Monitoring the Fatigue Life of Offshore Subsea HPHT Components

This paper presents the transference of a well-established nuclear power industry technique to perform environmentally-assisted fatigue monitoring for application to offshore, subsea High Pressure, High Temperature (HPHT) components using existing instrumentation. Applying fatigue monitoring is an effective way to manage these assets against the threat of fatigue failures and meet regulatory expectations during the service life. Our objective is to provide the background and overview of the approach so that design engineers better understand and evaluate its potential in contrast to traditional design changes that may actually produce an unintended consequence that increases the fatigue potential associated with heavy section thicknesses. This paper describes the overall analysis approach that may be used to perform fatigue monitoring of an HPHT component. At the conclusion, recommendations are provided for further research and development to close existing gaps.