Emily Persico can only guesstimate how many abandoned oil and natural gas wells there are in the United States. And she has a high level of expertise.
“Estimates range pretty wildly because we don’t know,” said Persico, a policy analyst for PennFuture, a Harrisburg-based nonprofit that advocates for clean energy and the environment in Pennsylvania.
She paused and said point blank, “There are a ton ... a ton of abandoned wells in this country.”
These wells, a number of them uncapped, are potential sources of methane pollution. The Keystone State has 300,000 to 760,000 abandoned wells, according to various estimates - a wild range, indeed.
Persico said the state has 15% of the country’s abandoned wells. If the total is closer to 760,000 - which she believes - the national figure would be upwards of five million. That’s more than a ton.
As the issue of global warming continues to simmer, leakage from abandoned wells threatens the environment in an almost clandestine fashion. Many sit innocuously in isolated areas, undetected and undocumented. This is an under-the-radar concern, the scope of which cannot be pinpointed.
It is overwhelmingly a legacy issue, to be sure, tracing back to 1859, when Edwin Drake drilled the nation’s first commercial oil well outside Titusville. Hundreds of thousands of them were built over the next 96 years, without oversight, until permitting requirements were enacted in 1955.
“There is a bunch of problems with (abandoned) wells,” Persico said. “It’s hard to locate them and hard to access them. There is equipment with some, and just a hole in the ground with some.
“This is a major source of methane pollution, and it’s hard to estimate how much. Some (wells) are super emitters. And it seems that in Pennsylvania, one of biggest issues is water contamination.”
Dan Weaver, president and executive director of the Pennsylvania Oil & Gas Association, said “hundreds of thousands of wells were drilled (in Pennsylvania), especially in the northwestern part of the state. We are the birthplace of the petroleum industry, where there was well on top of well on top of well.”
He acknowledged abandoned wells are an issue, but added, “I wouldn’t hit the panic button.”
“Obviously, there is a huge push against methane and greenhouse gases,” he said. “But the amount of gas potentially coming from these wells is minuscule compared with a large cattle farm.
“There are hundreds of thousands of shallow wells, 800 feet and under, and not a lot of gas there. But it’s still a hot-button topic.”
A McGill University study, published in Environmental Science & Technology, said Pennsylvania is second to Texas in the number of abandoned oil and gas wells. The Lone Star and Keystone states, likewise, are Nos. 1 and 2 in gas production.
Kansas, West Virginia and Oklahoma are third through fifth in abandoned wells, according to the McGill report, which determined these five states account for 65% of the nation’s so-called AOGs.
Abandoned wells are prevalent in Pennsylvania’s southwestern corner, although, it cannot be determined as to how prevalent. Persico said the state Department of Environmental Protection’s data base features 9,000 documented AOGs statewide, and that 175 are collectively in Washington County, which has 110, while Greene has 58 and Fayette has seven.
“These are what DEP knows about,” she said. “Many, many more are undocumented.”
One issue that is particular to Southwestern Pennsylvania, according to Persico, is “so much of this area is undermined, you can have interactions” between legacy coal operations and natural gas. “With abandoned mines, pollution can get into cavities and into water sources.”
The McGill study - based on a compilation of databases, research articles and national repositories of drilled and active wells - concluded there are about 1.56 million undocumented and 2.49 million documented AOGs nationwide - a little more than four million overall. That is below the previous estimate of five million, but a formidable figure nonetheless.
That study also said, “unplugged oil wells in West Virginia emit less methane than those in Pennsylvania and Oklahoma, and plugged gas wells in Pennsylvania emit an order of magnitude more methane than those in other regions. This difference can be explained by the fact that plugged wells in coal areas in Pennsylvania are vented, highlighting how regional practices can influence emission factors.
“In other regions, plugged wells emit much less methane than unplugged wells, which highlights the general effectiveness of plugging procedures in preventing methane migration to the atmosphere.”
Methane is a major environmental threat. It is a greenhouse gas that is more than 80 times more potent than carbon dioxide in driving global warming.
A study conducted by Cornell University researchers, published last April in the journal Environmental Science and Technology, found methane emissions were worse in Pennsylvania than previously believed.
The researchers examined 589,175 operator reports on methane leaks from unconventional and conventional wells from 2014 to 2018. They concluded that emissions were at least 15% higher than expected, and believe the national percentage was similar.
Tony Ingraffea, professor emeritus of engineering at Cornell and lead author of the study, told the website ehn.org: “Another 15% of methane going into the atmosphere that we didn’t know about is very significant for climate change in the short term.”
Oil and gas wells have been operating in the Keystone State for 162 years, dating to Drake’s day. Many abandoned wells are considered “orphan wells,” erected before regulation, accessed and eventually shut down - in many instances, haphazardly or uncapped.
The abandoned well issue is one that modern shale producers are striving to alleviate, said David Callahan, the new Marcellus Shale Coalition president.
“We have been part of the solution in addressing this long-standing issue,” he said in a statement. “To help this inherited problem, shale producers work collaboratively with government agencies and conservation groups to plug many of these older wells.”
Callahan added the state’s “unconventional shale development regulatory framework also includes well-construction standards, plugging and site reclamation requirements and well-bonding requirements.”
“Companies operating now have requirements to meet,” said Lauren Fraley, spokeswoman for the DEP’s Pittsburgh office. “It’s a matter of holding operators responsible, making sure there is proper capping of wells that are no longer producing.”
Before the DEP was formed, she said, “Wells were drilled and sometimes plugged without government oversight. That created a backlog or inventory of wells - some we know of, some we don’t. Some mom-and-pop operations were putting wells on their property and not plugging them properly at the end.”
The department recently fined Range Resources $294,000 over the status of the Shirocky No. 1 well in Fayette County in 2017. That well was supposed to have been listed as abandoned and sealed.
DEP, through the 1984 Oil and Gas Act, has the authority to plug AOGs. The agency has a well-plugging program through which the oil and gas industry pays a surcharge for each drilling permit issued in Pennsylvania. The money is deposited into an account to be used for that purpose. Other funding can be used for plugging when it is available.
The cost varies, but each plugging is generally in the thousands of dollars.
DEP advises anyone who discovers a well on their property to contact the department, which will ensure proper identification of the well and address possible environmental, health and safety issues. The department has four Oil and Gas District offices, including one in Pittsburgh, which can be reached at 412-442-4024.
Abandoned oil and gas wells, and methane that may be leaking from them, are concerns confronting Pennsylvania and other states. And Tony Ingraffea.
“Methane exposure,” the lead author of the Cornell study warned, is “a climate change exacerbator. It affects the health of every human on the planet.”