Corrosion-resistant oil country tubular goods and completion alloys for moderately sour gas service

摘要

In selecting materials for corrosive sour oil field environments, the materials of choice must be cost-effective and reliable. Materials have to meet criteria for mechanical properties and corrosion resistance in service environments for the required service life. Both age hardened nickel base alloys and cold worked solid solution nickel base alloys offer many advantages such as high-strength, toughness and excellent corrosion resistance. Incoloy alloy 825 (UNS N08825) and Incoloy alloy 028 (UNS N08028) are among the primary solid solution Corrosion Resistant Alloys (CRAs) currently used in the cold worked condition for Oil Country Tubular Goods (OCTGs) in moderately sour gas wells. The primary CRA machining quality age hardened bar products used with alloys 825 and 028 OCTGs for wellhead and subsurface completions of gas wells are Incoloy alloy 925 (UNS N09925) and Inconel alloy 718 (UNS N07718).