This study was carried out in an oilfield waterflood operation in which produced brine is reinjected to displace oil from the reservoir. Significant corrosion problems are associated with bacterial colonization of the water handling system. Previous work has focused on optimizing biocide treatments, but there are limits to what is economically achievable by this approach.

This report describes results of an audit of chemical, biological and corrosion parameters measured across the Wainwright waterflood operation over a 30-month period. The intent of the audit was to provide a basis for understanding and improving monitoring and control practices in such operations.

Corrosion-monitoring methods generally failed to correlate in a simple way with corrosion failures. Failure frequency correlated with several water chemistry parameters. Common treatment chemicals showed evidence of promoting bacterial growth. Sulfate-reducing bacterial numbers were found to be a function of position in the system, population composition and water chemistry.

Based on the insights obtained, a series of runs was carried out in a special test facility to assess the effects of trace nitrate, oxygen scavenger, and nutrient addition on the sessile bacterial populations present in an operating unit. Results are briefly described.