Erosion-corrosion maps for carbon steel in crude oil/water slurries : Impact angle and applied potential effects

In studies of erosion-corrosion, there have been few investigations into the effect of tribological issues, such as particle impact and impact angle, on erosion-corrosion of materials in oil field production. Despite this fact, erosion-corrosion in such environments is a major issue. In such conditions, it is important to define regimes where the effect of lubricating oil may modify the erosion properties of the materials. In this study, the combined effects of erosion and corrosion were investigated in three environments, crude oil (high API gravity 52), reservoir water, and 20% reservoir water with crude oil at a range of applied potentials. Erosion-corrosion maps were constructed, based on the results, showing the change in mechanisms and wastage rates as a function of impact angle and applied potential. Regimes of erosion-corrosion were described on such maps using such an approach. From this work, it can be seen that the corrosion contribution was increased with an increase in the percentage of reservoir water. In the crude oil environment, it was shown that the erosion contribution (Ke) was generally higher than that for corrosion suggesting that corrosion was reduced in crude oil. The results are interpreted in terms of the effect of the crude oil environment in modifying the impact properties of the particles therefore providing surprising resistance to particle impacts in nominally aggressive corrosion environments