Well update

Tullow Oil PLC
20 December 2007

News release



Mputa-4 Extended Well Test Completed


20 December 2007 - 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 programme 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 21 to 24 November 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 analysing 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.



For further information contact:
Tullow Oil plc                     Citigate Dewe Rogerson              Murray Consultants
([phone])                 ([phone])                  ([phone])
                                   Martin Jackson                      Joe Murray
Tom Hickey
                                   George Cazenove
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 100 Index. The Group has interests in over 110
exploration and production licences 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 programmes 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 www.tullowoil.com

                                      ENDS


                      This information is provided by RNS
            The company news service from the London Stock Exchange    

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