Tullow Oil plc (“Tullow”) announces that the Hanssen wildcat well, in production licence 537, offshore Norway, has encountered a 20-25 metre oil bearing sandstone with good reservoir properties in the main target (Stø Formation). The Hanssen well was drilled about 7 kilometres northwest of the Wisting Central oil discovery and about 315 kilometres north of Hammerfest.

The well also encountered hydrocarbon bearing sandstones in the Late Triassic (Snadd Formation) and in the Middle Triassic (Snadd Formation) but in poor reservoirs. Extensive coring and sampling have been carried out in all hydrocarbon bearing formations.

This discovery was tested and produced a maximum production rate of 2,006 bbls/d of oil and 325,000 scf/d of gas from a short test interval in a vertical well. Tullow anticipates that production rates from future development wells would be significantly higher. Preliminary volume estimates of up to 50 million barrels of recoverable oil from this discovery confirm the potential of the Wisting cluster.

The 7324/7-2 well was drilled to a vertical depth of 1,679 metres by the Transocean Barents rig in a water depth of 417.5 metres. This successful oil well will now be plugged and abandoned.

The Hanssen discovery is located in production licence PL537 in which Tullow has a 20% interest. OMV (Norge) are the operator with a 25% interest while Idemitsu (20%), Statoil (15%) and Petoro (20%) are also partners.

Angus McCoss, Exploration Director, Tullow Oil plc commented today,

“This success is an important follow-up to our Wisting Central oil discovery in September last year which opened up the Hoop area. The Hanssen discovery gives us significant insight into the potential of the Wisting cluster and further confidence that we are on track towards proving up a major new commercial oil resource. We and our partners are preparing to drill the Hassel and Bjaaland wells in the eastern part of the Wisting cluster next year.”

About Tullow Oil plc

Tullow is a leading independent oil & gas, exploration and production group, quoted on the London, Irish and Ghanaian stock exchanges (symbol: TLW) and is a constituent of the FTSE 100 Index. The Group has interests in over 150 exploration and production licences across 25 countries which are managed as three regional business units: West & North Africa, South & East Africa and Europe, South America and Asia.