In the last 5 years, a number of key advances have been made with threaded and coupled (T&C) risers. These advances together with high strength steels have enabled these products to reach parity with the current standard of weld-on connectors. The T&C riser concept demonstrates the same reliability, field proven history and high fatigue performance. This concept of connectors and engineered materials up to 125ksi, allow for significant weight savings on the riser system and platform construction. To meet the Global Energy needs now, the industry must move to deeper water and higher fatigue. Thus a new generation of connectors, fully optimized for fatigue, has been designed for inner and outer production riser applications.
These connections reach best-in-class fatigue performance and include innovative fatigue compliant sealing systems. The large number of full scale fatigue test results increases confidence to such a level that fatigue trends and influencing parameters now help to refine the qualification programs. This new standard will also allow the industry to look for new generations of heavy wall riser connectors for xHPHT, flow line, and SCR applications.
The purpose of this paper is to highlight the knowledge that has been accumulated in various fatigue enhancement techniques and the continuous improvement of analysis capabilities.