Tullow's Twiga South-1 exploration well in Block 13T, onshore Kenya, has encountered oil, the company confirmed 26 November 2012.
Twiga South-1 has encountered 30m of net oil pay with further potential to be assessed on test and has also encountered a tight fractured rock section with hydrocarbon shows over a gross interval of 796m.
Twiga South-1 has been drilled to a total depth of 3,250m and has been successfully logged and sampled. Three sandstone reservoir zones, analogous to Ngamia-1, were encountered and moveable oil, with an API greater than 30 degrees, has been recovered to surface. Further potential exists up dip of the well and will be subsequently appraised.
In addition to the net pay, the well also penetrated a thick section of tight fractured rock below 2,272m which had extensive hydrocarbon shows over a gross interval of 796m. Moveable oil with an API greater than 30 degrees was also successfully sampled from this section. This tight fractured rock section is a new play-type for the region that will require further evaluation to understand its extent and any productive potential.
The Twiga South structure is the second prospect to be tested in the Lokichar Basin as part of a multi-well drilling campaign in Kenya and Ethiopia and is the first oil discovery in Block 13T. It is located 22km to the north of the Ngamia-1A discovery and further de-risks a number of other similar features on the western margin of the basin.
A series of flow tests will now be conducted on the well over the next 4-8 weeks. Following completion of the testing programme, the rig will move back to flow test the Ngamia-1 well.
Tullow has a 50% operated interest in the Twiga South-1 well with Africa Oil holding the remaining 50% interest.