TRADING STATEMENT AND OPERATIONAL UPDATE - BY TULLOW OIL

* Record first half revenues; strong operational performance

* 79% E&A success ratio; frontier wells in new territories to feature in the second half

5 July 2011 - Tullow Oil plc (Tullow) issues this Trading Statement and Operational Update in respect of the first half of the 2011 financial year ended 30 June 2011. This is in advance of the Group's Half-Yearly Results, which are scheduled for release on Wednesday 24 August 2011. The information contained herein has not been audited and is subject to further review.

To view the full release please visit the Tullow website: www.tullowoil.com

HIGHLIGHTS

Production and Development activities
* Jubilee field has produced over 10 million barrels gross; production currently around 80,000 bopd with ramp up to 120,000 bopd expected to be reached in August.
* Tweneboa and Enyenra development progressing towards Government approval in first half of 2012; successful appraisal programme continues with Tweneboa-2 oil zone tested at 6,500 bopd.
* In Uganda, MoU signed with the Government; Sale and Purchase Agreements signed for the farm down to CNOOC and Total for $2.9 billion; completion conditions currently being finalised.
* Working interest production averaged 75,350 boepd in 1H 2011; 2011 full year production guidance now 90,000 to 94,000 boepd.

Exploration and Appraisal activities
* 79% exploration and appraisal success ratio year-to-date in 2011; 15 successful wells out of 19.
* West Cape Three Points drill-out continues with successes at Teak-1 and Teak-2.
* Seven successful E&A wells in Uganda year-to-date including the material Jobi-2 and Gunya-A wells.
* Zaedyus well in French Guiana commenced drilling in March; result expected in August.
* High-impact wells to commence drilling in 2H 2011 in Guyana, Liberia, Sierra Leone and Kenya.

Group operations and financials
* $300m acquisition of Nuon E&P completed; $305m acquisition of EO assets awaiting approval; pre-emption in Sierra Leone increases stake by 10% to 20%.
* Tullow to list on the Ghana Stock Exchange during July; 4 million share offer closed yesterday.
* First half capital expenditure of $675 million with forecast 2011 expenditure remaining at $1.5 billion.
* Record 1H 2011 revenue of $1.05 billion. Net debt at 30 June 2011 was approximately $2.6 billion.

COMMENTING TODAY, AIDAN HEAVEY, CHIEF EXECUTIVE SAID:
"The performance of our business since the beginning of 2011 has been excellent and we expect to deliver record financial results for the first half of the year. Jubilee production has been ramping up steadily. In Uganda we have signed the MoU with the Government and expect to complete the $2.9 billion Uganda asset sale with CNOOC and Total soon. We have enhanced our portfolio through acquisitions in the Netherlands and Ghana, and our high level of exploration and appraisal success continues. Looking forward, we have a busy programme of E&A activity in the second half including the result of our first exploration well in South America and a number of Jubilee follow-on campaigns in Guyana, Liberia and Sierra Leone."

Conference Call: In conjunction with this announcement Tullow has scheduled a conference call at 09:00 today