Oil & gas
operators and Argentina’s regulatory agencies should have been better prepared
to take on the known issue of induced seismicity when the Vaca Muerta play
began to take off in earnest in the mid-late 2010s. We now know how to manage
induced seismicity and minimize its effects. We know that hydraulic
fracturing can induce seismicity where injected fluids can connect to existing
basement faults, lubricating them enough to slip and produce earthquakes. While
hydraulic fracturing itself is only implicated in a small number of induced
seismicity events, the greater problem is injecting oil & gas wastewater.
Unfortunately, frac flowback water recycling has yet to be widely adopted in
the country. Another major issue is the lack of seismic monitoring stations in
the area which will be key to minimizing induced seismicity events.
Overall, I would
have to say that the oil & gas industry has been irresponsible in
attributing induced seismicity events to hydraulic fracturing and wastewater
injection. These links have been well-established for decades in general and
for at least a decade in the context of pressurized wastewater injection and
horizontal well fracturing. When an area that has been seismically quiet for as
long as anyone can remember and suddenly starts having frequent earthquakes
correlating with increasing oil & gas development, it doesn’t take a rocket
scientist to make the connection. We do need studies to confirm the connections,
and one study analyzed here was published in the journal Seismica in
December 2024.
The good news is
that induced seismicity events are rare and localized, which means they can be
isolated, and faults with the potential for slippage can be mapped. Hydraulic
fracturing operations and water injection operations can be halted in these
areas. For water injection, allowable volumes and pressures can be lowered to
avoid inducing seismic activity. The methods of monitoring both injections and
seismicity are often known as traffic light systems where operations can be
stopped until pressures drop or halted altogether if warranted. It is also good
news that these induced seismicity events are initiated at relatively shallow
depths, producing relatively mild earthquakes, unlike the earthquakes initiated
much deeper in non-anthropogenic tectonically-controlled earthquakes associated
with massive property damage and loss of life. However, minor to major property
damage has been well documented in oil & gas induced earthquakes. I believe
that the property owners whose properties were damaged are due significant
compensatory damages, ideally entirely from the oil & gas companies. Early
on, the oil & gas companies would call for proof that they were the cause
of the quakes but now there are monitoring networks in place (or should be, and
states help fund the effort) that allow us to attribute the quakes to injection
with much greater accuracy and detail. It was the same story with the Vaca
Muerta, where early on, the possibility that the seismicity was related to tectonic
plates in the Andes nearby to the west of the basin. However, that was not
likely since the area had no seismicity before the Vaca Muerta. Argentina’s
regulatory agencies should have begun establishing a better seismic monitoring
network much sooner than they have, but better late than never. Induced
seismicity from oil & gas operations is manageable but only if those
monitoring and traffic light systems are deployed.
Drilling and
producing Vaca Muerta oil and gas will continue to be an economic boon for
Argentina. Thus, the need to develop a functional traffic light system to
minimize seismicity events is imminent. The current government is decidedly
anti-regulatory so there are question marks on what will be done from the
regulatory side. On the industry side, there needs to be a better understanding of
faults that are vulnerable to slipping, a better acknowledgment of the industry
as the cause, better preventative and minimizing measures, and faster and
better compensation for victims of the induced earthquakes.
The
determinations from the paper in Seismica are given below and leave no
doubt as to the cause.
Abstract. Earthquakes are known to be induced by a
variety of anthropogenic causes, such as hydraulic fracturing. In the Neuquén
Basin of Argentina, hydraulic fracturing has been used to produce hydrocarbons
trapped in the shales of the Vaca Muerta Formation. Correspondingly, incidences
of seismicity there have increased. We collect information on well stimulations
and earthquakes to perform statistical analysis linking these two datasets
together. Spatiotemporal association filters suggest that the catalogue of
events is biased towards hydraulic fracturing operations. After accounting for
false-positives, we estimate that ~0.5% of operations are associated with
earthquakes. These associated event-operation pairs show highly correlated
temporal signals (>99.99% confidence) between seismicity/injection rates.
Based on this evidence, we argue that many of these earthquakes (up to M4) are
induced. We support this argument by comparing the geological setting of the
Neuquén Basin against conditions needed for fault reactivation in other
susceptible/seismogenic basins. This recognition adds to the growing list of
(hydraulic fracturing) induced seismicity.
Non-technical summary. Earthquakes have been
increasingly encountered in Argentina’s Neuquén Basin, a previously seismically
quiet region. Simultaneously, hydraulic fracturing operations have been
targeting shales in the Vaca Muerta Formation. Hydraulic fracturing injects
subsurface fluids under high enough pressure to split rocks, allowing access to
the hydrocarbons within. This type of operation is known to cause earthquakes
elsewhere. To determine if these earthquakes were caused by hydraulic
fracturing, we performed statistical tests. To high-degrees of confidence, we
find that many events tend to be clustered around hydraulic fracturing wells in
time and space. Sensitivity testing suggests that these correlations almost
certainly did not occur by accident. Faults, stress information, and other
factors in the Neuquén Basin are comparable against other basins that have
already induced earthquakes. We conclude that many of the events here were
induced. We discuss how future research could better answer some of our
unresolved questions.
In conclusion, we find that many of the earthquakes
recorded in the Neuquén Basin are likely induced by hydraulic fracturing. This
assertion is based on strong statistical evidence (>99.99% confidence)
linking the timings and locations of earthquakes to operations. The lower bound
estimate of wells that induced earthquakes is ~0.5%, with maximum magnitudes
reaching M4. We further infer causation based on a similarity comparison
against known hydraulic fracturing cases around the world.
Injected
saltwater is denser than freshwater and exerts more force, affecting faults
more. It can affect faults long after injection under certain circumstances but
in general, after injection is slowed or stopped induced seismicity will slow
and stop as well.
There are
companies that specialize in developing local seismograph networks to detect
induced seismicity. I attended a talk around 2016 at an Ohio Geological Society
meeting by one of these companies. At the time the state was developing a
seismograph network, and the presenters gave examples of a traffic light system
developed in Western Canada in the Duvernay and Montney plays in Alberta and British
Columbia, noting its success. Thus, it has been nearly a decade since we have
known how to successfully minimize induced seismicity events with minimal effects on
oil & gas companies and water injection well operators.
It should be pointed out that induced seismic events initiated at shallower depths than tectonic seismicity events have less impact. However, being initiated at shallower depths they can be “felt” more. That is why the Mercalli scale is a better indicator than the Richter scale.
Induced Seismicity Effects on Local Residents
Katie Surma of
Inside Climate News published an article in April 2024 about the effects of
induced seismicity in Argentina on real people. Many of those affected are from
the indigenous Mapuche community and thus, one might see this as an
envornmental justice issue. The earthquakes have been frequent and have caused
significant property damage, anxiety, and trauma among some of the inhabitants.
Right now, there
are not enough monitoring stations and seismicity data generated in the area.
That is beginning to change as the paper in Seismica shows. This is
despite frequent reports of damaging earthquakes early in the drilling. Local
residents have endured cracked walls, crumbling bricks and chimneys, and broken
windows. Sometimes the frequency of quakes causes anxiety for the residents who
have yet to be redressed for their damage. According to Inside Climate News the
locals noted that:
“…government and various energy company officials told
them that the rumbling was natural—about 90 miles west of Sauzal Bonito lay the
snow-capped Andes mountain range where two immense tectonic plates collide. A
few miles east of the towns are two large man-made lake reservoirs, created in
the late 1900s when hydroelectric dams were installed on the Neuquen river.
Both geographic features can, in theory, put stress on underground faults,
triggering earthquakes.”
In light of what we have known for years about oil & gas
induced seismicity, this unnecessary delay in acknowledging the problem can be
seen as deliberate obfuscation. The problem needs to be addressed effectively,
and the local residents need to be compensated for their damage. Those residents
had never experienced an earthquake before drilling began nor were there
records of them. Javier Grosso, a geographer at the National University of
Comahue, noted:
“…almost no infrastructure in the Neuquen basin was built
to withstand earthquakes, including the two hydroelectric dams located
kilometers away from the afflicted communities.”
“Shale oil and gas production carries a big risk that
these dams could be broken by induced seismic activity,” said Argentine
seismologist Andres Folguera. “That is a big risk, and it’s not quantifiable,
it’s not totally understood.”
By the late 2010s it became apparent that hydraulically
fractured horizontal wells and especially injected wastewater induced
seismicity. Grosso noted:
In the central United States, the number of annual earthquakes of 3.0 magnitude or greater grew from a historic annual rate of 25 to 1,000 in 2015. Much of that was attributable to wastewater injection. Similar damage has occurred in Argentina, mostly from injection during hydraulic fracturing operations rather than wastewater injection.
People have
complained that the constant shaking has been bothering them and their pets and
livestock. The local residents, including those in the Mapuche community, are
finally getting some recompense.
“…the provincial Neuquén government has offered small
anti-seismic replacement homes to some affected residents while working with
INPRES to ramp up seismic monitoring in the region, according to a spokesperson
for the Neuquen government.”
Argentina’s decentralized government gives power to local
regional governments to address problems like this. The oil and gas companies
should have been better engaged with the local authorities, and they should
have collaborated on this much sooner than they have. The oil & gas
companies have reflection seismic data that may indicate the presence of faults
that could slip. The nigger companies like Exxon, Chevron, and a Shell subsidiary
who are involved in the play early on should have been better prepared for
induced seismicity and as indicated below, made excuses for not addressing the
issue.
Since late 2018, Neuquen province’s environmental
ministry has said it is conducting research for a “Preventive Plan for the
Occurrence of Seismic Events,” but has not said when that plan will be
released.
“The Neuquen government spokesman said there are no plans
to enact new regulations aimed at controlling induced seismicity, but that the
province was working on a seismic traffic light plan and early warning system.
He did not say when those systems would be implemented. Currently, fracking
companies are not required to include seismic risk assessments in their
environmental impact studies, the regulatory document used to assess risk and
form the basis of licensing decisions.”
“According to the preliminary report, several of the
companies, including Chevron, told regulators that to adequately assess
fracking operations’ relationship with induced seismic activity, it’s necessary
to establish a baseline of natural seismic activity. Chevron began operations
in Vaca Muerta in 2013. The company did not respond to questions about whether
it carried out a background seismicity assessment at the time, or whether the
company asked the government to do so.”
“Shell’s Argentine subsidiary told regulators that it
does not have records of earthquakes in the areas where it is operating in Vaca
Muerta because it doesn’t own a network or contract seismographs that generate
data on seismic activity potentially induced by fracking operations. Shell was
a member of the consortium, also including Exxon, that operated in the
Netherlands where fracking operations were linked to over 1,000 induced
earthquakes in the Groningen area. Shell said it was now in the process of working
with INPRES and others to “quickly develop a network of seismographs that
provides us with information on monitoring,” according to the Neuquen
environmental ministry’s report. Shell did not respond to a request from Inside
Climate News for comment.”
“ExxonMobil said it did not have a record of earthquakes
where it operates in Vaca Muerta and that it has been making available its
“international experience” obtained by the company in the United States and
Canada, according to the Neuquen governmental report.”
Exxon also suggested that natural seismicity should also be
considered, which is a subtle nod to the denial of something that is obvious.
The Argentinian companies have seemingly been even slower to acknowledge blame.
There is a Need for Victims to Be Properly Compensated
Technically, we have
known about induced seismicity since the 1960s. It is only in more recent times
that we can better prove the exact causes. A 1998 paper in Tectonophysics addressed
liability under U.S. law. The authors noted:
“Induced seismicity may cause injuries by vibrations or
by seismically induced ground failure. In either case compensation for injuries
caused by induced seismicity should be paid for by the inducer. In the United
States the inducer of damaging seismicity can be made to pay for the harm
caused. Liability for damage caused by vibrations can be based on several legal
theories: trespass, strict liability, negligence and nuisance. Our research
revealed no cases in which an appellate court has upheld or rejected the
application of tort liability to an induced earthquake situation.”
In The U.S.
people affected by induced seismicity typically file lawsuits. Operators of
wastewater injection wells in particular can be liable for damages. Proper risk
management and due diligence by those companies are important. Law firm Brent
Blackstock PLC offers the following advice for well operators:
Operators must adopt a comprehensive approach that
combines scientific understanding, operational best practices and transparent
communication. By implementing these strategies, companies can potentially
safeguard themselves from legal repercussions while keeping their license to
operate. These strategies can include:
1)
Conducting thorough geological
assessments: Before drilling or injecting, perform comprehensive studies of the
local geology. Find fault lines, assess rock formations and evaluate seismic
history. This information helps in making informed decisions about site choice
and injection practices.
2)
Implementing real-time seismic
monitoring: Install robust monitoring systems to detect and track seismic
events as they happen. This data allows operators to adjust their activities
promptly if unusual patterns appear.
3)
Engaging with regulators and communities:
Keep open communication with local authorities and residents. Transparency
about operations and potential risks can help build trust and potentially
reduce the likelihood of legal action.
4)
Developing an emergency response plan:
Create and regularly update a plan for responding to induced seismic events.
This shows preparedness and commitment to public safety.
Traffic Light Systems: Utilizing Best Management Practices and Best Available Technologies (For All Potential Sources of Induced Seismicity)
I think the thing
to remember is that we now have a set of best management practices (BMPs) based
on the best available technologies (BATs) and regardless of costs operators
should be expected to implement those BMPs and BATs in a timely manner.
Another BMP is reusing frac water and produced water for future hydraulic fracturing operations. This water recycling is very common in the U.S. and serves to minimize the amount of water that is injected back into the subsurface which can further stress faults. Injection wells are used in Argentina but I am not sure if there are cases where they have been associated with induced seismicity. It depends on their proximity to potentially active basement faults. Thus, it depends on the depth of the reinjection zone. A 2025 paper presented at the SPE Hydraulic Fracturing Conference by researchers working with Argentina's YPF studied the logistics of frac water reuse in the Vaca Muerta and noted that:
"Preliminary conclusions indicate that the feasibility of
fracturing with blends of produced water within VM has been demonstrated;
through simply increasing the polymer concentrations, that were originally used
with the freshwater source alone, without potential impact on the productivity."
It should also be
noted that induced seismicity from hydraulic fracturing is likely to be a singular
event where it occurs since after the water is injected it is flowed back to
the surface, thus relieving further stress on faults. Wastewater injection is another
matter since by design the wastewater will continue to be injected.
Induced seismicity
does not result only from oil & gas operations. It is also well documented
in geothermal drilling and cycling projects that involve re-injection. It is a
potential problem with CO2 injection in CCS projects, although magnitudes seen
thus far have been small. Quarry blasting and even a well-attended Taylor Swift
concert produced recordable induced seismicity.
A 2019 article on
the effectiveness of traffic light systems in Seismographic Letters noted:
“In our case studies, whereas fluid injection–induced
seismicity generally starts at a low‐magnitude level and exhibits a
gradual temporal increase of the maximum earthquake magnitude with the duration
of the injection, the largest magnitude event frequently occurs postinjection.”
They also noted that that was a generality, and different geological
conditions mean variable effects.
Traffic light
systems have been proven to work effectively to decrease seismic events. They
have thresholds and protocols that trigger halting operations and for lowering
injection pressures and volumes.
“In Oklahoma, an area not prone to earthquakes,
regulators have, at times, ordered pauses or shut down pumping operations based
on seismic reports. In doing so, regulators there have brought down incidents
of induced quakes of 3.0 magnitude or greater from more than 900 in 2015 to 30
in 2022.”
Induced seismicity
is very well-known in geothermal development. This is especially true since
geothermal often accesses hot rock created by the movement of magma-heated fluids
along faults. U.S. company Fervo Energy has been working with the Dept. of Energy (note: the DOE's website has cut off access to certain information since the new administration has taken over) to develop enhanced geothermal which involves hydraulic fracturing to create a
fracture network to inject and produce hot water to be used to power steam
turbines for electricity production. Fervo’s seismicity management protocol is
given below.
“Component 1: Planning
Effective induced seismicity mitigation begins with
proactive planning. Before starting subsurface operations, Fervo’s operations
and resource teams draft an induced seismicity screening report that evaluates
seismic risk near the project site. Fervo’s Cape Station screening report
provides a fault map of the area, a geologic prognosis based on our
understanding of fault zones, and a characterization of natural fractures in
subsurface rock.
This background research, coupled with sophisticated
modeling, allows Fervo to account for potential seismic risk when designing
subsurface operations.
Component 2: Seismicity Measurement
With a strong plan in place, Fervo then focuses on
accurate seismicity measurement. At Cape Station, Fervo has built a robust
seismic monitoring network using three tools: partner organization seismometers
(specialized instruments used to record the motion of the ground during an
earthquake, even ones far too small to be felt by humans), Fervo seismometers,
and a seismic event catalog. Together, these strategies enable Fervo to collect
high-fidelity seismic information before subsurface activity poses meaningful
risks to the project, workers, and the surrounding community.
Some monitoring stations are installed several hundred
feet under ground and others are installed on the surface. This network serves
to “listen” to the underground, where seismic events may occur. These seismic
events, characterized by short-term vibrations of the earth, are triggered by
changes in fluid pressure and subsurface stress. These events may vary in
intensity, ranging from events that are imperceptible to those that cause
vibrations able to be felt on surface.
Partner Monitoring
Fervo benefits from partner organizations’ widespread
deployment of seismometers near Cape Station. As a result of the Utah Frontier
Observatory for Research in Geothermal Energy (FORGE), seventeen permanent
seismic stations surround our project site.
The University of Utah, which oversees FORGE, publishes
detailed information about the date, time, location, magnitude, and depth of
seismic events through the University of Utah Seismographic Stations (UUSS)
website. Third party experts review and analyze this data, providing both Fervo
and FORGE with trustworthy information about seismic activity in Beaver County.
Accelerometers at the Blundell geothermal plant and Milford high school help
provide additional information on ground motion before, during, and after
stimulation.
Fervo Monitoring
Fervo supplements these third-party seismic readings with
its own array of six seismometers. These tools enable Fervo to collect its own
on-site data and validate readings from UUSS, increasing the accuracy of
seismic information. Additionally, with multiple Fervo seismometers across Cape
Station, Fervo can guarantee network functionality even if one monitor fails,
faces an unplanned outage, or requires routine maintenance. Around-the-clock
tracking helps promote rapid risk management and safe operations.
Seismic Event Catalog
Finally, Fervo has produced a backward-looking seismic
event catalog to determine whether seismic activity on-site aligns with seismic
trends in southwest Utah. According to the United States Geological Survey’s
Comprehensive Earthquake Catalog, seven seismic events between magnitude 2.1
and 2.8 were detected between 1999 and 2023 within 10 km of Cape Station. This
historic data provides Fervo with an appropriate benchmark to characterize
real-time seismic data and evaluate on-site subsurface risks.
Component 3: Seismicity Response
Monitoring seismicity is only the first step to promoting
local health and safety. Ultimately, data must feed into a prompt Induced
Seismicity Mitigation Protocol (ISMP) that allows on-site work to account for
changing seismic conditions. Fervo’s ISMP, which adheres to best practices
outlined by US Department of Energy’s Induced Seismicity Mitigation Protocol
for Enhanced Geothermal Systems, encompasses operational changes, stakeholder
communication, and formal, conclusive external reporting.
Thus, we can see that Fervo’s traffic light system is robust
and comprehensive.
Ground motion thresholds for traffic light systems best involve the Mercalli intensity (MMI) scale for earthquakes rather than the more well-known Richter scale. This is because the Mercalli scale better quantifies scale based on felt movement. This can be converted to peak ground velocities (PGVs) to get thresholds as a 2020 paper in Bulletin of the Seismological Society of America demonstrated.
A 2022 paper in Nature
Scientific Reports where Javier Grosso was a co-author studied induced seismicity
in the Neuquen Basin and in another area of Argentina. The authors also
utilized ground deformation or movement as measured by satellite radar
interferometry (InSAR) in their analysis. The relationship between injecting
water for hydraulic fracturing and seismic events was again very strongly indicated
as would be expected. Thus, there is a strong need for an effective traffic
light system in the Neuquen Basin.
References:
Fracking-Induced
Earthquakes Are Menacing Argentina as Regulators Stand By. Katie Surma. April
14, 2024. Fracking-Induced Earthquakes Are
Menacing Argentina as Regulators Stand By - Inside Climate News
Chasing
the ghost of fracking in the Vaca Muerta Formation: Induced seismicity in the
Neuquén Basin, Argentina. Ryan Schultz, Guillermo Tamburini-Beliveau, Sebastián
Correa-Otto, and Javier Grosso-Heredia. Seismica. Vol. 3, No. 2. December 2024.
Chasing the ghost of fracking in the
Vaca Muerta Formation: Induced seismicity in the Neuquén Basin, Argentina |
Seismica
Oil
And Gas Wastewater Can Cause Earthquakes Up To Ten Years After It's Injected
Into The Ground. Ali Budner. High Plains Public Radio. July 19, 2019. Oil And Gas Wastewater Can Cause
Earthquakes Up To Ten Years After It's Injected Into The Ground | HPPR
Induced
earthquake damage assessment methodology for potential hydraulic fracturing
sites: Application to Manaus, Brazil, Andréia HA Silva, Gonzalo L Pita, […],
and Luiz CM Vieira, Jr. Sage Journals. Volume 37, Issue 1. Induced earthquake damage assessment
methodology for potential hydraulic fracturing sites: Application to Manaus,
Brazil - Andréia HA Silva, Gonzalo L Pita, José A Inaudi, Luiz CM Vieira, 2021
Induced
seismicity and the potential for liability under U.S. law. Darlene A. Cypser and
Scott D. Davis. Tectonophysics. Volume 289, Issues 1–3, 15 April 1998, Pages 239-255. Induced seismicity and the potential
for liability under U.S. law - ScienceDirect
How
can well operators avoid induced seismicity lawsuits? On Behalf of Brent
Blackstock PLC Oil & Gas Law . October 25, 2024. How can well operators avoid induced
seismicity lawsuits?
Induced
Seismicity Primer Update. Ivan Wong. Introduction to POTENTIAL INDUCED
SEISMICITY GUIDE – A Resource of Technical and Regulatory Considerations
Associated with Fluid Injection
Traffic
light system regulation of induced seismicity under multi-well fluid injection.
Miao He, Qi Li, Xiaying Li, and Yao Zhang. Energy Geoscience. Volume 6, Issue
2, June 2025, 100368. Traffic light system regulation of
induced seismicity under multi-well fluid injection - ScienceDirect
Traffic
Light Systems: To What Extent Can Induced Seismicity Be Controlled? Stefan
Baisch; Christopher Koch; Annemarie Muntendam‐Bos. Seismological Research Letters
(2019) 90 (3): 1145–1154. March 27, 2019. Traffic Light Systems: To What Extent
Can Induced Seismicity Be Controlled? | Seismological Research Letters |
GeoScienceWorld
Induced
seismicity closed-form traffic light system for actuarial decision-making
during deep fluid injections. A. Mignan, M. Broccardo, S. Wiemer & D.
Giardini. Scientific Reports volume 7, Article number: 13607 (October 2017). Induced seismicity closed-form
traffic light system for actuarial decision-making during deep fluid injections
| Scientific Reports
Fervo’s
Approach to Induced Seismicity Management. Fervo Energy. February 28, 2024.
Fervo’s Approach to Induced
Seismicity Management - Fervo Energy
Risk-Informed
Recommendations for Managing Hydraulic Fracturing-Induced Seismicity via
Traffic Light Systems. Ryan Schultz, Greg Beroza, William Ellsworth, and Jack
Baker. Bulletin of the Seismological Society of America. Volume XX Number XX–
2020. Schultzetal2020a.pdf
Assessment
of ground deformation and seismicity in two areas of intense hydrocarbon
production in the Argentinian Patagonia. Guillermo Tamburini-Beliveau, Javier
A. Grosso-Heredia, Marta Béjar-Pizarro, Raúl Pérez-López, Juan Portela, Martín
Cismondi-Duarte & Oriol Monserrat. Scientific Reports volume 12, Article
number: 19198 (2022). Assessment of ground deformation and
seismicity in two areas of intense hydrocarbon production in the Argentinian
Patagonia | Scientific Reports
Vaca Muerta: A Technical Approach to the Path of Sustainability in Water Reuse. Rosario Daniela Velo; María Lila Arias; Mauro Iván Weimann; Nicolás Mottes; Sebastián Miguel Pérez. Paper presented at the SPE Hydraulic Fracturing Technology Conference and Exhibition, The Woodlands, Texas, USA, February 2025.Paper Number: SPE-223566-MS. Vaca Muerta: A Technical Approach to the Path of Sustainability in Water Reuse | SPE Hydraulic Fracturing Technology Conference and Exhibition | OnePetro
No comments:
Post a Comment