So far as I know, the only overall figure for world shale gas resources comes from The World Energy Council (WEC). It has patched together a questionably high estimate of world shale gas resources putting the recoverable resource at 6744 tcf.11 WEC is obviously betting on shale gas. It puts world shale gas resources at 2.44 times “conventional gas”, two-thirds of them in North America and the erstwhile Soviet Union area. It puts the recoverable North American shale gas resources at 1778 tcf. That includes Canada, but still it puts recoverable U.S. shale gas resources far higher than the USGS estimate.
Shale oil: We have no serious worldwide estimates. The national estimates of shale oil resources are much lower than the gas estimates. The USGS figure for all U.S. oil resources, including shale oil, is 35 billion barrels, which is less than half its 1950 estimate.12 The DOE/EIA cites a mean estimate for recoverable shale oil in the U.S. of 24 billion barrels, only one-fifth of its figure for shale gas, in energy terms. Most of it is thought to be in the Monterey formation in California, with the Bakken field second. These estimates will change. The oil rigs are out in force, and we may expect a confusing series of new claims – probably hyperbolic – from drillers. As this paper is being written, the Texas driller Anadarko has claimed a discovery of “up to one billion barrels” of recoverable oil in Colorado. Maybe. The situation is, shall we say, fluid.
Speaking of energy independence, I would note that the EIA estimate above would replace just 2.6 years of U.S. crude oil imports, if it all proved out and all was pumped.
It has become fashionable to describe fracking as a “game changer” for fossil energy. Not necessarily. Fracking will add extra innings to the game, but the resource is finite, even with a high success rate. We will come to the end of the fossil energy era, but somewhat later than had been anticipated. That delay will, however, reverberate around the world.
Estimates of the date of peak world gas production have always been uncertain and mutually inconsistent, because of the multiplicity of gas sources and the difficulty of predicting how much is recoverable. The U.S. experience suggests, however, that gas shale will move the peak back some years or decades and substantially increase the ultimate recovery. It will replace oil and probably coal in many uses.
As to shale oil: peak world crude oil production from conventional sources may have been reached in 2005, and subsequent production has been on a fluctuating plateau.13 The advent of shale oil will extend that plateau by an unpredictable period and may lead to another peak. Bear in mind, however, that production from existing fields is declining something like 6.3% per year, worldwide. At that rate – just to stay even – new fields must be found to supply 73% of current production by 2030.14 Shale oil production will have to grow dramatically just to fill that growing gap, and it takes time to find and develop new fields. This all suggests that the era of decline will still begin before then, despite the advent of shale oil.
Even so, shale oil will delay the effective end of the petroleum era and mean that more oil will ultimately be recovered and burned than we expected.
What Are the Consequences of “Success”? People who live for the moment will celebrate the prospect that we will be able to continue our present wasteful ways for a few more years and that the shift to a more sustainable way of living – which will be painful – will be deferred. That comes, however, at the price of faster climate warming and a more rapid and painful adjustment when the oil and gas run down.
Perhaps I should begin this section on one small but cheerful note: shales are widespread around the world. The monopoly power of OPEC over oil will probably erode. Beyond that, there won’t be much good news.