Life Cycle Structural Integrity Design Approach for the Components of Subsea Production System: SCSSV as a Case Study

Large-scale production systems such as offshore oil platform and subsea production system (SPS) usually have the characteristics of long service life, high economic value, high risk, and difficult to maintain. Existing reliability-based design methods are difficult to meet the requirements of high reliability, risk control, and maintenance economy in their full life cycle. In order to solve this problem, a life cycle structural integrity design method integrating operational reliability, risk controllability, and maintenance economy is proposed. Based on the existing reliability design theory, risk and maintenance are added, and the time dimension is extended to the full life cycle of structures. The interactions between the system, the subsystem, and the components are considered. Prediction of component degradation using existing mature theoretical methods or experimental studies is adopted. The advanced first-order second moment method is applied to calculate the structural reliability. Risk assessment and maintenance are based on the results of the reliability analysis. The SPS of an oilfield in the South China Sea is the application scenario and data is collected, and a surface-controlled subsurface safety valve is designed using the proposed method.

Automated summary

This article proposes a life cycle structural integrity design method that integrates operational reliability, risk controllability, and maintenance economy. By considering the interactions between system, subsystem, and components, component degradation is predicted using existing theoretical methods or experimental studies, and the advanced first-order second moment method is applied to calculate structural reliability. Risk assessment and maintenance are based on the results of the reliability analysis. The proposed method is applied to the design of a surface-controlled subsurface safety valve in an oilfield in the South China Sea.