Subsea flowline connectors are crucial components of subsea production system (SPS), ensuring the structural integrity and the pressure-containing connection between SPS components. This paper presents a correlation study between verification analysis and validation testing (V&V) results of a flowline connector structural capacity, hub separation and leak tightness performance requirements at extreme and accidental loads and according to API spec 17D, API spec 6A and API-RP-17R standards.
The presented V&V study consists of two steps:
In the first step, the flowline connector design verification requirements were defined and calculated using finite element analysis (FEA) in accordance to the applicable industry standards and considering combined separation loads.
In the second step, physical validation tests were used to validate the obtained FEA results. Strain gauges were used to verify the combined separation loads such as, bending Moment load and the connector locking force. In addition, four linear variable displacement transducers (LVDTs) mounted in the connector hubs and spaced with equal circumferential distance to quantify the actual hub separation at metal seal location.
The study highlights a significant and positive correlation between results from verification FEA and validation testing and proved the accuracy of FEA methodology that been used to determine the structural capacity, hub separation and leak-tightness performance requirements.
Additionally, a digital twin of the physical flowline connector has been established with a high confidence level which will be used to understand and predict the performance of flowline connectors at unpredicted extreme or accidental loads and for future development and optimization of subsea flowline connectors.
Finally, this paper, for the first time, presents a detailed and insightful correlation study between V&V results of subsea flowline connectors.