Offshore support vessels (OSV) operate world-wide. They support many tasks in the offshore business like supply of rigs, anchor handling, research tasks etc.
The OSV baseline ship is a seismographic research vessel. This type of vessel is used in the oil and gas industry for exploration of new sources of oil and gas.
The baseline OSV is equipped with two redundant propulsion plants with each 8970kW installed power (2500kW main engine, 3360kW aux diesel, 1110kW aux diesel). It has an overall length of 127m, is 28m wide and has a deadweight of about 6200 tdw.
The vessel is designed for world-wide operation. Usually it spends a whole year in uninterrupted service at sea. Therefore, the ship provides large accommodation areas with 68 single cabins and additional rooms for leisure activities. The ship gets refueled at sea by support vessels, the crew will be exchanged by helicopter. This means there is no harbour time considered in the annual operating profile. Usually it is 15% of the time in transit mode and 85% it does seismic service.
2025 Ship Concept
The 2025 design is supposed to be the first step to an even more efficient and environmental friendly future. The objectives for reduction of CO2-emissions for the 2025 design (20% compared to baseline vessel) shall be achieved through efficiency enhancement by including waste heat recovery technologies for exhaust gas and cooling water system. Other energy efficiency enhancement like frequency controlled sea cooling water pumps and ventilation as well as further engine optimization (e. g. two stage turbo charging system) will be considered. In order to build up a high efficient system configuration the system compatibility of all implemented technologies will be checked by an energy grid simulation.
According to first approximations we may expect a reduction of CO2-emissions of about 14 % from the efficiency enhancements. The remaining 6% of the 20% CO2 reduction that is requested will be realized with drop-in fuels from renewable sources. We will investigate two options in this respect, namely the production of liquid fuel from 2nd generation bio-mass (also called BtL-Diesel) or the conversation of carbon sources from industrial processes (or even segregation from atmosphere) to liquid fuel using the Fischer-Tropsch Synthesis.
Though first findings revealed that due to the high amount of energy that is necessary to produce these fuels and the availability of feedstock from bio-mass for the shipping industry may be critical to be secured, we still think that due to the strong restrictions to the fuel properties (mainly high energy density and easy handling) that result from the operation profile and the need to refuel at sea these fuels are the best energy source for this type of ship.
2050 Ship Concept
The goal of CO2 reduction in accordance with the DOW for the 2050 design is 40%.
The energy system of the 2050 design will be identical with the 2025 design. The improvement that will be made in 2050 will be the fuel. In 2050 this vessel will be driven by alternative fuels from renewable sources. Especially synthetic diesel (biomass or power to liquid) is considered to be a good solution. Due to the very large operation range and the necessity of refueling at sea other fuel types have been excluded. E.g. the use of methanol would cut the time at sea in half.
Since the fuel will be gained from renewable sources it is assumed that the goal of 40% CO2-emission reduction will be reached.
