Exploring Hydrocarbon Depletion
Page added on January 24, 2012
Here’s a brief explanation of why net-energy aka EROEI (energy returned on energy invested) debunks wild claims of “energy independence” from U.S. oil shale deposits like the Bakken Formation, and especially dry kerogen shale that can’t release its oil via fracking. Dry shale gets included in bogus claims about America’s reserves exceeding Saudi Arabia’s, but most shale is a poor energy source. Deniers just ignore the math.
Per the USGS, Bakken shale yields may never exceed 2 or 3%, and are typically on the order of 1% (the bulk of energy input is wasted). The shale exists over a wide area, but in shallow layers, and its porosity is highly variable. Hopefully, the analogy of getting water from clay vs. a lake will open some eyes on this topic.
Various official reports on the Bakken shale and other formations (e.g. http://www.usgs.gov/newsroom/article.asp?ID=1911) have been taken out of context by people who ignore total fuel and water consumption required to extract even a small fraction of hypothetical reserves. Many “conservatives” claim that loosening environmental regulations would create miraculous yields from energy-poor shale. They are deluded on many levels, including the idea that more pollution means progress.
A 2006 EIA report (ftp://ftp.eia.doe.gov/features/ngshock.pdf) led to false claims of of “503 billion” (also cited as “504 billion”) recoverable barrels in the Bakken, when it really meant gross potential reserves, not accounting for EROEI. Internet chain letters have broadcast false hype to the right-wing echo chamber. Read that EIA report for the true context.
Realistic recoverable oil from Bakken is probably under 5 billion barrels, or less than a year of total U.S. consumption. In addition, the Bakken formation contains “wet” oil that can be released via fracking, while the majority of U.S. shale is “dry” (kerogen) that must be cooked to released its oil, which requires far more energy, and has yet to be proven feasible on a large scale. That’s why the relatively free-flowing Bakken oil is being targeted first. Dry shale deposits with much lower EROEI are being deceptively categorized as similar to the Bakken, with net reserves overhyped even more.
Crackpots like Michelle Bachmann who call America the new “Saudi Arabia” ignore the past century we’ve spent depleting all our cheap oil. America can easily burn 20 million barrels each DAY, and getting that sort of flow-rate from shale is physically impossible.
The EROEI concept also applies to any fossil fuel that’s progressively more difficult to extract over time, such as ever-deeper offshore drilling, lower-grade goal and the need for natural gas fracking. The cheap, easy stuff is long gone and it’s reflected in prices, if nothing else will convince deniers.
END NOTE: The recent uptick on the U.S. oil production graph (at 0.51 in video) reflects increased U.S. (wet) shale oil production via horizontal drilling and hydraulic fracturing. Yes, yields are rising, but it’s a sign of desperation, not easy energy. Shale extraction and intensified offshore drilling will only create a mild bump on the historical curve and the 1970 peak will stand.