If the next Tom Clancy were writing a techno-thriller about the future of natural gas, then the frozen solids called methane hydrates—a.k.a. “the ice that burns”—might be the perfect “macguffin” plot device to set the melodrama in motion. Scientific adventurers could dash around the planet after these exotic materials, which represent a gigantic and long-overlooked energy source. International intrigue could hinge on the potential of methane hydrates to make countries such as Japan suddenly energy independent. The heroes could strive to turn a nascent, ingenious technology for exploiting the hydrates into a weapon against disastrous global warming, while diabolical forces would threaten to use the hydrates to unleash an environmental Armageddon.
Reality, alas, has a poor sense of theater. Methane hydrates could indeed become important parts of the world’s energy infrastructure over the next couple of decades. But the twist is that old-fashioned supply-and-demand economics, not some new sci-fi tech wizardry, will ultimately determine whether methane hydrates can really save the day.
Recently, I had a chance to learn more about the status of methane hydrates while on assignment for the new Txchnologist (www.txchnologist.com) online magazine. My article for Txchnologist focused on what the hydrates’ potential as an energy source might be and what technologies were under development to make use of them. Inevitably, some worthwhile information that came out of the reporting didn’t fit within that scope, however, so I thought I might share some of it with you.
First, a few words of background. Methane hydrates are a form of water ice in which the lattice of frozen H2O molecules encloses molecules of methane. They can seem magically strange because they live up to their “ice that burns” nickname: if touched off with a flame, they burn bright blue with combusting methane. And they turn out to be surprisingly commonplace in nature—at least under the northern permafrosts and portions of the seabed where the temperature is low, the ambient pressure is high and methane can seep out from deep subterranean reservoirs.
As I noted for Txchnologist:
Estimates of how much methane is tied up in hydrates globally vary widely but are on the order of 1,000,000 trillion cubic feet. Most of that is flatly unattainable, explains Ray Boswell, the methane hydrates technology manager for the U.S. Department of Energy’s National Energy Technology Laboratory. Nevertheless, in 2010, he and Timothy S. Collett, a research geologist for the U.S. Geological Survey, estimated that even if gas producers restricted themselves to the most workable, sandy formations, the amount of recoverable methane in hydrates could be around 10,000 trillion cubic feet. That quantity compares favorably to the roughly 16,200 trillion cubic feet that the M.I.T. Energy Initiative’s 2010 “Future of Natural Gas” report lists as recoverable from all of the world’s remaining conventional sources.
That much natural gas ought to be irresistible if it can be captured safely and economically. No one yet knows whether it really can but the signs are at least currently promising.
Originally, people thought that gas companies might need to mine the hydrates by dredging the bottom of the ocean for them. That perception blunted interest in the hydrates as an energy source for years because such an approach would have been costly and inefficient, and raised the specter of disrupted hydrate formations accidentally releasing great clouds of methane—the last thing that our greenhouse gas-beset planet would need right now.
Fortunately, a vastly better way has come to light: preliminary studies suggest that wells dug into very deep sandy hydrate formations can simply pump methane and water to the surface. The opportunities for methane leakage are minimal because the hydrates are so deeply sealed beneath other sediments and because they spontaneously refreeze as soon as the pumping stops. The potential for an uncontrollable wellhead blowout like the one that destroyed the Deepwater Horizon and polluted the Gulf Coast thus appears to be impossible.
Researchers are also looking into another way of tapping the hydrates that involves injecting carbon dioxide into them. The carbon dioxide can displace the trapped methane in the hydrates and release it for collection. An additional advantage of this approach would be that it would sequester the CO2 beneath the seafloor, which could only help further in attempts to curtail climate change from industrial emissions.
(See my article for more details on both these pumping approaches.)
But of course, in the real world, a capability to use methane hydrates as a source of natural gas won’t matter unless it can do so cost-competitively. And right now, gas companies and politicians are most keenly excited about the relatively new prospect of using horizontal drilling and controversial “fracking” techniques to capture the natural gas inside oil shale formations. The U.S. Energy Information Administration notes that “adding the identified shale gas resources to other gas resources increases total world technically recoverable gas resources by over 40 percent to 22,600 trillion cubic feet.” It may be tough for methane hydrates, as a new and unorthodox gas resource that may not be able to reach a significant commercial scale for 10 to 15 more years, to make much headway against that competition.
Then again, maybe not. Certain factors might be more advantageous to methane hydrate development than one would think.
The first is that nations like Japan, which now have huge and expensive industrial energy costs, have extraordinary incentives to use the methane hydrates off their coasts. Japan has already announced that it hopes to begin some level of methane production from its Nankai Trough hydrates by 2018. So whether or not methane hydrates seem to make much economic sense here in the U.S., for example, other countries will be pushing the technology ahead regardless.
Energy companies may also see reasons to develop methane hydrates based on synergies with their other interests. In my interview with Timothy Collett of the U.S. Geological Survey, he pointed out that conventional natural gas comes out of the ground carrying a lot of CO2. (For example, the natural gas emerging from Alaska’s North Slope wells is about 10 percent CO2 [pdf].) By law, natural gas producers must remove that CO2 before they can store or transport their product but they cannot release it into the air. Yet if CO2 sequestration into hydrates proves feasible, Collett says, gas companies could use waste CO2 from their conventional gas wells to drive further methane production from the hydrates.
He also pointed out that oil companies working Alaska’s North Slope might find that developing methane hydrates could help them to maintain oil production. As oilfields there run dry, the companies now keep wells alive by pumping gas down into the reservoirs to maintain pressure. The methane from hydrates could become a handy local source of gas for recharging the wells: instead of distributing the methane as fuel, the companies could use it to keep their production of more valuable oil going.
(That incentive would surely be a mixed blessing in the eyes of climate hawks looking to move the global economy away from production and use of oil and coal. Still, perhaps it is still of value as a lesser-of-two-evils transitional step toward an energy infrastructure in which natural gas can more easily substitute for oil.)
It is also not yet a foregone conclusion that natural gas production from oil shales has a clear way forward. Though I am personally pessimistic about the odds of environmental or public health concerns standing in the way of the moneyed energy interests in this case, the huge and unsettled controversies about whether fracking is safe might yet trip up oil shale development. If so, the environmental desirability to find good, affordable sources of natural gas will still exist, which could help sustain interest in methane hydrates.
Expanded natural gas development is not ideal from a climate change perspective. Burning natural gas for energy is more appealing than using oil or coal because it produces less CO2 and other particulates—but on a rapidly growing global industrial scale, it still will contribute a lot. The best result for the environment would be for natural gas to grow as a transitional energy source while solar, wind and other green alternatives become still less expensive and more practical. (And making that transition may be a challenge in itself once natural gas is still more entrenched.) Whether methane hydrates can or will play a part in that strategy remains to be seen.
But methane hydrates are not just a resource. They remain, more darkly, one of the veiled menaces whose existence should urge action on the climate. The deep hydrate formations that developers might tap seem reasonably secure against big unwanted releases of methane—but the more shallow deposits on parts of the seafloor and under the Siberian and North American permafrosts are not. If global temperatures continue to rise, and if the oceans (which absorb most of the trapped greenhouse-effect heat) rise in temperature by a few degrees Celsius, then those more exposed methane hydrates will begin to decompose on their own. How much methane they could abruptly burp into the atmosphere is uncertain, and may depend on the precise circumstances. But any additional atmospheric methane will be unwanted and could greatly accelerate greenhouse effects for a few decades, further complicating any efforts to adapt to the new climate.
Maybe Neil Young’s lyric “It’s better to burn out than fade away” captures the odd paradox of methane hydrates best. Better to burn some of their methane in the short run, and suffer a CO2-driven aggravation of greenhouse problems en route to a more sustainable energy solution, than to continue with the energy status quo and wait for melting hydrates to worsen the climate problem for us.
Some additional resources on methane hydrates:
NETL Energy Resource Potential of Methane Hydrate (pdf). A good primer on methane hydrates and their energy resource potential.
MIT Energy Initiative’s 2010 “The Future of Natural Gas” report. A solid overview of natural gas in general that helps to put the still speculative potential of methane hydrates in perspective.
NETL National Methane Hydrates R&D main page. Filled with summaries and updates on the U.S. Department of Energy’s National Energy Technology Laboratory initiatives on developing methane hydrates.
National Academies Report 2010: “Realizing the Energy Potential of Methane Hydrate for the United States.” From the Committee on Assessment of the Department of Energy’s Methane Hydrate Research and Development Program: Evaluating Methane Hydrate as a Future Energy Resource.