Session: DA-08-01 Fracture Mechanics in FFS Assessment

Paper Number: 122035

122035 - Fitness-for-Service Assessment of a Hydrogen-Induced Crack in an Inlet Gas Separator Pressure Vessel Using Computational Modelling 

Hydrogen-induced cracking is the cracking of carbon steel or low-alloy steel in a wet H₂S environment, driven by the diffusion of hydrogen atoms into the steel due to a corrosion reaction. The formation of blisters and hydrogen-induced cracks in pressurized components in the oil and gas or petrochemical industries imposes a serious risk to personnel safety and production continuity. In this study, a fitness-for-service assessment of a gas separator pressure vessel containing 3.76% H₂S and 3.47% CO₂ was analyzed using finite element analysis as required by level III assessment in API 579-1/ASME FFS-1 2021. Different load scenarios, including internal pressure, static head from liquid, dead weight, and wind loads, were considered using elastic-perfectly plastic stress analysis. The assessment of API 579-1/ASME FFS-1 in level I and II failed due to the presence of a hydrogen-induced crack near the weldment. However, the evaluation in level III assessment considered the influence of welding residual stresses on both longitudinal and circumferential cracks in their as-welded state. 

The gas separator pressure vessel underwent FFS assessment in level 3 using Abaqus software, considering an elastic-perfectly plastic condition. Due to the significant presence of hydrogen-induced cracking (HIC) near the weld joint, the original tensile properties were disregarded, and the specified minimum yield strength (SMYS) was used for FEA analysis under various load case scenarios. It was established that the pressure vessel with the HIC defect, measuring 2650 mm×900 mm and having a depth of 8.5 mm, could withstand an internal design pressure of 8.963 MPa, considering welding residual stresses.

Presenting Author: Shahab Zangeneh Razi university

Presenting Author Biography: I have extensive and diverse research in structural integrity. I have developed my expertise by collaborating with some well-known research institutions and industries especially in oil & gas companies through large-scale projects in the Middle East. These opportunities have fortified my knowledge and experience in Fitness-For-Service (FFS) assessment, and fracture mechanics. In addition to my invaluable experiences obtained during past several years as a result of research, the outcome of my work has resulted in the publication of over 55 peer-reviewed articles (Google Scholar) cited over 800 times.
I got my B.Sc. (2006), M.Sc. (2009) and Ph.D. (2014) degrees in Materials and Metallurgical Engineering. Since 2014, I have been working at the Department of Materials and Textile Engineering, at Razi University as an assistant professor. My main research has focused on failure analysis and Fitness-For-Service (FFS) assessment of pressurized components in oil & gas industries. Before joining Razi University, my research area was focused on the failure investigation of high-risk components in some high-tech industries. At that time, my work provided a helpful link between the reason for failure and industrial component applications.

Best regards,
Shahab Zangeneh
Razi University, Department of Materials and Textile Engineering, Kermanshah, Iran.

Authors:

Shahab Zangeneh Razi university