Corrosion Inhibition of Calcium Chloride

摘要

Calcium chloride is one of the basic chemicals that has a diverse range of industrial applications, from its uses for the de-icing and anti-icing functions in snow and ice control, to heavy brine fluid in the oil and gas well operations, and to its use as an additive in food products. However, it imparts corrosive effects on metal surfaces. The selection and development of chemical additives that inhibit corrosion by calcium chloride are dictated by the environment under which calcium chloride is to be applied. In de-icing applications, invariably the calcium chloride ends up in the environment at uncontrollable concentrations. As a consequence, the corrosion inhibitor has to be effective at a wide range of concentrations and under different conditions. In oil and gas well applications, calcium chloride being mostly used at elevated temperatures and pressures and inevitable presence of contaminants in the drilling and completion process environment create a formidable formulation challenge. This paper reviews the physico-chemical aspects of corrosion in the presence of calcium chloride. Corrosion rate testing methods for the low and high temperature applications of calcium chloride are discussed. Environmental restrictions that limit the selection and design of corrosion inhibitors are reviewed. Particular references are made to the problems that are associated with the use of corrosion inhibiting additives of oil and gas well environment. Developments in corrosion inhibition technology for calcium chloride brines in these environments are presented.