Combining marine and coastal engineering skills with an extensive knowledge of ice sciences, Sandwell has more than 30 years' experience in Arctic and offshore engineering.
We have worked extensively in the Alaskan and Canadian Beaufort seas, as well as in areas of less severe ice: the east coast of Canada; off Sakhalin Island; the Pechora Sea and Kara Sea areas of Russia; and the Bohai Gulf in China. We have direct experience in preparing designs for structures in the Russian Arctic, and have worked with Russian design institutes and shipyards.
Completed offshore arctic projects number in the hundreds and include:
- gravity platforms (caissons, cones, column structures)
- artificial islands (sand and spray ice)
- movable and fixed caisson retained islands
- ice-resisting offloading platforms
- jackets and jack-up platforms (loading terminals)
- floating structures (semi-submersibles and ships)
- offshore engineering
- arctic transportation
- ice research, instrumentation and scientific work.
Sandwell has scored a number of notable "firsts" in Arctic engineering:
- first artificial island [Esso]
- first cone concept [Esso]
- first concrete caissons [Tarsuit]
- first deep water steel caisson [Molikpaq]
- first sectional steel caissons [Esso CRI]
We make extensive use of both commercial and proprietary simulation programs to study ice interactions with semi-submersibles (both fixed and floating) and moored ships, and to model bulk oil and natural gas marine transportation.
Tanker Loading Structure (TLU)
Nippon Steel Corporation
Sandwell carried out the Front End Engineering and Design of a gravity based TLU substructure. Later working for the EPC contractor, Nippon Steel Corporation, Sandwell was responsible for the detailed design of the pile based TLU substructure, with SBM of Holland responsible for the design of the rotating head structure. The TLU is installed 4km offshore in Aniva Bay at the south of Sakhalin Island, in a water depth of approximately 30m. Crude oil and condensate is delivered to theTLU via a 30” subsea pipeline.
'Orlan', Sakhalin-1, Russia
Exxon Neftegas Ltd Gravity Based Structure Upgrade
Study and design development for converting an existing steel/concrete arctic drilling platform (CIDS) to a Drilling and Quarters Platform. The project started as a series of conceptual studies, proceeded to the preliminary engineering stage, and then to detailed design for the EPC contractors.Sandwell was responsible for the design of the steelwork modifications to the deck and mudbase, corrosion protection, specialist aspects of the riser analysis, seismic analysis and design, wave force analysis, and design of the erosion protection system around the mudbase. The structure is located in an area which is ice covered for up to half the year, is in a seismically active zone, and has a severe wave climate in the open water season. It was installed on location in the summer of 2005.
BP Exploration (Alaska) Inc., Prudhoe Bay, Alaska
Northstar production island
Built six miles offshore in water approximately 12 m deep, BP's Northstar production island supports oil and gas production wells plus processing facilities for oil to be shipped to the Trans-Alaska Pipeline via subsea and aboveground pipeline.
Sandwell was responsible for the island engineering, including a sheet pile perimeter wall and concrete spread footings. The design pushed the frontier of knowledge regarding sheet piling in frozen gravel and the placement of footings on frozen fill. The ice engineering related to installation of the pipeline was also Sandwell's responsibility, as were the design, construction monitoring and quality assurance services for the six-mile ice road.
Laying and lowering of the pipeline was done through an open slot in the ice with heavy equipment, a unique engineering and construction challenge that was completed successfully and without incident.
Mobil, Chevron and PetroCanada, Whiffen Head, Newfoundland
Oil transshipment terminal
This facility is the first oil terminal constructed in Canada in 25 years. Sandwell was responsible for the design of the marine structures, including the main jetty platform, associated breasting and mooring dolphins, the access trestle and a tug basin to shelter the new high-performance tugs that will assist all tankers coming to the facility. The tug basin incorporated slipformed concrete caissons as the primary breakwater and dock structure; these were constructed on a semi-submersible barge in Argentia and towed to the site.
Sakhalin Energy Investment Company Ltd., Sakhalin Oil Fields, Russia
Offshore arctic drilling and production platform
The Molikpaq, a bottom-founded arctic offshore drilling rig, was designed by Sandwell for Gulf Oil in the 1980s and used in the Canadian Beaufort Sea. Capable of drilling in depths from 9 m to 45 m, the platform has 24,000 tonnes of steel in hull and deck. In 1999, after modifications to accommodate the water depths and wave climate off the east coast of Sakhalin, the structure was deployed in the Piltun-Astokhskoye oil field off Sakhalin Island. It became the world's first arctic offshore production platform. Sandwell was involved in the design, wave testing and analysis, seismic analysis and other issues related to the refurbishment. Ice load panels designed and fabricated by our ice sciences team were fitted to the face of the Molikpaq to provide data for use in the design of future platforms.
Life aboard the Molikpaq (BBC News)
Amoco Production Company, Beaufort Sea, Alaska
MARS ice island
The MARS spray ice island was used as a drilling platform for an exploratory well in the Beaufort Sea. Located 8 km off Cape Halkett, Harrison Bay, it provided a 60-day drilling period. Sandwell designed and constructed the island using four pumps, each with a capacity of 5,000 US gallons per minute, a hydraulic drill rig mounted on a light all-terrain Rolligon vehicle, and a Failing 750 drill rig mounted on an RD-85 Rolligon. The island had a top area 1,000 ft in diameter and was formed by gradually increasing the thickness of the ice cover using spray ice.
