Hydrogen-Induced Cracking in Surface Production Systems: Mechanism, Inspection, Repair, and Prevention

Abstract

Summary Hydrogen-induced cracking (HIC) is a materials- and corrosion-related problem that occurs in surface production systems. Steels used to construct sour-gas production facilities and flowlines may corrode from wet hydrogen sulfide (H2S) gas in the production stream. The corrosion process generates hydrogen that may damage the steel, resulting in HIC and other forms of damage from hydrogen. HIC control and prevention are an important consideration in operating surface-facility equipment in a safe and efficient manner. By effectively controlling or preventing HIC damage in surface-facility equipment, operating costs are reduced, potential costly downtime from equipment failure is avoided, and a safe work environment is more easily realized. We developed an overall approach to understand and deal with the HIC problem in sour-surface production facilities. The approach dealt with understanding the mechanism in steel materials used in surface-facility equipment; implementing state-of-the-art inspection techniques; fitness-for-service (FFS) evaluation to assess damage effect on performance; repair procedures on existing equipment; and finally, establishing steel performance and fabrication requirements to eliminate or reduce HIC damage risk for newly fabricated equipment. This paper presents the results of laboratory examinations of over 40 steels covering both new and existing equipment, leading to the approaches developed for controlling HIC in existing equipment and for controlling or preventing HIC in new construction. We also present the basis for the approaches developed to deal with HIC in surface production facilities.