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The U.S. Geological Survey has estimated the undiscovered, technically recoverable conventional oil and gas in the Senegal Basin Province of northwest Africa (2021).
The Senegal Basin Province. Its boundary is the same as that of its one assessment unit, the Senegal Basin Reservoirs. U.S. Geological Survey
The estimate
| Mean | Range (F95–F5) | |
|---|---|---|
| Oil | 13,929 million barrels — about 13.9 billion | 5,749 to 26,079 million barrels |
| Gas | 193,721 billion cubic feet — about 193.7 trillion | 87,592 to 342,358 billion cubic feet |
| Natural gas liquids | 3,123 million barrels — about 3.1 billion | 1,401 to 5,554 million barrels |
F95 means a 95% chance of at least that amount; F5, a 5% chance. The estimates are fully risked.
Of the gas, 54,324 billion cubic feet (mean) is expected in oil fields and 139,397 in gas fields. The assessors' calculated means were 153.7 undiscovered oil fields and 215.1 gas fields, with median sizes of 10 million barrels and 72 billion cubic feet; the largest allowed for were 12,000 million barrels and 80,000 billion cubic feet.
How the basin formed
The province is one stretch of the rifted passive margin along northwest Africa that formed as North and South America pulled away in the Late Triassic. Its long, complex history from the Triassic to the Neogene shows in the wide range of reservoirs, traps and source rocks it holds.
Source rocks
All within one Mesozoic Composite Total Petroleum System of organic-rich shales, Triassic to Cretaceous:
| Shales | Thickness | Organic carbon | Hydrogen index (mg HC per g TOC) |
|---|---|---|---|
| Cenomanian–Turonian — thought the best source rocks | up to 60 m | up to 20 weight-percent | up to 600 |
| Aptian–Albian | up to 100 m | up to 34 weight-percent | 450–650 |
There are no geochemical data yet for Triassic rift-lake shales or Jurassic deep-water shales.
Reservoirs
- Triassic: river, delta and lake sandstones in structural and stratigraphic traps, perhaps sealed by salt — including along the flanks of salt diapirs.
- Lower Jurassic to Lower Cretaceous: carbonate platform-margin reefs, karst, off-platform gravity-flow deposits, and slope-channel and basin-floor sandstones where sediment bypassed the carbonate shelf edge.
- Upper Cretaceous to Eocene sandstones — from river-delta to basin-floor fan deposits — are the most important reservoirs today, and extensive, stacked basin-floor fans may hold the most undiscovered resources.
More results: USGS Energy Resources Program.
Sources
Based on Assessment of Undiscovered Conventional Oil and Gas Resources of the Senegal Basin Province of Northwest Africa, 2021, U.S. Geological Survey Fact Sheet 2022–3080, by Christopher J. Schenk and others, USGS Publications Warehouse; a work of the United States government in the public domain. The map caption's "Sengal" is corrected to Senegal.
Lizenz: CC0 1.0 (gemeinfrei) · Bearbeitet nach pubs.usgs.gov
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