Mputa-3 appraisal

Tullow Oil PLC
23 August 2007



Successful test of Mputa-3 appraisal well, Uganda


23 August 2007 - Tullow Oil plc (Tullow) announces the successful drilling and
testing of the Mputa-3 appraisal well in Uganda's Block 2 which the Group
operates with a 100% interest. The well was drilled to a total depth of 973m and
encountered hydrocarbons in three separate zones. One zone was tested and
produced at an average rate of 1,986 barrels of oil per day. Pressure and
sampling data from the other two zones indicates that all three zones could flow
at a combined rate in excess of 4,000 barrels of oil per day.



Mputa-3, the second of three wells in the Kaiso-Tonya area appraisal programme,
was drilled 1.5km southeast of the 2006 discovery well. The primary objectives
of the well were firstly to confirm the presence of oil at this location to
underpin the reserves and field development plan and secondly to confirm the
lateral extent and quality of the reservoir sands to verify the geological
model.



The well intersected three oil bearing zones with total net pay of 19.5m, the
best result to date in the Kaiso-Tonya area. The first two zones, 4.5m and 5.0m,
were encountered at 803m and 837m respectively. These zones were not production
tested but pressure testing and sampling indicated moveable oil with very good
permeabilities. The third zone, a 10m sandstone at 867m, was production tested
for two days at an average rate of 1,986 barrels of 33(o) API oil per day
through a 3/4 inch choke. Pressure data acquired during the test confirmed that
the sands are extensive with a permeability in excess of 1 Darcy.



The well is now being suspended as a future producer. On completion the rig will
move to the Mputa-4 location, 1.2km north-east. Mputa-3 is an important
component of the overall appraisal programme and has provided key information
for understanding ultimate reserve potential and for development planning. Data
from this well will be integrated with the results from the upcoming Mputa-4
well and the 3D seismic which is to be acquired by year-end.



Commenting today, Aidan Heavey, Chief Executive of Tullow said:

'We are very pleased to have continued our sequence of successful drilling in
Uganda having encountered producible hydrocarbons in all seven of the wells
drilled to date. The Mputa-3 well has exceeded our pre-drill expectations in
terms of sand development and production performance and has also provided
important regional geological information. The appraisal programme is
progressing well and remains on schedule to sanction the Early Production System
in the fourth quarter this year.'

For further information contact:

Tullow Oil plc           Citigate Dewe Rogerson          Murray Consultants
([phone])       ([phone])              ([phone])
Tom Hickey               Martin Jackson                  Joe Murray
Angus McCoss             Kate Delahunty

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 over 120
exploration and production licences across 23 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 large gas field
development and appraisal programme in Namibia. Tullow also has exploration
programmes in Mauritania, Senegal, Cameroon, 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, Suriname and the Falkland Islands.

For further information please refer to our website at www.tullowoil.com

                                      ENDS


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