Premier Oil has announced success on an exploration well and side track on its North Sea Bonneville prospect.
Bonneville, 4km south of the Burgman discovery in the Catcher area licence in the central North Sea, found oil on well 28/9a-6 and its side track, 28/9a-6z).
The firm said the discoveries are in excellent quality reservoirs with average porosities of approximately 30% with oil in place estimated at 30million barrels. It is anticipated that the discoveries will be tied back to the Catcher field development.
The WilPhoenix rig, which drilled the well, will now move to the West of Shetland to start development drilling at the Premier-operated Solan project.
The success follows a find at Luno II offshore Norway and comes as Premier Oil also announced a gas discovery at Matang in Indonesia.
Simon Lockett, chief executive officer, said: "We are delighted with the strong start to our 2013 exploration drilling programme with the previously announced discovery at Luno II and now the discoveries at Bonneville and Matang. We look forward to the outcome of the test programmes at Luno II and Matang while the Bonneville discoveries will be tied back to our important Catcher area development, which is targeted for project sanction by year-end."
Bonneville 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 26ft, said Premier. It was then sidetracked to the Bonneville East prospect. This was drilled to a total depth of 4,441ft TVDSS and encountered 34ft of net oil pay in an overall gross oil column of 175 vertical feet in the Tay interval. 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 Matang-1 exploration well on Block A Aceh (Premier 41.67% equity) in Indonesia discovered gas and is to be tested. The Matang-1 well, which was drilled to a depth of 7,893 feet true vertical depth, penetrated a gross gas column in the Upper Bampo Limestone formation (the primary reservoir target) of at least 90 feet. The base of the gas column has not been encountered. While drilling the primary reservoir target, losses into the formation and gas influx into the well occurred. As a result, the decision was taken to suspend the well and to test the reservoir interval drilled to date to obtain flow rate and gas quality information. Premier will provide further information in May once the results of the test are known.
Testing of the Luno II discovery (Premier 30% equity) in Norway has started and results are expected before the end of the month, said Premier.