by Vaclav Smil
In contrast, nine months of monitoring tracers injected into six shale gas wells in Pennsylvania’s Marcellus shale showed no signs that fracking fluids are ascending toward the surface where they could contaminate well water (Stokstad, 2014). Contradictory findings are not surprising because the impact of shale gas extraction on regional water quality is not a topic for easy generalizations and simplistic conclusions (Vidic et al., 2013). Low, naturally occurring volumes of CH4 (<10 mg/l) pose no health hazards, higher levels can increase the solubility of arsenic and iron and stimulate the growth of anaerobic bacteria, and high accumulations could result in an explosion.
Stray methane can enter wells from natural biogenic or thermogenic sources as well as from such anthropogenic sources as landfills, coal mines, pipelines, and abandoned old oil and gas wells (of which there are hundreds of thousands in Pennsylvania or Texas)—but, undoubtedly, the gas can also come from fractured casing and leaking cement seals that fail to insulate wellbores from aquifers that normally lie at least many hundreds of meters above the formations subjected to HVHF (Vengosh et al., 2013). Typical incidence rate of casing and cement problems is 1–2% but Vidic et al. (2013) found the frequency of 3.4% in Pennsylvania’s Marcellus formation. Pinpointing methane sources in a well may be difficult, and moreover, in some regions (notably in Marcellus shale in Pennsylvania), intensive fracture networks may provide hydraulic connectivity between deep shale gas formations and the overlying shallow aquifers.
There are reasons for encouragement but also arguments for caution. After more than one million of HVHF treatments, there is perhaps only one documented case of direct groundwater pollution resulting from injection of fracking chemicals—but confidentiality requirements (imposed by ongoing investigations), expanding scope of fracking, and possibility of cumulative, slowly developing impacts are arguments for caution (Vidic et al., 2013). There is no doubt that in all regions with extensive HVHF the extraction will have widespread acceptance only with strictly enforced regulations designed to prevent aquifer contamination.
Some of these concerns may have been exaggerated, public opinion has been manipulated by dubious claims, and many early problems should be reduced or eliminated as operating experience mounts and as innovative solutions, including the use of nontoxic fracking mixtures and the least offensive biocides, get widely adopted. In 2013, Halliburton introduced CleanStim, a mixture (not surprisingly, more costly than typical products) that uses only additives approved by food industry, and a year earlier EPA- and FDA-approved SteriFrac, a pH neutral biocide to kill bacteria without any toxic by-products. Surface spills of fracking liquid can be reduced by secondary containment including dikes and berms, retaining walls with heavy plastic liners (Powell, 2013). And waterless fracking, using LPG, may be the ultimate technical solution (Loree, Byrd, and Lestz, 2014).
We already have enough evidence to state with confidence that hydraulic fracturing will not invariably poison the air, will not cause everywhere spates of localized earthquakes, and will not produce flaming faucets in all nearby areas (to list just the key frightening impacts attributed to it by its opponents)—but there is also no doubt that hydraulic fracturing, done in thousands of hurried repetitions and sometimes without adequate planning, has the potential to be often not just unpleasant and disruptive but even outright damaging at the local level. Many people simply want to know more about the true risks of hydraulic fracturing: in September 2013, the Pew Research Center found 49% of Americans opposed to the increased use of the activity, while, a year after the Fukushima nuclear disaster, 58% of Americans also opposed the increased use of nuclear power (Pew Research Center, 2013). Such perceptions cannot be simply dismissed, and energy companies must address them and explain the true risks involved: recently Exxon, now the United States’ largest natural gas producer, promised to disclose more of such information.
In its media advertisement during 2014, Exxon stressed that “an amazing resource for Americans” can “be produced safely, while protecting water supplies” because there are “thousands of feet of protective rock between the natural gas deposit and any groundwater,” and “in addition, multiple layers of steel and cement are installed in shale gas wells to keep the natural gas and fluids used in the production safely within the well.” All true, but as I have just explained, neither reality makes contamination impossible, and we will need a longer record of cumulative performance (at least another 5 years) before we will be able to appraise with confidence the real degree of risk posed by HVHF to water supplies.
The best way to resolve any disputes concerning the impacts of fracking is to establish baseline conditions of water and air quality prior to drilling and fracturing, a step recommended by the International Risk Governance Council (IRGC, 2013). While it may be too late to do that as far as many intensively developed areas in the United States are concerned, future developments would clearly benefit from such measures. And careful assessment will be imperative in many of the world’s regions whose hydrocarbon-bearing shales are in arid regions where any fracking could lead to high or even extremely high stress on local water resources. Global assessment by Reig, Luo, and Proctor (2014) shows China and India in high-impact and Pakistan and Mongolia in extremely high-impact category.
Before I close this environmental section, I should note two important environmental advantages of gas compared to coal and oil. Unlike in the case of crude oil and refined oil products, where trucking and railroad accident and pipeline ruptures can lead to usually limited but still harmful spill, transportation of natural gas has no effect on water quality as any leaked fuel escapes into the atmosphere. And although the land claims of natural gas extraction are generally comparable to those of oil production, they are much smaller than for modern coal extraction, and in many countries producing all of these energies, they are the smallest of the three fossil fuels. These spatial claims are best quantified by calculating prevailing power densities, expressed as annual flux of energy per unit of surface (W/m2).
As already noted (in Chapter 3), power densities of natural gas extraction are typically between103 and 104 W/m2 and (commonly 2,000–12,000 W/m2), and this means that a gas field producing annually 1.2 Gm3 of natural gas (an equivalent of 1 Mt of crude oil) will have a land footprint as small as 10 ha or as large as 70 ha: even the latter total is a square with sides of less than 840 m. Gas output from hydraulically fractured horizontal wells has rapid production decline with power densities falling from 103 W/m2 in the first year to low 102 W/m2 just a few years later. Processing of natural gas has high-throughput densities of 104 W/m2, and power densities of long-distance pipeline transportation range from 102 to 103 W/m2.
As expected, power densities of oil extraction are similar, with the North American oil fields having long-term cumulative rates of about 2,500 W/m2 for more than 80 years in California and about 1,100 W/m2 for 50 years in Alberta, with the peaks of 104 W/m2 for the world’s most productive Middle Eastern fields (Smil, 2015). Only the largest underground coal mines tapping thick seams have power densities in excess of 10,000 W/m2; smaller operations are often above 2000 W/m2 and usually not below 1000 W/m2. The largest surface mines that extract thick seams of bituminous coal have power densities of more than 10,000 W/m2, but most common operations rate 1,000–5,000 W/m2, and for Appalachian mountain-top removal, it can be as low as 200 (or even below 100) W/m2.
Finally, I should note an indirect environmental impact of natural gas extraction that could have been expected but whose intensity in Oklahoma still came as a surprise. Localized earthquakes have been attributed to deep well injections of water, mainly from dewatering operations used to separate oil and gas from large volumes of target rock formation and to a lesser extent from recent injections of contaminated fracking water across Ohio, Arkansas, Texas, and Oklahoma (Hand, 2014). Van der Elst et al. (2013) found that areas with suspected anthropogenic earthquakes are also more susceptible to earthquake triggering from natural t
ransient stresses generated by the seismic waves of large remote earthquakes and that fluid injections can bring critically loaded faults to a critical state.
As a result in 2013 and 2014, Oklahoma registered a similar, or higher, number of magnitude 3 or greater quakes than California. Damage to structures has been in most cases minimal, but the largest event (magnitude 5.7 in 2011 in Prague, OK) damaged four spires on Benedictine Hall at St. Gregory’s University in Shawnee, OK, located 25 km from the epicenter. Given that the likelihood of larger quakes is correlated with the frequency of smaller quakes (for every 100 magnitude 5 events, there will be 10 magnitude 6 quakes), there is a legitimate concern about triggering a much stronger anthropogenic earthquake.
8
The Best Fuel for the Twenty-First Century?
Those who have written effusively about America’s recent natural gas-based energy revolution, or renaissance, boom, or bonanza that will change the world—and Gold (2014) packed it nearly all into the title and subtitle of his book: The Boom: How Fracking Ignited the American Revolution and Changed the World—would say that the title of this closing chapter should not have a question mark (implying at least some uncertainty, if not a real doubt) but that it should be a simple, affirmative statement. And two prominent American promoters of natural gas called for the fuel’s new central role even before the expansion of shale gas production showed the potential of this new source of energy and led to an impressive decline of gas prices: in 2008, they unveiled similarly bold plans that envisaged a large-scale reorientation of American economy from oil to gas.
The plan that got much more publicity (because his author was willing to spend a great deal of his own money on advertising it and was always available to promote it personally in media) was revealed during the summer of 2008 by T. Boone Pickens who made his considerable fortune first in Texan oilfields and then as a corporate raider (Pickens, 2014). The 10-year plan rested on twofold substitution: to begin with, Pickens called for making the Great Plains “the Saudi Arabia of wind power” and to use this new wind power to replace all electricity produced by natural gas combustion and, in turn, to compress the available natural gas to be used in clean, efficient vehicles.
That switch was to reduce America’s dependence on imported crude oil by more than a third (thus strengthening the country’s fiscal position) and to create a new, large-scale domestic industry that would bring much needed jobs and economic revitalization to the Great Plains, a region of ever larger farms and ever smaller population. Pickens presented his plan to the Congress and spent $58 million on advertisement to generate public support. His principal motivation was to curtail what he saw as America’s addiction to oil that poses threat to “our economy, our environment and our national security” and that “ties our hands as a nation and a people” (Pickens, 2008).
Before the second switch (gas for liquid automotive fuels) could be put in place, his plan called for building more than 100,000 large-capacity wind turbines and at least 65,000 km of high-voltage transmission lines to connect new generating capacities in Texas, Oklahoma, Kansas, Nebraska, and Dakotas to large coastal cities. Pickens estimated that his plan will need roughly $1 trillion in private investment for new wind power and at least another $200 billion for the requisite transmission lines. And that would have to be followed by conversions of tens of millions of cars to natural gas fuel. Just months after launching the plan, Pickens (before the end of 2008) acknowledged that the need for new transmission lines makes any rapid progress impossible, and he also changed his gas-switching proposal from cars to trucks (that would require fewer filling stations selling compressed natural gas).
Combination of economic downturn (it began just a few months after the plan was launched) and rapidly rising availability of inexpensive natural gas from hydraulic fracking ended the short-lived plan. In July 2009, Pickens still claimed that “Financing is tough right now and so it’s going to be delayed a year or two” (Rascoe and O’Grady, 2009, 1), but soon afterward, even his own key wind power project (a 4 GW wind farm, the world’s largest, near Pampa in Texas) was first delayed and then, in January 2010, canceled because the $4.9 billion worth of the needed transmission lines would not pass all regulatory requirements before 2013. Between 2010 and 2013, as shale gas extraction expanded and as natural gas prices fell, little was heard about Pickens and his plan.
But Pickens was back in July 2014 when he told CNBC (Belvedere, 2014, 1) that
we're down to 4 million barrels a day of OPEC oil (from 7 million) … and we can knock that out within the next three years…. All you have to do is switch natural gas over to the heavy-duty trucks…. If [Washington] had gone with me six years ago, you figure you could probably had the job done in three to four years…. If that were the case, you would have cut out 75 percent of OPEC, because 8 million trucks converted to natural gas off of diesel is 3 million barrels a day.
But in July 2014, there was still no large-scale program to switch heavy trucks to natural gas, and the chances of Pickens plan were no better than in 2008.
The second transformative plan was offered by Robert A. Hefner III, an Oklahoma oil and gas developer and the founder and owner of The GHK Company who pioneered ultradeep natural gas exploration and completed the world’s deepest and highest-pressure natural gas wells. Hefner’s work as gas explorer and producer led him to believe—already during the 1970s, decades before a new consensus began to emerge—that the US reserves of the fuel may be larger than even the country’s huge coal deposits, and he thought that the best use of this rich resource is to convert a large share of the US vehicle fleet to natural gas. Already in 1989, Hefner argued that “the Detroit of natural gas fueled vehicles in the future should be located in Oklahoma … Natural gas will be the principal energy to fuel the U.S. and global economies into the twenty-first century,” and in 1991, he told an interviewer that “the nation has enough natural gas to last 100 years even without imports.…. We can convert a third of our cars and trucks to natural gas” (GET, 2014).
Hefner’s Grand Energy Transition (GET), a comprehensive version of his plans, was finally published in 2009 (Hefner, 2009); its subtitle, The Rise of Energy Gases, Sustainable Life and Growth, and the Next Great Economic Expansion, made it clear that the author saw the rise of natural gas as the key unlocking unprecedented environmental, economic, and quality of life benefits—but, in essence, his plan was fundamentally the second part of the Pickens scheme, although with some notable tax adjustments. Hefner argued that the conversion would be relatively easy because the requisite infrastructure is already in place: most of the existing gasoline filling stations are already connected to gas distribution lines as are most of America’s homes whose owners could fill more than 130 million vehicles after installing convenient home-fueling devices.
Hefner’s calculations had crude oil imports falling by about 250 Mt/year with cumulative saving of trillions of dollars in a decade, with concurrent benefits of some $100 billion of private investment, and about 100,000 new jobs spurred by the rising demand for natural gas. But unlike the Pickens plan, Hefner’s GET was to rely on a fundamental tax restructuring that would eliminate taxes on labor and capital and replace them with levies on coal and oil (a green consumption tax). Success of Hefner’s plan was thus dependent not only on infrastructural changes and technical adjustments but also on the readiness of the US Congress to go along with his bold new tax schemes. The latter move had little chance to be enacted by now chronically dysfunctional Congress, and the Hefner plan has not been any more successful than the Pickens plan. This is not at all surprising as energy transitions are generally gradual, often protracted, processes (Smil, 2010a).
Their incremental progress can be accelerated or retarded by specific policies—but only rarely do such measures result in truly revolutionary shifts: energy systems are too complex and generally fairly long-lived and hence too inertial to be rapidly redirected by deliberate action designed to change their fundamentals. Grand pla
ns aimed at their basic redesign thus have a very low probability of success, and we are left trying to do the best we can to nudge the process in what we think is the best direction—but we still must keep in mind that, in retrospect, we may find such actions not as beneficial as we thought them to be at the beginning. In this book, I have endeavored to make a strong case for natural gas as a preferred fuel—but as a lifelong student of energy in modern society I also know that there are no ideal fuels, and as an interdisciplinary scientist trying to understand behavior of complex system, I always try to think about unanticipated impacts, unintended consequences, and counterintuitive outcomes.
That is why I insist on the question mark in the chapter’s title—and on another question mark in trying to outline how far the extraction and conversion of natural gas might go during the coming decades, more specifically during the first half of the twenty-first century. My intent is not to answer the question either by a comprehensive review of the recent US and global forecasts of natural gas extraction or by offering my own forecasting model or at least some probable ranges of future volumes. I have shown that energy forecasting, in common with nearly all other long-range forecasting endeavors, has a poor record (Smil, 2003, 2010a), and hence, it is best to avoid additional contributions to this futile intellectual effort. Instead, I will concentrate on exploring the range of the most likely outcomes based on the best physical and technical evidence.
8.1 HOW FAR WILL GAS GO?
Despite its dismal record, long-range forecasting—as attested by an endless procession of new studies and models—retains an irresistible appeal. I will review some of these recent efforts in order to illustrate their questionable nature, but first, I will address the validity of an influential forecasting technique that appeared to solve the intractable challenge of impartial forecasting by relying on a fairly simply numerical approach that appeared to yield, repeatedly and for a wide variety of phenomena, results that were closely corresponding to past realities and hence seemed to be by far the best way to predict future outcomes.