Major modifications to the Draugen platform

Pressurised welding habitat
About the project:

Draugen is an oil field operated by AS Norske Shell in the Norwegian Sea sitting above a sea depth of 250 metres (800 ft). The field has been developed with a concrete fixed facility and integrated topside. Stabilised oil is stored in tanks in the base of the facility. Two flowlines connect the facility to a floating loading buoy.

The Garn Vest and Rogn Sør deposits have been developed with a total of five subsea wells connected to the main facility at Draugen. The field has six subsea water injection wells. Additional resources in the Garn Vest structure came on stream in December 2001, while development of additional resources at the Rogn Sør structure were approved in the spring of 2001, coming on stream in January 2003.

The platform consists of a concrete monocolumn with integrated deck. Oil transport is accomplished through tanker via floating buoy.

Client:

Shell

Duration:

2013 - 2018 + 2 years + 2 years

Hours:

> 30 000 related to habitat work

Personel:

One - two team present onboard

Productivity:

In accordance with plan

HSE:

No accidents or incidents

Scope:

New pipeline, structural work and extension of living quarters

Scope

Draugen is undergoing major modifications while still being in production. A new pipeline has been installed, structural changes have been made and an entirely new living quarters installed.

Shell has stressed the importance of production being uninterrupted during the modifications, which has led to more than 245 welds being performed while in full production. Due to the amount of work being done simultaneously, the need for thorough planning and flawless execution has been, and remains, crucial.

Solution

More than 84 habitats of numerous sizes and shapes have been constructed on Draugen, facilitating 245 welds. For the pipeline phase, one our field engineers and project managers has planned and built 49 habitats, facilitating 172 welds, while phase two has seen more than 35 habitats, with 73 welds performed. Our focus during the planning and execution of these habitats has been to have little or no delay between the different welds and welding points.

For the structural work and installation of the new living quarters we were challenged by the contractor, Aibel, and the operator, Shell: Can StS somehow include all the welding points for the tie-in for the new living quarters in one habitat, ensuring maximum efficiency for the hot work and minimal or no delay.

We solved this by constructing a 600 m3 habitat, covering the length of the new living quarters. To ensure that the habitat remained pressurised during operations we connected three of our market leading, high-capacity fans in series against one habitat system. This habitat was in continuous operation for more than three weeks, with all welds conducted ahead of schedule and with no delay between welding points, due to eliminating the need for several smaller habitats being constructed.

Result

Hot work has been performed on Draugen continuously during the length of the contract, and still is being performed.

The feedback from Aibel and Shell has been positive, especially highlighting the quality and flexibility of the technical solutions, the planning of the jobs conducted by our project managers and finally the technical competence and proactive mindset of our field technicians.

All these factors have resulted in all the hot work being performed on time and without interruptions or incidents, which without our planning, equipment and execution, would not have been possible.

Main office

Norway

Telephone: +47 55 20 80 00
Email: habitat@stsgruppen.com

UK office

United Kingdom 

Telephone: +44 (0)1642 241014

No shutdown, no stress.

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