UK-listed Tullow Oil and Canadian partner Africa Oil have reported a positive update on drilling at their joint-owned Blocks 10BB and 13T in northern Kenya.After initial drilling at the Twiga-2 well encountered 18 metres of net oil pay at "limited reservoir quality", operator Tullow decided to sidetrack the well to explore north of Twiga-1 and found 62 metres of vertical net oil pay similar in quality to the initial Twiga-1 discovery.Tullow's Exploration Director Angus McCoss said he was "pleased" with the Twiga-2 sidetrack and labelled the oil-bearing sandstone reservoirs found there as "material". "The combined results from Twiga-2 and its successful sidetrack confirm the resource potential and have given us valuable insights for the locations of future exploration and development wells," he said.Elsewhere, the Ekunyuk-1 well found some five metres of net oil pay and "encountered the best developed reservoir sands so far on the east flank", McCoss added.He said that the reservoir quality was of an equal thickness of a basin-wide rich oil shale which "gives us new options to study the basin's substantial unconventional oil potential".BC