Ghana and Uganda exploration and appraisal well update

Tullow Oil plc (Tullow) announces a successful Tweneboa-4 appraisal well offshore Ghana and the commencement of a major exploration and appraisal campaign in the Lake Albert Rift basin, onshore Uganda.  

Successful Tweneboa-4 appraisal well

The Tweneboa-4 appraisal well in the Deepwater Tano licence offshore Ghana has successfully encountered gas condensate in good quality sandstone reservoirs. Results of drilling, wireline logs and samples of reservoir fluids have confirmed the western extent of the Tweneboa gas condensate accumulation.

The well, located 3.9 kilometres southwest of the Tweneboa-2 appraisal well was drilled in the western flank of the accumulation to complete the appraisal of the Tweneboa gas-condensate discovery. The well encountered 18 metres of net gas condensate pay in high quality stacked reservoir sandstones which are in static pressure communication with both the Tweneboa-1 and Tweneboa-2 wells.

The Deepwater Millennium dynamically positioned drillship drilled Tweneboa-4 to a total depth of 4,007 metres in water depths of 1,436 metres. On completion of operations, the well will be suspended for future use in field appraisal and development. The rig will then move to perform drill stem tests on the Tweneboa-2 oil and gas-condensate accumulations.

Tullow (49.95%) operates the Deepwater Tano licence and is partnered by Kosmos Energy Ghana (18%), Anadarko Petroleum (18%), Sabre Oil & Gas (4.05%) and the Ghana National Petroleum Corporation (GNPC) (10% carried interest).

Uganda exploration and appraisal campaign commences

Following the signing of the SPAs for the farmdown to CNOOC and Total on 29 March 2011, the exploration and appraisal programme has been reactivated and two wells are expected to commence drilling in Exploration Area 1 (EA 1) within the next two weeks. The OGEC 600 rig is preparing to spud the high-impact Jobi-East prospect and the OGEC 750 rig is getting ready to drill the first Mpyo exploratory appraisal well to test its upside potential. These wells are the start of a major programme of exploration and appraisal drilling, seismic acquisition, and well testing to access the significant remaining upside potential in the basin and further expand the resource base for development.

Commenting today, Angus McCoss, Exploration Director, said:

"Tweneboa-4 is an important milestone as it is the final well to be drilled in the Tweneboa appraisal programme. The upcoming programme of well testing in the Tweneboa field, along with drilling and well testing in the Enyenra field, will provide essential information on well deliverability, dynamic reservoir connectivity and hydrocarbon volumes, which will be used to optimise our development plans for these major fields. We are also delighted to be starting drilling activities again in EA 1 in Uganda and are now gearing up for a five-rig drill-out campaign in the second half of the year."