Microstructural Characterization of Environmentally Assisted Cracking (EAC) in Failure Analysis Case Studies for Oil and Gas Tubulars

Microstructural Characterization of Environmentally Assisted Cracking (EAC) in Failure Analysis Case Studies for Oil and Gas Tubulars

Environmental Assisted Cracking (EAC) (presents) includes distinct failure mechanisms, each driven by material characteristics, stress, and operational environment. Some of the major types of EAC are Stress Corrosion Cracking (SCC), Hydrogen Embrittlement (HE), and Sulfide Stress Cracking (SSC). These failures are some of the critical degradation mechanisms affecting tubing and casing in oil and gas wells.

Microstructural analysis is a crucial role within the failure analysis methodology that aids in diagnosing the subdivisions of EAC since each have distinct features. Optical microscopy allows for a quick insight into crack morphology, grain boundary attacks, and potential initiation sites. Additionally, the high resolution of the SEM provides access to failure mechanisms such as intergranular cracking/corrosion, cleavage steps, quasi-cleavage facets, and transgranular cracks.

The work provides case study examples of optical micrographs and SEM images that correlate defining characteristics across each subdivision of EAC for oil and gas tubulars. These distinct features, combined with production information, enable engineers to identify the root causes of EAC failures. Consequently, these relationships provide the basis for reliable decisions in material selection, heat treatment control, and environmental mitigation strategies that reduce the risk of catastrophic failures in pipelines and downhole tubing.