High-efficiency Corrosion Inhibitor for Acidizing: Synthesis, Characterization and Anti-corrosion Performance of Novel Indolizine Derivative

Abstract

A novel indolizine derivative inhibitor for acidization was introduced. It could exhibit effective corrosion inhibition at a much lower concentration without propargyl alcohol and shows economic and environmental advantages. From quinoline, benzyl chloride, and chloroacetic acid, two indolizine derivatives were prepared under certain conditions. These inhibitive indolizine derivatives were both synthesised from benzyl quinoline chloride (BQC), which one of the conventional quaternary ammonium corrosion inhibitors used for acidising. The target compound was purified and instrumental analysis methods including elemental analysis, high-resolution mass spectrometry (HRMS), and NMR were used to characterise the chemical structure. The inhibition performance of the indolizine derivatives in 15 wt.% HCl, 20 wt.% HCl, and mud acid (12%HCl + 3%HF) for N80 steel was investigated by weight loss measurement, electrochemical method (potentiodynamic polarization and EIS), and SEM surface morphology assessment. When 0.1 wt.% indolizine derivative was added, the inhibition efficiency of N80 steel in 15 wt.% HCl at 90 °C increased to 98.8 % and 99.1 % respectively without the synergistic effect of propargyl alcohol: however, in terms of BQC, even at a dosage of 1.0 wt.%, the inhibition efficiency of N80 steel only reached 83.3 % under the same conditions. The novel derivative could impart an improved corrosion resistance effect. Compared with BQC, there are more active adsorption sites in the derivative and therefore the inhibitor could be better fastened to the steel surface. The firmly adsorbed inhibitors would thereby prevent the metal surface from making contact with H+ ions and finally increase the inhibitory effect. As a high-efficiency corrosion inhibitor, the novel indolizine derivatives may offer a new strategy for corrosion protection in acidising.

Comparative Studies of the Corrosion Inhibition Efficacy of a Dicationic Monomer and Its Polymer against API X60 Steel Corrosion in Simulated Acidizing Fluid under Static and Hydrodynamic Conditions

“…1 Nevertheless, corrosion of well tubings, which are mostly fabricated from API-grade low carbon steels, is one of the problems associated with well acidizing. 2,3 A suitable, reliable, and cost-effective corrosion mitigation approach is the corrosion inhibitor technology, 3−6 which involves the addition of corrosion inhibitors to the acid solution. The inhibitors must offer effective protection to the tubings for at least 2 h while the acid is being pumped into the producing formation 4 and up to 24 h in a situation when the acid is used as a perforating fluid.…”

“…4 The commercial inhibitors used in stimulation acids are complex proprietary formulations that frequently contain quaternary heterocyclic ammonium salts and halogenated compounds that work in synergy with propargyl alcohol, which is known to be extremely poisonous. 2,7 Propargyl alcohol, an alcohol containing an alkyne functional group, has a lethal dose (LD 50 ) value of 20 mg/kg, an acute oral toxicity classification of category 3, and a chronic aquatic toxicity of category 2, according to the GHS classification. 8,9 Because government policies have continued to promote green alternatives to toxic petrochemicals, research efforts toward the development of green corrosion inhibitors have intensified in recent times.…”

“…8,9 Because government policies have continued to promote green alternatives to toxic petrochemicals, research efforts toward the development of green corrosion inhibitors have intensified in recent times. It was reported 2,10 that eco-friendly indolizine derivatives synthesized from quinoline, pyridine, and halide compounds through a 1,3-dipolar cycloaddition reaction effectively inhibited the corrosion of N80 steel in 15 wt % HCl and 20 wt % HCl solutions. With 0.1 wt % of the indolizine derivatives, inhibition efficiency as high as 99% was reported at 90 °C.…”