To main content

Platform reinforcement, DABRAT

Boskalis Offshore was awarded a contract by Maersk for the DABRAT project, involving both the preparation and construction work to the Dan A and Dan B offshore oil production facilities. The extensive scope not only included the subsea installation and removal work, but also fabrication of structural items, procurement, setting up and testing of lift equipment and structural examinations. The works covered the years 2013 and 2014.

The oldest Maersk Oil field, Dan Bravo, is located in the Danish sector of the North Sea. The first platform in the complex was installed in 1972. The complex consists of platforms A, B, C and D. The Dan B platform forms the production hub of the Dan Bravo Complex and Dan A platform is one of the wellhead platforms at the Dan Bravo complex. Maersk Oil decided to carry out a platform lifetime extension program for the forty year old jacket structure to extend the service period of the structure until 2042.

General summary of the work scope

  • Reduce sea wave load unto the jacket structure by removing old boat fenders and pump caissons.
  • Inspection history enhancement by investigating all available inspection data, searching for known cracks in the subsea structure and inspecting potential problem areas.
  • Remove crack or damaged areas and replace with new structure (e.g. conductor guide level).
  • Reinforce subsea structure by adding retrofit (clamped) structures to strengthen key areas.
  • Renew consumables by retrofitting additional anodes by means of clamps due to depletion and removing some of the original anodes.
The 2013 offshore campaign started in July and was completed in September. During this campaign Boskalis performed the 3D subsea photogrammetry activities, classified as world’s largest ever undertaken, by air/saturation diving and ROV operations acquiring exact geometrical information of subsea K-joints to be able to design reinforcement clamps. Operations were performed on depths varying from 10 to 41 meters. Besides the technical challenges the environmental conditions as sea-state, fog and subsea reduced visibility (minimum 2 meter required for image taking) dictated the progress of the work.

Related projects

Selected filters

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.

Rock_installation_near_wellhead_tower.jpg

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.

HL_Stralsund_header.jpg

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.

Nearshore_excavation_header.jpg

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.

Backhoe_dredger_Cornelius_trench_dredging_header.jpg

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.

IMG_2683_header.jpg

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.