Tullow Oil PLC and Africa Oil Corp. have discovered more apparent thick oil pay at the Ngamia-1 wildcat in the South Lokichar basin in northern Kenya.
Test equipment including downhole pumps is being mobilized to flow-test a number of zones in the Upper and Lower Lokhone sands at the well on Block 10BB. Total depth is 2,340 m.
In addition to the more than 100 m of net light oil pay in the Upper Lokhone sand section previously disclosed, the well encountered 43 m of potential oil pay based on logs and the recovery of light oil on an MDT sample over a gross interval of 150 m (OGJ Online, May 7, 2012).
Oil was encountered in sands throughout a 1,100-m interval, including a 300-m thick section of Lokhone shale, which is believed to be the primary source interval in the South Lokichar basin. More than 100 leads and prospects have now been identified in seven basins in the Kenya and Ethiopia Tertiary rift basin acreage. Those located in the South Lokichar basin have been substantially derisked due to their proximity to Ngamia.
Drilling concluded 360 m shallower than the predrill estimate when the well encountered the basin bounding fault, which is interpreted to have cut out some 100 m of prospective reservoirs. Farther from the fault the companies expect to encounter the complete reservoir section and for reservoir thickness and quality to improve.
The rig is now preparing to move to drill the Twiga-1 well 30 km northeast in Tullow-operated Block 13T along the western basin bounding fault on trend with Ngamia. Once this drilling has completed it is planned to use this rig to return to Ngamia-1 for the above mentioned flow testing.
Two more rigs are being sourced, one for the Pai Pai prospect in Kenya Block 10A and one for the Sabisa prospect on the South Omo block in Ethiopia. These wells are expected to spud late in the third and the fourth quarters of 2012, respectively. Three seismic crews are shooting in the Teritiary rift trend, and a proposal to acquire 3D seismic over the Ngamia discovery is under consideration.
Tullow has a 50% operated interest in seven onshore licenses in the Kenya and Ethiopia rift basins covering a combined area of more than 100,000 sq km. Africa Oil, Vancouver, BC, holds the other 50% interest in Block 10BB.
Alan Petzet | Chief Editor Exploration
Alan Petzet is Chief Editor-Exploration of Oil & Gas Journal in Houston. He is editor of the Weekly E&D Newsletter, emailed to OGJ subscribers, and a regular contributor to the OGJ Online subscriber website.
Petzet joined OGJ in 1981 after 13 years in the Tulsa World business-oil department. He was named OGJ Exploration Editor in 1990. A native of Tulsa, he has a BA in journalism from the University of Tulsa.