and comprises the following steps: (1) Carrying out a first reaction on a compound shown in a formula (A) and 1,3, 5-trioxane in the presence of ethanol to obtain an intermediate product; Formula (A); in formula (A), R is- (CH 2 ) 7 CH=CH(CH 2 ) 7 CH 3 ); (2) Dropwise adding the acetophenone into the intermediate product in the presence of ethanol to perform a second reaction to obtain the double Mannich base corrosion inhibitor, wherein the dropwise adding rate of the acetophenone is 0.0125-0.05mL/s relative to 1mol of the compound shown in the formula (A); Wherein the molar ratio of the compound shown in the formula (A), the acetophenone and the 1,3, 5-trioxane is 1:2.0-2.3:2.0-2.3.
  2. 2. The method according to claim 1, wherein in the step (1), the ethanol is used in an amount of 480 to 720mL based on 1mol of the total amount of the compound represented by the formula (a) and the 1,3, 5-trioxane.
  3. 3. The process according to claim 1, wherein in step (2), the ethanol is used in an amount of 300 to 500mL relative to 1mol of the acetophenone.
  4. 4. A process according to any one of claims 1 to 3, wherein in step (2), the acetophenone is added dropwise at a rate of 0.016 to 0.05mL/s relative to 1mol of the compound represented by the formula (a).
  5. 5. A process according to any one of claims 1 to 3, wherein in step (1) the conditions of the first reaction comprise a rotation speed of 300 to 400rpm, a temperature of 21 to 25℃and a time of 0.5 to 1h.
  6. 6. A process according to any one of claims 1 to 3, wherein in step (2) the conditions for the second reaction comprise a rotation speed of 300 to 400rpm, a temperature of 80 to 90℃and a time of 4 to 8 hours.
  7. 7. The method according to any one of claims 1 to 3, wherein in the step (2), the method further comprises the step of subjecting the material obtained by the second reaction to impurity removal treatment to obtain the double Mannich base-type corrosion inhibitor.
  8. 8. The method according to claim 7, wherein the impurity removal treatment is rotary distillation, and the conditions of the rotary distillation include a vacuum degree of 0.05-0.12MPa, a temperature of 40-60 ℃ and a time of 1-2h.
  9. 9. A bis-mannich base corrosion inhibitor prepared by the method of any of claims 1-8.
  10. 10. The use of the bis-mannich base corrosion inhibitor of claim 9 in CO 2 flooding.

Description

Double Mannich base corrosion inhibitor and preparation method and application thereof Technical Field The invention relates to the technical field of CO 2 utilization and sealing, in particular to a double Mannich base corrosion inhibitor and a preparation method and application thereof. Background Under the global energy structure adjustment and carbon peak, carbon neutralization strategic background, the CO 2 oil displacement and CO 2 geological sequestration (CCS) technology is increasingly paid attention to. The CO 2 oil displacement is not only an important technology for improving the recovery ratio (EOR), but also has the function of storing industrial waste gas CO 2 in an oil field, and realizes win-win of energy exploitation and carbon emission reduction. However, this process inevitably introduces a serious risk of corrosion. The CO 2 dissolves in the reservoir to form carbonic acid, exposing the well casing to a strongly acidic environment. With increasing production depth, the temperature and pressure of the casing are increased significantly (for example, the deep well casing can reach more than 150 ℃), and the corrosion rate of CO 2 increases exponentially with the increase of the temperature. Although the imidazoline corrosion inhibitors widely used in the industry at present are effective under the conventional condition, the stability and durability of an adsorption film of the imidazoline corrosion inhibitors are challenging in a high-temperature and high-pressure environment with CO 2 for oil displacement. And Shan Manni Highway alkali corrosion inhibitors have poor corrosion inhibition performance, for example, CN119954723A discloses a CO 2 tall oil-resistant imidazoline Mannich alkali corrosion inhibitor, which is prepared by synthesizing an imidazoline ring by mixing tall oil mixed fatty acid with organic polyamine, and then condensing an aromatic ketone, trioxymethylene and a terminal amino group of an imidazoline ring side chain to obtain the imidazoline Mannich alkali corrosion inhibitor with a hydrophilic group and a hydrophobic group. The corrosion inhibitor is compounded with a surfactant and a solubilizer, the corrosion inhibition efficiency reaches over 92% only at the service temperature of 50 ℃, the corrosion inhibition effect is to be improved, and the high-temperature adaptability is to be enhanced. Moreover, the conventional double Mannich base synthesis generally needs to undergo two independent Mannich reactions, has complicated process and obvious defects that if the conversion rate of the first reaction is low and the separation of intermediates is incomplete, the residual raw materials often cause side reactions such as excessive alkylation (high molecular amine byproducts are generated), self-condensation (unsaturated compounds or high molecular heterocycles are generated), cyclization or decomposition and the like, so that the corrosion inhibition rate of the final product double Mannich base is lower. Disclosure of Invention The invention aims to overcome the defect of low corrosion inhibition efficiency of the existing corrosion inhibitor under the high-temperature condition. In order to achieve the above object, a first aspect of the present invention provides a method for preparing a bis-mannich base corrosion inhibitor, the method being performed at a pH of 3 to 4, the method comprising: (1) Carrying out a first reaction on a compound shown in a formula (A) and 1,3, 5-trioxane in the presence of ethanol to obtain an intermediate product; Formula (A); in formula (A), R is- (CH 2)7CH=CH(CH2)7CH3); (2) Dropwise adding the acetophenone into the intermediate product in the presence of ethanol to perform a second reaction to obtain the double Mannich base corrosion inhibitor, wherein the dropwise adding rate of the acetophenone is 0.0125-0.05mL/s relative to 1mol of the compound shown in the formula (A); Wherein the molar ratio of the compound shown in the formula (A), the acetophenone and the 1,3, 5-trioxane is 1:2.0-2.3:2.0-2.3. Preferably, in the step (1), the ethanol is used in an amount of 480 to 720mL, based on 1mol of the total amount of the compound represented by the formula (a) and the 1,3, 5-trioxane. Preferably, in step (2), the ethanol is used in an amount of 300 to 500mL relative to 1mol of the acetophenone. Preferably, in step (1), the conditions of the first reaction include a rotation speed of 300-400rpm, a temperature of 21-25 ℃ and a time of 0.5-1h. Preferably, in the step (2), the acetophenone is added at a dropping rate of 0.016 to 0.05mL/s with respect to 1mol of the compound represented by the formula (a). Preferably, in step (2), the conditions of the second reaction include a rotation speed of 300-400rpm, a temperature of 80-90 ℃ and a time of 4-8 hours. Preferably, in the step (2), the method further comprises the step of removing impurities from the material obtained by the second reaction to obtain the double Mannich base corrosion inhibi