Inhibitive Properties of Crude Oils: Can We Count on Them?

It is observed that some crude oils show inhibitive properties, supposedly from components that are passing from the oil phase to the water. In laboratory tests this phenomenon is observed from lower corrosion rates in the aqueous phase after contacting it with crude oil, without any direct contact between the crude and the steel surface, as in a stratified flow regime.

Taking advantage of this inhibitive effect may allow delaying the start-up of inhibitor injection and/ or reducing inhibitor dosage, i.e. a joined environmental and economical interest.

The nature of compounds that are passing into water phase and the main parameters influencing this behaviour (water’s pH and salinity, crude composition) are investigated.

Neither existing data from the literature nor additional results allow yet relating this inhibitive behavior to individual compositional factors of the crude (SARA, TAN, TBN, density…). The effect of temperature and water-cut is minimal.

Defining a relevant and accurate methodology to evaluate this inhibitive effect is thus presently the sole practical way until these inhibitive effects are better understood.