Sterling keen to assess Sifaka

Offshore staff

LONDON -- Sterling Energy is looking to drill its first exploration well off northwest Madagascar next year, once the political situation on the island has stabilized.

The company is targeting the giant Sifaka prospect in its Ampasindava block, where water depths range from 200-3,000 m (656-9,842 ft).

Following a site survey, a drilling location was selected late last year on the flank of the structure. Earlier this year, the company completed an environmental impact assessment.

Studies indicate that the main Jurassic target sandstones will be at a subsurface depth of around 3,400 m (11,155 ft). Sterling estimates un-risked mean prospective resources at Sifaka of 2 Bbbl.

Last month, ExxonMobil withdrew from a joint venture in the Ambilobe offshore PSC, leaving Sterling as the sole licensee. Madagascan government agency OMNIS has since granted the company an extension to the current exploration phase, and terms are being finalized.

In Ambilobe, where water depths range from 0-3,000 m (0-9,842 ft), an additional 550 km (342 mi) of 2D seismic was acquired in 2008, and further studies were completed.

According to Sterling, these have improved understanding of the Jurassic and Cretaceous source rocks and reservoirs in outcrop, and its ability to predict their presence in un-drilled offshore basins.

The company is also reprocessing over 8,000 km (4,971 mi) of 2D data in an attempt to identify further exploration potential in both blocks.

In West Africa, the company holds 100% of the deepwater Ntem concession in Cameroon’s southern Douala/Rio Muni basin. Work has been suspended due to maritime border issues with Equatorial Guinea to the south, but both countries are working to resolve this issue.

Sterling has been re-evaluating the area in light of Noble Energy’s recent Tertiary discoveries north of Ntem. It claims to have identified numerous large leads and prospects in Tertiary and Upper Cretaceous plays following detailed interpretation of a large 2D/3D seismic database.

Recent seismic attribute analysis and inversion studies have shown large and widespread submarine fans with strong exploration potential.

In the Dome Flore offshore concession in the AGC joint exploration zone between Senegal and Guinea Bissau, Sterling is a partner to Malaysian operator Markmore.

There are plans to drill two stacked, Maastrichtian light oil reservoirs, with the well also penetrating a shallower, heavy oil accumulation. Markmore will carry Sterling’s share of the drilling costs.

06/01/2009