Confessions of a Former Petroleum Geologist
Prepared by Anne Dalke
Additions, revisions, extensions are encouraged in the Forum
Blythe began with a few humorous (and not-so-humorous) feints, including the prediction of the end of the petroleum age, in 2040; and the claim of a linear correlation between the cost of oil and the numbers of students taking geology. She then explained how natural oil, gas and water are arranged underground in terms of relative density; how oil needs to move into a place where it can be captured, and so tapped; and how extraction from a petroleum reservoir takes place. The first big challenge is to work out the subsurface geology; but even when you know where the reserves are, it is not possible to extract all the petroleum. Blythe explained the differences--and progressive difficulty--of primary, secondary and tertiary extraction. She then gave accounts of our consumption habits, production capacity, and import quotas. In the late nineties, the global spare capacity was high, but at this point we have a small margin of excess capacity; there is not much room for error. It took millions of years to create hydrocarbons, and it will take a very long time to replenish what we are using at such a rapid rate. There is a huge amount of carbon locked up in rocks, and we may be able to get more oil out of the ground. But this is a dangerous process: removing all the fluids in the base can lead to collapse of the land form.
Blythe looked next at what we do with the oil. She predicted that, although science will find ways to replace, with other sources, the fuel we need both for car transportation and the heating of buildings, we are "going to be in trouble" in trying to replace jet fuel ("unless we are willing to slow down again") and other products (such as plastics and pharmaceuticals). "What is really scary" is that the producers with investments in oil shale are now promoting alternative sources of energy and advising consumers to conserve their petroleum use. Blythe described herself a "personally a big fan of conservation; we create a lot of unnecessary waste." But if the companies that produce the product are telling us to use less of it--that's significant!
Discussion turned first to the cost balance of energy in/energy out: do for-profit companies always derive more energy than they put into the extraction process? (Costs include not just finding and pumping petroleum, but refining and transporting it--the "downstream" part of the industry.) The suggestion was made that the significant calculation is not about energy use, but is rather monetary. A physicist knows that "you cannot create or destroy energy; you cannot break the second law of thermodynamics"; energy used up in one part of the system has to be balanced with energy production somewhere else. But the cost-benefit ratios for marketing are very different from those of the physics underlying the process.
The question was then posed of how difficult it might be to make high-carbon molecules inorganically. Can we use solar energy to make long-chain carbons? There was some debate about whether we currently have the knowledge necessary to do this. There was no debate that, at this point, we don't know how to do it efficiently; monetarily, it's "not worth doing" at the present time. "We know the energy balance, but not the economic balance." But--it was insisted--plants do it; why couldn't chemists? (This seemed akin to saying, "Humans think; why can't computers?") We pursued this idea for a while: rather than "thinking like a petroleum engineer, or a geologist, think like a biologist." Rather than worrying about the diminishment of our existing store, we could start making carbons. Mention was made of the recent brown bag discussion advocating increased use of nuclear energy; but here's another alternative.
We have plenty of carbon dioxide. We now use amounts of energy to "stuff carbon dioxide somewhere" (in the bottom of the ocean, in gas fields). Instead of "sequestering it," couldn't we instead usefully re-cycle is, as living systems do? Most oil companies are mitigating the environmental damage caused by their extraction processes by planting trees in clearcut areas. Mightn't they "just make more oil by recycling carbon dioxide directly"? It is already known that a trade-off works between costs of hydrating carbon and using that form to create other things--our whole life system is based on that process. There is no question but that it is worth while to store energy in form of hydrated carbon, then break it down to get energy out. Life does that on a large scale. "Life has solved this problem, and has an answer to this question, at an advantageous cost-benefit ratio."
The "problem with petroleum" is that it constitutes a "fixed known quantity of energy," and we are "close to finishing tapping" it. Our only "free," open--and essentially "endless"--source of energy is the sun. The "natural end of this logic" is that "we have to also be like plants." Why have we never explored the possibility "just making hydrocarbons"? Mightn't it be possible to develop a technology that, for a reasonable economic cost, could "cram electrons onto carbon"? We could learn to produce CO2, and become, like plants, part of the cycle of recycling it.
But why use solar power to make hydrocarbons? Why not just use solar power directly? Because we don't have the engines to use it efficiently, and a number of products (like plastics and pharmaceuticals) require petroleum for their production--for which, at this point, there is no good substitute. It might well be worth it to expend the energy to do the hard chemical work of making longer chains of carbon-carbon bonds. It would take a huge processing plant; but if we "want it bad enough," we could try this alternative.
But--it was countered--"we're not just asking for survival, but luxuries: make-up, plastics." Well, "life is doing all of that, and much more." All we think of as so demanding, life is doing in a million different places, and we are part of this supported system. The bio-system creates a lot waste, loses a lot of useable energy. As a receiving surface of energy for whole bio-system, plants use much less than 1% of the energy available from the sun. They are in turn transforming it into useable categories (including hydradrated hydro-carbons). They are burning energy to make a different form of energy. We should "get with the program."
Living the life to which we are accustomed is not supportable by current forms of energy production and use. The lives of our great-great grandchildren will not involve our current petroleum use. We know the thermodynamics behind this: we cannot create energy. We also know the calculations for sustainability--and (we here closed by evoking a number of cliches): "we are running in the red"; "there is no free lunch."
This conversation is invited to continue on-line.
The semester's brown bag series on "Rethinking Science in Society" will be in abeyance next week (for Thanksgiving break), but continue in person the following Friday, December 2, when Ralph Kuncl and Elizabeth Logue will lead a discussion of "Ethical Issues in Drug Development."