The U.S. Geological Survey assessed how much undiscovered, technically recoverable conventional oil and gas may lie in five basins of northern Africa — the Berkine, Illizi, Hamra, Murzuq and Erdis Kufra Basins — and the uplifts between them.
Key results
| Resource | Mean estimate | Range (95% to 5% chance) |
|---|---|---|
| Oil | 419 million barrels | 177–810 million barrels |
| Natural gas | 5,451 billion cubic feet (about 5.5 trillion) | 3,556–7,919 billion cubic feet |
| Natural gas liquids | 230 million barrels | 152–335 million barrels |
Location of the seven conventional assessment units. USGS.
How the basins formed
- In the early Paleozoic, northern Africa was a north-facing passive continental margin on the paleo-Tethys Ocean.
- In the Late Carboniferous to Permian, the Hercynian orogeny — a series of continental and microplate collisions — reactivated old faults and broke the margin into a mosaic of basins and uplifts: the five basins, separated by the Tihemboka Uplift, Talemzane Arch, Nefusa Uplift and Qarqaf Arch.
- Silurian and Devonian source rocks laid down on the old margin survive in the basins but were mostly eroded from the uplifts.
- Differences in subsidence, uplift and erosion meant the source rocks matured at different times: in some basins gas formed before or during the Hercynian collisions; in others, the rocks reached the oil or gas window in the Mesozoic.
Source rocks
USGS defined one Paleozoic Composite Total Petroleum System, fed by two shales:
| Source rock | Organic carbon | Other traits |
|---|---|---|
| Lower Silurian Tanezzuft Shale (and equivalents) | Average 2% by weight, up to 24% | Hydrogen index up to 530 mg of hydrocarbon per gram of organic carbon; up to 100 m thick |
| Upper Devonian Frasnian shales | Up to 3% | Up to 80 m thick |
How far the source rocks extend in the Erdis Kufra Basin, and how mature they are, is unknown.
In the geologic model, oil and gas formed from these shales at times ranging from the Carboniferous through the Mesozoic, then moved into stratigraphic and structural traps in the basins and migrated updip into reservoirs on the flanks and crests of the uplifts. Reservoir rocks vary greatly from place to place.
By assessment unit
| Assessment unit | Probability | Oil, mean (million bbl) | Gas in oil fields, mean (billion cu ft) | Gas in gas fields, mean (billion cu ft) |
|---|---|---|---|---|
| Tihemboka Uplift | 1.0 | 16 | 9 | 1,078 |
| Talemzane Arch | 1.0 | 26 | 52 | 529 |
| Berkine Basin | 1.0 | 51 | 103 | 1,621 |
| Illizi Basin | 1.0 | 26 | 77 | 818 |
| Hamra Basin | 1.0 | 16 | 16 | 1,035 |
| Murzuq Basin | 1.0 | 153 | 61 | — |
| Erdis Kufra Basin | 0.72 | 131 | 52 | — |
| Total | 419 | 5,451 (all gas) |
The Murzuq and Erdis Kufra units were assessed for oil fields only.
The Murzuq and Erdis Kufra Basins hold the most undiscovered oil; the Berkine Basin, the most gas.
Sources
Based on Schenk CJ, Mercier TJ, Woodall CA, et al., "Assessment of Undiscovered Conventional Oil and Gas Resources in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of Northern Africa, 2026," U.S. Geological Survey Fact Sheet 2026–3009; a work of the United States government in the public domain.
Licence: CC0 1.0 (public domain) · Adapted from pubs.usgs.gov
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