Central North Africa
The Central North Africa region (Algeria, Tunisia and Libya) contains two major
shale gas basins: (1) Ghadames Basin: in eastern Algeria, southern Tunisia
and northwestern Libya (2) Sirt Basin: in north-central Libya. These basins hold significant volumes of shale gas resources, with 1,861 Tcf of risked gas in-place in the prospective areas.
Algeria is the sixth largest gas producer in the world, with marketed production of 8.2 Bcf per day and reserves of 159 Tcf, as of 2009. Gas production has been increasing over the recent decade, though at a slower rate than proved reserves.
The country’s natural gas infrastructure is well developed and includes one existing plus one planned LNG liquefaction plant and a regional natural gas pipeline system.
The US Energy Information Administration estimates that northern Algeria has 653 Tcf of risked shale gas in-place with 428 Tcf in the
Silurian Tannezuft Shale and 225 Tcf in the Middle Devonian Frasnian “Hot Shale” of the Ghadamas Basin.
Additionally, the Tindouf Basin of southwestern Algeria, contains 159 Tcf of risked gas. Once developed, this would represent a very large increase over the current proved natural gas reserves of Algeria. At the recent World Energy
Congress (September 2010), the Oil Minister of Algeria announced interest in assessing the natural gas resources of its shales and tight gas sands.
Libya is also a major hydrocarbon supplier, with 1.5 Bcfd of natural gas production from reserves of 50 Tcf and 1.7 million barrels per day of oil production from reserves of 41 billion barrels, in 2008. The US Energy Administration estimates that Libya has 1,147 Tcf of risked shale gas in-place, with 49 Tcf in the Silurian Tannezuft Shale and 8 Tcf in the Middle Devonian Frasnian Shale of the Ghadames Basin. An estimated 647 Tcf is in the Sirt Shale and 443 Tcf is in the Etel Shale of the Sirt Basin. The US Energy Administration estimates a risked technically recoverable resource of 290 Tcf, representing a major increase over current proved natural gas reserves. No public announcements of shale gas activity are reported for Libya. Libya’s natural gas production has more than doubled since 2004, when the “Greenstream”pipeline came online, linking Libya’s previously unconnected productive capacity to European markets.
Though it shares many of the same geologic features with Algeria and Libya, Tunisia has
a much smaller land mass than either of its neighbors, and thus much lower oil and gas production. In 2008, with gas consumption of 0.4 Bcfd and gas production of 0.3 Bcfd (from reserves of 2 Tcf), the country was a net natural gas importer. However, because of its favorable oil and gas investment incentives,
Tunisia has attracted many international E&P countries, and it is the only country in North Central Africa where unconventional natural gas potential is being actively explored. Tunisia had the first shale gas well in North Africa and is actively supporting the pursuit of thier resource.
The US Energy Administration estimates that Tunisia has 61 Tcf of risked shale gas in-place,
with 43 Tcf in the Silurian Tannezuft shale and 18 Tcf in the Frasnian “Hot Shales” of the Ghadames Basin. The US Energy Administration estimates a risked technically recoverable resource of 18 Tcf, representing a major increase over current proved natural gas reserves.
Western North Africa
Morocco has large accumulations of Late-Cretaceous immature oil shale (kerogen), at
depths suitable for surface mining. San Leon and Petrobras are beginning operations in
this area and estimate their potential at over 50 billion barrels. However, Morocco also possesses organically rich Silurian- and
Devonian-age shale gas potential in the Tindouf and Tadla basins, mapping and
resource characterization of these shales is difficult because regional deformation,
erosion, and subsidence of Morocco’s shale deposits resulted in their discontinuous and complex present day distribution.
The country’s primary shale target, the lower Silurian “Hot Shale,” was deposited during the
late Ordovician to early Silurian when glacial melting across the African super continent lead to a large sea-level rise across much of what is
now North Africa. During the early Silurian, sediments from the glacial melt settled in
regional lows and precipitated thin, but very organically rich layers of marine organic matter during a regional anoxic event, from wells drilled across the country confirms the presence of organic rich Silurian shales, though these areas do not always correspond to currently recognized hydrocarbon basins. The
presence of thick Silurian sections, observed in many Moroccan hydrocarbon basins, does not guarantee the presence of organically rich shale, as areas that were regional highs during the early Silurian did not receive organically
rich sediments. Morocco is heavily dependent on natural gas imports to meet its consumption needs. In 2009, the country consumed 0.05 Bcfd of natural gas, of which 0.049 Bcfd were
South Africa has one major sedimentary basin
that contains thick, organic rich shales. This basin is known as the Karoo Basin in central and southern South Africa. The Karoo Basin extends across nearly two-thirds of the country, with the southern portion of the basin
potentially favorable for shale gas. However, the basin contains significant areas of volcanic (sill) intrusions that may impact the quality of the shale gas resources, limit the use of seismic imaging, and increase the risks of shale gas exploration.
Natural Gas Profile
Southern Africa produced 115 Bcf of natural gas in 2008. With annual consumption that year of 228 Bcf, South Africa is a net importer, primarily from neighboring Mozambique and Namibia. The natural gas is used primarily for electricity production and as feedstock for the Mossel Bay gas-to-liquids (GTL) plant. (New
natural gas production is expected from the Jabulani field in 2012 and the Ibhubesi field in 2013.) Natural gas from Mozambique is imported via a 535-mile pipeline, with current peak capacity of 524 MMcfd. Assuming access to new natural gas reserves, a variety of plans have been set forth to expand the
natural gas pipeline system of South Africa. The technically recoverable shale gas
resource for South Africa is estimated at 485 Tcf.
Source: eia U.S. Energy Information Administration, April 2011, World Shale Gas Resources: An Initial Assessment of 14 Regions Outside the United States http://www.eia.gov/analysis/studies/worldshalegas/