Acidizing corrosion inhibitor is the most commonly used chemical additives in the process of oil and gas well acidizing and sour pressure. In recent years, although the development of efficient acidizing corrosion inhibitors has made new progress, the existing acidizing corrosion inhibitors are still based on Mannich base and heterocyclic quaternary ammonium salts developed earlier. Therefore, the development of new structure of acidizing corrosion inhibitors and the development of new acidizing corrosion inhibitor products that are more cost-effective and environmentally friendly is an important issue for oilfield chemists in the new era. This is of great significance to promote the upgrading of acidizing corrosion inhibitor products and to improve the knowledge of the action mechanism of corrosion inhibitors.
In the present work, a series of 13 indolizine derivatives with acidic corrosion inhibition properties were synthesized by taking the corresponding precursor quaternary ammonium salts as raw materials, and adding oxidizing agent sodium nitrite and solvent isopropanol; and the synthesized indolizine derivatives were subjected to the evaluation of corrosion inhibition properties and the study of corrosion inhibition mechanism, and the results showed that benzyl quinoline quaternary ammonium salt derivatives of benzyl chloride (BQD) have excellent corrosion inhibition properties, and the molecules of them are composed of 5 conjugated cyclic units with conjugated planes, which is a very important issue for the new era oilfield chemists. Its molecules are adsorbed on the metal interface at parallel angles based on the conjugation plane composed of five conjugated cyclic units, so that it has better corrosion inhibition performance; the synthesis path of BQD with excellent performance is optimized, so that the content of BQD in the crude synthesis product can reach 58%, and at the same time, the BQD is obtained from the raw materials of quinoline, benzyl chloride and ethanol through the simple “one-pot” reaction in two phases. At the same time, using quinoline, benzyl chloride and ethanol as raw materials, through a simple “one-pot method” two-stage reaction, the “one-pot method” quaternary ammonium salt crude product with higher content of BQD was obtained to be directly used as a corrosion inhibitor; the compounding performance of BQD was found to be able to effectively adsorb and fill the interstices between the BQD and the surface of the metal substrate with urolithiocarbamate and potassium iodide, which resulted in a better corrosion inhibition and enhancement performance. In order to establish two new corrosion inhibitor compounding system: DS-1 (formula for BQD pure: urotropine: solvent = 10: 1: 31), at 60 ℃ -90 ℃ lower than the evaluation of the standard corrosion inhibitor dosage, 20% hydrochloric acid solution in the N80 steel corrosion rate is still better than the evaluation of the standard requirements, with excellent corrosion inhibition; HS-1 (formula for “” one-pot method “ quaternary iodide molecules can effectively adsorb and fill the gap between the BQD and the metal substrate surface, thus having a good corrosion inhibition performance. HS-1 (formulated as “ one-pot method ” quaternary ammonium corrosion inhibitor: urotropine: potassium iodide: solvent = 10: 5: 2: 33), at 100 ℃ -120 ℃, lower than the evaluation of the standard corrosion inhibitor dosage of the N80 steel sheet has an excellent high-temperature corrosion inhibition effect.
