Tullow Oil reported a 15 per cent jump in first half revenue to 1.3bn dollars on the back of an increase in production.Production for the six months to the end of June climbed 14% to 88,600 barrels of oil equivalent per day (boepd), driven by exploration and appraisal success in Kenya.The group achieved a 16% increase in sales volumes primarily relating to the Jubilee field in Ghana.Pre-tax profit, however, plunged 41% to $486m primarily due to last year's $701m gain on the Uganda farm-down. The company also blamed a $67m hike in operating costs and lower overall exploration write-downs, about $275m down from the previous year.During the period, the firm drilled 13 exploration wells and 14 appraisal wells with a 63% overall success ratio. Six campaigns including 20 exploration wells are planned for the second half, targeting multiple basins in Kenya, Ethiopia, Mozambique, Mauritania and Tullow's first operated well in Norway.Tullow has revised its full year average production forecast to 84-88,000 boepd.Aidan Heavey, Chief Executive, said: "Our exploration-led growth strategy delivered major successes in Kenya and Ethiopia, further enhancing East Africa as a new oil region. "Our business has a very firm financial foundation with strong production and revenue growth and significant annual operating cash flow. I am very confident we are well placed for future growth and value creation."The interim dividend remained unchanged at 4.0p per share. RD