Well Test Update

Tullow Oil PLC 16 November 2006 News release Tullow Oil plc - Nzizi-1 Exploration Well and Chinguetti Reserves Update 16 November 2006 -Hardman Resources, the operator of the Nzizi-1 exploration well in Uganda, in which Tullow Oil plc (Tullow) is a 50% partner, today issued the following press release. Hardman also commented on an investor presentation given by Woodside, the operator of the Chinguetti field in Mauritania in which Hardman has a 19.008% stake. Exploration Area 2: Nzizi-1 Since the last report on the Nzizi-1 well, logging operations have been completed and pressure measurements taken. Good oil shows were encountered during drilling over a gross interval of approximately 180 metres, directly above basement, in a similar section to that encountered by the Mputa-1 well, 6 kilometres northeast of Nzizi-1. Wireline logs and pressure measurements indicate an interbedded sequence of oil bearing sands and shales. No fluid samples or testing operations were planned for this well as it was drilled in a slimhole configuration and consequently it will now be plugged and abandoned. The well result suggests there is scope to significantly increase the recoverable volume reported so far for the Mputa/Waraga area, of around 30 million barrels, and hence further enhance the potential resource base in the Albertine Basin. Studies are underway to establish a range of development options for the existing discoveries, which allied to additional seismic currently being acquired and future appraisal drilling, will determine ultimate commerciality. Commenting on the Nzizi-1 result, Mr. Simon Potter, Hardman MD and CEO, said: 'The fourth discovery in four wells drilled by Hardman in Exploration Area 2 proves that the working oil system extends over a significantly greater area, adding to the resource base established so far this year, and providing encouragement for future exploration of the basin.' Equities in Block 2 are: Exploration Area 2 Hardman Petroleum Africa Pty Ltd (Operator) 50.0% Tullow Oil plc 50.0% OPERATOR UPDATE ON CHINGUETTI RESERVES (MAURITANIA) Hardman notes that the Chinguetti field operator, Woodside, has today provided in a presentation to investors an update on the Chinguetti field (Hardman 19.008%), including an interim update of Chinguetti field reserves. The operator's estimate of proven and probable reserves for the Chinguetti field of 53 mmbbls is consistent with the estimate provided by the Independent Technical Expert for the purposes of the Scheme of Arrangement for the acquisition of Hardman by Tullow Oil plc and included within Hardman's Explanatory Memorandum to shareholders dated 14 November 2006. Hardman will provide additional information on the results of the operator's reserves review for Chinguetti when that review is made available to the joint venture. For further information contact: Tullow Oil plc Citigate Dewe Rogerson Murray Consultants (+44 20 8996 1000) (+44 20 7638 9571) (+353 1 498 0300) Tom Hickey Martin Jackson Joe Murray Chris Perry 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 across 17 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 exploration and production 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, Congo (DRC), Madagascar, Angola and Ghana. In South Asia, Tullow has exploration and production in Pakistan and Bangladesh and high impact exploration activities in India. 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

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