Tullow Oil said it has struck oil at its 20%-owned Hanssen wildcat well offshore Norway, which it estimates carries up to 50m barrels of recoverable oil.Hanssen, located in production licence 537 near the Wisting Central oil discovery, encountered a 20-25 metre oil bearing sandstone with good reservoir properties in the main target.The discovery was tested and showed a maximum production rate of 2,006 barrels of oil and 325,000 standard cubic feet of gas per day."Tullow anticipates that production rates from future development wells would be significantly higher," the company said, adding that preliminary estimates confirmed the potential of the Wisting cluster after an initial discovery in September.Tullow has a 20% interest in the licence 537, while operator OMV (Norge) has a 25% stake. Partners Idemitsu and Petoro both own 20% each while Statoil has a holding of 15%."This success is an important follow-up to our Wisting Central oil discovery in September last year which opened up the Hoop area," said Tullow's Exploration Director Angus McCoss."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."Tullow shares rose 0.5% to 853.5p in early trading.BC