Since the Eastern Shale Gas boom began in Pennsylvania in 2007, public concerns over water issues have been building. So have business concerns among drillers over cost and supply problems with hydraulic fracturing. So, alternatives for “water-less” or “reduced-water” fracking have been getting a closer look.
Brook Lenker is head of the non-profit, public-access research and data website FrackTracker…Whether it is reports of water contamination, spills of contaminated flow back water, water consumption from streams and rivers, there’s this whole host of issues that the public really identifies with. So certainly, minimizing the use of water, minimizing the risk of contamination is a significant development. 20
And some of those alternatives are being put into use in Ohio.
According to Penn State hydrologist David Yoxheimer, three alternative frac-fluids are getting particular attention: Nitrogen, Carbon dioxide, and propane.
The objective in using each is two-fold: to put pressure in a rock formation to expand tiny cracks to release oil and gas trapped there; and, to move what’s called a “propant”—usually fine grains of sand—into the expanded cracks to hold them open.
Doing that with water requires three to five million gallons of water per well, raising concerns over everything from supply to disposal of waste water.
So Yoxheimer says field experiments with mainstreaming alternatives are getting underway. “Alternative technologies are going to be tried. I know a couple of carbon dioxide fracturing treatments occurred in the Utica shale.”
One experiment was at a well drilled in November off Congress Lake Road near the Portage County, Stark County line. It was a CO2 foam frac.
Yoxheimer says that process adapts an approach developed long ago for specialized geological conditions where the rock is very porous and water wouldn’t work well. “If you’re using water to open up some more porous formations, they’re going to want to absorb the water, and CO2 can be used as a sort of fracking carrier agent if you will.” (reporter question) “So the CO2 fluid becomes the fluid that brings the propant in, like the water used to. How well, though, does the CO2 work to create effective fractures in the rock?” (Yoxheimer) “It depends on the stresses that are put on the shale down there; how much horsepower you use; and how extensive the existing fractures are. And the, you know, the actual fractures themselves, you’re looking at more or less hairline fractures. Just opened up a couple of sand grains wide—and that’s enough to let the hydrocarbons flow out of the shale and into the well bores.”
Another specialized fluid used for a long time is nitrogen. Rick Bender is vice president of Black Bridge Resources, a major driller in Kentucky and Tennessee and major user of nitrogen. “It’s compressed, liquefied—and it’s an inert gas, so it’s totally harmless —so they bring it out in a liquid form. They bring it up to a temperature where it becomes gas. And they inject that just like you would water. And they pressure up to crack the rock.”
Bender says geology in his area dictates nitrogen instead of water because unlike the here, shale there is full of clay. “When you put water on clay materials they tend to swell. So when you put water on and try to frac our shale, it doesn’t open it up, it closes it up. So we use nitrogen almost exclusively for the Devonian shale of Kentucky, northeast Tennessee and Virginia."
Bender says, where it can be used, water tends to be preferred over Nitrogen as a frac-fluid because it offers more precise control of pressure being pumped into the well bore. And, in places like Ohio where water is abundant, it’s usually cheaper to use. But, giventhat nitrogen just goes away as air after a fracking job, its environmental benefits may make it more widely popular in the future.
Kyle Ward works for GasFrac, a Canadian company that took a different route to a frac-fluid alternative. Instead of adapting a technology, it invented one. GasFrac uses a jellied propane and butane mix to pressure rock, and carry sand into the resulting cracks. And, he says, because it is a hydrocarbon itself it too has the environmental pluses of no clean-up and no waste for disposal. “Once it stimulates the hydrocarbons in the formation, it turns into whatever we’re stimulating. If we’re stimulating crude oil, then it turns back into a liquid. And it leaves the formation with the oil. If we’re stimulating a dry gas, it turns back into a vapor and it goes back with the dry gas. So, all we’re leaving down in the hole is sand.
Beyond that, Ward says GasFracs formula is less environmentally scary because it doesn’t include exotic and secret chemical additives found in a lot of conventional frac-water . “Its a mix of propane and butane: a phosphate ester, a very common household ingredient, used to jell it; Iron sulfate, which is a plant fertilizer; and then Magnesium oxide, which is the primary ingredient in Milk of Magnesia. So those are the four ingredients. We’re very transparent about what it is.
FrackTracker’s Brook Lenker says the alternatives to water sound intriguing…but…“there could be unique concerns with the new technologies that haven’t come fully to light yet.”
The questions include, for example, whether some of the mixtures could blow up, or burn violently. With the Nitrogen or CO2 foam technologies no. But, a propane/butane mix could be very explosive. Asked if this means there’s a risk of turning an eight-thousand foot deep well bore into an 8-thouand foot long cannon barrel, GasFrac’s Kyle Ward said, no more risk than is already there, because propane, butane and hydrocarbons just like them are what is coming out of the well to begin with. But what about handling the propane at the well site? We’re a closed environment, totally pressurized system. So, if you think about it in your everyday life, think about your propane tank on your gas grill at home. That’s a pretty safe tank. You’re not worried about walking by that or anything like that. What’s flammable is the vapor that comes out of it, right? I mean, you could stick a match in the actual tank and it would be fine because there’s no oxygen in there. And that’s what our whole system is. It’s in that, kind of, propane tank. “ (Reporter question) “I understand you have monitoring procedures for catching leaks and so forth, but there have been reports of flash fires and accidents at your sites? (Ward) “We’ve had two incidents in over 16-hundrd jobs. And the most major incident was a second degree burn on a person’s nose. And he was back to work a week later.”
Another issue with the alternative processes is expense. All three tend to be more costly than water fracking…sometimes twice as much. But in all three cases, supporters say savings on the “after-fracking” end, when there are no cleanup and waste disposal costs, are evening that out and the alternatives are becoming economically viable. And the public opinion and political benefits of being less environmentally threatening has a value too.
Finally, Brook Lenker of FrackTracker says, while addressing the water concerns is an important step in the fracking debate, it’s a step that can only go so far. “Reducing the use of water is a significant development. That said, there are other aspects of sale gas development—the air quality issue, social and economic impacts in communities, land use issues and forest fragmentation—there are a whole number of issues that just changing the way a well is fracked won’t necessarily erase, or minimize.
The Ohio Department of Natural Resources, which oversees gas well development, is gathering information on fracking technologies being used by well drillers in the state. But the way Ohio law is written, operators do not have to seek ODNR approval, or even advise the agency of what particular fracking technology they’re using.