The primary exploration target for wells 25/2-24 S and A was to prove and delineate remaining petroleum deposits in the Frigg Formation in the Øst Frigg Beta structure, which produced gas from 1988 to 1997. Oil was proven in exploration wells 25/2-9 and 25/2-2 which were drilled in the 1970s, but oil was never produced from the field.
The primary exploration target for well 25/2-24 C was to prove and delineate petroleum deposits in the Frigg Formation in the Øst Frigg Alfa structure, north of the Beta structure.
The primary exploration target for well 25/2-24 B was to prove petroleum deposits in the Frigg Formation in the Epsilon prospect, east of the Beta structure.
The secondary exploration target for well 25/2-24 B was to delineate the Frigg Gamma discovery (25/2-10 S) in the Frigg Formation, which is part of the Yggdrasil development.
25/2-24 S – Øst Frigg Beta
Well 25/2-24 S encountered a 12.5 metre oil column in the Frigg Formation, in a sandstone reservoir totalling 117 metres with very good to extremely good reservoir quality. The oil/water contact was encountered 1949 metres below sea level. The well was not formation-tested, but data acquisition and sampling have been carried out.
The well was drilled to a vertical depth of 2029 metres below sea level and was terminated in Eocene sandstone layers in the Frigg Formation.
25/2-24 A – Øst Frigg Beta
Appraisal well 25/2-24 A was drilled horizontally along the Beta structure. The well proved a continuous oil column up to 20 metres thick, with indication of an oil/water contact at 1945 metres below sea level, and was drilled to a measured depth of 5156 metres.
25/2-24 C – Øst Frigg Alfa
Appraisal well 25/2-24 C proved oil in the Alfa structure. The well was drilled to a measured depth of 4078 metres, but did not reach the planned depth. The oil/water contact is estimated at 1949 metres below sea level.
25/2-24 B – Epsilon
Appraisal well 25/2-24 B encountered a continuous oil column about 14 metres thick with up to 30 metres of overlying gas cap in the Epsilon structure. Here too, the Frigg Formation exhibited very good to extremely good reservoir properties. The gas/oil contact was encountered 1935 metres below sea level and the oil/water contact was encountered at 1949 metres below sea level.
25/2-24 B also encountered oil and gas in the western part of the Frigg Gamma structure, which is already included in the Yggdrasil PDO. The well encountered the previously proven gas/oil and oil/water contacts. The well was terminated in the Frigg Formation at a vertical depth of 1925 metres below sea level and measured depth of 8168 metres, more than 6000 metres horizontally in the Frigg Formation.
Preliminary estimates place the total volume of the Epsilon and Øst Frigg structures between 8.5 and 14.3 million standard cubic metres of recoverable oil equivalent. The licensees will assess the deposits as part of the development of the Yggdrasil area.
The horizontal sidetracks 25/2-24 A, B and C were not formation-tested, but data acquisition has been carried out.
These are the third, fourth, fifth and sixth exploration wells in production licence 873, awarded in APA 2016.
Water depth at the site is 110 metres. The wells are now permanently plugged and abandoned.
The wells were drilled by the Scarabeo 8 drilling facility, which will now proceed to drill wildcat well 6405/7-2 S in production licence 1005, where Aker BP ASA is the operator.
Source:https://www.energy-pedia.com/