The Basic Facts of Oil Shale and Tar Sands
Oil Shale Fact Sheets
- Oil Shale's Triple Threat
- Oil Shale Energy Demands
- Oil Shale Economics
- Oil Shale's Questionable Energy Return
- Water on the Rocks Exec. Summ. and 2-page summary
- Fossil Foolishness Exec. Summ.
The Problems with "Unconventional" Petroleum
Petroleum resources cover a spectrum of materials that vary greatly in their physical properties, energy content and accessibility. The sweet spot, conventional crude, is in the middle of this spectrum. It is relatively cheap to produce and refine and produces the bulk of our transportation fuels. Conventional crude is what most people have in mind when they think of oil. Other petroleum products, known as unconventional resources, look and act very different than conventional petroleum, requiring more energy and labor-intensive methods to extract and convert into a useable fuel.
On opposite ends of the petroleum spectrum are the unconventional resources of oil shale and tar sands. Oil shale is fossilized plankton and algae that has turned into a waxy solid called kerogen. With millions more years of pressure and heat, kerogen will eventually transform into crude oil. Kerogen will only liquify when heated in excess of 600°F. Tar sands are essentially crude oil that has spoiled. Tar sands are what remains when crude oil has been broken down and degraded by bacteria, leaving behind a thick substance called bitemn that has only a fraction of the energy content of crude oil. Other petroleum resources less desireable than conventional crude are high sulphur "sour" grades of crude oil and heavy and extra-heavy oils that are sludge-like and difficult to pump. A relatively recent addition to this list is shale oil, which is conventional crude trapped in very tight rock formations that must broken open, or fracked, to allow the oil to flow. As conventional crude oil deposits are depleted, "unconventional" petroleum products are drawing interest as possible substitutes.
Oil Shale
The more that's understood about oil shale, the less realistic its various development schemes appear. As the current public debate over oil shale's future prospects grows louder, many of the pertinent facts about oil shale have fallen by the wayside. Below are some of the basic facts about oil shale that are being overlooked:
- There’s no oil in oil shale.
Oil shale is a controversial “unconventional” hydrocarbon resource that is poorly understood by the general public. Contrary to its name, oil shale contains no petroleum but is instead a dense rock that has a waxy substance called kerogen tightly bound within it. When kerogen is heated to high temperatures, it liquefies, producing compounds that can eventually be refined into synthetic petroleum products.
- Getting liquid from a stone.
The Achille's heel of oil shale is that it must undergo an energy-intensive conversion process to turn from a solid into a liquid. There are two basic methods to get kerogen out of oil shale. The first is to mine it through traditional hard rock mining methods, crush the rock, and cook it in a device called a retort that heats it without the presence of oxygen. The second method, called in situ, is to heat the rock where it lies underground to liquefy the kerogen and pump it to the surface. Both methods are far more energy and water intensive and expensive than traditional drilling methods for crude oil and thus does compete economically with crude oil.
- History of oil shale.
Humans have known about oil shale for thousands of years. Its first use as a commercial resource began in the 1830 in France, when it was mined and cooked in small quanitities to produce oil to light oil lamps. Oil shale's usefulness as a fuel source for illumination disappeared with the introduction of cheaper and safer electrical lighting. Efforts to develop oil shale in quantities sufficient for use as a transportation fuel have come and gone over the last one-hundred years, succumbing to technological insufficiency, unprofitability, and unsolvable environmental side effects.
- Oil shale in the US.
Oil shale is unevenly distributed around the world. The United States possesses roughly 70% of world oil shale deposits, with the vast majority located in the Green River shale regions in Colorado, Utah and Wyoming.
Interest in developing these western oil shale deposits has led to a number of booms and subsequent busts, often spurred on by incentives and prodding from the federal government. The first came between 1916 and 1920, when a land rush by prospectors and speculators led to a boom in interest in oil shale. Without adequate technology, and the emergence of a flourishing crude oil industry, this first wave of US oil shale development crashed.
Fears over domestic energy supplies sparked small oil shale booms in the 1950’s due to Cold War energy concerns, and again in the 1970’s as a result of the Arab oil embargo. But by 1980, the federal government had assembled a pot of subsidies, price supports, loans, and other incentives luring major oil companies to make substantial investments in the Piceance Basin area of western Colorado. This boom would be short lived. On May 2, 1982 -- “Black Sunday” -- ExxonMobil pulled out of oil shale due to falling oil prices and vanishing federal subsidies. The economy of western Colorado collapsed and the entire state of Colorado entered an economic slump as a result.
- Reemergence of oil shale
Oil shale has returned to the world stage due to rising oil prices and concerns about national energy independence. What has not changed is the lack of a technology capable of turning oil shale rocks into transportation fuels in a commercially viable manner. The George W. Bush Administration provided incentives to lure the oil industry back into oil shale with low royalty rates, access to federal lands, and relaxed regulations. But this time the traditional technological hurdles are being compounded by:
- questions about oil shale’s high carbon footprint and climate change consequences
- it’s high energy usage
- the large amount of water it would consume in a very dry part of the nation
- concerns over its potentially devastating environmental, social and economic consequences in western shale-bearing lands.
Tar Sands
- Turning pavement into fuel?
Utah's tar sands deposits have been used since the 1930's as a paving material for roads in Utah and surrounding states. Similar to oil shale, Utah's tar sands have a history of failed attempts to commercially extract liquid fuels from these bitumen-impregnated sandstone rocks. Paving has been this resource's most profitable use so far.
- Utah is not Alberta
Tar sands deposits in Alberta Canada are being exploited on a commercial scale. The negative environmental and social consequences of this tar sands boom are profound, but industry has figured out the technological solutions to make the industry profitable --when crude oil prices are high enough. The monetary success witnessed in Alberta will not be able to be mirrored in Utah, home to the United States' largest tar sands deposits. In Alberta, a thin layer of water binds the tar to the surrounding sands, allowing an energy and water-intense steaming process to readily separate the two. Utah tar sands, in sharp contrast, have no such layer of water binding the tar to the sands and will require discovering a new and different technology to make developing this resource economical.
Utah tar sands is also harder to mine that its Alberta counterpart. Whereas Alberta's tar sands are softer and more pliable, making them easy to scoop up with shovels and haul to a processing facility, the denser and harder Utah tar sands must be mined used hardrock mining techniques that greatly increase the cost and effort required to remove it from the ground. Utah tar sands will have higher mining costs, higher development costs, less economies of scale, and more financial risk involved than seen in Alberta.
- Not much fuel in a barrel of tar sands
Tar sands were at one point crude oil, but because of hydrocarbon-eating bacteria and other environmental degredation, much of the material that could have been turned into a fuel is gone. The bulk of what remains is a thick gooey substance called bitumen that cannot be burned to produce energy. In a barrrel of conventional light crude oil, roughly 10% out of each barrel is tar. With tar sands, over 2/3rds of each barrel is tar, with only about 1/3 being compounds that could be refined into any sort of fuel, and only a fraction of that can be turned into gasoline that can power your car.