Nitrate treatment is increasingly used for selective control of sulfate-reducing bacteria (SRB) and
associated biogenic generation of hydrogen sulfide. Nitrate is now widely added to seawater
injection systems to mitigate reservoir souring. The use of nitrate in seawater injection has not
been observed to increase corrosion rates of carbon steel and there is some evidence that it may
actually reduce corrosion. However, in produced water re-injection (PWRI) systems the situation
with respect to corrosion is more unpredictable and nitrate treatment has sometimes been
associated with increased general and localised corrosion.