Tullow Oil said attempts to find more gas at its Mbawa-1 exploration well in Kenya had met with failure.The FTSE 100 explorer previously announced drilling at the offshore well had encountered 52 metres of net gas pay in the primary target. However, an attempt to find deeper pockets of hydrocarbons had come to nothing after drilling reached a total depth of 3151 metres.The company said operator Apache was running wireline logs - making records of the geological formations encountered during drilling - after which the well would be plugged and abandoned."Although the deeper targets at this location were unsuccessful these results will be vital in evaluating the still significant prospectivity of this block," said Tullow's Exploration Director, Angus McCoss.The firm's shares were trading down around 1% following the announcement.