Tullow Oil has announced that the Giraffe-1 exploration well, which is located in the Butiaba region of Uganda Block 1, has encountered over 38m of net oil pay within an 89m gross oil bearing interval.

The company said that these results demonstrate Giraffe to be a down-dip extension of the Buffalo discovery, making this the largest discovery in the Lake Albert Rift Basin to date.

The well was drilled 5km from Buffalo-1 to a total depth of 705m and has been logged and sampled. These data indicate a net reservoir thickness of 38m, the largest encountered in the area to date, and good reservoir quality in all pay zones with moveable oil being recovered to surface, the company claimed.

Interpretation of the well and seismic data indicates that the reservoir sands intersected in the Giraffe-1 well are in communication with those in the Buffalo discovery. An oil-water contact was penetrated and is interpreted as being common to the entire Buffalo-Giraffe structure with the potential for a single continuous oil column of some 140m.

This latest result further extends the play fairway and de-risks several adjacent prospects, located in Blocks 1 and 2, which are scheduled for drilling in 2009.

The well will now be suspended as a future producer and on completion of operations the light land rig will move to the Tullow Operated Block 2. Drilling operations will recommence in early February 2009 with the drilling of the Mputa-5 appraisal well to calibrate recently enhanced seismic data. Thereafter the rig will return to the Block 2 Butiaba campaign.

Tullow has interests in three licences in the Lake Albert Rift Basin in Uganda. Tullow operates Block 2 with a 100% interest and has a 50% interest in Blocks 1 and 3A which are operated by Heritage Oil, which has 50% interest.

Aidan Heavey, CEO of Tullow Oil, said: Buffalo-Giraffe is a large onshore oil discovery in Africa. Combined with our other finds in the region, we have now clearly exceeded the thresholds for basin development. Options for commercialization and first oil production are currently being fast-tracked.