Abstract
In the early 2000, a consortium of Oil and Gas Companies operating the Kashagan, a super-giant oil field located in the North East of Caspian Sea, Kazakhstan area, embraced the challenge of maritime transportation in ultra-shallow waters, combined with a 5-months ice season per year and the potential risk of exposure to sour gas as a result of a blowout. The paper will present the ad hoc solution studied, tested and implemented for the first time in the naval architecture literature.
A fleet of bespoke vessels was designed, model tested in the ice tanks of internationally recognized research centers, constructed and successfully tested in real scale in the field. For such vessels, unique of their type, Classification Societies were involved through all project stages, in order to comprehend these new technical characteristics, thus issue a new set of Class Rules accordingly. A multidisciplinary activity of reverse engineering was performed, involving Environmental, Metocean, Ice Engineering and Naval Architecture teams, starting from the probabilistic forecasted of the ice thickness, its temperature and corresponding actual tensile strength. Vessels structure and propulsion power were dimensioned as a direct consequence of that, allowed to achieve minimum weight, hence minimum draft.
Such approach resulted in the construction of 2 highly specialized prototypes: the Mangystau, an ultra-shallow ice breaker for marine logistics supply chain, capable to break up to 1m level ice and navigate at 2.5m draft, as well as and the IBEEV, Ice Breaking Emergency Evacuation Vessel, intended to execute the task of EER - Emergency Evacuation Response, capable to rescue up to 340 people in ice infested waters, with the presence of an H2S toxic gas cloud. These pioneering vessels continue to support the development of the Kashagan oil field today.
The novelty of the above is mainly constituted by the nonstandard approach to the problem, exploring for a new way to apply technology rather than applying an existing one, which resulted in the realization of vessel prototypes and the publication of new set of Class Rules.
