LONDON -- An appraisal well on the deepwater Tweneboa discovery offshore Ghana has intersected a large hydrocarbon column, according to operator Tullow Oil.
Tweneboa -2 was drilled by the semisub Atwood Hunter in the Deepwater Tano block to an interim sub-surface depth of 3,860 m (12,664 ft), in a water depth of 1,321 m (4,334 ft). The location is around 6 km (3.7 mi) southeast of the Tweneboa-1 discovery. Analysis of drilling, wireline logs, and reservoir fluids confirm this is a major oil and gas-condensate field, Tullow claims.
The well encountered a gross reservoir interval of 153 m (502 ft) containing 32 m (105 ft) of net hydrocarbon pay in stacked reservoir sandstones: this comprised a 17-m (56-ft) oil bearing zone below a 15-m (49-ft) gas-condensate bearing zone.
Tullow adds that a combined hydrocarbon column of at least 350 m (1,148 ft) has been established between the lowest known oil in Tweneboa-2 and the top of the gas-condensate at Tweneboa-1, proving a highly prospective and extensive turbidite fan system which will need to be evaluated through further wells.
Following completion of logging operations, Tweneboa-2 will be deepened to test added exploration potential beneath the Tweneboa structure. The well will then be suspended for future use appraisal/development programs.
The rig will next be mobilized to drill an exploration well in the nearby West Cape Three Points block, east of the Jubilee field. Tullow (49.95%) operates the Deepwater Tano license, in partnership with Kosmos Energy (18%), Anadark Petroleum (18%), Sabre Oil & Gas (4.05%), and the Ghana National Petroleum Corp. (GNPC) (10% carried interest).