Methane Emissions and Low-Producing Oil & Gas Wells in Appalachia


Last December, the Ohio River Valley Institute published Stayin’ Alive: The Last Days of Stripper Wells in the Ohio Valley, a report chronicling the more than 177,000 low-producing, “stripper” oil and gas wells in Appalachia that could soon become abandoned and would need to be decommissioned at a total cost of $5 to $16 billion. Stripper wells, which produce fewer than 15 barrels of oil equivalent (90 thousand cubic feet) of gas per day, make up more than 90% of active wells in the four-state Ohio River Valley region, which includes Kentucky, Ohio, Pennsylvania, and West Virginia. What is less known about these low-producing wells is the significant amount of methane they emit in Appalachia, despite producing just 7% of oil and gas in the region.

Methane, which is the primary component of natural gas, is a powerful greenhouse gas that has over 80 times the warming power of carbon dioxide over a 20-year time span. According to the EPA, methane accounts for 10% of all greenhouse gas emissions. About 20% of all methane emissions come from natural gas and oil production. Recent studies suggest that the methane emissions from oil and gas production may be twice as high as EPA estimates.

A groundbreaking new study co-authored by Mark Omara, a Scientist at the Environmental Defense Fund, finds that low-producing (stripper) wells in the United States are responsible for 50% of all oil and gas methane emissions from well sites. Low-producing well sites allow approximately 10% of their gas to leak into the atmosphere, enough gas to run 3.6 million homes for a year. The study reveals the extent to which low-producing wells are contributing to climate change and why it will be critical for policymakers to take action to clamp down on these leaky wells.

Omara recently joined ORVI’s Ted Boettner to discuss the report and its implications for climate change, landowners, and the oil and gas industry.

The following interview has been lightly edited for clarity.

Ted Boettner, Ohio River Valley Institute: Mark, thanks for joining me today.

Mark Omara, Environmental Defense Fund: Thank you for having me.

TB: Yes, this is great. I was very impressed with your study. It’s very apropos to the work that we’ve been doing at ORVI in the region. And it’s very important in terms of dealing with climate change. That leads to one of my first questions about the study—your study is focused on methane emissions from these low-producing oil and gas wells in the United States, and all the headlines are usually about the high-volume fracking wells that produce the majority of the gas. They tend to get all the headlines and the discussion. But lately, we’ve seen more discussion about these low-producing wells. Why should we be worried about the emissions coming from these wells?

MO: Yeah, Ted, as you mentioned, low-producing wells are the most abundant types of oil and gas wells in the US. About 80% of the nearly 1 million actively producing oil and gas wells in the US fall in this category. Despite their very large number, they account for only a small proportion of national oil and gas production: just about 6% in 2019. Now, importantly, even as their production rates continue to decline over the years, measurement-based data indicate that methane emissions can and do occur at these well sites. As mentioned, methane is a hard-hitting, climate-warming pollutant. One ton of methane emitted today packs more than 80 times the short-term heat-trapping effect of one ton of CO2. And so these emissions from oil and gas operations contribute to the climate warming we are experiencing today, in addition to adverse public health outcomes, including degraded air quality, not to mention the billions of dollars worth of natural gas that’s just wasted annually due to these emissions. So yes, if there are methane leakages occurring across the vast network of oil and gas infrastructure that’s used to extract, that’s used to process, that’s used to transport oil and gas at low-producing well sites in other oil and gas facilities, those methane emissions are concerning on many levels.

TB: How much methane are we talking about? Is this a big chunk of the methane that’s being emitted in the country? Or is it a small amount?

MO: It is huge. In our study, we estimate that 4 million metric tons of methane is emitted annually from low-producing wells in the US. And this represents about one half of the total methane emissions from the US oil and gas production sector and 30% of the total methane emissions from the entire US oil and gas supply chain. For context, 4 million metric tons of methane is enough natural gas to supply 3.6 million American homes, or the annual residential natural gas demand for the entire state of Ohio. Now, according to the most recent estimates from the US Environmental Protection Agency, apart from the methane emitted from oil and gas sources, there are only two other sectors that emit more methane annually than this. That is methane emitted from landfills, and methane emitted from enteric fermentation in animal operations. In other words, methane emitted from low-producing oil and gas wells is significant. And our study suggests that these emissions cannot be ignored if large, meaningful reductions in climate-warming pollution from US oil and gas operations are to be attained.

TB: Yeah, that’s a really great point. One of the hard things about methane is that we can’t see it, right? And sometimes, if we don’t see it, it’s out of our mind. I’m based here in Charleston, West Virginia, and we have low-producing wells all across the county. Hundreds of them. I actually saw one the other day going to the YWCA. I looked up and there was a low-producing well right up the hill from me. They’re all over the place, especially in this area. But if I’m a landowner or a royalty-owner in West Virginia, and I have several of these low producing wells on my property, and many of them might be emitting high rates of methane or volatile organic compounds, why should I care about this? If I’m Ted Boettner the farmer in rural West Virginia?

MO: I’ve been to West Virginia. One of my first studies was conducted in southern Pennsylvania and West Virginia, looking at methane emissions from conventional wells. And yeah, you’re right, there are a lot of these wells. And if you are a land owner this should matter because the negative impacts of these emissions can be enormous. Every time there is methane leaking from oil and gas infrastructure, it is bad news for the climate. It’s also bad news for air quality and public health, because of a whole host of other dangerous air pollutants that can be co-emitted with methane. And it’s also bad news for the owner’s or the operator’s bottom line, because methane emitted is literally natural gas wasted, and natural gas wasted is lost revenue. And if I may add one thing here, Ted, these emissions are unnecessary, and are avoidable, because the technology to mitigate these emissions is widely available today.

TB: Are oil and gas operators just not paying attention to all the methane coming out? Are there monitors on these wells to tell people that there’s methane coming out? To tell operators that there’s methane? Or to alert landowners? Or are you just finding this because there isn’t any monitoring going on? A lot of these leaky wells, like you talked about, are very fixable; the oil and gas operators could be fixing this problem. Why don’t they fix the problem? That might be beyond your study a little bit.

MO: Right, that’s beyond the scope of the study. But I think one of the important things to note here is that it’s really important to have studies like this that illustrate the scope of the problem, because if you don’t have the data that underscores the magnitude of these issues, it’s really difficult to take action on it. We need these sorts of studies to be able to say that these reductions are needed. These mitigation actions are necessary.

TB: Absolutely. One of the things that really struck me about this study that was different from previous studies in the Ohio River Valley, or the Appalachian region—Ohio, Pennsylvania, and West Virginia—they’ve typically found that wells are emitting about one metric ton of methane annually. Your study finds that these wells are emitting about seven metric tons of methane annually. Why did your study find higher rates of methane leakage compared to previous studies?

MO: The seven metric tons that you mentioned represents the average methane emissions. But there is a range on that: some wells will have methane emissions that are well below this figure, and others that are well above it. I think the comparison, though, is not really an apples-to-apples comparison because there are methodological differences. Our study represents a synthesis of previous peer-reviewed and published site-level methane emissions measurements at low-producing oil and gas well sites, and it incorporated data collected by over 50 scientists using well-established, ground-based measurement methods to quantify methane emissions from low-producing well sites in six major oil- and gas-producing basins in the US.

One thing I will note here is that the data that we’ve consolidated and analyzed represents methane emissions not only from the low-producing wellheads, but also from auxiliary equipment at the well site. So this would include emissions from separators and storage tanks and pneumatic devices and so on. Now, the one metric ton of methane per well—I believe that comes from a couple of recent studies that measured only the methane emissions from the wellheads. But there are often lots of other equipment at low-producing well sites from which methane leakages can occur. Methane emissions can be much higher once we look at the total well site emissions.

I think another important point to note here is that our study also looked at methane emissions from the full range of low-production rates. That is, we included all the sites with production rates up to 15 barrels of oil equivalent per day (BOED), compared to previous studies that focused on just the ultra-low-production cohort of less than 1-3 BOED per day. And so the wide range of production rates that we analyze in our study means that we are better able to assess the frequency and the magnitude of emissions, particularly from the high-emitting, low-producing well sites, which are important and are responsible for a significant proportion of the total methane emissions from these wells.

The last thing I will mention on methodological differences is that the measurement methods that were used in the studies that we analyzed do not require operator-provided access to the sites before measurements can be conducted. This approach has certain advantages, in that it increases the potential for obtaining methane emissions data that are more representative of both normal and abnormal oil and gas operations across a diversity of operators. This can be especially important in characterizing the methane emission profiles for low-producing wells nationally.

TB: That makes a lot of sense. It’s really important that these studies have come out over the last, say, decade or so, a lot of on-the-ground studies of methane. Now we have a federal orphan well funding bill, and one of the requirements, I believe, is to begin to measure methane as we’re plugging wells. So this is something that’s going to be happening a lot more, say, over the next decade, is that we’re going to be finding out a lot more information, especially about these so-called “orphan” wells—wells that don’t have an owner and are wards of the state. We’re going to be able to have a lot more information soon about some of those things.

In our study, we really looked at these ultra-low-producing wells that are producing less than 1 barrel of oil per day. These are the wells that could likely need to be decommissioned or plugged and abandoned soon. If companies aren’t in a good position, they could go out of business, and these wells could end up being owned by the states, so we’re very concerned about those. Looking at these sort of ultra-low-producing wells, a good chunk of which are teetering at being economically viable or are uneconomic wells—when you looked at this in your study, were there different rates of methane leakage between wells that were producing 1 BOED and 5 BOED, or 10 BOED, or 15 BOED? Are these wells leaking at the same rates?

MO: One thing I’ll mention is that all of these wells, whether they’re ultra-low-producing or not, have the potential to emit methane emissions. Methane emissions can occur due to the normal functioning of the equipment or due to unintentional leakages. And we have seen these emissions at both ultra-low-producing websites and non-ultra-low-producing websites. And so, when looking at the national total, we estimate that about three quarters of these emissions above 4 million metric tons are contributed by those sites that produce about 5-10 BOED. When we look at the ultra-low-production cohort, or the sites that are producing less than 1-2 BOED, they emit a far greater proportion of their production than the sites producing about 5 BOED. And we estimate, on average, that these ultra-low-producing sites are emitting about 20% of their production, compared to less than 10% for the sites producing about 5-10 BOED. Now, there are going to be some regional differences in the relative importance of methane emissions from ultra-low-producing sites, because some regions, like Appalachia, are dominated by these ultra-low-producing sites. So the Appalachian region is 90% ultra-low-producing. It’s a significant number, right? And we estimate that their methane emissions account for as much as 60% of the total methane emissions of well sites in the region.

TB: Yeah, that’s a very big concern. There’s different numbers on this, of course, but about 10 million oil and gas wells have been drilled in the United States since the mid-18th or -19th century, and a large chunk of these, 2.1 million of these, are unplugged, abandoned wells, or what’s sometimes called legacy wells, that have been left around. Most of them aren’t even accounted for. Sometimes when you go out to these well sites, you’ll find wells that are in the database of the state agencies. And then sometimes you’ll find dozens of wells, or several, that aren’t even in the database. That’s what a previous study by Stuart Riddick showed, that in West Virginia, he went out measuring methane at a couple of sites in West Virginia, and he said he found about six times as many wells when he went out and did this field campaign, than that were in the database. And he estimated that a state like West Virginia had approximately 400,000 of these abandoned wells, which is shocking, right? I mean, we only have about 56,000 in West Virginia that are actively producing. So it’s like, you’re gonna tell me there’s a whole other 400,000 around here? The abandoned wells are an issue too. But the fact is that these leaking wells are also these very ultra-low-producing wells. So, as the wells get older, do they leak more, do they leak less? Did you look at age in terms of methane leakage of the wells?

MO: Not necessarily in terms of the methane leakage, because age as a parameter wasn’t really reported in most of the studies that we looked at. But it is clear that a lot of these low-producing well sites are pretty old. The average age is around 20 years old, but we have low-producing wells that are more than 60 years old.

TB: And you looked at conventional wells here, right? Mostly?

MO: In the Appalachian region it’s going to be mostly conventional wells. That’s right.

TB: So these aren’t the wells that were really grabbing the headlines, contributing to Appalachia sort of being the biggest gas-producing region in the country. You know, Appalachia doesn’t produce very much oil, but we produce a lot of gas since the advent of high-volume, hydraulic fracking, horizontal drilling, that has taken place since 2008. That’s sort of grabbed all these headlines, but it’s interesting to see all these conventional wells come back into the spotlight. And the fact that we’re looking at methane emissions, that these low-producing wells, the ones that are kind of an afterthought, these are the ones that are producing half of the methane emissions. To me, that’s just astonishing that that’s what’s happening.

MO: It is a big problem. Yeah, absolutely.

TB: Some of the studies that look at methane emissions sites have looked at just a few outliers causing these problems. So what share of the emissions are coming from a few outliers? If you have 100 of these wells, are most emissions happening in the top 10%, or is it evenly distributed?

MO: Yeah, it’s interesting that you mention that. So there have been scores of measurement-based studies conducted in the US, and a unifying result from those measurements is that a small fraction of oil- and gas-emitting sources, usually about 5%, account for a large proportion of total methane emissions, usually about 50%. And this is often referred to as the fat tail methane emissions distribution. And our study actually finds very similar results: the top 5% of high-emitting, low-producing well sites are responsible for about 50% of the total methane emissions from all low-producing well sites in the country. But what we have learned about methane emissions distributions is that the exceptionally high methane emissions can occur randomly in space and time, and that while it’s really important to address those emissions at the tail of the distribution, we also cannot ignore the other sources representing the main body of the emissions distribution, because while those site level emissions may be comparatively lower, the cumulative total can be significant, as is the case here for low-producing wells.

TB: Yeah, that’s very fascinating. That makes a lot of sense. I think the study and what you’ve talked about has outlined just how big of an issue this is and why we should be concerned about it. What I would ask you, Mark, is what should we do about it? Is there anything we can do? What actions can we take? Is there anything happening at the federal level that could reduce these methane emissions? Because as you said, we’re just wasting this fuel. We’re wasting it, and it’s going into the atmosphere. It’s not even being used, but it could heat 3.6 million homes. If you’re in West Virginia, that’s more homes in the entire state. That’s more than double the homes in the state. That’s a lot of lost power and waste and inefficiency. So what are some things that are happening? What can we do to stop this from happening?

MO: Yeah, so this study really underscores the importance of reducing the outsized methane emissions from low-producing wells. It suggests that significant reductions of the climate-warming pollution from oil and gas operations cannot be attained by leaving half emissions on the table, right? And we have seen some actions already, particularly in states like Colorado and New Mexico, that have already advanced pollution rules that help address methane emissions from low-producing wells. These states show that the mitigation of these emissions is not only feasible, but also cost-effective. The majority of low-producing well sites and the production from these sites are actually owned and operated by well-capitalized mid-sized to large operators with hundreds to thousands of assets. Importantly, what we do know is that the technology that’s needed to mitigate these emissions is widely available today, and by estimates from the International Energy Agency, if we look at today’s elevated natural gas prices, almost all of the global oil and gas methane emissions can be reduced at no net cost, meaning that the investment in the abatement technologies basically pays for itself because of the dollar value of the captured gas.

So what can we do? There are some basic things and there are some more advanced, technology-dependent approaches that can be taken. And one of the recent studies, again going back to the Appalachian region in Ohio, actually reported several instances of emissions that were audible, that were visible, and that were smelly, meaning that simple, low-tech, audiovisual and olfactory assessments could be sufficient to determine there is a leak occurring, and from there to repair those leaks, which may be as simple as tightening loose valves and feedings, or closing hatches on tanks that are accidentally left open, or replacing broken pressure regulators. All of these actions can reduce methane emissions. But, you know, that requires a deliberate effort to frequently inspect and maintain the site. And here is really where I think carefully designed policy actions can be essential.

There are also other approaches that are more advanced, including regular leak detection and repair programs, using advanced infrared cameras to identify those emission sources and fix them. Other approaches include replacing the high- and low-bleed pneumatic devices with zero-bleed alternatives and installation of emission controls—for example, vapor recovery units on storage tanks.

The bottom line, Ted, is that abatement technologies that are needed to reduce these emissions are widely available today. And it is feasible and cost-effective to deploy them to achieve significant reductions in climate-warming pollution from oil and gas operations.

TB: If I told somebody that, at your house, you know, 10% of the gas that you use in your house is leaking out, and you’re paying for it, but it’s leaking, I’m sure they would want to fix that. Because you’re paying $150, $160 a month for your gas bill. And if I said, hey, 10% of your gas you’re wasting, wouldn’t you like to control that? I think that makes a lot of sense to a lot of people to try to do something about that. I’m trying to help people understand what we’re talking about here, and why it’s so important, too. And also, imagine if that 10% of gas is leaking, it’s leaking in your house, and it’s unhealthy for the air, and for the kids that are in your house, too. I mean, that’s one way to sort of think about that.

Last fall, the Environmental Protection Agency released some proposed safeguards to cut methane and other harmful pollutants from new and existing oil and gas operations. And I think the proposal excluded some of the small well sites, perhaps some of the ones that you’re considering in the study. Does this report sort of highlight why the EPA might want to include these small wells into the rule? And do you think it’d be difficult for gas companies to comply with that rule?

MO: Yes. This study highlights why it’s really important to include low-producing oil and gas wells in methane abatement policies. As I mentioned, the pollution from these wells accounts for about one half of the total methane emissions from oil and gas production sites in the country. Significant reductions really cannot be attained by leaving that half of the emissions on the table. And with respect to your question about why this would be difficult, or, potentially, will that be difficult, I think for small operators, we have looked at the mechanism, we have looked at the oil and gas production ownership for low-producing well sites in the country, and available data indicate that the majority of these low-producing well sites, about 80%, as well as their production, about 80%, too, are actually owned and operated by these well-capitalized, mid-sized to large operators that have hundreds to thousands of assets. So, in addition to the fact that the technology exists today, in that it basically pays for itself to be able to deploy it, we think that this will be important in that it’s cost-effective, and that it’s feasible to reduce methane emissions from the sides.

TB: Yeah, it aligns, too, with one of the things we found in our reports, we did a report on stripper wells called Stayin’ Alive. And we calculated using a database that Diversified energy owns about 30% of all the stripper wells—these are wells that are highlighted in your study that are under 15 BOED. So there are some of these larger companies like Graylock and others that own a big portion of these wells, including them. This study, to me, highlights that we tend to think of leaky wells being on these so-called fracking sites all the time. This report really highlights to me that you cannot leave out these conventional wells, which, in our region, make up 90% of the oil and gas wells in Appalachia. So we have to include those and why it’s so important if we’re going to, you know, tackle climate change and the fact that methane is so potent in the short term. And the social cost of not doing something about that today has huge ramifications. We can really be able to meet some of these carbon reduction targets and meet some of these goals if we look at methane first, because it is so potent. So your study highlights where we go to find that. And one portion of that are these low-producing wells that are scattered just all across the United States, particularly in the several regions you looked at. But, you know, thank you for coming on. Thank you for discussing this. And if people want to download the report, find it, where would they find a copy of the study that you did?

MO: It’s available from Nature Communications.

TB: Well thanks, Mark, for taking time on a Friday to talk about this. Thanks for getting in the weeds with me about the report. I hope we didn’t lose some people, but these things are just so important, and I think the magnitude of the findings of this report show all policymakers that we have to include these low-producing wells in any type of strategy to reduce methane in this country. Thanks so much for coming on, Mark. Really appreciate it.

MO: Appreciate it. Thank you for having me.

Ted Boettner

Ted focuses on pathways that bring sustainable economic development and shared prosperity to the region through research and analysis and has over 15 years of public policy experience. Prior to joining ORVI, Ted was the founding executive director of the WV Center on Budget and Policy.