Royal Dutch Shell's gas discovery at Norway's Ormen Lange field has attracted uncertainty about the field's overall potential from the Norwegian Petroleum Directorate.
In a statement released today the directorate said: "It is uncertain whether the original upside potential can be realised.
"The result of this appraisal well will be incorporated into a major interpretation task aimed at providing a better resource estimate for the Ormen Lange field."
Shell is the operator of production licence 209, with a 15% interest. Norway's StatoilHydro holds a 40% interest, state-owned Petoro has 35% and ExxonMobil 10%.