Technology Qualification of Tendon Connectors for Deep and Ultra Deep Water Application

When new technology is deployed, it is critical to have the confidence that it will perform safely and as reliably as designed. For many years, DNV GL has helped companies that develop new technologies to implement a systematic, risk based Technology Qualification process (DNV RP-A203, 2013) [1]. The objective of this process is to ensure that all identified risks are properly addressed and the system performs the duties for which it was designed to. The field example described in this paper is based on Moho Nord's TLP located offshore Africa at 1,050 meters of water depth. Hutshinson, contracted by Hyundai Heavy Industries (HHI) and Total in 2013, supplied the complete scope of connectors for the project. The overall qualification process covered a solution to install a tension leg platform in deep water, which required the utilization of a tendon connector system. It consisted of a Tendon Top Connector (TTC), Tendon Bottom Connector (TBC) and Intermediate Tendon Coupling (ITC). The focus of this paper will be the TBC which connected the TLP tendons to the sea floor. Although Hutchinson has supplied this type of connection for many years, this was the first time it was used for TLP application. This paper provides an overview of Hutchinson's TBC, and the main steps covered by DNV GL's Technology Qualification process, as well as the results obtained. The understanding of the novel elements of this technology was obtained through a system to component assessment. The execution of the TBC Technology Qualification Plan carried out activities addressing the failure modes defined for the novel components. All qualification activities were documented, and the data generated collected to ensure its traceability and to determine the performance margin for each failure mode. The performance assessment was carried out to ultimately compare the available qualification evidence against the boundary conditions established in the technology qualification basis, confirming that the technology had met or exceeded all of the requirements. Once the TQ process was completed, the equipment was considered as fully qualified within the intended application.