Evolution Securities says that Tullow Oil's recent success in Ghana bodes well for the Irish oil company, and could result in upside forecast changes to reserve estimates.Tullow reported Monday that it found oil at the Teak-2 exploration well in the West Cape Three Points licence offshore Ghana."The Teak-2 exploration success today may only add around 5p to our core plus risked upside but its success, indicating a contiguous system between Jubilee [oil field 60km off Ghanaian coast] and Teak, could see upward revisions of the proven and probable estimates for Jubilee and Teak," said analyst Richard Griffith.The broker leaves its target price of 1,520p unchanged until Tullow's reservoir engineers have reworked their models and give revised estimates. A 'buy' rating is confirmed.BC