The success of these latest wells has substantially increased the proven areal extent of both the Jubilee and Kingfisher fields and is likely to lead to material upgrades of current resource estimates.
Hyedua-2, Deep Water Tano, offshore Ghana
The Hyedua-2 appraisal well which is being drilled to appraise the Jubilee field offshore Ghana, has intersected a significant light oil column. Results of drilling, wireline logs and samples of reservoir fluid indicate an extension of the Jubilee field some 4km northwest of the Mahogany-1 discovery well in the West Cape Three Points licence and 5km north of the subsequent Hyedua-1 discovery well in the Deepwater Tano licence.
Hyedua-2 is located in the Deepwater Tano block and is the second appraisal well on the Jubilee field. The well has encountered a gross reservoir interval of 120 metres containing approximately 55 metres of high quality oil bearing reservoir sandstones.
A drill stem test will now commence on Hyedua-2 to determine potential production rates and to collect further oil samples for analysis. Testing is expected to take approximately four weeks and the well will then be suspended for use as a potential development well.
The Blackford Dolphin semi-submersible drilled Hyedua-2 to a total depth of 3,663 metres in water depths of 1,246 metres. On completion of testing the rig will move to a new location to drill a Jubilee development well before performing a drill stem test on the Mahogany-1 discovery well.
The Eirik Raude semi-submersible is currently drilling the Mahogany-3 exploratory-appraisal well in the West Cape Three Points licence. This well is targeting an extension of the Jubilee field to the southeast and is being extended to intersect a deeper exploration prospect, Mahogany Deep. Mahogany-3 is expected to reach Total Depth in approximately four weeks.
Tullow (49.95%) operates the Deepwater Tano licence. Other partners include Kosmos Energy (18%), Anadarko Petroleum (18%), Sabre Oil & Gas (4.05%) and the Ghana National Petroleum Corporation (GNPC) (10% carried interest). Tullow is also the Unit Operator of the Jubilee field.
Kingfisher-3, Block 3A, Uganda
The Kingfisher-3 appraisal well was drilled to evaluate the south-western flank of the Kingfisher structure. The well encountered oil in three reservoirs which were all structurally higher than expected. Results of drilling, wireline logs and samples of reservoir fluid indicate that these oil-bearing sands have a total thickness of up to 40 metres over a gross interval of approximately 110 metres. Pressure data indicates that the three intervals are in communication with the three reservoir intervals previously production tested in the Kingfisher-1 and Kingfisher-2 wells.
Analysis from the previous two wells on the structure had suggested the potential for this well to encounter the oil-water contact. No contact has however been intersected and pressure data indicates that the oil-water contacts for the three zones are significantly deeper than the original prognosis.
The success of this well has significantly increased the areal extent of the Kingfisher field and in conjunction with the deeper oil-water contacts gives increased confidence in a resource upgrade. The Kingfisher field is now the largest light oil discovery in East Africa.
The well will now be sidetracked to an anticipated depth of 2,860 metres and then suspended. Operations are expected to be completed by late January or early February 2009.
Commenting today, Aidan Heavey, Chief Executive, said:
“Encountering significant hydrocarbon columns outside of the proven area of both the Jubilee and Kingfisher fields is an outstanding result. Our continued success in both basins will likely lead to material upgrades of current resource estimates with the Hyedua-2 result underpinning the requirement for additional phases of development on the Jubilee field. We are entering an exciting period for Tullow’s Ghanaian and Ugandan operations with four potentially transformational wells to be drilled over the next four months.”