Sidetrack extends oil pay in find off Ghana

A sidetrack of the deepwater Owo-1 discovery off Ghana has “significantly extended the column of high-quality light oil discovered,” reports Tullow Oil PLC, the operator.

Sept. 13, 2010

2 min read

By OGJ editors
HOUSTON, Sept. 13 -- A sidetrack of the deepwater Owo-1 discovery off Ghana has “significantly extended the column of high-quality light oil discovered,” reports Tullow Oil PLC, the operator.

Drilling, wireline logs, and reservoir fluid samples indicate the Owo-1 well cut 174 ft of net oil pay in two Turonian-age zones of high-quality stacked reservoir sandstones. The sidetrack, 0.4 mile east of the discovery well, encountered a total net pay section of 115 ft, including 52 ft of net oil pay in the lower part of the Owo channel system, according to Kosmos Energy, a partner.

The companies earlier reported that pressure data indicate the zones are part of the same accumulation over a gross oil column now estimated at 656 ft (OGJ, Aug. 2, 2010, Newsletter). The Owo 1 sidetrack also discovered 43 ft of net condensate pay and an additional 20 ft of gas pay in the deepest sand encountered. Combined gross hydrocarbon column in both wells is 896 ft.

Neither the well nor the sidetrack encountered water.

The Transocean Sedco 702 semisubmersible drilled the sidetrack to 13,117 ft in 4,685 ft of water. The main well went to 12,766 ft.

The Owo discovery is on the Deepwater Tano block, 37 miles offshore and 19 miles west of Jubilee oil field.

Tullow estimates the Owo oil resource at 70 million bbl at 90% probability, 200 million bbl at 50%, and 550 million bbl at 10%.

Interests in the Deepwater Tano block are Tullow 49.95%, Kosmos and Anadarko Petroleum 18% each, Sabre Oil & Gas 4.05%, and Ghana National Petroleum Corp. 10% carried.