Enyenra-3A well result announcement

Pressure data indicates that the Enyenra‑3A well has confirmed an up‑dip extension of the Enyenra oil field.

Located 6.5km north of the Owo‑1 discovery well and 14km north of Enyenra‑2A, the well was drilled to test the up‑dip extent of the Enyenra oil field. Results of drilling, wireline logs, samples of reservoir fluids and pressure data show that Enyenra‑3A has intersected 17 metres of 35° API net oil. Pressure data confirms a continuous oil column of at least 365 metres and that the oil at Enyenra‑3A is in static pressure communication with both the Owo‑1 discovery well and the Enyenra‑2A appraisal well.

The Deepwater Millennium drillship drilled Enyenra‑3A to a total depth of 4,031 metres in water depths of 1,102 metres. On completion of drilling operations, prior to flow testing the Enyenra field in late 2011, pressure gauges will be deployed in Enyenra‑2A and Enyenra‑3A to determine reservoir connectivity. The drillship will depart the Deepwater Tano block in late October having recently been replaced by the Sedco Energy drillship.

The Sedco Energy will later drill the Enyenra‑4A well to further appraise the downdip extent of the field. The well will be located 6.8km south of Enyenra‑2A and over 20km downdip from the Enyenra‑3A well and a result is expected at the end of the year. The Enyenra‑5A well also is then likely to be drilled north of Enyenra‑3A to test the ultimate updip extent of the field.

Tullow (49.95%) operates the Deepwater Tano licence and is partnered by Kosmos Energy (18%), Anadarko Petroleum (18%), Sabre Oil & Gas (4.05%) and the Ghana National Petroleum Corporation (GNPC) (10% carried interest).

Elsewhere in West Africa, Tullow now expects to announce the result of the Montserrado‑1 well offshore Liberia during October.

COMMENTING TODAY, ANGUS MCCOSS, EXPLORATION DIRECTOR, SAID:

“This excellent result demonstrates that we are close to declaring the Enyenra and Tweneboa development commercial. Although the ultimate extent of the fields are yet to be fully determined, confirmation of this up‑dip extension and long oil column in Enyenra is very encouraging.”

Tullow Group Overview

Tullow is a leading independent oil & gas, exploration and production group, quoted on the London, Irish and Ghanaian (symbol: TLW) stock exchanges and is a constituent of the FTSE 100 Index. The Group has interests in over 90 exploration and production licences across 22 countries and focuses on four core areas: Africa, Europe, South Asia and South America.

In Africa, Tullow has production in Ghana, Gabon, Côte d’Ivoire, Mauritania, Congo (Brazzaville) and Equatorial Guinea with two large appraisal and development programmes in Ghana and Uganda. Tullow also has exploration interests in Gabon, Côte d’Ivoire, Liberia, Sierra Leone, Mauritania, Senegal, Tanzania, Madagascar, Namibia, Kenya and Ethiopia.

Tullow’s European interests are focused on gas in the UK Southern North Sea where it has significant interests in the Caister-Murdoch System and the Thames area and in the Netherlands where it has offshore gas production, development and exploration opportunities.

In South Asia, Tullow has exploration and production in Bangladesh and exploration interests in Pakistan. In South America, Tullow has exploration interests in Guyana, French Guiana and Suriname.