Oil Mining Lease 113 (OML 113) is located in the extreme western part of offshore Nigeria, adjacent to the border with Benin and close to the producing Seme field in the Benin Embayment. The licence covers approximately 960 sq km and contains the Aje oil field, located directly on the present-day shelf break margin. The Benin Embayment is located along the West African Transform Margin, a prolific petroleum fairway containing the Jubilee field and Vitol E&P’s Sankofa and Gye Nyame fields, offshore Ghana.
The Aje field lies in water depths of 300 to 800 metres, with landfall at a distance of around 25 km and the West African Gas Pipeline approximately 15 km away at its closest point. Vitol Exploration Nigeria Ltd holds a 32.07% non-operated working interest in the field.
Although formed in a conventional four-way dip closure trap, deeply incised canyons on the sea floor and Aje’s location under the modern-day shelf break make the interpretation of seismic data extremely challenging. The original discovery well, Aje-1, was drilled in the mid 1990s and three subsequent appraisal wells have all encountered hydrocarbons at several levels. Gas condensate and black oil accumulations lie in Turonian and Cenomanian age reservoirs, while an additional gas reservoir was penetrated in the deeper Albian formation at the Aje-4 well, drilled in 2008.
Studies are in progress to define an optimal development scenario for the field, focussing on the combined or sequential exploitation of all of the reservoirs. Conceptual engineering studies were completed in 2011 and a final investment decision for field development is expected in 2013.
Aje field subsurface model showing main reservoir horizons gridded for simulation
