Energy prospector, Tullow Oil, today said it encountering over 40 metres of net oil bearing reservoir in two zones at its Ngiri-2 appraisal well.

The well is located in the Butiaba region of Uganda Block 1.

The well was drilled 1.7 km north of the Ngiri-1 discovery well (drilled on the Warthog prospect) to a total depth of 892 metres.

Successful logging and sampling operations have confirmed the presence of moveable oil in two zones. The lower zone encountered an oil water contact while pressure data acquired within the upper zone indicates the possibility of a deeper contact than expected. Reservoir quality is also excellent, akin to the Kasamene field in Block 2, where a production rate of 3,500 bopd was achieved during testing in 2009.

The Ngiri-2 well was the first of a multi-well appraisal programme planned to further evaluate the extent and recovery potential of the Ngiri field. Further activities will take place in 4Q 2010 with the drilling of down-dip appraisal wells Ngiri-3 and Ngiri-4 designed to establish oil water contacts and reservoir distribution.

The well has been suspended and the IRR-600 rig is moving to the Mpyo-1 location where material wildcat drilling operations will commence.

Tullow operates its 100pc interests in three licences, Blocks 1, 2 and 3A, in the Lake Albert Rift Basin in Uganda.

Commenting today, Angus McCoss, Exploration Director said: "The 40 metres of net oil pay in Ngiri-2 is the thickest oil pay so far encountered in the Butiaba area, demonstrating that after 32 successes in 33 wells the Lake Albert Rift Basin continues to deliver from the undrilled upside potential. Our exploration and appraisal campaign in Uganda has now discovered over 950 million barrels of oil (P50). In addition to this, our estimate of the yet to find prospective resource remains unchanged at 1.5 billion barrels of oil (P50). This continued success supports our planning for the accelerated basin-wide development with our future new partners Total and CNOOC."