May 24, 2011

Energy Return on Energy Invested (Heavy Oil)

This piece from the Wall Street Journal ("The End of Easy Oil") discusses the development by Chevron of the Wafra heavy oil field straddling the border between Saudi Arabia and Kuwait. The big oil companies, having lost their reserves to nationalization, are forced to engage in high risk projects in exchange for gaining access to oil. On the one hand, the piece suggests that a lot more oil is out there so long as the price is right--Chevron estimates it can make a profit at $60 to $70 a barrel. However, the "energy return on energy invested" for a project like this is low, as this depiction of the process suggests, and the implications for carbon emissions are especially grim.
To get to Wafra's thick oil, workers are injecting steam into the ground to heat the oil and make it less viscous, allowing it to flow to the surface. The technique is tricky, expensive and unproven in the type of rock that holds Wafra's oil.. . . .
Chevron is conducting what amounts to a four-year, $340 million test in a small corner of Wafra. Oil, like molasses, thins when heated. Large silver pipes carry 600-degree-Fahrenheit steam underground, flooding the oil-rich rock. Nearby, a grid of pumps pulls up the oil.
So far, the results have been encouraging. As of November, the wells were producing 1,500 barrels per day, seven times what they produced before steam injection began in 2009. . . .
Using steam to extract oil isn't a new idea. Chevron has been using the method to recover heavy oil at its Kern River field in Bakersfield, Calif., since the 1960s. That field yielded less than 10% of its oil using traditional methods. Using steam injection, Chevron is now on its way to pumping as much as 80% of the crude.
The Wafra project, however, is far more of a challenge than traditional steam projects. As in most of the Middle East, the oil at Wafra is trapped in a thick layer of limestone that also contains minerals that can build up inside pipes and corrode equipment.
An even bigger challenge is getting the two crucial elements for generating steam: water and a source of energy to boil it. Most successful steam projects are in places with easy access to relatively pure water and a cheap fuel source, usually natural gas. Saudi Arabia and Kuwait have little of either.
With no fresh-water sources in the Arabian desert, Chevron has been forced to use salt water found in the same underground reservoirs as the oil. That water is full of contaminants that must be removed before it can be boiled and injected into the ground.
Finding the energy to boil the water will be even tougher. Chevron could use oil instead of natural gas—literally burning oil to produce oil—but that would burn profits, too. So the company likely will be forced to import natural gas from overseas, an expensive process that involves chilling it to turn it into a liquid, then shipping it thousands of miles.
Some experts are shaking their heads.
"They're in trouble," says Robert Toronyi, a retired Chevron engineer who now serves as chief operating officer for Quantum Reservoir Impact, a Houston-based consulting firm. He says the project is so challenging that it will be hard for Chevron to turn much of a profit.
Expectations that "peak oil" would be beneficial because the scarcity of energy would reduce carbon emissions seem clearly misguided from this example. The scarcer that ready-to-access oil becomes, the greater the incentive to expend energy to get energy. The consequence is a lower net return on energy invested and a greater impact on emissions for every barrel of oil consumed.

The essential points were made in a paper by Alex Farrell and A.R. Brandt in 2006 (cited the other day by Climate Progress). There were two basic propositions:
[T]he oil transition is not a shift from abundance to scarcity: fossil fuel resources abound. Rather, the oil transition is a shift from high quality resources to lower quality resources that have increased risks of environmental damage, as well as other risks.

[T]he oil transition brings more long-term environmental concerns than long-term economic or security threats because tradeoffs have strong potential to be resolved by accepting increased environmental damage in order to avoid economic or security risks. The global petroleum industry has begun to recognize this interaction, but strategies to deal with them have not yet emerged.

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