Well Test Results

RNS Number : 5984C

Tullow Oil PLC

03 September 2008

News Release

Tullow Oil plc

Uganda Block 3A: Positive Kingfisher-2 well test results

3 September 2008 - Heritage Oil, the operator of the Kingfisher-2 exploratory appraisal well in Block 3A, Uganda, in which Tullow Oil plc (Tullow) is a 50%partner, today issued the following press release.

Kingfisher-2, Block 3A, Uganda, Test Results

Three reservoirs with a cumulative vertical net pay of approximately 37 metres between 2,654 metres and 2,783 metres measured depth produced at a cumulative flow rate of 14,364 bopd on test as follows:

Drill Stem Test	Gross Measured Depth Interval Thickness	Maximum Flow Rate	Oil Quality	Choke
(DST)	(metres)	(bopd)	(API)	(inches)

1	20.2	5,178	29.7	48/64th
2	26.5	4,798	30.5	64/64th
3	12.0	4,388	32.0	48/64th
	58.7	14,364

The higher rates recorded from all three test intervals were constrained by the surface test equipment. It appears that these three zones are equivalent to the same three intervals tested in the Kingfisher-1 well, which flowed at a combined rate of 9,773 bopd. Pressure data recorded from the DST-1 and DST-2 intervals indicate that the two lowermost sands are possibly in vertical communication and therefore could comprise the same reservoir. This could potentially lead to higher oil volumes.

The oil is good quality, of light to medium gravity and sweet, with a low gas-oil ratio and some associated wax. The reservoirs are highly permeable sandstones, with an estimated permeability from DST-1 of 2,250 milliDarcies.

It is likely that there will be an upgrade to potential oil reserves following drilling of the Kingfisher-2 well. Management of Heritage will look to update their estimated volumes following full evaluation of the test data. Prior to the drilling of Kingfisher-2, the gross contingent resources of Kingfisher were independently evaluated by RPS Energy to have a most likely volume of 118 million barrels.

The Nabors 221 rig will now move approximately three kilometres south of Kingfisher-2, along the Lake Albert shoreline, to drill the Kingfisher-3 appraisal well, which will evaluate the southern portion of this field.

Block 1, Uganda, Drilling Programme

The first drilling programme in Block 1 is scheduled to commence this month, with the drilling of the Warthog prospect. This is part of a three well programme which also includes the Buffalo and Giraffe prospects. Exploration risks in Block 1 have been significantly reduced due to the recent drilling success in Block 2, very close to the Block 1 border. A structural trend, characterised by high amplitude anomalies in the seismic data, can be traced northwards from Tullow Oil Plc's Kasamene-1 discovery, just 2.5 kilometres south of Block 1, through the Warthog, Giraffe and Buffalo prospects in Block 1.

FOR FURTHER INFORMATION CONTACT:

Tullow Oil plc
(+44 20 8996 1000)
Aidan Heavey
Tom Hickey

Chris Perry

Citigate Dewe Rogerson
(+44 207 638 9571)
Martin Jackson

George Cazenove

Murray Consultants
(+353 1 498 0300)
Joe Murray

Ed Micheau

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 100 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. The company also has interests offshore the Netherlands and Portugal.

In Africa, Tullow has exploration and production in Gabon, Côte d'Ivoire, Mauritania and Equatorial Guinea and two large appraisal and development programmes in Ghana and Uganda. Tullow also has exploration interests in Mauritania, Senegal, Congo (DRC), Tanzania, Madagascar, Namibia and Angola.