A life cycle reliability testing and assessment method for deepwater oil and gas equipment systems

A life cycle reliability testing and assessment method for newly developed deepwater oil and gas equipment systems is proposed to evaluate potential design defects. Due to the large and complex nature of deepwater oil and gas equipment, it is decomposed into several key components. A new reliability testing process is designed. Accelerated life testing is interspersed with stage performance testing (SPT) to obtain accurate degradation trends of components. The life cycle reliability assessment of system is based on accurate component degradation models, which are established from physical models, reliability testing data, and prior information to address any potential data shortage. SPT data are also used to verify component degradation models. Based on the system working principle and component degradation models, the system performance degradation model is established and discretized, and the advanced first order second moment method is used to calculate system reliability. This method is used to evaluate reliability of the newly developed all-electric surface controlled subsurface safety valve transmission system and guide its subsequent design improvement work.