A censorious appraisal of the oil well acidizing corrosion inhibitors

Well acidizing is a common stimulation technique for maximizing the output of oil reservoirs. It helps to overcome the low permeability of wellbore by creating new flow channels or enlarging old ones. Corrosion challenge is encountered during the process since tubings are metallic. Corrosion inhibitors are the defence mechanism used in mitigating corrosion problem during acidizing. This review has identified and grouped acidizing corrosion inhibitors into organic-, and polymer-based. The performance of these inhibitors at temperatures of ≥60 °C and acid concentration of ≥15 wt% is considered. It is noted that greater percentage of studies revolve round the 60 °C. Above 100 °C, the number of scientific articles decreased considerably. Four classes of intensifiers for acidizing corrosion inhibitors have been identified: formic acid, potassium iodide, copper iodide, and antimony chloride. Their chemistries have been discussed. The research gaps identified include (i) scanty information on acidizing inhibitors at temperatures ≥150 °C, (ii) limited information on natural polymers and plant biomaterials as acidizing inhibitors, (iii) scanty information on the mechanism of inhibition at temperatures ≥150 °C, and (v) limited information on the composition of corrosion products under acidizing conditions. Thus, recommendations for future researches have been given.