The objective of this paper is to present a design and testing methodology to improve subsea connection system reliability by correlating the analysis and experimental data per the latest industry recommended practice.
In most cases, a theoretical approach has been used to establish different load capacities; however, no good method has been established for monitoring critical components of the clamp style connection system to matchthe computer analysis. The result is a lack of confidence for scaling the connector design up or down or extrapolating the load capacity for different offshore scenarios.
To improve on the historical approach, a new method has been developed that applies ASME section VIIIDivision 2 elastic and plastic analysis method to designing the core system capacity of asubsea flowline connector. To have full confidence that the critical components is within ASME code and functional requirements, several strain gauges, and Linear Variable Differential Transformers (LVDTs) are used to monitor data under various load cases to give confidence that this critical component of the subsea connector system is within ASME code and functional requirements. A good correlation between qualification physical test data from the data acquisition system (DAQ) and analysis results illustrates the functionality of the critical component of the connection system under different extreme loading cases. This method and process were used on Horizontal, Vertical,and Remotely Operated Vehicle (ROV)stab type connectors in alignment with API 17R "Recommended Practice (RP) for Flowline Connectors and Jumpers."
The authors present the details of the design, verification, and validation process, and compare the data captured through the DAQ system with the finite element analysis (FEA) results. The satisfactory correlation between numerical methods and physical tests provides reliability in design and validation method to develop and qualify subsea flowline connection systems.