CORROSION PROTECTION OF CRUDE OIL STORAGE TANKS BOTTOMS INTERNAL SURFACE

摘要

Crude oil contains water and different soluble inorganic and organic compounds. During storage and transportation of crude oil, the aqueous solution sediment (ASS) contains high concentration of H2S, Cl-, SO42-, etc. The corrosion rate of tank bottoms can vary from 0.05 to 3.0 mm/year. The service life of tank bottoms is unpredictable and it can be in the range of 2 to 20 years. The traditional corrosion protection systems (cathodic protection, coatings, and inhibitors), in many cases, are not inefficient, have low service life, or they cannot be applied at all. Now available is a newly-created multistage corrosion protection system, which combines different types of soluble corrosion inhibitors (SCI) and cathodic protection system (CPS). The synergistic effect that allows the decrease of the concentration of inhibitor by 3 to 6 times and the current density by 2 to 5 times has been achieved. In addition, special devices, which deliver inhibitors, are presented.