Mechanical Properties of oil and gas transportation steel in the absence of inhibitors

Abstract

This dissertation explores the mechanical properties of pipeline steels when used in oil and gas transportation pipelines subjected to harsh environmental conditions involving corrosion and fatigue. The study starts with a review of pipelines systems, oil and gas transportation systems, material classifications, types of defects typically encountered within pipeline systems, and environmental stressors that may affect the mechanical properties of pipeline steel. A fatigue testing machine was designed for digital fabrication with SolidWorks, which simulated the behaviour using ANSYS to determine the fatigue life, damage accumulation, and safety factors of the pipeline steels under cyclic loading. The results indicated that mechanical stress combined with environmental factors (i.e., corrosion) may significantly impact the structural integrity and lifespan of pipeline steel. It was concluded that material design, application of proper design safe factors, and maintenance of energy infrastructure is an important consideration.