Construction and exploitation of gas-oil field equipment are impossible without considering data about its corrosion characteristics, methods and their anti-corrosion protection means. It is necessary to consider medium corrosion level at all stages of constructing this equipment. The given work concerns the investigation of corrosion durability of the units prepared from metals and exploited in the conditions of oils and water-oil emulsions influence. To take into account imprecision of experimental results, fuzzy numbers and intervals are used.