Galvele introduced a new framework for localized corrosion with his seminal paper on acidification and chloride accumulation in pits & the need for a critical product of current density & pit depth to sustain this chemistry. This paper is to review the progress in these areas with a particular focus on repassivation potential.
In Upstream, CRAs (Corrosion Resistant Alloys) are widely selected to handle seawater and brines in piping, valves, pumps, heat exchangers, vessels, and seawater injection1-4. Also, disposal of produced water is commonly performed through injection into spent fields. Water from a variety of sources including produced water, seawater and surface/fresh water may also be injected to create pressure drive for existing fields. Usually dissolved oxygen (DO) is not fully controlled when there are multiple sources of injection water and sometimes even possibility of injection of fully oxygenated water exists. For oxygenated seawater, the PREN (Pitting Resistance Equivalent Number = %Cr + 3.3 *(%Mo + 0.5 %W) + 16 %N) shall be >40 and limits are applied to the temperature4. Other applications involve Solid CRA or cladded production pipelines which may get flooded with seawater during installation and precommissioning.
Seawater desalination with waste heat from nuclear or fossil power plants is an attractive alternative for the production of potable water.1 Multi-effect desalination process (MED) relies on the evaporation of water from a thin film of seawater.2 The heat of condensation is used in the evaporation of water from a subsequent film of seawater.