Notice of RetractionDynamic wave-loading fatigue reliability analysis of deepwater drilling riser

Abstract

Deepwater drilling riser is a major component of offshore drilling system that connects drilling platform with subsea wellhead. The primary damage mode of a drilling riser is fatigue failure due to oscillatory environmental loads. Riser fatigue is sensitive to varieties of uncertainties, such as structural loads and material properties. It is vital to evaluate the fatigue failure using probabilistic approach. This paper focuses on dynamic fatigue reliability of deepwater drilling riser under random waves together-with drilling platform motion. Several parameters that contribute meaningfully to the uncertainty of riser fatigue are firstly considered. A sensitivity study is then conducted to identify critical random variables. It is found that S-N parameter A, response amplitude operator (RAO) of drilling platform and Palmgren-Miner's index Δ have a pronounced influence on the uncertainty of fatigue damage in splash zone. Subsequently, dynamic reliability analysis model for wave-loading fatigue is established in the form of second-order polynomial. Monte Carlo simulation (MCS) is used for solving the established model. In the calculations, fatigue reliability at different service time can be determined.