Corrosion mitigation of the oil well steels using organic inhibitors-A review

Abstract

Oil well stimulation, usually done with hot solutions of hydrochloric acid, may induce severe corrosion attack on production tubing, downhole tools and casing. Inorganic, organic and combinations of acids along with surfactants are used in a variety of well stimulation treatments. To reduce the aggressive attack of the acid on tubing and casing materials (N80 steel), inhibitors are added to the acid solution during the acidifying process. The inhibition in oil and gas field is more complicated and requires special eco-friendly inhibitors depending on the area of application such as in refineries, wells, recovery units, pipelines etc. Aggressive gases such as H2S, CO2, and organic acids complicate the problem of inhibition in wells. Various factors have to be considered while dealing with corrosion problems of oil and gas industry. The type of reservoir rocks, the acids used for stimulation, the oil well equipments such as tubings and casings and the operating conditions are some of the important factors that affect the corrosivity. Each and every case has to be considered in its totality before a decision is made on the proper materials. No particular material is the cure for all the evils of corrosion. It is imperative to the field operators, pipeline engineers, designers to have corrosion awareness concerning the oil and gas industries in their day to day activities to compact and mitigate corrosion. This work is an attempt in this direction.