Quick Enquiry

Smart and environmentally friendly caisson replacement

A green and cost-effective method of replacing caissons

Client: Wintershall
Industry: E&P
Asset: Brage platform
Location: North Sea
Year: 2019


When Wintershall acquired the Brage platform in 2013, one of the oldest producing platforms in Norway, they were approved to extend its lifetime up to 2030 and beyond. Besides optimising its processes, they also needed to repair and replace the damaged structures and components. One example was its aging caissons.  

With over 25 years in service, the caissons have suffered from corrosion and cracking, posing threats to other components of the platform and the subsea architecture. As previously contracted to replace one of the platform’s caissons in 2013, Axess Group was again commissioned to replace seven caissons in 2018 to 2019. 


An investigation and feasibility study resulted in an innovative and climate-efficient method of replacing the caissons. Instead of using support vessels, Axess’ engineering department performed the lifting operations below the platform deck with the aid of a tailor-made Construction ROV (CROV) that was platform deployed. This prefabricated CROV was designed to carry out various activities with maximum flexibility – cutting, cleaning, torqueing and other clamp capabilities.

The high-risk method involved safety measures for lifting above pressurised equipment according to the strict requirements found in NORSOK R-002 Annex K, including double redundant load paths, and implementing fail-safe systems throughout the design. In addition, a lifting system was also developed to catch potential parts that have fallen off after a breakage in one of the caissons. The lifting clamps were custom-designed to provide a complete material handling solution – a more factory / turnkey way of thinking rather than the conventional offshore project approach.


Due to its compact design and multiple mechanical capabilities, the bespoke platform deployed CROV exceeded the weather-sensitive limitations of large ROV systems on IMR vessels – especially in the splash zones. Not only did the lifting solution provide a huge cost savings on support vessel chartering, it also reduced a significant amount of emissions.  Over 1,700 tons of CO2 were saved by using this method, largely by avoiding the use of support vessels.

Overall, Wintershall was very pleased with the proposed plan and the execution as it was cheaper than the conventional method and with minimal emissions. The work was undertaken in all weather conditions including the challenging winter months in the Norwegian North Sea. 


Contact Information

Axess AS
Oscar Hanssens vei 5
6415 Molde
+47 982 43 600
Axess AS
Kokstadflaten 35
5257 Bergen
(duty): +47 982 43 600
Axess AS
Travbaneveien 3
4031 Stavanger
(duty): +47 982 43 600
St. John's
Axess Baffin Inc.
702 Water Street, Suite 201
St. John's, Newfoundland
+1 709 758 7937
Axess North America Inc.
1400 Broadfield Suite 300
Houston Tx. 77084
+1 (281) 994-0367
Ciudad del Carmen
Axess Operations De Mexico S de RL de CV
Calle Bosque de Ciruelos 180 PP 101
Colonia Bosque De Las Lomas
CP 11700 Cuidad De Mexico
+52 938-152-7688
Axess North Sea Ltd.
Axess House,
Twin Spires Business Park,
Mugiemoss Road, Bucksburn,
Aberdeen, AB21 9NY
(duty): +44 (0) 78 5303 6111
Axess Guyana Inc.
2 Avenue of the Republic
Georgetown, Guyana
+592 222 2216
Rio de Janeiro
Axess do Brasil Ltda
Rua Dezenove de Fevereiro
171 - Botafogo
CEP 22280-030 Rio de Janeiro
+55 (21) 4108-0532
Axess Petrorig Ghana Limited
3rd floor, The Pelican
8 Blohum Street, Dzorwulu
Accra, Ghana
+233 (0) 30 397 0548
Axess Offshore Africa Ltd.
Edificio Joia Rara, 3º Andar 3.5/3.6,
Av. Revolução de Outubro No 8, Cassenda, Maianga
Luanda, Angola
+244 933 316 388
Cape Town
Axess Offshore Africa Ltd.
Office 106, 1st Floor, Block 2,
Northgate Park, Brooklyn
Cape Town, South Africa
+27 21 001 9540
Axess AS
Nedre Bakklandet 58C
7014 Trondheim
(duty): +47 982 43 600
Axess AS
Grønøraveien 1
7300 Orkanger
(duty): +47 478 37 300
Axess AS
Fridtjof Nansens plass 4
0160 Oslo
(duty): +47 982 43 600
Axess for Oil Services
3141 Anas Bin Malik, Al Malqa Dist.
Riyadh, Kingdom of Saudi Arabia
+966 59 427 0293
Axess Middle East DMCC
807 X2 Tower, X Cluster,
Jumeriah Lake Towers
Dubai, UAE
+971 4565 7913
Axess Offshore Korea LLC
22nd Floor KNN Tower, Centum-ro 30
2203-ho, Haeundae-gu
Busan, South Korea
+82 10 2696 2016
Axess AIM India Pvt. Ltd.
B2-701, 7th Floor,
Kanakia Boomerang,
Chandivali Farm Road
Andheri East, Mumbai- 400072
+91 22 4604 3533
Axess Offshore Pte Ltd
Nordic European Centre, #05-31 South Wing,
3 International Business Park
Singapore 609927
+65 6908 4174
Axess Offshore Australia Pty Ltd
304 Newcastle St
Perth WA 6000
+61 4 3373 0739