Seismic Design of Subsea Jumper per ISO: Part I- Preliminaries

Subsea rigid steel spools (spool) are used to connect subsea equipment using diver-less connectors. Spools must meet functional requirements such as pressure, temperature, thermal expansion, environmental load, installation loads, lack of fit (misalignments), etc., yielding numerous loading conditions.  The installation accuracy that the installation contractor can achieve is another issue.  Thus, it is inevitable that numerous geometries to be investigated and perform several iterations in search of a suitable configuration.  The no-burst concept, in conjunction with a High Integrity Pressure Protection (HIPP) system, leads to heavier spool wall thickness, hence less structural flexibility which in turn increases reactions on the subsea connectors, which in turn is transferred to the adjoining equipment. Add to this complexity, the seismic qualification requirement if a jumper is in an earthquake-prone area.