Gas is an essential component of the energy mix in the transition to a sustainable energy future of the world. The forecasted global demand for gas shows continued growth till 2033 and it remains a dominant source of energy until 2050. According to the International Energy Agency, about 43% of the world's natural gas reserves (2,576 TCF), excluding North America, are sour. In the Middle East, which has the world's most sour gas reserves, 60% of the reserves contain sour gas. Transporting wet sour gas with high CO2 content in steel pipelines is one of the main challenges for the upstream oil and gas processing industry. The highly corrosive tendencies of the sour wet gas in many projects warrant the use of expensive corrosion resistant alloys (CRA) or stainless steel to prevent corrosion. The associated costs for fabrication and logistics are significantly higher (6 to 10 times) compared to the costs for C-Mn steels, which are still used extensively as line pipe materials for sour service applications. This paper discusses the material selection, integrity assessment and associated test programs needed to qualify the C-Mn line pipe for severely sour service. Test data from DNV’s database of sour service fracture resistance and fatigue crack tests are presented showing severe degradation of these properties for C-S.
Hydrogen is expected to become an increasingly important component in the sustainable energy mix beyond 2030. The transport of high-pressure hydrogen in C-Mn pipelines, is also discussed in view of the adverse effect high pressure hydrogen gas have on fracture toughness& fatigue performance of the pipe& girth welds.
As sour oil and gas need to be processed in refineries& gas processing plants, this paper also presents failure cases of refinery processing equipment operating in sour wet gas and make-up hydrogen environments.