StatoilHydro’s latest appraisal of its North Sea Dagny discovery on block 15/5 indicates that the field holds reserves in the range 130-170million barrels oil equivalent.
Include the related Ermintrude find and total recoverable reserves are estimated to be 180-240million boe. The sidetrack that boosted Dagny was drilled by the semi-submersible drilling rig, Transocean Winner.
Appraisal of the Dagny structure confirmed that Dagny and Ermintrude, which was located in 2007, have identical pressures and are located in the same structure. A joint development of Ermintrude and Dagny phased into the Sleipner field is being evaluated. Dagny lies some 10km north-west of the Sleipner West field.
“This is a very exciting discovery which confirms that there is still a chance of finding larger volumes of oil in established areas such as Sleipner,” said Tim Dodson, senior VP for StatoilHydro’s exploration activities on the Norwegian Continental Shelf.
“These are positive contributions to reaching our goal of maximising the potential on the NCS.”
Gas was confirmed in the Dagny discovery as early as 1978 and StatoilHydro said that a “creative exploration organisation” presented the idea that there might be an oil column below the gas.
Dodson added: “It is encouraging to see that the organisation’s new ideas in mature areas can lead to such good results.”
Elsewhere on the NCS, StatoilHydro has concluded the drilling of its Haklang-1 exploration well on Norwegian Sea block 6707/10 and has confirmed gas in a reservoir with good production qualities. The company said well 6707/10-2S was drilled in its operated production licence 218, which is located south-east of the Luva gas discovery and 280km west of Sandnessjoen, in mid-Norway.
The Haklang well was drilled using the semi-submersible, Transocean Legend, and proved a 127m gas column. Core drilling in the sandstone was carried out and fluid and pressure samples were taken, resulting in the discovery being estimated in the range 282.5-494.4billion cu ft of recoverable gas.
A joint development of Haklang and the nearby Luva and Snefrid South discoveries is now on the cards. Luva was confirmed by BP in 1997
But the potential of the area is considerably more, according to Oystein Michelsen, who is responsible for StatoilHydro’s activities on the Norwegian Continental Shelf.
Indeed, the Transocean Leader is now drilling sidetrack well 6707/10-2A with the aim of exploring a deeper prospect in the same production licence.
“It is gratifying to hear that gas has been proven also in this well (6707/10-2S),” said Michelsen.
“We took over as operator and increased our interest in the licence to 75% in 2006. This year, we have drilled two exploration wells in the area, Snefrid South and Haklang.
“The total resource potential of these three finds is expected to be 40-60billion cu m (1.41-2.11TCF) of recoverable gas.
“This well is an important step in order to prepare for a new deepwater development in the Norwegian Sea.”
The well is the third exploration well in production licence 218, which was awarded in the 15th Norwegian licensing round in 1996. It was drilled to a depth of 3,356m below sea level and was completed in the Nise formation in Late Cretaceous rock.
StatoilHydro holds a 75% interest in block 6706/10 (production licence 218), while ExxonMobil has 15% and ConocoPhillips 10%.