Mechanical Properties and Erosion-Corrosion of High Strength Steels for Oil and Gas Transportation Pipelines in H2S environment

The need to understand erosion-corrosion is one prerequisite in preventing failures by developing strategies for prolonging the life of pipelines. In oil and gas production systems, erosion–corrosion due to sand is a significant problem. Unfortunately, the erosion-corrosion phenomenon is not understood in sour environments (H2S gas). This is relevant to Qatar as many of the oil and gas resources contain appreciable amounts of H2S gas. Recently, microalloying of plain carbon steels with small amounts of strong carbide and nitride forming elements such as Nb, Ti and V has achieved great improvement in their mechanical properties. These additions in combination with controlled rolling and accelerated cooling has allowed production of low carbon (0.05 to 0.1 wt. %) plain carbon steels with high yield stresses (up to 120 ksi) and good toughness. These steels are known as High Strength Low Alloy (HSLA) steels. HSLA steels are becoming more popular as the material of choice for large pipeline projects because of the advantages they provide such as low price-to-yield ratio. The overall objective of the proposed project is to study mechanical properties and erosion-corrosion for API X-80, API X-100, and API X-120 transmission oil and gas steel pipelines in H2S environment. The main challenge is separating the individual contributions of erosion and corrosion to the overall metal loss and evaluating the synergistic effects of one mechanism over the other in the presence of