The Caspian Sea Icebreaking Supply Vessel Tulpar

Abstract

Some of the world’s largest recent hydrocarbon discoveries are located beneath the waters of the Northern Caspian Sea, or offshore Kazakhstan. The Kashagan field alone is believed to contain in excess of 10 billion barrels of oil, and there are fields at containing billions of barrels at several other locations. The exploitation of these reserves is now moving from discovery and exploration phases towards production. The Northern Caspian Sea is an unusual environment for offshore development. The water is generally extremely shallow; less than 10 m water depth in almost all locations and down to 1.5 m in several areas above the oil and gas reservoirs. While the Caspian has minimal tides, storm surges can lead to rapid depth changes of over 1 m in depth, up or down. For 3-5 months of the year, depending on location and on the severity of the winter, ice cover is present. Some of the ice is land fast, and the rest is more or less mobile. Large ridge and rubble fields build up, often becoming grounded. Two other challenges for operations are that the environment is sensitive, with important and endangered species. The oil is also associated with high concentrations of sour gas, whose high toxicity presents additional safety risks in the event of blowouts or other accidents. All the drilling and production platforms in the area are and will be gravity based. They range in (planned) size from several square kilometers with over 1000 persons on board to small wellhead installations that will normally be unmanned. The platforms must be supplied and supported by a large fleet of vessels including OSVs, tugs, barges, and other specialized vessels. The flagship of this fleet are the icebreaking supply vessels. This paper describes the genesis, design, construction, and entry into service of the largest of the vessels now in operation, the Ice Breaking Supply Vessel (IBSV) Tulpar, the Kazakh flying horse. BMT SHIP DESIGN Limited was approached in April 2001 by BUE to ascertain whether it was possible to design a shallow water icebreaker with a large deadweight capability and also meet with the requirements of transiting the canal system into the Caspian Sea. The vessel was to be delivered into the Caspian by November 2002 in time for the winter ice season. After exploratory discussions with BUE, BMTSD entered into an agreement to jointly support each other in the development of a suitable vessel design, later to be designated SWIMSS, (Shallow Water Ice Management Standby Supply) and then present this design to AGIP as a viable solution to their requirements. The design was to be based upon design study information supplied by BMT Fleet Technology Limited and was a development of a river icebreaker concept. Agip KCO’s program for the design, build and delivery of the vessel in what was effectively a fourteen-month timeframe was ambitious to say the least at the outset, it was further complicated by the requirements changing twice in the design phase and the contact award being correspondingly delayed. How these challenges were met is set out below.