The Norwegian Petroleum Directorate (NPD) reports that Aker BP ASA, operator of production licence 033, has concluded the drilling of appraisal well 2/11-12 S and wildcat well 2/11-12 A
The wells were drilled about 1.5 kilometres west-southwest of the Hod field in the southern part of the North Sea and 350 kilometres southwest of Stavanger.
The Hod field was proven in Upper Cretaceous reservoir rocks (the Hod formation) in 1974 and produced up to 2013. The current licensees are considering whether the field should be redeveloped. Before the appraisal well was drilled, the operator’s resource estimate for the discovery was between 6 and 12 million standard cubic metres (Sm3) of oil.
The primary exploration target for appraisal well 2/11-12 S was to delineate the western part of the Hod field. The secondary exploration target was to examine reservoir rocks (diatomites) in the Miocene in the Hordaland group.
In the primary exploration target in the Hod formation, a limestone interval of about 120 meters with poor reservoir properties was encountered. There were traces of oil in the limestone rocks.
In the secondary exploration target in the Hordaland group, 200 metres of reservoir rocks with poor reservoir properties and traces of oil were encountered. The appraisal well is classified as dry. Preliminary estimates of the size of the Hod field are within the range of uncertainty prior to drilling. A new resource estimate is being prepared.
The primary exploration target for wildcat well 2/11-12 A was to prove petroleum in Upper Jurassic reservoir rocks (the Eldfisk and Ula formations). The secondary exploration target was to prove hydrocarbons in Permian reservoir rocks (the Rotliegendes group) or older rocks.
The well did not encounter reservoir in the primary exploration target. The secondary exploration target was not reached. In the Lower Cretaceous, the well encountered a carbonate-rich rock of about 45 metres in the Tuxen and Åsgard formations with traces of oil, but with poor reservoir properties. The wildcat well is classified as dry.
Extensive data acquisition and sampling have been carried out in the wells.
These are the 10th and 11th exploration wells in production licence 033. The licence was awarded in Round 2-A in 1969.
Wells 2/11-12 S and 2/11-12 A were drilled to respective measured depths of 2,956 metres and 3,427 metres, and to respective vertical depths of 2,884 metres and 3,189 metres below the sea surface. Well 2/11-12 S was terminated in the Hidra formation in the Shetland group in the Upper Cretaceous, and well 2/11-12 A was terminated in the Zechstein group in the Permian.
Water depth at the site is 70.5 metres. The wells have now been permanently plugged and abandoned.
The wells were drilled by the Maersk Interceptor drilling rig, which will now drill two development wells on the Ivar Aasen field in the central part of the North Sea, where Aker BP ASA is the operator.