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Landfall construction
Balearic submarine pipeline

As part of its network expansion program, Enagas undertook the installation of a submarine pipeline providing natural gas from the Spanish mainland to the Balearic Islands of Ibiza and Mallorca, integrating them into the Spanish gas system. This 20" nominal diameter pipeline was constructed in two distinct sections, one of 123 km between the mainland and Ibiza and another of 146 km between Ibiza and Mallorca.

Boskalis constructed the four landfalls of these pipeline sections at the three shore approach locations. Each shore approach posed highly different conditions:
  • a sandy beach at Dénia,
  • a rocky cliff at Ibiza and a shallow gravel and
  • sandstone approach at Mallorca,
the latter further complicated by space restrictions onshore.

Denia landfall

The landfall at Playa Les Deveses was characterized by a sandy seabed and beach and small dunes. A trench would provide protection for the pipeline along the shore approach.

Ibiza landfall

At Punta de Cala Gració the shoreline consisted of a rocky cliff. To cover the height difference between the seabed and the cliff two micro tunnels had been drilled previously, into which 48" casing pipes of 150 m each had been installed.

Mallorca landfall

The Mallorca landfall at San Juan de Dios featured a gravelly / rocky seabed and sandstone coastline with space onshore limited by an existing water plant and fish farm.

Related projects

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Installation gas pipeline, Balgzand-Bacton

BBL Company was established to design, construct, operate and exploit the Balgzand-Bacton Pipeline (BBL) for the transmission of natural gas from Balgzand, the Netherlands to Bacton in the United Kingdom. The overall length of the 36" offshore pipeline is some 230 kilometers. The capacity is around 42 million m3 of gas a day. As part of the pipeline installation, Saipem UK Ltd awarded Boskalis Offshore the contracts for the shore approaches at Julianadorp, the Netherlands and Bacton in the United Kingdom and the presweeping and rock dumping works along the pipeline route on the North Sea.

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Platform installation,
De Ruyter field

The De Ruyter field, discovered in 1996, straddles Blocks P10a and P11b in the North Sea, which are both operated by Petro-Canada. The development consists of a Gravity Base Structure (GBS) with wellhead and lattice towers supporting an Integrated Production Deck (IPD). De Ruyter joins Hanze as Petro-Canada’s second operated offshore field in the Dutch North Sea. Heerema Zwijndrecht was awarded the fabrication, installation and hook-up of the GBS and IPD. The transportation, installation and stabilisation of the GBS was subcontracted to a consortium between Smit Marine Projects and Boskalis Offshore.

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Bridge construction, Stralsund

SMIT’s 1,200 tonnes sheerlegs Taklift 7 completed a major German bridge building programme during 2006. The sheerlegs had spent several months at the new Stralsund Bridge, on the German Baltic coast. This suspension bridge links the mainland with the island of Rügen.

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Pipeline construction, Mumbai Highfields to Uran Trunkline

The Mumbai High Fields to Uran Trunkline Project is situated near Mumbai (Bombay) in India. ONGC Ltd (Oil & Natural Gas Corporation) has constructed two new pipeline connections from the Mumbai High Fields to Uran over a total length of 204 kilometers. These new pipelines have been constructed in order to replace the existing Bombay High Fields to Uran Trunkline, which had already completed more than 25 years of successful operation and had surpassed its design life. The new pipelines are a 30" oil pipeline and a 28" gas pipeline.

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Construction gas pipeline
Beachfield Upstream
Development

The BUD project entailed the construction of a 66 kilometer, 36" gas pipeline, 63 kilometers offshore and 3 kilometers onshore underground to the treatment facilities. The offshore pipeline runs from the east coast at Beachfield (Rustville), Guayaguayare, to the 'Cassia B' platform complex. At the NGC Abyssinia facilities, 3 kilometers off Beachfield, a new sludge catcher has been developed to separate the liquid or condensate from the natural gas. The condensate is separated from water and metered. The station is also designed to control the pressure of gas, as it enters into the land gas transmission system. NGC's existing 30" and 24" gas pipelines have also been diverted to the new Abyssinia sludge catcher.

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Seabed preparations, Changi Outfall

The Public Utilities Board implemented the Deep Tunnel Sewerage System as a long-term solution to meet the needs for sewerage water collection, treatment and disposal to help maintain Singapore’s clean and healthy environment. In phase one of the Deep Tunnel Sewerage System, the Changi Water Reclamation Plant was constructed in the east of Singapore, from which the Changi Outfall was subsequently constructed. Treated effluent from the water treatment plant will flow through outfall pipelines and be discharged through series of diffusers, dispersing the effluent in the seawater. Boskalis International was awarded the contract for the Changi Outfall in 2002 and formed a joint venture with Archirodon to construct the project.