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Caisson Replacement

Caisson replacement made cost-effective

For many years, caisson replacement was considered time-consuming and too expensive. In some projects, the replacement of one caisson can cost almost 20 million USD. As there can be 10 to 15 caissons on an offshore platform, it is understandable that some energy companies have postponed these replacement projects and relied on temporary repairs instead.

In the past 20 years, Axess Group has developed safe, lean and innovative methods for lifting operations, allowing us to replace caissons faster and at a fraction of the cost of what it used to be. We have gained substantial experience within the field and replaced many caissons in recent years, with excellent feedback from our clients.

Damage to caissons

Caissons are key components of steel jacket structures – one of the most common types of offshore platform foundation in shallow and mid-water. Damage to caissons can cause severe problems if not dealt with correctly, with production shutdown and major accidents being the most critical.

Common types of damages:

  • Corrosion and resulting wall thickness reduction due to wear and damages in surface treatment, lack of cathodic protection
  • Galvanic corrosion problems due to the use of dissimilar metals in caissons and pumps
  • Structural fatigue cracks due to dynamic movements and loads
Caisson replacement

Risks associated with caisson replacement

Caissons come in many different designs. For a typical mid-water installation, they have a length of 50 to 100 meters and weigh 20 to 40 metric tons. Caissons are usually manufactured and installed at the same time as the jacket structure itself. They are usually not designed to be replaced during the expected lifespan of the platform. Most are produced with either welded or flanged joints, with welded joints being the most common.  

It is impractical to replace or install caissons in its complete length, thus, it must be done section by section. Removing the old caisson by cutting it into smaller sections can be challenging and time-consuming, if not planned and executed accurately. Furthermore, as the reason for replacement is typically excessive corrosion or fatigue cracks, it is very important to secure the caissons to prevent them from breaking during these operations.

What we offer

A caisson replacement project is complex. The most important factor to success is having an efficient and cost-effective solution for installation of the new caisson elements. We have experience with both flanged and welded types, and more recently, the pin-box connection type, which has proven to be a very robust and cost-effective solution.

We strive to meet any request from clients, but typical deliverables for caisson replacement are as follows:

Planning and engineering

  • Project management and administration
  • Technical and engineering management
  • Design engineering
  • Structural engineering
  • Lifting method planning
  • Mechanical work and equipment planning
  • Subsea work and equipment planning
  • LCI engineering

Fabrication and procurement

  • Assistance with the procurement of new caissons, or
  • Complete delivery of design and procurement of new caissons
    • Production follow-up / inspection and quality assurance
    • Special focus on installation friendliness
  • Fabrication of custom made lifting equipment

Offshore execution

  • Installation management
  • Complete offshore crew and equipment package
    • Subsea preparation work
    • Mechanical and cutting work
    • Lifting/rigging/rope access operations
    • Subsea installation operations
    • Pin-box installation crew and/or welding crew
    • Inspection and certification work

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Contact Information

Molde
Axess AS
Oscar Hanssens vei 5
6415 Molde
+47 982 43 600
Bergen
Axess AS
Kokstadflaten 35
5257 Bergen
(duty): +47 982 43 600
Stavanger
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
Houston
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
Aberdeen
Axess North Sea Ltd.
Axess House,
Twin Spires Business Park,
Mugiemoss Road, Bucksburn,
Aberdeen, AB21 9NY
(duty): +44 (0) 78 5303 6111
Georgetown
Axess Guyana Inc.
2 Avenue of the Republic
Georgetown, Guyana
Rio de Janeiro
Axess do Brasil Ltda
Rua Dezenove de Fevereiro
171 - Botafogo
CEP 22280-030 Rio de Janeiro
+55 (21) 4108-0532
Accra
Axess Petrorig Ghana Limited
3rd floor, The Pelican
8 Blohum Street, Dzorwulu
Accra, Ghana
+233 (0) 30 397 0548
Luanda
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
Trondheim
Axess AS
Nedre Bakklandet 58C
7014 Trondheim
(duty): +47 982 43 600
Orkanger
Axess AS
Grønøraveien 1
7300 Orkanger
(duty): +47 478 37 300
Oslo
Axess AS
Fridtjof Nansens plass 4
0160 Oslo
(duty): +47 982 43 600
Dammam
Axess for Oil Services
3141 Anas Bin Malik, Al Malqa Dist.
Riyadh, Kingdom of Saudi Arabia
+966 59 427 0293
Dubai
Axess Middle East DMCC
807 X2 Tower, X Cluster,
Jumeriah Lake Towers
Dubai, UAE
+971 4565 7913
Busan
Axess Offshore Korea LLC
22nd Floor KNN Tower, Centum-ro 30
2203-ho, Haeundae-gu
Busan, South Korea
+82 10 2696 2016
Mumbai
Axess AIM India Pvt. Ltd.
B2-701, 7th Floor,
Kanakia Boomerang,
Chandivali Farm Road
Andheri East, Mumbai- 400072
+91 22 4604 3533
Singapore
Axess Offshore Pte Ltd
Nordic European Centre, #05-31 South Wing,
3 International Business Park
Singapore 609927
+65 6908 4174
Perth
Axess Offshore Australia Pty Ltd
304 Newcastle St
Perth WA 6000
+61 4 3373 0739