Yttergryta: From Find to Field in No Time

Less than one year has passed since hydrocarbons were proven during exploration drilling in the Yttergryta prospect. Now the plan for development and operation (PDO) has been approved by the authorities.

"We are proud to have obtained approval of Yttergryta in such a short time," says Hege Marie Norheim, head of reserve replacement and business development in the Exploration & Production Norway business area.

"Yttergryta is a good example of how to apply subsurface knowledge, known technology and existing infrastructure in order to maximise the potential on the Norwegian continental shelf," says Ms. Norheim.

Early start of development

"This was a very fast process," says project manager Helge W. Albertsen.

Already before the exploration well was drilled, the first part of the subsea production facility was installed on the seabed. The reason is the high discovery potential of the Yttergryta prospect and it was therefore important to start production as soon as possible. The gas from the field contains very little carbon dioxide and will help maintain the production flow to the Aasgard B platform.

Standard solution

Both pressure and temperature are about the same throughout the whole area, and the technology used is a familiar standard solution. Development could therefore start before the discovery was confirmed.

"If no discovery had been made in Yttergryta, the equipment could have been used for a different project in the same area," explains Mr. Albertsen.

Used as mixing gas

Yttergryta is being developed with a simple subsea production facility on the seabed and a pipeline tied back to the Asgard B platform.

Start-up is scheduled for the second quarter of 2009, and the production period will be three to five years. Daily production capacity will be 3.5 million standard cubic meters (Sm3), but will be regulated by the demand on Asgard B. The gas from Yttergryta will be used as a mixing gas for the gas from Smørbukk, which has higher carbon dioxide content.

Development costs will total around NOK 1.2 billion, including drilling expenses.


  • Gas field located around 33 kilometers east of Åsgard B in the Norwegian Sea
  • Developed with a subsea template and one production well of about 2,400 meters
  • The exploration well on Yttergryta was drilled in June 2007. The plan for development and operation (PDO) was submitted to the authorities on 18 January 2008 and has now been approved
  • Recoverable reserves are 1.75 billion Sm3 of gas with very low carbon dioxide content, some condensate in addition
  • Licensees: StatoilHydro (operator) 45.75 percent, ENI 9.80 percent, Total 24.50 percent, Petoro 19.95 percent