Uganda Drilling Update

Tullow Oil PLC 30 May 2006 News release Tullow Oil Plc - Uganda Activity Update 30 May 2006 - The following announcement has been released by Hardman Resources today: Uganda: Block 2 - Mputa-2 Appraisal Well As of midnight on Saturday 27 May, Mputa-2 has been cased and suspended as a potential future oil producer. This follows the completion of extended wireline logging activities after some equipment malfunctions. The results of Mputa-2 confirm that the upper reservoir sands intersected in Mputa-1 and Waraga-1 are laterally extensive, but at this location are water wet. Pressure data indicates that the hydrocarbon column height in the upper zone of the Mputa field is potentially of the order of 100 metres, although at this upper level, the Mputa and Waraga structures do not have a common oil leg. The implications of this pressure data and the fact that the target sands came in over 100 metres shallow to prognosis are both positive to the interpretation of the Mputa Field; the new data is being integrated with existing models in order to provide estimates of oil in place for these upper sands shortly. The extent to which these sands will flow commercial volumes of oil will be determined when flow testing operations begin on Waraga-1, expected to commence mid June. Oil samples have been recovered from the lower reservoir zone in Mputa-2, which can be correlated to similar oil bearing zones in both Mputa-1 and Waraga-1. The presence of oil saturated sands in these basal units in all wells drilled to date implies an extensive stratigraphic trapping mechanism at this level. The gross interval of these units is variable and there does not appear to be pressure communication between them. But contained within the sequence are obvious oil bearing zones of around 5 metres thickness that will be flowed in our testing programme at Waraga-1 to determine whether they are capable of sustaining commercial flow rates. The information derived will then determine which of either Mputa-1, or Mputa-2, or both, will be subsequently tested. Assessing where the thicker sand units and more extensive net pay exists in these sequences will be key to their commercial potential and the need for 3D seismic acquisition is currently being evaluated. The results from the three discovery wells and the testing programme will be integrated to define the reserve estimates, commerciality and potential development scenarios for the onshore area. Planning for additional exploration/ appraisal wells onshore and a test of a prospect just offshore has commenced with onshore drilling scheduled for 4Q 2006. Plans for the acquisition of further 2D seismic in the north of the block are also well advanced. For further information contact: Tullow Oil plc Citigate Dewe Rogerson Murray Consultants (+44 20 7333 6800) (+44 207 638 9571) (+353 1 498 0300) Aidan Heavey Martin Jackson Joe Murray Tom Hickey Notes to Editors Tullow is a leading independent oil & gas, exploration and production group, quoted on the London and Irish Stock Exchanges (symbol: TLW) and is a constituent of the FTSE 250 Index. The Group has interests in approximately 90 exploration and production licences in 15 countries and focuses on three core areas: NW Europe, Africa and South Asia. Tullow's NW Europe interests are primarily focused on gas in the UK Southern North Sea where it has significant interests in the Caister-Murdoch System and the Thames/Hewett areas and operates over 60% of its production. In Africa, Tullow has production and exploration in Gabon, Cote d'Ivoire, Congo (Brazzaville) and Equatorial Guinea and a large gas field development and appraisal programme in Namibia. Tullow also has exploration programmes in Mauritania, Senegal, Cameroon, Uganda, Madagascar and Angola. In South Asia, Tullow has production and exploration interests in Pakistan and Bangladesh and high impact exploration activities in India. In addition to onshore Block 9, Tullow also operates Blocks 17/18 offshore Bangladesh where a 2d seismic survey recently completed. Tullow has applied for an extension to this licence, to permit a sizable work programme to be carried out, and has requested that part of Tullow's interest is assigned to Total. Both are currently awaiting Government approval. For further information please refer to our website at www.tullowoil.com ENDS This information is provided by RNS The company news service from the London Stock Exchange

Companies

Tullow Oil (TLW)
UK 100

Latest directors dealings