Uganda’s First Oil Development - Kasamene

McFerran, Claire ¹
(1)Tullow Oil, London, United Kingdom.

The Kasamene field is located in the northern part of EA2 in the Butiaba region of the Albertine Basin, Uganda. The Kasamene discovery in July 2008 formed part of a highly successful exploration campaign carried out by Tullow Oil, delivering 10 discoveries in EA1 & EA2 between May 2008 and August 2010.

Kasamene-1 was drilled some 1.5km from the crest of the structure to a total depth of 957m MDBRT. Downhole pressure testing and sampling confirmed the presence of gas and moveable oil. The well encountered over 31m of net oil pay and 6m of net gas pay. The well results confirmed the presence of excellent quality reservoir and seal units within the centre of the basin, and de-risked several adjacent prospects in EA 1 and EA 2, many of which have subsequently been drilled as part of the basin-wide exploration drilling campaign.

Production potential of these reservoirs was demonstrated in March 2009 though a highly successful testing operation on Kasamene-1A during which an 18m perforated interval delivered 3,600 bopd.

In July 2009 the Wahrindi-1 well encountered oil accumulations in very close proximity to the Kasamene-1 discovery, characterized by similar reservoir quality and oil properties. Infill 2-D seismic data acquired in December 2009 and April 2010, and results of wells Kasamene-2 and Kasamene-3/3A drilled in Q1 2010 formed part of a highly successful appraisal campaign confirming the areal and vertical extent of the stacked accumulations encountered by Kasamene-1 and Wahrindi-1. The reservoirs are of late Pliocene age comprising several stacked sand/shale sequences in a fluvial/lacustrine deltaic setting.

Simulation models have been used to assess the production and recovery potential of these accumulations, with results being used to define the optimal development strategy and infrastructure requirements. The strategy includes implementation of a water flood from startup to allow for maintenance of reservoir pressure and ensure efficient sweep of oil from the injectors to the producers.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.