United States is thought to have 862 tcf of shale gas, Libya's shale resources are put at 290 tcf, and Algeria's at 231 tcf.
The EIA study did not assess shale accumulations around the Middle East Gulf or in Russia and the other countries of the former Soviet Union, but they are thought to be extensive.
The report did not assess shale oil resources at all. But given the geology of total petroleum systems, it is very likely large shale accumulations will be found in the same areas and countries that already have large accumulations of conventional oil.
Crude-laden shale formations like North Dakota's Bakken, Eagle Ford and Permian in Texas, Oklahoma's Anadarko and California's Monterey are all in areas that have produced billions of barrels of conventional oil in the past.
The relationship between conventional and unconventional production in the same area is interesting and has not been properly explored yet. The basic question can be stated simply: Are unconventional oil and gas accumulations in areas already producing substantial volumes from conventional fields more or less likely to be developed than those in areas without substantial conventional petroleum production?
There are some reasons to think unconventional oil and gas deposits may be developed more quickly if an area has a (recent) history of conventional production.
Producing areas like North Dakota, Texas and the North Sea already have pipelines and other infrastructure to enable quick development of extra oil and gas from fracked wells. They benefit from a well-developed network of service companies. Local residents may be more comfortable about oil and gas drilling in their midst.
But in other countries, shale gas and oil accumulations may be developed much more slowly, or not at all, if there are already substantial conventional resources.
If Saudi Arabia discovered significant quantities of shale oil that doubled its conventional resources, would it double output? The answer is almost certainly that it would not. Marketing significant quantities of unconventional oil or gas would threaten to undermine the price for its existing conventional output.
Saudi Arabia is prospecting for shale accumulations, but for gas, not oil.
The same logic probably applies to Algeria (which