Further potential will be assessed on test and the well has also encountered a tight fractured rock section with hydrocarbon shows over a gross interval of 796 metres.
Twiga South-1 has been drilled to a total depth of 3,250 metres 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 2,272 metres, which had extensive hydrocarbon shows over a gross interval of 796 metres. 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 program, the rig will move back to flow test the Ngamia-1 well.
Elsewhere in Tullow’s East African Rift basin acreage, a result from the Paipai-1 well in Block 10A in Kenya is expected by the end of the year and the Sabisa-1 well in the South Omo Block in Ethiopia is expected to commence drilling by the end of December.
Tullow has a 50% operated interest in the Twiga South-1 well with Africa Oil holding the remaining 50% interest.
Angus McCoss, Exploration Director, commented,
"Following the basin-opening Ngamia-1 well result earlier this year, I am pleased to announce that our second well in our onshore Kenya rift basins campaign has also discovered oil. This immediate follow on discovery reaffirms the considerable prospectivity of the Lokichar Basin. Having significantly expanded our plans in Kenya and Ethiopia, there is much to look forward to as the exploration campaign and testing programme move ahead."