HPNG SHIP TO PLATFORM/SUBSEA
This customised transfer system has been developed by MIB Italiana to deliver high pressure natural gas from a permanently moored FSRU vessel to an offshore platform or to a subsea infrastructure network (PLET, PLEM) by means of high pressure free hanging hoses.
The system includes the following main equipment:
- Quick Connect/Disconnect Coupling c/w built-in alignment & recovery facilities and hydraulic power and control pack;
- High Pressure Hoses and accessoiries;
- A common deck mounted skid based structure c/w lifting/handling aids, braking system and recovery winches;
The following advantages of the flexible hose system transfer versus other traditional methods would include:
- Optimisation of CAPEX investment;
- No major ship modifications or special reinforcements are required;
- Significant reduction in weight. This will positively reflect on the ship construction/modification itself;
- Significant reduction in costs and time for installation.
- No need for scaffolding or removal of the equipment to an off-site area for servicing; hence reduced down time and subsequently cost;
- Reduced number of potential leak paths;
- Lower shipping cost to site. The skid module is suitable to be containerized and, as alternative, could be also built locally;
- The hose system does not involve any requirement for hydraulic power, except for the ERS which in any case requires hydraulic power only in case of an emergency release;
- The hoses and the skid structure do not require any maintenance during normal operating not involving any moving part such as swivels, bearings, hydraulic cylinders, ropes, motors, etc;
- The lead time for a complete system is significantly reduced; this being particularly important for many FSRU projects which are time-driven, over those of other possible options:
- Reduction in OPEX cost for spare parts and intervention activities;
- Part of the scope (integration of the ERS with relevant power and control system) is typically done at shipyard or outfitting location, thus reducing further the activities needed at site when FSRU arrives.
To suit the vessel motions and ensure safe transfer within a wide drift operational envelope, a project specific catenary configuration analysis is performed order to cater for all extreme cases.
Static and dynamic analysis will also be performed to calculate the loads exerted on the skid structure and on the jumper hoses in the extreme load case scenarios including the release. Dimensioning of the skid structure is done on the basis of such analysis results.