UK Business Update

Tullow Oil PLC
23 May 2006


News release


Tullow Oil plc - UK Business Update


23 May 2006 - Tullow Oil plc (Tullow) announces first production from the
Schooner-10 well in the UK, an update on UK drilling activity and a new
production strategy for Horne and Wren.

A detailed update on Tullow's business will be provided in our Trading Statement
and Operational Update in early July.

FIRST PRODUCTION FROM SCHOONER-10 (Tullow 90.35%)

The Schooner-10 production well, the first of the Schooner-Ketch redevelopment
programme, commenced production through the Tullow-owned CMS infrastructure on
16th May 2006 at a stabilised rate of 22 mmscfd. Further well stimulation is
under review.  At the time of acquisition in March 2005, production rates from
the combined fields were expected to decline to below 28 mmscfd within 12
months.  Tullow's facilities optimisation and well management programmes have
resulted in a sustained production rate of around 50 mmscfd and raised
facilities uptime to over 98%.  The addition of Schooner-10 will increase the
production capability of Schooner and Ketch to approximately 70 mmscfd.

Further production enhancements for the Schooner field are being completed
before the Ensco 101 rig moves to the Ketch field at the end of the month where
it will drill three development wells - two new horizontal wells and a sidetrack
of an existing well. It will then return to Schooner to drill a further
development well.

In addition to the ongoing redevelopment work, the Borgsten Dolphin
semi-submersible rig is scheduled to arrive at the end of May to drill the NW
Schooner Extension appraisal well on the flank of the Schooner field. If
successful, NW Schooner would be developed via a subsea tie-back to the Schooner
platform.

UK DRILLING UPDATE

Cygnus (Tullow 35%)

The Cygnus appraisal well (44/12-2) has been suspended, having encountered
several gas-bearing reservoir zones and following a successful well test of the
principal target, the Rotliegendes Lower Leman reservoir.  The results of the
well test, the well logs and the core analysis are now being evaluated to
determine the commerciality of the discovery. This work is scheduled to be
completed by the end of the year and if deemed to be a commercial project, first
gas is anticipated in 2008.

K4 (Tullow 22.5%)

The K4 exploration well (44/23b-13), targeting a Carboniferous prospect
analogous to that drilled by the K3 (Kelvin) discovery well in 2005, commenced
drilling on 26 April. The K4 well, adjacent to Tullow-owned CMS infrastructure,
is currently at 10,158 ft and is expected to reach the total depth of 13,800 ft
in mid-June.

HORNE AND WREN PRODUCTION STRATEGY (Tullow 50%)

Horne and Wren, Tullow's first UK offshore operated development, commenced
production in July 2005 and has achieved sustained rates in excess of 100 mmscfd
gross. However, with Winter/Summer UK gas price differentials reaching
unprecedented levels, the decision has been taken to shut in the fields during
the summer months of 2006 and 2007 to maximise production over the next two
winter periods. This adds significant value to Tullow and contributes additional
gas to the UK market during periods of peak winter demand.


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

'Today's announcement clearly demonstrates the strength of Tullow's acreage
position in the Southern North Sea. Over the last 12 months we have transformed
the Schooner and Ketch assets, made a total of four exploration discoveries and
completed Tullow's first operated offshore development. Our increasing control
over our operations, allied to the ongoing strength and seasonality of UK Gas
pricing, allows Tullow to optimise returns from assets such as Horne and Wren by
managing production to meet periods of peak demand and pricing.'



For further information contact:
Tullow Oil plc                     Citigate Dewe Rogerson              Murray Consultants
([phone])                 ([phone])                  ([phone])
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
exploration and production licences in 15 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, Madagascar and Angola.

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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