HOUSTON, Oct. 15 -- Groups led by Russia’s OAO Lukoil and Vanco Energy Co., Houston, plan to drill at least five wells in 2011-12 in the Gulf of Guinea off Ghana and Ivory Coast near discoveries off both countries.

State oil company partners Ghana National Petroleum Co. and Petroci will participate in the program, which includes exploratory and appraisal wells.

The drilling contractor Ocean Rig, a subsidiary of Dryships Inc., signed contracts to drill four wells on the Cape Three Points Deep Water block off Ghana, including two exploratory wells on new structures and two appraisal wells on the Dzata structure, where an oil and gas discovery was announced in February.

The Dzata discovery in a Cenomanian-Albian faulted anticlinal trap that opened a new prospective trend in the eastern part of the Tano basin (see map, OGJ, Mar. 15, 2010, p. 34).

Dzata-1 went to a total depth of 4,433 m in 1,878 m of water 45 miles south of Cape Three Points, Ghana, and cut 94 m of gross hydrocarbon column topped at 3,653 m with 25 m of net stacked oil and gas pay. The primary reservoir sandstone at 3,663-90 m contains gas and light oil. Volatile black oil was recovered from a zone at 3,701-09 m.

In Ivory Coast, the drillship is to drill one exploratory well in Block CI-401, where the Orca-1X bis well was completed in May. The contracts provide for one more optional well and an optional further 1-year term.

Drilling is to start off Ghana in April-May 2011 and off Ivory Coast in the first quarter of 2012. Each well is to be drilled in roughly 1,900 m of water by a dynamically positioned, sixth-generation drillship capable of working in as much as 3,000 m of water. The unit is being prepared for flotation at the Samsung shipyard in South Korea.

The CTPDW and CI-401 projects share similar ownership structures whereby Lukoil holds 56.66% and 28.34% belongs to Vanco Ghana Ltd. and Vanco Cote d’Ivoire Ltd., respectively; the state companies each own 15%.

Seismic surveys and drilling of one exploratory well have been performed on each block thus far.