Mputa-4 Extended Well Test Completed

LONDON, Dec. 20 /PRNewswire/ — Tullow Oil plc (Tullow) announces that Mputa-4 well test operations have been completed and the data taken from the well will now be integrated with the Kaiso-Tonya appraisal program well data and the recently acquired 3D seismic.

Mputa-4 was production tested from a 5m interval at 944m for an extended flow period of three days from November 21 to 24, 2007. The well tested at rates of 950 to 1,100 bbls/day on a small 1/2″ choke and the oil produced was a 31 degree API waxy sweet crude, consistent with that encountered elsewhere in the Kaiso-Tonya Area. The well was then shut-in for an extended 16-day pressure build-up period with downhole reservoir pressure gauges installed.

The objective of the test was to enhance the understanding of the lateral connectivity and geometry of the sandstone reservoir by analyzing production and pressure trends. The pressure data indicated some depletion over the test period and this data will now be integrated into the subsurface evaluation along with an updated 3D seismic geological model to refine reserve estimates and development planning assumptions ahead of the anticipated sanction of the Early Production System in late Q1 2008.

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 100 Index. The Group has interests in over 110 exploration and production licenses across 22 countries and focuses on four core areas: Europe, Africa, South Asia and South America.

Tullow’s European 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 70% of its production.

In Africa, Tullow has exploration and production in Gabon, Cote d’Ivoire, Congo (Brazzaville), Mauritania and Equatorial Guinea and a gas field development in Namibia. Tullow also has exploration programs in Mauritania, Senegal, Uganda, Congo (DRC), Tanzania, Madagascar, Angola and Ghana.

In South Asia, Tullow has exploration and production in Pakistan and Bangladesh and high impact exploration activities in India.

In South America, Tullow has high impact exploration interests in Trinidad and Tobago, French Guiana and Suriname.

   For further information please refer to our website at http://www.tullowoil.com/.    Contact:  Tom Hickey             Chris Perry             Tullow Oil plc             + 44-20-8996-1000             or             Brian J. Rafferty             Taylor Rafferty             212-889-4350  

Tullow Oil plc

CONTACT: Tom Hickey or Chris Perry, both of Tullow Oil plc,+44-20-8996-1000; Brian J. Rafferty of Taylor Rafferty, +1-212-889-4350

Web site: http://www.tullowoil.com/