Perilous Pathways: The Danger Of Drilling Near Abandoned Wells
There are probably around 200,000 abandoned oil and gas wells in Pennsylvania. We know where just a slim fraction – probably four percent – of these wells are.
The information gap is a problem, because abandoned wells are dangerous.
Abandoned wells provide pathways for methane gas to seep to the surface, where it can, under the right settings, trigger explosions. Active drilling near unplugged abandoned wells is dangerous, too. In June 2012, the intersection between a Shell fracking operation and a forgotten well drilled in 1932 likely led to a 30-foot geyser of methane and gas.
Pennsylvania’s Department of Environmental Protection has been working to identify and plug abandoned wells since 1989, but it’s a slow process, due to limited funds.
StateImpact Pennsylvania takes a look at this issue in “Perilous Pathways,” a four-part online series answering questions about abandoned wells. Click on the links below to read each part of the series, as well as an infographic explaining methane migration, and a map documenting every known abandoned well in Pennsylvania.
The gas didn’t come from the Butters well, nor did it originate from the Marcellus Shale formation that a nearby Shell well had recently tapped into. What most likely happened to cause the geyser in June, Shell and state regulators say, was something of a chain reaction. As Shell was drilling and then hydraulically fracturing its nearby well, the activity displaced shallow pockets of natural gas — possibly some of the same pockets the Morris Run Coal company ran into in 1932. The gas distrubed by Shell’s drilling moved underground until it found its way to the Butters well, and then shot up to the surface.
Pine runs the DEP’s division in charge of finding abandoned wells and plugging them with cement so that they won’t do harm. Simply by the numbers, it’s an overwhelming job. The best guess of both the state and the energy industry is that somewhere in the neighborhood of 325,000 wells have been drilled in Pennsylvania since Drake’s. Of those, about 120,000 have state permits on file. “Just do the math,” Pine says. “There’s probably close to 200,000 wells that are largely or relatively unaccounted for in the commonwealth.”
The state does know where some of them are. A spreadsheet on DEP’s websitelists the location of 8,257 abandoned and orphaned oil and gas wells. StateImpact has mapped them all here. (The difference between “abandoned” and “orphaned’ is largely an administrative distinction.) If Pine’s math is right, regulators know the locations of only 2 to 4 percent of the abandoned wells in Pennsylvania.
Yet the whereabouts of the vast majority of these old wells remains a mystery. Time has marched on in the decades since the wells were first drilled. Trees and brush have covered their holes. Scrap collectors have pried metal casing — often the most obvious sign of a well’s presence — out of the ground. And towns and cities have been built on top of them.
So finding old wells can require a good amount of forensic work. To find one, you can employ high-tech radar or use a musty antique survey map. Whatever method you choose, it’s going to be a time-intensive effort.
As Shell’s summer geyser demonstrated, drilling near abandoned wells can be dangerous. Yet for all the things Pennsylvania requires companies to survey before they drill — there are a dozen items on the checklist — abandoned wells are not one of them. No Pennsylvania laws or regulations bar energy companies from drilling within a certain distance of an unplugged well. Additionally, drillers aren’t required to search for or plug abandoned wells within a certain radius of their site.
Pennsylvania isn’t alone in this omission. A number of other states, including Texas, Oklahoma and West Virginia, have both an abandoned well problem at the same time that they’re seeing a shale drilling boom. Of those states, only Ohio considers the presence of these dangerous pathways when deciding whether or not to approve a permit. Essentially, most of the states are leaving the question of how to handle abandoned wells up to the drilling companies.
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