Nairobi – British explorer Tullow Oil has struck more oil in two Turkana wells, a discovery it said has raised the potential of the area to one billion barrel of oil. Tullow said it has discovered oil at Amosing-1 and Ewoi-1 onshore Kenya and increased discovered resources for the basin to over 600 million barrels of oil.Tullow added its exploration programme added over 200 million barrel of oil equivalent to its contingent resources in 2013 through important wells in Kenya and Norway. The company said it incurred an exploration expenditure of $1b.