The enclosed extract is part of an Exploration Drilling Update issued this morning by Premier Oil plc (50%; operator) with regard to the Bonneville exploration well in the Catcher licence in the UK North Sea, in which Cairn has a 30% interest (Wintershall, 20%).
“Oil discovery at Bonneville, UK
Premier is pleased to announce that both the Bonneville exploration well (28/9a-6) and its side track (28/9a-6z) have discovered oil. The Bonneville prospect is located four kilometres south of the Burgman discovery on the Catcher licence in the UK Central North Sea.
The Bonneville well was drilled to a total depth of 4,481 feet true vertical depth subsea (TVDSS). The well encountered a gross oil column of 66 vertical feet in the Tay interval with an estimated net oil pay of 26 feet. The Bonneville well was subsequently sidetracked to the Bonneville East prospect. The sidetrack was drilled to a total depth of 4,441 feet TVDSS and encountered 34 feet of net oil pay in an overall gross oil column of 175 vertical feet in the Tay interval.
The Bonneville discoveries are in excellent quality reservoirs with average porosities of approximately 30 per cent. Initial sampling indicates that the API of the oils in Bonneville is of similar quality to that established at the nearby Burgman discovery which was 25 degrees API.
The estimated oil in place from the Bonneville discoveries is approximately 30 million barrels which is in line with pre-drill predictions. It is anticipated that the discoveries will be tied back to the Catcher field development.
The WilPhoenix rig will now move to the West of Shetland to start development drilling at the Premier-operated Solan project.”