OIL CHARACTERISTICS, WATER /OIL WETTING AND FLOW INFLUENCE ON THE METAL LOSS CORROSION. PART 1: EFFECT OF OIL AND FLOW ON CO2/H2S CORROSION

摘要

The presence of crude oil in the oil and gas production has a significant effect on the corrosion rates of steel in CO2/H2S containing environments. The crude oil inhibition mechanisms can be combined into two main effects: 1) A chemical effect, related to inhibiting properties of compounds present in the crude oil; and 2) A physical effect, related to the capacity of the oil to prevent the water from contacting the steel surface. This paper presents an overview of the work that has been performed during the last two decades addressing the physical effect of crude oil on corrosion and the models used to describe it. This effect has been traditionally modeled through oil wettability predictions, mostly based on the density of the crude oil, water cut and liquid velocity. Knowledge gaps and disagreements have been identified and further work is recommended in order to establish the key parameters controlling the mechanism, their critical values and interactions. Some of these parameters are: physical-chemical properties of the crude oils and water, water cut, hydrodynamics in multiphase flow conditions, and partial or intermittent coverage of the surface by the crude oils.