Dredging in the Gulf of Ob completed
Dredging works for the reconstruction of the Sea Channel facility (Ship Fairway in the Gulf of Ob of the Kara Sea) have been completed in 2020. The total amount of excavated soils was more than 32 million m3. The result will allow the large-capacity vessels to sail in the gulf ensuring export of liquefied natural gas and liquefied gas condensate by sea along the new section of the channel this winter and spring.
The work is planned in 2 stages. After the completion of Stage 1 in 2021, the channel width will increase by 180 meters in the straight section (from 295 m to 475 m) and by 278 meters (to 573 m) in the turning section. The length of the channel will increase from 48.9 km to 51.6 km, and the depth will be 15.1 meters (BSE-77).
Dredging and auxiliary fleet were mobilized from the various ports of Europe and Russia, amongst others the port of Antwerp (Belgium), the port of Bremerhaven (Germany), the ports of Amsterdam and Rotterdam (Netherlands). The Russian auxiliary fleet arrived at the Site from Murmansk and Arkhangelsk. Sailing of the dredging spread to the Facility took 4 to 35 days. Preparation of vessels for the sailing to the project was carried out directly in the ports of mobilization. At the same time, the office of Mordraga, LLC carried out preparatory work in terms of obtaining the necessary permits and approvals; geodetic and hydrographic work was carried out on the Site before the start of dredging.
The client requesting the construction of the Sea Channel facility is FSUE Hydrographic Enterprise (part of the State Corporation Rosatom). Mordraga, LLC was selected as the dredging contractor.
The work was carried out in only 79 days due to the short period ice-free navigation on the construction site.
Almost 1000 crew members and staff participated in the project.
‘Sea Channel is designed to provide year-round navigation of sea transport necessary for the implementation of hydrocarbon projects located in the Gulf of Ob. The reconstruction is needed due to a significant increase in planned turnover and, consequently, increase of vessels sailing in the channel, as well as due to a fast ice zone with active hummocking and contraction in the northern part of the current channel, - said Vyacheslav Ruksha, Director of the NSR Directorate and Deputy Director General of the State Corporation Rosatom. ‘It was decided to change the planned position of the channel – the turn of the northern bend. This will help to cut down possible meetings of vessels sailing through the channel in the winter under critical hydrometeorological conditions.’
The calculations of navigation capacity showed that if the current configuration of the Sea Channel remains, the maximum number of vessels, up to four a day, will be reached already in 2023.
‘Upon completion of the works, it will be possible for Yamalmax vessels with a length of 299 m and a deadweight of 80 thousand tonnes to sail in the channel; also, special pockets will be created to ensure the possibility of transportation of gravity-based platforms for the creation of a gas liquefaction plant of the Arctic LNG 2 project. In the future, until 2030, up to nine vessels will be able to sail through the channel per day,’ – said Yuri Mikhov, the General Director of FSUE Hydrographic Enterprise.
Continuous environmental monitoring was carried out throughout the dredging operations.
All vessels were removed from the waters of the Gulf of Ob through the Northern Sea Route before the ice formation began.
The Sea Channel facility (Ship Fairway of the Gulf of Ob of the Kara Sea) is included in the list of activities of the federal project ‘The Northern Sea Route’, aimed at achieving the target of 80 million tonnes of cargo traffic vis the NSR by 2024, established by decree No. 204 dd. 07/05/2018 ‘On national goals and objectives for the development of the Russian Federation for the period up to 2024’ of the President of the Russian Federation.
FSUE Hydrographic Enterprise provides navigational and hydrographic support for the vessels sailing in the water area of the Northern Sea Route, including a study of the underwater bottom topography for the maintenance of nautical charts, guidelines and manuals for navigation up-to-date and securing the waters of the Northern Sea Route by means of navigation, and informing sailors about the changes of the navigation situation.
Mordraga, LLC was established in Russia in 2005 as a holding structure of DEME Group. Mordraga, LLC performs full cycle of dredging, alluvial and hydraulic engineering works in ports and offshore when laying underwater pipelines and installing marine structures.
