Tullow Oil plc provides an update on a series of exploration and appraisal activities in onshore Kenya Blocks 10BB, 13T and 10BA.
Epir-1 exploration result
The Epir-1 exploration well is located in block 10BB in the North Kerio Basin, a separate sub-basin from that tested by the Kodos-1 well, 25 km to the southwest. Whilst not a discovery, the well encountered oil and wet gas shows over a 100 m interval of non-reservoir quality rocks, demonstrating a working petroleum system in this lacustrine sub-basin. Further exploration activities will be considered in the North Kerio Basin following analysis and integration of the valuable data collected from the well.
The Weatherford 804 rig drilled the Epir-1 well to a final depth of 3057 m. The well will be plugged and abandoned, following which the rig will move to the Ekales-2 location in the South Lokichar Basin where it will conduct appraisal of the discovery made by the Ekales-1 well. The well will target reservoirs in a separate fault block to the east of the discovery well, further away from the basin bounding fault.
Engomo-1 exploration well commenced drilling
The new SMP-106 rig has commenced drilling the Engomo-1 well, the first test of the prospective North Turkana Basin in Kenya Block 10BA. This onshore prospect is to the west of Lake Turkana where numerous naturally occurring oil slicks and seeps have been observed. A result is expected during early March 2015.
Ngamia and Amosing appraisal wells
The PR Marriott 46 rig recently completed drilling the Ngamia-5, Ngamia-6 and Amosing-3 appraisal wells. Both Ngamia wells were drilled from the Ngamia-1 discovery well pad. Ngamia-5 was drilled to a final depth of 2317 m and was deviated approximately 500 m northeast of Ngamia-1, encountering between 160 - 200 m of net oil pay. Ngamia-6 was drilled to a final depth of 2480 m and was deviated approximately 800 m north of Ngamia-1, encountering up to 135 m of net oil pay. Both wells have been suspended and remain available for use in an Extended Well Test programme that will commence in the second quarter 2015.
The Amosing-3 well in Block 10BB continued the successful appraisal of the Amosing oil field. The well was drilled approximately 1 km northwest of the Amosing-1 discovery well and successfully encountered over 107 m of net oil pay in good quality reservoir sands. The well reached a final depth of 2403 m and has been suspended for use in future appraisal and development activities. The PR Marriott 46 rig will now be moved to continue the appraisal of the Ngamia field, drilling the Ngamia-7 well to test the field’s eastern flank.
South Lokichar Basin 3D seismic
Acquisition of the large 951 km2 3D seismic survey has completed over the series of significant oil discoveries in the western basin bounding fault play of the South Lokichar Basin. The fast-track processed data is already being used in the south of the basin whilst the remainder of the survey will be available for seismic interpretation by the end of the first quarter 2015. Initial evaluation of the 3D seismic data indicates significantly improved structural and stratigraphic definition and additional prospectivity not evident on the previous 2D seismic data. In addition, the partnership has acquired over 1100 m of core samples from the South Lokichar Basin wells and an extensive programme of detailed core analysis is ongoing that will provide results from the first quarter 2015 onwards, to measure oil saturation and assess recovery factors of the reservoir sands.
Tullow Operates Blocks 10BB, 13T and 10BA with 50% equity and is partnered by Africa Oil Corporation, also with 50%.
Continued development studies
Angus McCoss, Exploration Director, said: “The Epir-1 wildcat well proved the existence of a working oil system in the North Kerio Basin, encouraging us to consider further exploration activities. The Ekales-2 exploratory appraisal well is a bold step-out away from the South Lokichar Basin bounding fault with follow up potential. Continued success in the appraisal of the Ngamia and Amosing oilfields is highly encouraging as we continue with development studies for the South Lokichar Basin.”
Adapted from press release by Cecilia Rehn