Oil and gas group Tullow Oil (LON:TLW) reported this morning that the latest appraisal well on its Tweneboa field offshore Ghana had successfully encountered gas condensate and that results from well had confirmed the western extent of the Tweneboa gas condensate accumulation. The news came as Tullow said that drilling was about to get under way in Uganda following a deal in March with the country’s government that partly resolved a long-running tax dispute between the two sides.

Last year Tullow and its partners kicked off production from Ghana’s first major oil and gas development, the massive offshore Jubilee field. Now the company is eyeing a similar outcome for the Tweneboa and nearby Enyenra fields and is planning a number of appraisal wells this year in order to determine reservoir extent and connectivity and to provide rock and fluid data. The original Tweneboa discovery well was drilled on the Deepwater Tano licence in 2009 and established Tweneboa as a major gas-condensate and oil field. A successful appraisal well was drilled in February 2010, which intersected a significant combined hydrocarbon column. Tweneboa-3 was drilled in December 2010, which also confirmed producible gas-condensate at its location.

The latest well, Tweneboa-4, successfully encountered gas condensate in good quality sandstone reservoirs. The well lies 3.9km south-west of the Tweneboa-2 well and was drilled in the western flank of the accumulation to complete the appraisal of the Tweneboa 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).

Separately, Tullow said that following its agreement last month to farm-down part of its holdings in licences in Uganda to CNOOC and Total, an exploration and appraisal programme had been reactivated. Two wells are expected to…

Unlock the rest of this article with a 14 day trial

Unlock with Email
Unlock with Google

Already have an account?
Login here