Drilling & Acquisition Update

Tullow Oil PLC 06 December 2005 News release Tullow Oil plc - Drilling and Acquisition Update 6th December 2005 - Tullow Oil plc (Tullow) announces updates on recent drilling activities and the acquisition of additional equity in the Hewett Field Unit which includes the Bacton Terminal. A full update on the rest of Tullow's activities will be provided in our Trading Statement and Operational Update on 31 January 2006. MAURITANIA - FAUCON-1 EXPLORATION WELL (Tullow 20%) The Faucon-1 exploration well, currently being drilled in Block 1 offshore Mauritania, has encountered hydrocarbon-bearing sandstones within the main Cretaceous target zone. Drilling has been temporarily suspended at 3,536m while a full suite of wireline logs, formation pressures, fluid and core samples are obtained. Thereafter, it is the intention to deepen the well by up to a further 700m in order to fully explore the Cretaceous section. ROMANIA - COSTISA-1Z SUSPENDED (Tullow 42%) The Costisa-1Z exploration well, located in the EPI-3 Brates block in Romania, reached a final total depth of 4,350m on 30 November and is currently being plugged back prior to suspension. The well's primary objective was not encountered and due to poor borehole conditions, a logging programme was not undertaken. Subject to agreement with the partners and government approval, Tullow now intends to transfer the Operatorship and its interest in the licence to Europa Oil & Gas (Holdings) plc. ANGOLA - BLOCK 10 WORK PROGRAMME ONGOING (Tullow 15%) Drilling operations on the Ngueve-1 well in Block 10 offshore Angola are in progress. Once operations are completed, the rig will move onto the Henda-1 prospect in the same block. UGANDA - M'PUTA 1 EXPLORATION WELL TO SPUD IN MID-DECEMBER (Tullow 50%) The rig for the M'Puta prospect in Uganda is currently being mobilised to the drilling location and the well is scheduled to spud in mid-December. It will target a structural prospect with multiple objectives. Oil seeps have been identified in the immediate area and the prospect has been defined by the 2005 onshore seismic survey. The planned total depth for the well is 1,100m. GABON - EQUATA WELL TO SPUD NEXT WEEK (Tullow 47.5%) The exploration well on the Equata prospect in the Kiarsseny licence in Gabon is scheduled to commence next week. The planned total depth for the well is 1,500m and it is expected to take approximately 30 days to drill. UK - TULLOW TO ACQUIRE ADDITIONAL 13% IN HEWETT-BACTON (Tullow 51.68%) Tullow and Eni have exercised rights of pre-emption in relation to the sale to Petrofac of Centrica's 23.15% interest in the Hewett Field Unit area. Tullow will gain an additional 12.87% interest in the Hewett fields and the Bacton terminal on the same terms that were originally agreed with Petrofac. Completion of the transaction is subject to governmental approvals and is expected to occur in early 2006. Commenting today, Aidan Heavey, Chief Executive of Tullow said: 'Today's announcement reinforces the strength and diversity of Tullow's international portfolio and the preliminary results from Mauritania appear very encouraging for both the Faucon prospect and the region. Over the next six months, Tullow will participate in a total of 13 exploration wells across six countries.' If you have any questions on this announcement please contact: Tullow Oil plc Citigate Dewe Rogerson Murray Consultants (+44 20 8996 1000) (+44 207 638 9571) (+353 1 498 0300) Aidan Heavey Martin Jackson Joe Murray Tom Hickey Chris Perry 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 production and exploration licences in 16 countries and focuses on three core areas: NW Europe, West 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. Tullow operates 60% of its production from these areas following the recent start-up of production from its Horne and Wren fields and the acquisition of the Schooner and Ketch assets. In Africa, Tullow has production and exploration in Gabon, Cote d'Ivoire, Congo (Brazzaville) and Equatorial Guinea. Tullow also has exploration programmes in Morocco, Mauritania, Senegal, Cameroon, Uganda and Angola. In South Asia, Tullow has production and exploration interests in Pakistan and exploration activities in India and Bangladesh. 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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