Tullow Oil plc and its partner Africa Oil have announced a new round of successful results from a series of exploration, appraisal and testing activities conducted in Blocks 10BB and 13T onshore Kenya.
Amosing-2 appraisal well
The Amosing-2 well in Block 10BB is the first appraisal well on the Amosing field discovered in January 2014, and was drilled from the Amosing-1 well pad. The well was deviated 1,350 metres towards the northeast and downdip from the discovery well to calibrate the oil-water contacts of the several oil pools identified in Amosing-1. The Amosing-2 well encountered up to 30 metres net oil pay. As planned, the well was then sidetracked back to some 400 metres from the discovery well to provide additional insight into reservoir distribution in the area and for use in interference testing, planned to start later in 2014. The Amosing-2A sidetrack encountered up to 90 metres net oil pay in several oil pools.
The Sakson PR5 rig drilled Amosing-2 to a final depth of 2,878 metres and the Amosing-2A sidetrack to a final depth of 2,165 metres. The rig will now be moved to explore the southern extent of the South Lokichar basin to drill the Ekosowan-1 well in September 2014, 11.9 km south east of the Amosing-1 well.
Ngamia-3 appraisal well
The Ngamia-3 well in Block 10BB continued the appraisal of the Ngamia field. The well was successfully drilled 1.6 km north of the Ngamia-1 discovery well and encountered 150 metres of net oil pay in both Auwerwer and Lokone reservoirs. The well has been suspended for likely use in future interference testing, appraisal and development activities.
The Marriott PR46 rig drilled Ngamia-3 to a final depth of 2,700 metres. The rig will now be moved to continue the appraisal of the Ngamia field, drilling the Ngamia-4 and Ngamia-5 wells which are planned to be used in an interference testing programme in the Ngamia field.
Etom-1 exploration well
The Etom-1 well in Block 13T is the most northerly well drilled to date in the South Lokichar basin, 6.5 km north of the previous Agete-1 discovery. The well encountered approximately 10 metres of net oil pay, extending the proven oil basin significantly northwards. Based on this result the ongoing 550 sq km 3D seismic survey in the South Lokichar basin has been extended to cover a further 247sq km in this northern area, including several similar prospects which are scheduled to be drilled in 2015.
The Weatherford 804 rig drilled the Etom-1 well to a final depth of 2,000 metres. The well will be suspended for use in future appraisal and development operations, following which the rig will move to drill the Kodos-1 well in September 2014 to test the first of several prospects identified in the neighbouring Kerio Basin.
“We are quite pleased with the Etom discovery which extends the proven petroleum system to the northern portion of the Lokichar basin and derisks several large prospects in that area. We are also encouraged that the Ngamia and Amosing appraisal wells have found thick reservoir and pay intervals that will give us further confidence that these two fields to anchor our development project and look forward to the results of the extended wells tests to confirm the reservoir performance,” says Africa Oil CEO Keith Hill.
Ewoi-1 flow test
The SMP-105 testing/workover rig recently completed testing activities at the Ewoi-1 well. The well demonstrated good permeability in the water-bearing Lokone reservoirs and a programme to target these updip is under consideration. Flow rates from the Auwerwer reservoir DST were limited to around 50 bopd, potentially due to the high wax content and shallow depth of this DST.
The lightweight rig is currently testing the Twiga South-2A appraisal well where two to three tests are planned.
“Etom-1 has successfully extended the South Lokichar rift bounding fault play northwards and we look forward to testing the southern area of the basin with Ekosowan-1. Continued success in appraisal of the Ngamia and Amosing fields reinforces our belief that the South Lokichar basin holds very considerable potential which we hope to replicate in additional basins. The next basin-opening test will be in the neighbouring Kerio Basin, with the Kodos-1 well expected to spud in early September,” he said.
According to exploration director at Tullow Oil Angus McCoss the company now looks to testing the neighbouring Kerio basin which it hopes will replicate the success seen in the South Lokichar basin.
The Kodos well is the first well to be drilled in the highly prospective Central Kerio basin in Kenya Block 10BB and will target a three way dip closed feature against the main basin bounding fault similar to the Ngamia/Amosing/Twiga trend in the Lokichar Basin.
The Ekosowan well is located on the western ‘string of pearl’ prospects in the Lokichar basin and is directly south of the Ngamia and Amosing fields which have demonstrated the thickest net pay and reservoir in the basin. Both wells are expected to be completed in the fourth quarter.
Two additional new basin opening wells are planned to spud before the end of the year in the North Kerio Basin (Epir-1) and the North Turkana Basin in Block 10 BA (Engomo-1).
Tullow Operates Blocks 10BB and 13T with 50% equity and is partnered by Africa Oil Corporation, also with 50%.