Tyra South East A - Design of unmanned wellhead platform for gas condensate field

Unmanned wellhead platform, Tyra South East A

Unmanned wellhead platform, Tyra South East A


Asmus Dalsgaard Nielsen Ramboll Oil & Gas

Asmus Dalsgaard Nielsen

B.Sc., mechanical eng., Director, Engineering Methods
T: +45 51617350
As part of the Tyra field development in the Danish North Sea, operator, Maersk Oil, contracted Ramboll to assist with a number of engineering services for the design of the Tyra South East A platform. Tyra South East A came on stream in 2002.

From conceptualization to design

Tyra South East A is a minimum-facility wellhead platform tied-back to the Tyra East host platform. In the design phase, Ramboll carried out:
  • Tie-in studies
  • Detailed engineering for the monotower substructure
  • QRA (Quantitative Risk Assessment)

A minimum-facility platform

The platform design was based Maersk Oil’s STAR platform concept accommodating up to seven wells. The concept for the platform was normally unmanned; – and only manned during daylight and favorable weather conditions allowing safe access by boat. The primary escape was via FRB (fast rescue boat) to the nearby standby boat. The minimum-facility platform concept implied that there were no personnel facilities other than a shelter for bad weather.  

Production exported to host platform

The well stream at Tyra South East A is separated in a two phase separator and the liquid is exported at low pressure outside the hydrate formation region, while gas is exported at high pressure and inhibited with hydrate inhibitor. The production is exported to the Tyra East host platform where it is tied-in to the existing gas treatment and condensate stabilization facilities.

The monotower substructure

Ramboll's scope of work comprised the detailed design of the monotower substructure sitting in 43.6 m water depth. In connection with the monotower design, Ramboll carried out all required structural analyses such as:
  • In-place
  • Dynamic
  • Fatigue
  • Boat impact
  • Lifting and transportation


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PO Box 116921, Dubai, UAE
Tel:+971 4 334 3616
Fax:+971 4 334 3617

Mail: info@ramboll.ae

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