Mputa-4 Well Test Completed, Flow Rates to 1,100 bbl/d

Tullow Oil plc (Tullow) announces that Mputa-4 well test operations have been completed and the data taken from the well will now be integrated with the Kaiso-Tonya appraisal program well data and the recently acquired 3D seismic.

Mputa-4 was production tested from a 5m interval at 944m for an extended flow period of three days from 21 to 24 November 2007. The well tested at rates of 950 to 1,100 bbls/day on a small ½” choke and the oil produced was a 31 degree API waxy sweet crude consistent with that encountered elsewhere in the Kaiso-Tonya Area. The well was then shut-in for an extended 16-day pressure build-up period with downhole reservoir pressure gauges installed.

The objective of the test was to enhance the understanding of the lateral connectivity and geometry of the sandstone reservoir by analyzing production and pressure trends. The pressure data indicated some depletion over the test period and this data will now be integrated into the subsurface evaluation along with an updated 3D seismic geological model to refine reserve estimates and development planning assumptions ahead of the anticipated sanction of the Early Production System in late Q1 2008.