Well Test Update

Tullow Oil PLC
06 November 2006

News release


Tullow Oil plc - Kingfisher-1 Exploration Well Test Update


6 November 2006 - Heritage Oil, the operator of the Kingfisher-1 exploration
well in Uganda, in which Tullow Oil plc (Tullow) is a 50% partner, today issued
the following press release.



      Heritage Oil's Kingfisher-1 well in Uganda test produces 4,120 BOPD



Heritage Oil Corporation (TSX: HOC) today announced that the upper zone of the
Kingfisher-1 well in Block 3A, Uganda was tested (DST#2) at a stabilized flow
rate of c. 4,120 barrels of oil per day (bopd) through a fixed one inch choke at
a flowing well head pressure of 221 psia. The oil was light (c. 30degrees API)
and sweet with a low gas-oil ratio and some associated wax. The test rate was
constrained by the available completion and test facilities, and the flow data
indicated that when equipped for production, the well should be capable of
flowing at stable rates of approximately 5,600 bopd. The flow data from the test
indicated an extremely high permeability of over 2,000 milliDarcies, which
partly explains why the test was constrained.



Two firm production tests, DST#1 and DST#2 were undertaken. DST#1 did not flow
hydrocarbons to surface. DST#2 tested two zones totalling 10 metres over the
interval from 1,783 to 1,795 metres which flowed at a stable rate of c. 4,120
bopd. Following interpretation of the data from these two tests a decision was
taken not to proceed with any further testing. The tests represented a secondary
exploration objective for the well, which will now be sidetracked and drilling
will continue to the deeper primary objectives. It could take a further 45 to 60
days to reach target depth of between 3,000 and 4,000 metres. The test equipment
will remain on location to test the primary target.



The Kingfisher prospect is a very large structural high that is expressed at
surface on the bed of Lake Albert. Seismic data indicate the Kingfisher prospect
has an areal extent of up to c. 70 square kilometres, although the Kingfisher-1
well will only investigate a limited part of such a large structure.



Tony Buckingham, Heritage's CEO stated 'The Albert Basin now looks increasingly
like it has the elements to make it a world-class petroleum basin. The flow
rates, even constrained by available completion and test facilities, far
exceeded our expectations. We are delighted with the test results that have been
produced from an upper zone which is not the primary target of the well. This
discovery proves there is a working hydrocarbon system in Block 3A significantly
reducing the exploration risk of the other high impact prospects that have been
identified throughout our licenses in the Albert Basin. We look forward to
accelerating the work programs in the basin.'



Heritage is the Operator of Blocks 3A and 1 in Uganda with a 50% equity in the
license, with Tullow Oil holding the remaining 50% interests.



For further information contact:

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




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            The company news service from the London Stock Exchange