John E. McElhiney, John A.Hardy
Marathon Oil Co.Littleton, Colo.
Tony Y. Rizk, James F.D. Stott, Robert D. Eden Capcis, Umist Manchester, U.K.
Low-sulfate seawater injection can reduce the potential of an oil reservoir turning sour because of sulfate-reducing bacteria.
Sulfate-reducing bacteria (SRB) convert sulfate ions in seawater used in waterflooding into sulfide with the concomitant oxidation of a carbon source. In the case of seawater-flooded oil reservoirs, these carbon sources are water soluble organic acids or their anions.1 The most important organic acid anion is acetate. It is naturally present in most North Sea formation waters at concentrations greater than 100 m...