Tullow appraises Jubilee oil field off Ghana

Tullow Oil PLC has tested 4,448 b/d of oil from the Mahogony-2 appraisal well in Jubilee field off Ghana. Tullow reported that it expects to start oil production from Jubilee field in 2010. Its suggested upside could be as much as 1.8 billion bbl of oil.

Uchenna Izundu
International Editor

LONDON, July 16 -- Tullow Oil PLC has tested 4,448 b/d of oil from the Mahogony-2 appraisal well in Jubilee field off Ghana. Tullow reported that it expects to start oil production from Jubilee field in 2010. Its suggested upside could be as much as 1.8 billion bbl of oil.

The well also produced 5.1 MMscfd of associated natural gas through a 36/64-in. choke with a flowing tubing pressure of 1,936 lb/sq in. Oil was 39° gravity.

"The test encompassed a 23-m perforated interval representing 40% of the oil-bearing pay in the well's upper sands," said Kosmos Energy, a partner in the field. "The flow rate was limited by equipment and facilities."

This second set of drill stem test results on the upper zone is significant because it indicates that a Jubilee production well should produce more than 20,000 b/d with 5 1/2-in. tubing.

The Songa Saturn drillship remained on location following the first drill stem test in June that struck a single 17-m interval in the well's lower zone and produced 5,200 b/d of 36° oil. About 5.5 MMscf of associated natural gas flowed through a 40/64-in. choke with a flowing tubing pressure of 1,543 lb/sq in (OGJ Online, June 11, 2008).

Jubilee and Odum, another discovery13 km from the field, have proved two new plays and derisked substantial follow-up prospects scheduled for drilling in Ghana and Cote d'Ivoire within the next 12 months, Tullow Oil said.

Partner Kosmos Energy plans to drill other exploration and appraisal wells on the West Cape Three Points block, which it operates, and Tullow will drill on its deepwater Tano block in September, using the deepwater Blackford Dolphin, Eirik Raude, and Atwood Hunter rigs.

The partners will use a floating production, storage, and offloading vessel to produce oil and subsea wells from Jubilee in its first development phase. Jubilee was discovered last year in 1,500 m of water and is estimated with 90% probability to hold 170 million bbl of recoverable oil. It straddles the boundary between the West Cape Three Points Block and Tullow Oil's Deepwater Tano Block (OGJ, May 26, 2008, Newsletter).

The West Cape Three Points block is 1,761 sq km and in water depths of 50-1,800 m.

Kosmos Energy is operator of the deepwater West Cape Three Points Block and holds a 30.875% interest. Anadarko Petroleum Corp. has a 30.875% interest; Tullow 22.896%; the E.O. Group 3.5%; and Sabre Oil & Gas Holdings a 1.854% interest in the block. Ghana National Petroleum Corp. (GNPC), which has a 10% participating interest in the project, will be carried through the exploration and development phases.

Contact Uchenna Izundu at uchennai@pennwell.com.

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