Low-Alloy Steel Corrosion Resistance in Natural Gas Preparation Production Solutions

Abstract

Corrosion resistance of low-alloy steels 20-KSKh, 07GBK, 06GBF, 13FKhA, 09GSF, and 20 with different overall contents of corrosion-active nonmetallic inclusions (CANI) in process media for preparation and drying moist casing-head gas is studied. A study in a model medium simulating seam water of the Khar’yagin deposit, and in a moist hydrogen sulfide atmosphere for ten days shows that a reduction in CANI reduces the corrosion rate of low-alloy steels in a model medium compared with steel St20 by about a factor of two. In a moist hydrogen sulfide atmosphere after testing a steel 20 surface is coated with a uniform layer of corrosion products; in low-alloy steels, corrosion damage occupies 1–7% of the overall area. The results obtained agree with the role of CANI determined previously in developing overall and local corrosion.