23 Oct 2014

Kenya exploration and appraisal update

Tullow Oil plc (Tullow) announces the results of a series of recent exploration and appraisal activities conducted in Blocks 10BB and 13T onshore Kenya.

Kodos-1 wildcat exploration well in the Kerio Basin

The Kodos-1 exploration wildcat in Block 10BB is the first well drilled in the Kerio Basin, northeast of the successful South Lokichar Basin. Hydrocarbon shows were encountered in Kodos-1 which indicates the presence of an active petroleum system. However reservoirs were mixed quality alluvial sands close to the basin boundary fault at this well location.

The Weatherford Rig-804 drilled Kodos-1 to a final depth of 2,500 metres and the well will be plugged and abandoned. The rig will now be moved to drill the second well in the basin at Epir-1, 25 km north of Kodos-1 in a separate sub-basin. Following up on the encouraging hydrocarbon shows at Kodos-1, further drilling in the greater Kerio Basin can be expected during 2015.

Ekosowan-1 exploration well in the South Lokichar Basin

The Ekosowan-1 well in block 10BB is the most southerly well drilled to date in the South Lokichar Basin, 12 km south east and up-dip of the previous Amosing-1 oil discovery. The well extended the proven oil basin southwards having encountered a 900 metre section of near continuous oil shows throughout an interval of tight faulted sands.

The Ekosowan area is located within the ongoing 3D seismic survey in the South Lokichar Basin, acquisition of which is expected to complete in December this year. Follow up drilling will target better developed reservoir expected between Amosing-1 and Ekosowan-1, further away from the faulting at the basin margin. 

The Sakson PR-5 rig drilled the Ekosowan-1 well to a final depth of 2,029 metres. The well will be plugged and abandoned, following which the Sakson PR-5 rig will be replaced by the new SMP-106 rig which is currently mobilising to the Engomo-1 wildcat well location, the first test of the North Turkana Basin.

Ngamia-4 appraisal well in South Lokichar Basin

The Ngamia-4 well in Block 10BB continued the successful appraisal of the Ngamia oil field. The well was drilled 1.1 km west of the Ngamia-1 discovery well and successfully encountered up to 120 metres of net hydrocarbon pay, of which up to 80 metres was oil. The well has been suspended for use in future appraisal and development activities.

The PR Marriott Rig-46 drilled Ngamia-4 to a final depth of 1,814 metres. The rig will now drill the Ngamia-5 appraisal well which will help assess reservoir connectivity in the Ngamia field, the largest oil discovery to date in the South Lokichar Basin.

Twiga-2A well test in South Lokichar Basin

The SMP-5 Workover Rig has successfully completed four flow tests on the Twiga-2A well in Block 13T, achieving production rates between 150 and 3,270 bopd under natural flow with no depletion, the highest oil production rate seen to date in Kenya. With optimised equipment the maximum flow potential from the best zone could have increased to around 10,000 bopd demonstrating excellent reservoir deliverability.

The SMP-5 rig will now move to the Amosing oil field to begin Extended Well Testing, where production and injection interference testing, involving the Amosing-1 and 2A wells, will help provide dynamic flow characterisation of the Amosing stacked reservoirs.

Tullow Operates Blocks 10BB and 13T with 50% equity and is partnered by Africa Oil Corporation, also with 50%.

Commenting today, Angus McCoss, Exploration Director, said:

"The Kodos-1 well is the first test of the Kerio Basin and hydrocarbon shows provide encouragement, indicating the presence of an active petroleum system. The potential of the Kerio Basin remains highly prospective and the rig is now moving to drill the next well, Epir-1, in a sub-basin to the north of Kodos-1.

South Lokichar Basin activity continued with exploration and appraisal drilling and well testing. The Ekosowan-1 well encountered a significant interval of oil shows however reservoirs at this location were tight. We look forward to stepping out from Ekosowan towards the Amosing oil field in pursuit of better reservoirs. Appraisal and well testing success continues with Ngamia-4 finding a substantial section of oil pay and Twiga-2A recording our highest flow rates to date."