Tullow Oil has announced that the Tweneboa-3 appraisal well in the Deepwater Tano licence offshore Ghana has successfully encountered gas condensate in excellent quality sandstone reservoirs. Results of drilling, wireline logs and samples of reservoir fluids, together with the well’s down-dip position confirms the Greater Tweneboa Area resource base potential.
The well, located over 6 kms south-east of the Tweneboa-2 well and 12 kms south-east from the Tweneboa-1 discovery well, was planned with two deviated boreholes to test separate areas of the Tweneboa field. The first leg was drilled to calibrate the potential of an area with a very weak seismic response. Within prognosis, this leg encountered thin reservoir sands and approximately 9 metres of gas condensate pay. The well was then sidetracked 550 metres west, targeting the significant Ntomme anomaly, an area of strong seismic response. This leg successfully encountered a gross vertical reservoir interval of approx. 65 metres containing 34 metres of net gas condensate pay in two zones of high quality stacked reservoir sandstones. Work is underway to integrate seismic, pressure and hydrocarbon phase data in order to progress development options for the Tweneboa and Enyenra (Owo) fields in the Greater Tweneboa Area.
Tweneboa-3 was drilled by the Deepwater Millennium drillship to a total depth of 3,906 metres in a water depth of 1,601 metres. On completion of operations, the well will be suspended for future use in the field development. The rig will remain in the Deepwater Tano block to drill the top-hole section of the Tweneboa-4 appraisal well which will then be suspended before moving to drill the high impact Enyenra-2A well which will appraise down-dip from the Owo-1 oil discovery. The significant oil discovery, made by the Owo-1 exploration well has now been named the Enyenra field.
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).
Commenting today, Angus McCoss, Exploration Director, said: ‘Tweneboa-3 was a bold appraisal step-out in a vast stratigraphic trap. Confirming producible gas-condensate in excellent quality reservoirs at this location is a great result that also demonstrates the strong predictive capabilities of our seismic data and prospecting techniques. As a result, we can now move forward confidently to assess the development options for the Tweneboa and Enyenra (Owo) fields in the Greater Tweneboa Area.’