Current Exploration Status And Future Potential of The Frontier Basins in The Republic of Mali

Scott, John¹ (1) PGA Consultants, Maida Vale, WA, Australia

For the first time for over 30 years, exploration is occurring in Mali. The technical basis for the current activities is presented.

Mali is virtually unexplored with only semi-regional seismic grids recorded and just 5 exploration wells drilled.

There are three potential petroleum systems. The oldest is in the Taoudeni Basin. This play is based on Late Proterozoic source rocks feeding fractured carbonates in large anticlines. The source rocks are well exposed on the northern side of the basin. Major uncertainties remain the timing of generation, and the development of seals. Positive encouragement is given by gas and condensate production on test in one well in the Mauritanian sector of the Taoudeni.

The second play is based on Silurian source rocks, predicted on regional evidence, feeding Palaeozoic reservoirs. Major unknowns remain the actual distribution of the source and the timing of generation. This Silurian based system is postulated in both the Taoudeni and the Tamesna basins.

The third potential system occurs in Mesozoic grabens, part of the Cretaceous to Early Tertiary series of central Africa. These have proven commercially productive to the east in Chad and Sudan. Lacustrine source rocks, the fundamental ingredient, are predicted in the deepest parts of the half-grabens. Only one exploration well has been drilled to test this play, in the Gao Graben of eastern Mali. Oil and gas shows in a water well near the city of Gao attest to the presence of a source system, although the extent and volume remain undefined.