Matt Kelso, BA

Getting Rid of All of that Waste – Increasing Use of Oil and Gas Injection Wells in Pennsylvania

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Oil and gas development generates a lot of liquid waste.

Some of the waste comes that comes out of a well is from the geologic layer where the oil and gas resources are located. These extremely saline brines may be described as “natural,” but that does not make them safe, as they contain dangerous levels of radiation, heavy metals, and other contaminants.

Additionally, a portion of the industrial fluid that was injected into the well to stimulate production, known as hydraulic fracturing fluid, returns to the surface.  Some of these substances are known carcinogens, while others remain entirely secret, even to the personnel in the field who are employed to use the additives.

The industry likes to remind residents that they have used this technique for more than six decades, which is true. What separates “conventional” fracking from developing unconventional formations such as the Marcellus Shale is really a matter of scale.  Conventional formations are often stimulated with around 10,000 gallons of fluid, while unconventional wells now average more than 10 million gallons per well.

Conventional Well: 10,000 gallons
Olympic Swimming Pool: 660,253 gal
Unconventional Well: >10 Million gal

In 2017 alone, Pennsylvania oil and gas wells generated 57,653,023 barrels (2.42 billion gallons) of liquid waste.

Managing the waste stream

Liquid waste can be reused to stimulate other oil and gas wells, but reuse concentrates the contaminant load in the fluid. There is a limit to this concentration that operators can use, even for this industrial purpose.

Another strategy is to decrease the volume of the waste through evaporation and other treatment methods. This also increases the contaminant concentration. Pennsylvania used to permit “treatment” of wastewater at sewage treatment facilities, before being forced to concede that the process was completely ineffective, and resulted in contaminating streams and rivers throughout the Commonwealth.

In many states, much of this waste is disposed of in facilities known as salt water disposal (SWD) wells, a specific type of injection well. These waste facilities fall under the auspices of the US Environmental Protection Agency’s Underground Injection Control (UIC) program. Such wells are co-managed with states’ oil and gas regulatory agencies, although the specifics vary by state.

Morrow Co. Ohio, Fishburn Walter II injection well
Morrow Co. Ohio, Fishburn Walter II injection well
Ashtabula OH, Brine Waste Truck
Ashtabula OH, Brine Waste Truck
These photos show SWD wells in other states, but what about in Pennsylvania?

The oil and gas industry in Pennsylvania has not used SWD wells as a primary disposal method, as the state’s geology has been considered unsuitable for this process.  For example, on page 67 of this 2009 industry report, the authors saw treatment of flowback fluid at municipal facilities as a viable option (before the process was  banned in 2011), but underground injection as less likely (emphasis added):

The disposal of flowback and produced water is an evolving process in the Appalachians. The volumes of water that are being produced as flowback water are likely to require a number of options for disposal that may include municipal or industrial water treatment facilities (primarily in Pennsylvania), Class II injection wells [SWDs], and on-site recycling for use in subsequent fracturing jobs. In most shale gas plays, underground injection has historically been preferred. In the Marcellus play, this option is expected to be limited, as there are few areas where suitable injection zones are available.

The ban on surface “treatment” being discharged into Pennsylvania waters has increased the pressure for finding new solutions for brine disposal.  This is compounded by the fact that the per-well volume of fluid injected into shale gas wells in the region has nearly tripled in that time period. Much of what is injected comes back up to the surface and is added to the liquid waste stream.

Chemically-similar brine from conventional wells has been spread on roadways for dust suppression. This practice was originally considered a “beneficial use” of the waste product, but the Pennsylvania Department of Environmental Protection (DEP) halted that practice in May 2018.

None of these waste management decisions make the geology in Pennsylvania suddenly suitable for underground injection, however, they do increase the pressure on the state to find a disposal solution.

Concerns with SWD wells

There are numerous concerns with salt water disposal wells.  In October 2018, the DEP held a hearing in Plum Borough, on the eastern edge of Allegheny County, where there is a proposal to convert the Sedat 3A conventional well to an injection well. Some of the concerns raised by residents include:

  • Fluid and/or gas migration- There are numerous routes for fluids and gas to migrate from the injection formation to drinking water aquifers or even surface water.  Potential conduits include coal mines, abandoned gas wells, water wells, and naturally occurring fissures in crumbling sedimentary formations.
  • Induced seismicity- SWD wells have been linked to increased earthquake activity, either by lubricating or putting pressure on old faults that had been dormant. Earthquakes can occur miles away from the injection location, and in sedimentary formations, not just igneous basement rock.
  • Noise, diesel pollution, loss of privacy, and road degradation caused by a constant stream of industrial waste haulers to the well location.
  • Complicating existing issues-  Plum Borough and surrounding communities are heavily undermined, and in fact the well bore goes right through the Renton Coal Mine (another part of which has been on fire for decades).  Mine subsidence is already a widespread issue in the region, and many fear that even small seismic events could exacerbate this.
  • Possibility of surface spill-  Oil and gas is, sadly, a sloppy industry, with unconventional operations having accumulated more than 13,000 violations in Pennsylvania since 2008.  If a major spill were to happen at this location, there is the possibility of release into Pucketa Creek, which drains into the Allegheny River, the source of drinking water for multiple communities.
  • Radioactivity and other contaminants- Flowback fluids are often highly radioactive, contain heavy metals, and other contaminants that are challenging to effectively clean.  The migration of radon gas into homes above the injection formation is also a possibility.
Download Sedat 3A File Review Documents

The current state of SWDs in Pennsylvania

Pennsylvania has numerous data sources for oil and gas, but they are not always in agreement. To account for this, we have mapped SWDs (and a five mile buffer around them) from two different data sources in the map below. The first source is a subset of SWD wells from a larger dataset of oil and gas locations from the DEP’s mapping website. The second source is from a Waste Facility Report, represented in pink triangles that are offset at an angle to allow users to see both datasets simultaneously in instances where they overlap.

Map of existing, proposed, and plugged salt water disposal (SWD) injection wells in Pennsylvania.

 View map fullscreen | How FracTracker maps work

According to the first data set of DEP’s oil and gas locations, Pennsylvania contains 13 SWDs with an active status, one SWD with a regulatory inactive status, and eight that are plugged. The Waste Facility Report shows 10 SWD wells total, including one well that was left out of the other data set in Annin Township, McKean County.

It is worth noting that Pennsylvania’s definition for an “active” well status is confusing, to put it charitably. It does not mean that a well is currently in operation, nor does it even mean that it is currently permitted for the activity, whether that is waste disposal or gas production, or some other function. An active status means that the well has been proposed for a given use, and the well hasn’t been plugged, or assigned some other status.

The Sedat 3A well in Plum, for example, has an active status, although the DEP has not yet granted it a permit to operate as a SWD well. Another  status type is “regulatory inactive,” which is given to a well that hasn’t been used for its stated purpose in 12 months, but may potentially have some future utility.

Karst, coal mines, and streams

While there are numerous factors worthy of consideration when siting SWD wells, this map focuses on three: the proximity of karst formations, coal mines and nearby streams that the state designates as either high quality or exceptional value.

Karst formations are unstable soluble rock formations like limestone deposits which are likely to contain numerous subsurface voids. These voids are concerning in this context. For one reason, there’s the possibility of contaminated fluids and gasses migrating into underground freshwater aquifers. Also, the voids are inherently structurally unstable, which could compound the impacts of artificially-induced seismic activity caused by fluid injections in the well.

Our analysis found over 78,000 acres (123 square miles) of karst geology within five miles of current, proposed, or plugged SWD wells in Pennsylvania.

Coal mines, while a very different sedimentary formation, have similar concerns because of subsurface voids. Mine subsidence is already a widespread problem in many of the communities surrounding SWD well sites.  Pennsylvania has several available data sets, including active underground mine permits and digitized mined areas, which are used in this map.  Active mine permits show current permitted operations, while digitized mine areas offer a highly detailed look at existing mines, including abandoned mines, although the layer is not complete for all regions of the state.

In Pennsylvania, there are 56,542 acres (88 square miles) of active mines within five miles of SWD wells. Our analysis found 97,902 acres (153 square miles) of digitized mined areas within five miles of SWD wells.  Combined, there are 139,840 acres (219 square miles) of existing and permitted mines within the 5 mile buffer zone around SWDs in Pennsylvania.

Streams with the designation “high quality” and “exceptional value” are the best streams Pennsylvania has to offer, in terms of recreation, fishing, and biological diversity. In this analysis, we have identified such streams within a five mile radius of SWD wells, irrespective of the given watershed of the well location.

While the rolling topography of Western Pennsylvania sheds rainwater in a complicated network of drainages, groundwater is not subject to that particular geography. Furthermore, groundwater regularly interacts with surface water through water wells, abandoned O&G wells, and natural seeps and springs. Therefore, it is possible for SWDs to contaminate these treasured streams, even if they are not located within the same watershed.

Altogether, there are 716 miles of high quality streams and 110 miles of exceptional value streams within 5 miles of the SWDs in this analysis.

Conclusion

For decades, geologists have concluded that the subsurface strata in Pennsylvania were not suitable for oil and gas liquid waste disposal in underground injection wells.  The fact that vast quantities of this waste are now being produced in Pennsylvania has not suddenly made it a suitable location for the practice.  If anything, additional shallow and deep wells have further fractured the sedimentary strata, thereby increasing the risk of contamination.

The only factor that has changed is the volume of waste being produced in the region. SWD wells in nearby Ohio and West Virginia have capacity issues from their own production wells, and it is not clear that the geologic formations across the border are that much better than in Pennsylvania. But as new wells are drilled and volumes of hydraulic fracturing fluid continue to spiral into the tens of millions of gallons per well, the pressure to open new SWD wells in the state will only increase.

Perhaps because of these pressures, DEP has become quite bullish on the technology:

Several successful disposal wells are operating in Pennsylvania and options for more sites are always being considered. The history of underground disposal shows that it is a practical, safe and effective method for disposing of fluids from oil and gas production.
Up against this attitude, residents are facing an uphill battle trying to prevent harm to their health and property from these industrial facilities in their communities.  Municipalities that have attempted to stand up for their residents have been sued by DEP to allow for these injection wells.  The Department’s actions, which put the interests of industry above the health of residents and the environment, is directly at odds with the agency’s mission statement:
The Department of Environmental Protection’s mission is to protect Pennsylvania’s air, land and water from pollution and to provide for the health and safety of its citizens through a cleaner environment. We will work as partners with individuals, organizations, governments and businesses to prevent pollution and restore our natural resources.
It’s time for DEP to live up to its promises.

By Matt Kelso, Manager of Data and Technology, FracTracker Alliance

Bird's eye view of an injection well (oil and gas waste disposal)
Ted Auch, PhD

A Disturbing Tale of Diminishing Returns in Ohio

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Utica oil and gas production, Class II injection well volumes, and lateral length trends from 2010-2018

The US Energy Information Administration (EIA) recently announced that Ohio’s recoverable shale gas reserves have magically increased by 11,076 billion cubic feet (BCF). This increase ranks the Buckeye State in the top 5 for changes in recoverable shale natural gas reserves between 2016 and 2017 (pages 31- 32 here). After reading the predictable and superficial media coverage, we thought it was time to revisit the data to ask a pertinent question: What is the fracking industry costing Ohio?

Recent Shale Gas Trends in Ohio

According to the EIA’s report, Ohio currently sits at #7 on their list of proven reserves. It is estimated there are 27,021 BCF of shale gas beneath the state (Figure 1).

Graph of natural gas reserves in different states 2016-2017

Figure 1. Proven and change in proven natural gas reserves from 2016 to 2017 for the top 11 states and the Gulf of Mexico (calculated from EIA’s “U.S. Crude Oil and Natural Gas Proved Reserves, Year-End 2017”).

There are a few variations in the way the oil and gas industry defines proven reserves:

…an estimated quantity of all hydrocarbons statistically defined as crude oil or natural gas, which geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Reservoirs are considered proven if economic producibility is supported by either actual production or conclusive formation testing. – The Organization of Petroleum Exporting Countries

… the quantity of natural resources that a company reasonably expects to extract from a given formation… Proven reserves are classified as having a 90% or greater likelihood of being present and economically viable for extraction in current conditions… Proven reserves also take into account the current technology being used for extraction, regional regulations and market conditions as part of the estimation process. For this reason, proven reserves can seemingly take unexpected leaps and drops. Depending on the regional disclosure regulations, extraction companies might only disclose proven reserves even though they will have estimates for probable and possible reserves. – Investopedia

What’s missing from this picture?

Neither of the definitions above address the large volume of water or wastewater infrastructure required to tap into “proven reserves.” While compiling data for unconventional wells and injection wells, we noticed that the high-volume hydraulic fracturing (HVHF) industry is at a concerning crossroads. In terms of “energy return on energy invested,” HVHF is requiring more and more resources to stay afloat.

OH quarterly Utica oil & gas production along with quarterly Class II injection well volumes:

The map below shows oil and gas production from Utica wells (the primary form of shale gas drilling in Ohio). It also shows the volume of wastewater disposed in Class II salt water disposal injection wells.


 View map fullscreen | How FracTracker maps work

Publications like the aforementioned EIA article and language out of Columbus highlight the nominal increases in fracking productivity. They greatly diminish, or more often than not ignore, how resource demand and waste production are also increasing. The data speak to a story of diminishing returns – an industry requiring more resources to keep up gross production while simultaneously driving net production off a cliff (Figure 2).

Graph of Utica permits in Ohio on a cumulative and monthly basis along with the average price of West Texas Intermediate (WTI) and Brent Crude oil per barrel from September, 2010 to December, 2018

Figure 2. Number of Utica permits in Ohio on a cumulative and monthly basis along with the average price of West Texas Intermediate (WTI) and Brent Crude oil per barrel from September 2010 to December 2018

The Great Decoupling of New Year’s 2013

In the following analysis, we look at the declining efficiency of the HVHF industry throughout Ohio. The data spans the end of 2010 to middle of 2018. We worked with Columbus-area volunteer Gary Allison to conduct this analysis; without Gary’s help this work and resulting map, would not have been possible.

A little more than five years ago today, a significant shift took place in Ohio, as the number of producing gas wells increased while oil well numbers leveled off. The industry’s permitting high-water mark came in June of 2014 with 101 Utica permits that month (a level the industry hasn’t come close to since). The current six-month permitting average is 25 per month.

As the ball dropped in Times Square ringing in 2014, in Ohio, a decoupling between oil and gas wells was underway and continues to this day. The number of wells coming online annually increased by 229 oil wells and 414 gas wells.

Graph showing Number of producing oil and gas wells in Ohio’s Utica Shale Basin from 2011 to Q2-2018

Figure 3. Number of producing oil and gas wells in Ohio’s Utica Shale Basin from 2011 to Q2-2018

Graph of Producing oil and gas wells as a percentage of permitted wells in Ohio’s Utica Shale Basin from 2011 to Q2-2018

Figure 4. Producing oil and gas wells as a percentage of permitted wells in Ohio’s Utica Shale Basin from 2011 to Q2-2018

Permits

The ringing in of 2014 also saw an increase in the number of producing wells as a percentage of those permitted. In 2014, the general philosophy was that the HVHF industry needed to permit roughly 5.5 oil wells or 7 gas wells to generate one producing well. Since 2014, however, this ratio has dropped to 2.2 for oil and 1.4 for gas well permits.

Put another way, the industry’s ability to avoid dry wells has increased by 13% for oil and 18% for gas per year. As of Q2-2018, viable oil wells stood at 44% of permitted wells while viable gas wells amounted to 71% of the permitted inventory (Figure 4).

Production declines

from the top-left to the bottom-right

To understand how quickly production is declining in Ohio, we compiled annual (2011-2012) and quarterly (Q1-2013 to Q2-2018) production data from 2,064 unconventional laterals.

First, we present average data for the nine oldest wells with respect to oil and gas production on a per day basis (Note: Two of the nine wells we examined, the Geatches MAH 3H and Hosey POR 6H-X laterals, only produced in 2011-2012 when data was collected on an annual basis preventing their incorporation into Figures 6 and 7 belwo). From an oil perspective, these nine wells exhibited 44% declines from year 1 to years 2-3 and 91% declines by 2018 (Figure 5). With respect to natural gas, these nine wells exhibited 34% declines from year 1 to years 2-3 and 79% declines by 2018 (Figure 5).

Figure 5. Average daily oil and gas production decline curves for the above seven hydraulically fractured laterals in Ohio’s Utica Shale Basin, 2011 to Q2-2018

Four of the nine wells demonstrated 71% declines by the second and third years and nearly 98% declines by by Q2-2018 (Figure 6). These declines lend credence to recent headlines like Fracking’s Secret Problem—Oil Wells Aren’t Producing as Much as Forecast in the January 2nd issue of The Wall Street Journal. Four of the nine wells demonstrated 49% declines by the second and third years and nearly 81% declines by Q2-2018 (Figure 7).

Figure 6. Oil production decline curves for seven hydraulically fractured laterals in Ohio’s Utica Shale Basin from 2011 to Q2-2018

Figure 7. Natural gas production decline curves for seven hydraulically fractured laterals in Ohio’s Utica Shale Basin from 2011 to Q2-2018

Fracking waste, lateral length, and water demand

from bottom-left to the top-right

An analysis of fracking’s environmental and economic impact is incomplete if it ignores waste production and disposal. In Ohio, there are 226 active Class II Salt Water Disposal (SWD) wells. Why so many?

  1. Ohio’s Class II well inventory serves as the primary receptacle for HVHF liquid waste for Pennsylvania, West Virginia, and Ohio.
  2. The Class II network is situated in a crescent shape around the state’s unconventional wells. This expands the geographic impact of HVHF to counties like Ashtabula, Trumbull, and Portage to the northeast and Washington, Athens, and Muskingum to the south (Figure 8).
Map of Ohio showing cumulative production of unconventional wells and waste disposal volume of injection wells

Figure 8. Ohio’s unconventional gas laterals and Class II salt water disposal injection wells. Weighted by cumulative production and waste disposal volumes to Q3-2018.

Disposal Rates

We graphed average per well (barrels) and cumulative (million barrels) disposal rates from Q3-2010 to Q3-2018 for these wells. The data shows an average increase of 24,822 barrels (+1.05 million gallons) per well, each year.

That’s a 51% per year increase (Figure 9).

A deeper dive into the data reveals that the top 20 most active Class II wells are accepting more waste than ever before: an astounding annual per well increase of 728,811 barrels (+30.61 million gallons) or a 230% per year increase (Figure 10). This divergence resulted in the top 20 wells disposing of 4.95 times the statewide average between Q3-2010 and Q2-2013. They disposed 13.82 times the statewide average as recently as Q3-2018 (Figure 11).

Cumulative and average well volumes for all 226 of Ohio’s Class II Salt Water Disposal wells from Q3-2010 to Q3-2018

All of this means that we are putting an increasing amount of pressure on fewer and fewer wells. The trickle out, down, and up of this dynamic will foist a myriad of environmental and economic costs to areas surrounding wells. As an example, the images below are injection wells currently under construction in Brookfield, Ohio, outside Warren and minutes from the Pennsylvania border.

Image of construction on injection wellSeneca Resources Class II Salt Water Disposal Injection well under construction, Brookfield, Ohio
Image of construction on injection well
Image of construction on injection well
road leading up to injection well
road leading up to injection well
Overhead view of injection well
Overhead view of injection well

More concerning is the fact that areas of Ohio that are injection well hotspots, like Warren, are proposing new fracking-friendly legislation. These disturbing bills would lubricate the wheels for continued expansion of fracking waste disposal and permitting. House bills 578 and 393 and Senate Bill 165 monetize and/or commodify fracking waste by giving townships a share of the revenue. Such bills “…would only incentivize communities to encourage more waste to come into their existing inventory of Class II… wells, creating yet another race to the bottom.” Co-sponsors of the bills include Democratic Reps. Michael O’Brien, Glenn Holms, John Patterson, and Craig Riefel.

Lateral Lengths

The above trends reflect an equally disturbing trend in lateral length. Ohio’s unconventional laterals are growing at a rate of 9.1 to 15.6%, depending on whether you buy that this trend is linear or exponential (Figure 12). This author believes the trend is exponential for the foreseeable future. Furthermore, it’s likely that “super laterals” in excess of 3-3.5 miles will have a profound impact on the trend. (See The Freshwater and Liquid Waste Impact of Unconventional Oil and Gas in Ohio and West Virginia.)

This lateral length increase substantially increases water demand per lateral. It also impacts Class II well disposal rates. The increase accounts for 76% of the former and 88% of the latter when graphed against each other (Figure 13).

Figure 12. Ohio Utica unconventional lateral length from Q3-2010 to Q4-2018

Figure 13. Ohio Utica unconventional water demand and Class II SWD injection well disposal volumes vs lateral length from Q3-2010 to Q4-2018.

Conclusion

This relationship between production, resource demand, and waste disposal rates should disturb policymakers, citizens, and the industry. One way to this problem is to more holistically price resource utilization (or stop oil and gas development entirely).

Unfortunately, states like Ohio are practically giving water away to the industry.

Politicians are constructing legislation that would unleash injection well expansion. This would allow disposal to proceed at rates that don’t address supply-side concerns. It’s startling that an industry and political landscape that puts such a premium on “market forces” is unwilling to address these trends with market mechanisms.

We will continue to monitor these trends and hope to spread these insights to states like Oklahoma and Texas in the future.

By Ted Auch, Great Lakes Program Coordinator, FracTracker Alliance – with invaluable data compilation assistance from Gary Allison

Data Downloads

FracTracker is a proponent of data transparency, and so we often share the data we use to construct our maps analyses. Click on the links below to download the data associated with the present analysis:

  • OH Utica laterals

    Ohio’s Utica HVHF laterals as of December 2018 in length (feet) (zip file)

  • Wastewater disposal volumes

    Inventory of volumes disposed on a quarterly basis from 2010 to Q3-2018 for all 223 active Class II Salt Water Disposal (SWD) Injection wells in Ohio (zip file)
Matt Kelso, BA

Pennsylvania Drilling Trends in 2018

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With the new year underway, it’s an opportune moment to reflect on the state of unconventional oil and gas extraction in Pennsylvania and examine a few of the drilling trends. A logical place to start is looking at the new wells drilled in 2018.

As always, but perhaps even more so than in previous years, unconventional drilling in Pennsylvania is a tale of two shale plays, with hotspots in the southwestern and northeastern corners of the state. The northeastern hotspot seems to be extending westward, including 25 new wells in Jones Township in Elk County (an area shown in dark red near the “St Marys” label on the map). In the southwestern hotspot, the industry continues to encircle Allegheny County, closing in on the City of Pittsburgh like a constrictor.

Screen shot showing spud report for Indiana Township, Allegheny County from 1/1/2017 through 1/4/2019. We suspect these spud dates of 11/29/17 and 11/30/17 are incorrect.

Screen shot showing spud report for Indiana Township, Allegheny County from 1/1/2017 through 1/4/2019. We suspect these spud dates of 11/29/17 and 11/30/17 are incorrect.

Data error? As Pittsburgh-area residents reflect on the past year, some of them must be wondering why a new well pad in Indiana Township, just northeast of the city isn’t shown on the map above. The answer is that the data the Department of Environmental Protection (DEP) has for these wells indicate they were drilled November 29-3o, 2017, although we believe this to be incorrect. FracTracker obtained the data from the Spud Report on January 2, 2019, which indicates seven wells spudded in that two day span on the “Miller Jr. 10602” well pad. This activity drew considerable opposition from families in the Fox Chapel School district in May of 2018, and was therefore widely reported on by the media. An article published on WESA indicates an expected drill date of July 2018, for example.

It turns out the new year is also a good time to remember that our understanding of the oil and gas industry around us is shaped, molded, and limited by the availability and quality of the data. We brought the Indiana Township data error to the attention of DEP, which only confirmed that the operator (Range Resources) entered the spud dates into the DEP’s online system. Perhaps these well were drilled in November of 2018 not 2017? There is even a possibility these wells have yet to be drilled.

Here are a few more dissections of the data, such as it is:

Graph of unconventional (fracking) wells drilled in PA, YTD - Drilling trends

Figure 1: Unconventional wells drilled in PA by year: 2005 to 2018

Wells Drilled Over Time

Barring more widespread data issues, the status of a handful of wells in Indiana Township does not have much of an impact on the overall trend of drilling in the state. There were 779 wells on the report, representing just under 40% of the total from the peak year of 2011, when industry drilled 1,958 wells. The year 2019 was the fourth year in a row where the industry failed to drill 1,000 wells, averaging 719 per year over that span. In contrast, the five years between 2010 and 2014 saw an average of 1,497 wells per year, more than twice the more recent average. As mentioned in our Hazy Future report, projections based on very aggressive drilling patterns are already proving to be out of phase with reality, although petrochemical commodity markets might change drastically in the coming decades.

How long before wells are plugged?

We also like to periodically check to see how long these wells stay in service. In Pennsylvania, there are two relevant well statuses worth following: plugged and regulatory inactive. While there are a number of conditions that characterize regulatory inactive wells, they are essentially drilled wells that are not currently in production, but may have “future utility.” Therefore, the wells are not required to be permanently plugged at this time.

Unconventional wells drilled since 2005 in PA - Drilling trends

Figure 2: This chart shows the percentage of unconventional wells drilled since 2005 with a plugged or regulatory inactive status as of December 31, 2018.

In order to understand some of the finer points, it’s best to use Figure 1 (above) in conjunction with Figure 2. We can see that most of the wells drilled in the initial years of the Marcellus boom have already been plugged, although Figure 1 shows us that the sample size is fairly low for these years. In 2005, for example, 7 of the 9 (78%) unconventional wells drilled in the state that year are already plugged. The following year, 24 of the 37 (65%) wells drilled are now plugged, and an additional 4 (11%) wells have a regulatory inactive status as of the end of 2018. The following year, the combined plugged and inactive wells account for just over 50% of the 113 wells drilled that year, and this trend continues along a fairly predictable curve. An exception is the noticeable bump around the most active drilling years of 2010 and 2011, where there are slightly more wells with a plugged or inactive status than might be expected. It is interesting to note that even the most recent wells are not immune to being plugged, including 8 plugged wells and 4 inactive wells drilled in 2018 that were not able to get past their very first year in production.

Overall, of the 11,675 drilled wells accounted for on this graphic, 851 (7%) are plugged already, with an additional 572 (5%) of wells with an inactive status.  Unconventional wells that are 11 years old have a roughly 50% chance of being plugged or inactive, and we would therefore expect to see the number of these wells skyrocket in the coming years before leveling off, roughly mirroring the drilling boom and subsequent slowdown of Marcellus Shale extraction in Pennsylvania.

Conclusions

Many factors contribute to fluctuations in drilling trends for the Marcellus Shale and other unconventional wells in Pennsylvania. Very cold winters result in high consumption by residential and commercial users. New gas-fired power plants can increase the demand for additional drilling. Recessions and economic conditions are known to reduce the demand for energy as well, and drillers’ heavy debt burdens can slow down operations appreciably. Additionally, other fossil fuel and renewable energy sources compete with one another, altering the market conditions even further. And finally, every oil and gas play eventually reaches a point where the expected results from new wells are not worth the money required to get the hydrocarbons to the surface, and unconventional wells are much more expensive to develop than more traditional operations.

Because of all of these variables, month to month or even year to year fluctuations are not necessarily that telling.  On the other hand, a four-year period where drilling is roughly half of previous extraction is significant, and can’t be easily dismissed as a blip in the data.

By Matt Kelso, Manager of Data and Technology, FracTracker Alliance