U.S. Geological Survey Fact Sheet Fact Sheet FS U.S. Department of the Interior U.S. Geological Survey 2327-69162327-6932 2026-3009 10.3133/fs20263009Assessment of Undiscovered Conventional Oil and Gas Resources in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of Northern Africa, 2026 National and Global Petroleum Assessment 2026 U.S. Geological Survey Reston, Virginia Abstract

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 419 million barrels of oil and 5.5 trillion cubic feet of gas in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa.

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 Introduction

The U.S. Geological Survey (USGS) assessed the potential for undiscovered, technically recoverable conventional oil and gas resources in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa (fig. 1). During the early Paleozoic Era, northern Africa had a north-facing passive continental margin of the paleo-Tethys Ocean. Late Carboniferous to Permian contraction from the Hercynian orogeny—a series of continental and microplate collisions—reactivated regional fault systems that segmented the passive margin into a mosaic of basins and uplifts (Badalini and others, 2002; Dixon and others, 2010; Eschard and others, 2010; Galeazzi and others, 2010). The Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins and intervening Tihemboka Uplift, Talemzane Arch, Nefusn Uplift, and Qarqaf Arch resulted from the orogenic events. Silurian and Devonian source rocks deposited during the passive-margin phase are preserved in the basins but were largely eroded from the uplifts (Eschard and others, 2010). Variations in the magnitude of subsidence, uplift, and erosion among the basins led to temporal and spatial variations in thermal maturation of the source rocks (Underdown and Redfern, 2008; Bora and Dubey, 2015). In some basins, gas is interpreted to have been generated before or during Hercynian contraction, and in other basins, the source rocks reached the thermal window for oil or gas generation in the Mesozoic Era (Makhous and others, 1997; Boote and others, 1998; Davidson and others, 2000; Yahi and others, 2001; Makhous and Galushkin, 2003; Underdown and Redfern, 2008; Eschard and others, 2010; English and others, 2016; Jaeger and others, 2017).

Map showing the location of seven conventional assessment units (AUs) in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa.

Seven assessment units span Tunisia, Libya, Sudan, Chad, Niger, and Algeria. Total Petroleum System and Assessment Units

The USGS defined the Paleozoic Composite Total Petroleum System (TPS) in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa. Seven conventional assessment units (AUs) were defined within the TPS (table 1). The main source rocks for this composite system are the organic-rich lower Silurian Tanezzuft Shale (and equivalent shales; Boote and others, 1998; Cochran and Petersen, 2001; Hassan and Kendall, 2014; Albriki and others, 2024) and Upper Devonian Frasnian shales (Lüning and others, 2004; Hassan and Kendall, 2014; Albriki and others, 2024). Petroleum generated from these shales was combined into a composite TPS for this assessment. Silurian shales contain an average of 2 weight percent (wt. pct.) residual total organic carbon (TOC) with as much as 24 wt. pct., have initial hydrogen index values as much as 530 milligrams of hydrocarbon per gram of TOC, and have shale thickness as much as 100 meters (Lüning and others, 2000; Kaced and Arab, 2012; Arfaoui and others, 2024). Devonian shales contain as much as 3 wt. pct. residual TOC and have shale thickness as much as 80 meters (Kaced and Arab, 2012). The extent and thermal maturity of the source rocks in the Erdis Kufra Basin are not known (Lüning and others, 1999).

Key input data for seven conventional assessment units in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa.

[Gray shading indicates not applicable. AU, assessment unit; MMBO, million barrels of oil; BCFG, billion cubic feet of gas]

Assessment input data—Conventional AUs Tihemboka Uplift Conventional Reservoirs AU Talemzane Arch Conventional Reservoirs AU
Minimum Median Maximum Calculated mean Minimum Median Maximum Calculated mean
Number of oil fields 1 2 4 2.1 1 3 6 3.1
Number of gas fields 1 20 40 20.5 1 10 20 10.2
Size of oil fields (MMBO) 5 7 20 7.5 5 7 60 8.5
Size of gas fields (BCFG) 30 48 180 52.6 30 48 150 51.6
AU probability 1.0 1.0
Assessment input data—ConventionalAUs Berkine Basin Conventional Reservoirs AU Illizi Basin Conventional Reservoirs AU
Minimum Median Maximum Calculated mean Minimum Median Maximum Calculated mean
Number of oil fields 1 5 10 5.1 1 3 6 3.1
Number of gas fields 1 30 60 30.7 1 15 30 15.4
Size of oil fields (MMBO) 5 7 150 10.0 5 7 50 8.3
Size of gas fields (BCFG) 30 48 180 52.6 30 48 200 53.3
AU probability 1.0 1.0
Assessment input data—Conventional AUs Hamra Basin Conventional Reservoirs AU Murzuq Basin Conventional Reservoirs AU
Minimum Median Maximum Calculated mean Minimum Median Maximum Calculated mean
Number of oil fields 1 2 4 2.1 1 20 40 20.5
Number of gas fields 1 20 40 20.5
Size of oil fields (MMBO) 5 7 20 7.5 5 7 20 7.5
Size of gas fields (BCFG) 30 48 120 50.5
AU probability 1.0 1.0
Assessment input data—ConventionalAUs Erdis Kufra Basin Conventional Reservoirs AU
Minimum Median Maximum Calculated mean
Number of oil fields 1 10 40 11.0
Size of oil fields (MMBO) 5 10 300 16.5
AU probability 0.72

The geologic model for the Paleozoic Composite TPS is for oil and gas to have been generated from Silurian and Devonian organic-rich shales, with generation possibly ranging from the Carboniferous through the Mesozoic. Oil and gas migrated into conventional reservoirs within stratigraphic and structural traps in the basins and migrated updip from the source rocks into conventional reservoirs along the flanks and crests of the intervening uplifts. Reservoirs in the basins and uplifts are characterized by complex spatial heterogeneity of facies and petrophysical properties (Dixon and others, 2010; Jabir and others, 2020). The assessment input data for the seven defined AUs are summarized in table 1 and Schenk (2026).

 Undiscovered Resources Summary

The USGS quantitatively assessed undiscovered, technically recoverable conventional oil and gas resources in seven AUs (table 2) in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa. The estimated mean resources are 419 million barrels of oil (MMBO), with an F95 to F5 fractile range from 177 to 810 MMBO; 5,451 billion cubic feet of gas (BCFG), or 5.5 trillion cubic feet of gas, with an F95 to F5 fractile range from 3,556 to 7,919 BCFG; and 230 million barrels of natural gas liquids (MMBNGL), with an F95 to F5 fractile range from 152 to 335 MMBNGL.

Results for seven conventional assessment units in the Berkine, Illizi, Hamra, Murzuq, and Erdis Kufra Basins of northern Africa.

[Gray shading indicates not applicable. Results shown are fully risked estimates. F95 represents a 95-percent chance of at least the amount tabulated; other fractiles are defined similarly. MMBO, million barrels of oil; BCFG, billion cubic feet of gas; NGL, natural gas liquids; MMBNGL, million barrels of natural gas liquids]

Total petroleum system and assessment units (AUs) AU probability Accumulation type Total undiscovered resources
Oil (MMBO) Gas (BCFG) NGL (MMBNGL)
F95 F50 F5 Mean F95 F50 F5 Mean F95 F50 F5 Mean
Paleozoic Composite Total Petroleum System
Tihemboka Uplift Conventional Reservoirs AU 1.0 Oil 12 15 23 16 7 9 14 9 0 0 0 0
Gas 715 1,050 1,536 1,078 26 38 56 39
Talemzane Arch Conventional Reservoirs AU 1.0 Oil 13 24 45 26 27 48 92 52 3 5 9 5
Gas 349 516 756 529 28 41 61 42
Berkine Basin Conventional Reservoirs AU 1.0 Oil 25 45 99 51 49 90 200 103 2 3 7 4
Gas 1,086 1,581 2,298 1,621 54 79 115 81
Illizi Basin Conventional Reservoirs AU 1.0 Oil 13 24 43 26 40 72 129 77 1 2 4 2
Gas 536 798 1,172 818 24 35 52 36
Hamra Basin Conventional Reservoirs AU 1.0 Oil 12 15 23 16 12 15 23 16 0 0 1 0
Gas 695 1,011 1,464 1,035 14 20 29 21
Murzuq Basin Conventional Reservoirs AU 1.0 Oil 102 149 217 153 40 60 87 61 0 0 0 0
Gas
Erdis Kufra Basin Conventional Reservoirs AU 0.72 Oil 0 117 360 131 0 45 148 52 0 0 1 0
Gas
Total undiscovered conventional oil and gas resources 177 389 810 419 3,556 5,295 7,919 5,451 152 223 335 230
For More Information

Assessment results are also available at the USGS Energy Resources Program website, https://www.usgs.gov/programs/energy-resources-program.

 Northern Africa Basins Assessment Team

Christopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Thomas M. Finn, Heidi M. Leathers-Miller, Michael E. Brownfield, Phuong A. Le, Stephanie B. Gaswirth, and Marilyn E. Tennyson

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