Pipelines carrying heavy crude oil from oil sand developments may be subject to corrosion caused by
deposition of oil sand sediments, a sludge containing oil, water, and bacteria in a particulate matrix. A
test methodology to determine the corrosive nature of the sludge and evaluate inhibitor performance is
explored, consisting of exposure testing and electrochemical measurements of corrosion potential and
linear polarization resistance (LPR) measurements. The corrosive nature of the sludge was
demonstrated and differences in the corrosivity of various sludges were observed. Inhibitor
performance was evaluated, where inhibitor was mixed with the sludge, or added to the bulk
environment. The electrochemical measurements provided mechanistic data and information on the
characteristics of the sludge that may be important in selecting an effective inhibitor.
Keywords: inhibition, underdeposit corrosion, sludge, oil sand, bacteria