A common question arises when people talk about “fracking,” the colloquial term for the drilling process of hydraulic fracturing — how much oil and gas is really down there? New research led by the University of Texas at Austin says it’s not as much as some expected, but not as little as expected, either. And it can largely depend on where you drill.
A team of researchers, led by UT’s Bureau of Economic Geology Director Scott Tinker, took a “bottom-up” approach in measuring the production of wells drilled using fracking in the Barnett Shale of Texas. “We were looking at shale gas potential in the United States, and we asked the question: what is the production and what are the reserves of natural gas in that shale over the next couple of decades?” Tinker tells StateImpact Texas.
They got production data for 16,000-plus wells in the region, every single well that had been drilled up until that point, and then looked at what areas still hadn’t been drilled. “When that was all said and done, we came away with the conclusion that a lot of gas has been produced up there,” Tinker says. “But there’s still quite a bit left to produce over the next couple of decades.”
The assessment “foresees slowly declining production through the year 2030 and beyond, and total recovery at greater than three times cumulative production to date,” the University writes in a press release. The research doesn’t look at environmental impacts of drilling, only at how much gas can likely be drilled.
And the Barnett Shale has some sweet spots.
Those are primarily at the intersection of Denton, Tarrant and Wise County, as well as along the border of Johnson and Tarrant County. Wells drilled in the Western parts of the shale were less productive. The report estimates that about two thirds of the wells needed have already been drilled, with about 10,000 wells left that could still be drilled in the region. The Barnett Shale started becoming attractive to drillers about five years ago.
“In the better areas, [drillers] might drain half of the rock. In the poor areas, they might drain ten percent of the rock,” Tinker says. “What that means is, there aren’t going to be very many wells drilled in the poor quality areas. But there’s still quite a bit of upside in the good quality rock.”
Tinker’s group received funding for the study from Alfred P. Sloan Foundation, and Tinker’s ties to the industry (he sits on the board of three oil and gas companies) are noted in the assessment’s press release.
The Barnett Shale currently produces around ten percent of the nation’s gas annually. While the study estimates that natural gas produced from the Barnett Shale will decline by more than half by 2030, in total, some 44 trillion cubic feet (TCF) of gas can be recovered from the formation. That’s roughly enough gas to meet the entire current U.S. demand for two years.
But that only happens at the right price, and because of the rapid increase in domestic drilling, natural gas prices have been very low over the last few years. If gas prices stay low, you may see less drilling taking place, like what’s happened in the Barnett Shale. The research finds that “when prices are low, it does not pay to pursue expensive parts of the formation, and this fact lowers the overall reserves estimate” and the opposite is true when prices go up: it makes the harder-to-reach areas more viable to drill.
An abundance of natural gas and low prices has led to a marked decline in coal usage in the United States. Since the fracking boom began in 2008, coal use in power plants has fallen by nearly half, according to federal government statistics. Several coal plants that were being planned for Texas have been cancelled, and there are currently no new traditional coal power plants in the works for the state. Carbon emissions have fallen as a result, dropping to their lowest levels in the U.S. in twenty years. And emissions of sulfur dioxide and nitrogen oxide, common pollutants from coal power plants, have also fallen, to their lowest levels in thirty years, as more gas power displaces coal and older coal plants are upgraded.
While the studies only look at gas drilling in the U.S., Tinker says their research and methods bode well for the oil shale drilling booming in parts of Texas and North Dakota. “I think you’re going to see some similar things,” Tinker says. “The wells in the Bakken and the Eagle Ford, they come on pretty strong, and then they decline. You have to continue to drill to maintain that production.”
Tinker’s group will complete the same reports for three other major natural gas shales by the end of the year: the Marcellus in Pennsylvania, the Haynesville in East Texas and Louisiana, and the Fayetteville in Arkansas.