Guest geology by David Middleton
In a recent post of mine (ExxonMobil & Chevron Eviscerate Democrat Frac’ing Ban Fantasies) I made this passing comment:
There is no evidence whatsoever that frac’ing has ever polluted groundwater or triggered palpable earthquakes.
Regarding my earthquake comment, I was referring to specific attribution, not generalized correlations. One very polite commentator from British Columbia was quite insistent that the BC government had proven that frac’ing is causing palpable earthquakes in BC… So insistent that he forwarded me a copy of a BC Oil & Gas Commission report (hat tip to PeterT). The report goes into great detail correlating the timing of frac’ing operations to the timing and epicenters of 2.5 to 4.4 ML earthquakes within up to 5 km of the frac’ing operations. Despite the fact that such tremors were associated with “only 0.15 per cent of wellbore stage completions during the investigation period”, they still determined that 193 tremors must have been caused by frac’ing. 99.85% of specific frac’ing operations were not even correlated with such tremors.
The Full Montney: Canada’s Marcellus
Montney tight natural gas production has literally exploded from nothing in 2006 to more than 30% of Canada’s natural gas production today.
It is currently projected that the Montney will account for nearly half of Canada’s natural gas production by 2040, with most of the growth occurring in the British Columbia portion of the play.
Is it physically possible for frac’ing to cause palpable earthquakes?
Yes it is possible.
Large-volume disposal of produced brine (Keranen et al. 2014; Schultz et al. 2014; Weingarten et al. 2015) or hydraulic fracturing (Schultz et al. 2015a, 2017;Atkinson et al. 2016; Bao&Eaton2016; Lei et al. 2017) can induce earthquakes by increasing pore pressure or stress on faults (Ellsworth 2013; Segall & Lu 2015). Necessary conditions for the occurrence of injection-induced seismicity include a source of elevated pore pressure, a proximal, critically stressed fault and a pathway for fluid pressure to propagate from the injection site to the fault (Ellsworth 2013; Eaton 2018). Extraction of hydrocarbons from unconventional low-permeability reservoirs, such as organic-rich shale, makes extensive use of hydraulic fracturing to increase reservoir permeability. Earthquakes have been observed in association with a small fraction of well completions (Atkinson et al. 2016), yet pre-development assessment is hindered by a paucity of validated predictive models to forecast site-specific seismic hazard. Of particular importance is the need to achieve a better understanding of specific geological factors that impact the likelihood of induced seismicity (Schultz et al. 2016; Ghofrani & Atkinson 2016; Pawley et al. 2018).
Eaton & Schultz, 2018
One of the objectives in unconventional resource development is to avoid “proximal” faults of all varieties. Frac’ing into a fault is is a fast track to a junked & abandoned (J&A) wellbore. However, some faults are effectively impossible to resolve on reflection seismic data. You can’t avoid a fault, if you can’t see it.
That said, a lot of other factors can lead to induced seismicity.
In past decades, reported cases of induced seismicity in the WCSB (Western Canada Sedimentary Basin) have been attributed to stress changes from hydrocarbon production (Baranova et al., 1999), enhanced oil recovery (Horner et al., 1994), and wastewater disposal (Schultz et al., 2014).
Atkinson et al., 2016
Atkinson et. al., 2016 established a statistical correlation between frac’ing and induced seismicity in the WCSB… And it might be valid… However…
However, validated predictive models are not yet available to assess the likelihood, rates, or magnitudes of induced events from specific operations (National Research Council, 2013).
[…]
The causative details of the correlation between hydraulic fracturing and seismicity, in terms of how it works on the level of specific wells, formations, and tectonic regimes are beyond our current scope, but can be explored in future case studies.
Atkinson et al., 2016
They have a model and they have a statistical correlation… Sound familiar?
Has there been an increase in seismic activity in the vicinity of the Montney play?
It depends on location and time frame
All of the increased assumed induced seismicity has occurred in the seismically active over-pressured portion of the play.
Fluid-injection processes such as disposal of saltwater or hydraulic fracturing can induce earthquakes by increasing pore pressure and/or shear stress on faults. Natural processes, including transformation of organic material (kerogen) into hydrocarbon and cracking to produce gas, can similarly cause fluid overpressure. Here we document two examples from the Western Canada Sedimentary Basin where earthquakes induced by hydraulic fracturing are strongly clustered within areas characterized by pore-pressure gradient in excess of 15 kPa/m. Despite extensive hydraulic-fracturing activity associated with resource development, induced earthquakes are virtually absent in the Montney and Duvernay Formations elsewhere.
Eaton & Schultz, 2018
Natural Resources Canada has a searchable earthquake database (Earthquakes Canada). I downloaded the data for three time periods for the Lat-Lon range of the map in Figure 2. The database only includes 80 earthquakes from 1985-2019, far less than the 200+ induced quakes asserted by the BCOGC. The additional quakes were of too low magnitude to register in the national database.
As a result of recommendations from the investigation (Appendix 2), eight new seismograph stations (funded by the Commission, Geoscience BC, and the Canadian Association of Petroleum Producers) were added to
the existing two Canadian NationalSeismograph Network (CNSN) stations to provide more accurate detection and location capabilities. Six went online in August 2013, and two in November 2014. With the new stations the CNSN began recording many more lower magnitude events than previously recorded, enhancing the Commission’s ability to track seismicity. This report’s primary focus is on the investigation into events recorded between August 2013 and October 2014 in the Montney.
The investigation found that during this period 231 seismic events in the Montney were attributed to oil and gas operations – 38 induced by wastewater disposal and 193 by hydraulic fracturing operations. None of the recorded events resulted in any injuries, property damage or loss of wellbore containment.
BCOGC
There is no “before” in this data set from which to draw a baseline. Does this sound familiar? Directly comparing a recent high-resolution data set to the pre-existing low resolution data and declaring an anthropogenic anomaly… Very Mannian,
The BCOGC “found” 231 seismic events, attributed to oil & gas operations in the Montney between August 2013 and October 2014 . The Earthquakes Canada database only tabulates five (5) seismic events, of all causes, within the Montney over that time period. The Earthquakes Canada database appears to have a consistent resolution over its record length. There is no trend of detecting lower magnitude quakes over time. It is a reasonable “before and after” tool.
Prior to 2005, there was very little Montney production (“Pre-Montney”). The “Montney” time period is from January 1, 2005 to today. “Full Montney” is the period over which Montney production has boomed. I’m hard-pressed to see a statistically meaningful increase in seismic activity from Pre-Montney to Montney.
| Numbers of Quakes | ||||||
| Magnitude | ≤ 2 | 3 | 4 | 5 | ≥6 | |
| Pre-Montney | Feb 2, 1990 to Dec 31, 2004 | 27 | 20 | 4 | 1 | 0 |
| Montney | Jan 1, 2005 to November 25, 2019 | 8 | 11 | 5 | 0 | 0 |
| Full Montney | Jan 1, 2013 to November 25, 2020 | 6 | 3 | 5 | 0 | 0 |
| Quakes per Year | ||||||
| Magnitude | ≤ 2 | 3 | 4 | 5 | ≥6 | |
| Pre-Montney | Feb 2, 1990 to Dec 31, 2004 | 1.81 | 1.34 | 0.27 | 0.07 | 0.00 |
| Montney | Jan 1, 2005 to November 25, 2019 | 0.54 | 0.74 | 0.34 | 0.00 | 0.00 |
| Full Montney | Jan 1, 2013 to November 25, 2020 | 0.87 | 0.43 | 0.72 | 0.00 | 0.00 |
Here are maps of the three time periods:
I suppose a case could be made that the geographical distribution of earthquakes has shifted… if you want to grasp at straws. However, there hasn’t even been statistically meaningful change in the depths of earthquake epicenters. A shift from regional tectonic causes to anthropogenic causes, generally results in the epicenters becoming more shallow.
Can natural earthquakes be distinguished from frac-induced quakes?
Eaton et al., 2013 documented the detailed seismic monitoring of two frac’ing operations.
A research project was undertaken in August 2011 for continuous passive monitoring of a multistage hydraulic fracture stimulation of a Montney gas reservoir near Dawson Creek, B.C., with the main objective of investigating low-frequency characteristics of microseismic events. This work was motivated by a recently discovered class of long-period long-duration (LPLD) events, interpreted to represent slow slip along pre-existing fractures. The field deployment included a 6-level downhole toolstring with low-frequency (4.5 Hz) geophones and a set of 21 portable broadband seismograph systems. Time-frequency analysis of extracted high- and low-frequency microseismic events made use of the short-time Fourier transform. Observed low-frequency microseismic signals included tremor phenomena at various time scales, from a few seconds to the entire duration of high-pressure fluid injection, in addition to inferred regional earthquakes located ~150 km from the monitoring site. Relative to previously documented LPLD events from the Barnett, differences in low-frequency response for this Montney stimulation are interpreted to reflect a lower degree of complexity of preexisting and induced fracture networks. Analysis of low frequency microseismic signals shows promise for improving geomechanical understanding of fracture processes.
Eaton et al., 2013
They found that microseismic events occurred throughout the operations.
Yes… The tremors had negative moment magnitudes.
How can an earthquake have a negative magnitude?
Magnitude calculations are based on a logarithmic scale, so a ten-fold drop in amplitude decreases the magnitude by 1.
If an amplitude of 20 millimetres as measured on a seismic signal corresponds to a magnitude 2 earthquake, then:
–10 times less (2 millimetres) corresponds to a magnitude of 1;
–100 times less (0.2 millimetres) corresponds to magnitude 0;
–1000 times less (0.02 millimetres) corresponds to magnitude -1.
An earthquake of negative magnitude is a very small earthquake that is not felt by humans.
USGS
They did observe another phenomena which could be related to palpable earthquakes: “long-period long-duration (LPLD) events, interpreted to represent slow slip along pre-existing fractures. ” Unfortunately, they also recorded two natural earthquakes that had the same signature.
It is important to distinguish between potential LPLD events associated to the hydraulic fracturing treatment and local earthquakes. For example, Fig 12 shows a number of recorded signals that are interpreted here as regional earthquakes that are unrelated to this hydraulic fracture treatment.
Eaton et al., 2013
Conclusions
It is effectively impossible to specifically attribute earthquakes to specific frac’ing operations. This 2011 Oklahoma Geological Survey report is the closest thing I have seen to constituting evidence of a specific frac’ing operation triggering a specific earthquake:
Determining whether or not earthquakes have been induced in most portions of the stable continent is problematic, because of our poor knowledge of historical earthquakes, earthquake processes and the long recurrence intervals for earthquakes in the stable continent. In addition understanding fluid flow and pressure diffusion in the unique geology and structures of an area poses real and significant challenges. The strong spatial and temporal correlations to the hydraulic-‐fracturing in Picket Unit B Well 4-‐18 certainly suggest that the earthquakes observed in the Eola Field could have possibly been triggered by this activity. Simply because the earthquakes fit a simple pore pressure diffusion model does not indicate that this is the physical process that caused these earthquakes.
The number of historical earthquakes in the area and uncertainties in hypocenter locations make it impossible to determine with a high degree of certainty whether or not hydraulic-‐fracturing induced these earthquakes.
Whether or not the earthquakes in the Eola Field were triggered by hydraulic-‐ fracturing these were small earthquakes with only one local resident having reported feeling them. While the societal impact of understanding whether or not small earthquakes may have been caused by hydraulic-‐fracturing may be small, it could potentially help us learn more about subsurface properties such as stresses at depth, strength of faults, fluid flow, pressure diffusion, and long term fault and earthquake behaviors of the stable continent. It may also be possible to identify what criteria may affect the likelihood of anthropogenically induced earthquakes and provide oil and gas operators the ability to minimize any adverse affects as suggested by Shapiro et al. (2007).
Holland et al., 2011
Wastewater injection wells very likely have triggered induced seismicity, including some damaging quakes. It’s also likely that oil & gas formation, extraction and enhanced recovery processes can also induce seismicity. While it’s possible that frac’ing operations could directly trigger very minor earthquakes, there just isn’t any direct evidence for it… just models and statistical correlations.
References
Atkinson, G.M. et al., 2016. “Hydraulic fracturing and seismicity in the
Western Canada Sedimentary Basin”, Seismol. Res. Lett., 87, 631–647.
B.C. Oil and Gas Commission (2014). “Investigation of Observed Seismicity
in the Montney Trend”, https://www.bcogc.ca/node/12291/download
Eaton, David, et al. “Broadband Microseismic Observations from a Montney Hydraulic Fracture Treatment, Northeastern B.C.” CSEG RECORDER Magazine, 1 Mar. 2013, csegrecorder.com/articles/view/broadband-microseismic-observations-from-a-montney-hydraulic-fracture.
Eaton, David & Ryan Schultz. (2018). “Increased likelihood of induced seismicity in highly overpressured shale formations”. Geophysical Journal International. 214. 751-757. 10.1093/gji/ggy167.
Holland, A. “Examination of Possibly Induced Seismicity from Hydraulic Fracturing in the Eola Field, Garvin County, Oklahoma”. Oklahoma Geological Survey Open-File Report OF1-2011. August 2011.
“Montney Formation Play Atlas NEBC.” BC Oil and Gas Commission, 16 Jan. 2013, www.bcogc.ca/montney-formation-play-atlas-nebc.
National Energy Board. “Canada’s Energy Future 2018: Energy Supply and Demand Projections to 2040.” NEB, 28 Aug. 2019, www.cer-rec.gc.ca/nrg/ntgrtd/ftr/2018/index-eng.html.
Fracking Good report, David. The issue of fracturing black shale to release hydrocarbons is focused on two supposed negative issues, carbon pollution and earthquakes! I would like to see a first-movement solution, P-wave analysis, to know what type of fault movement produced the seismic event. My current belief, admittedly not based on detailed studies, is that waste water injection may lubricate faults already under stress and cause them to move. This is a net positive as the damage from ten earthquakes of 3 magnitude is less than from one 4 magnitude. Your report touches on the other problem, additional (and more sensitive) monitor systems are being introduced into the area of hydrocarbon fracturing activity. Who knows what the natural background is in a comparable area not undergoing active hydrocarbon fracturing? We should all remember that fracking became viable when Saudi Arabia ran crude prices over $100 per barrel, when their production costs were probably around $12 per barrel (currently around $60 per barrel). The USA is clearly the net beneficiary!
In the “release valve” mechanism postulated by Eaton & Schultz, hydrocarbon formation created the overpressure. As pressure builds up, faults become critically pressured and eventually slip, releasing some pressure. Then the pressure builds back up again, creating a cycle. Frac’ing simply triggers quakes that we’re about to happen anyway. If their model is correct, production will eventually depressurize the reservoir, effectively subduing the cycle.
The only problem is that they can’t identify the faults. Presumably, these would be minimal displacement strike-slip faults, which would be nearly impossible to resolve on reflection seismic data, and might not even be identifiable on log correlations.
My recollection of Rock Mechanics classes back in the 1970s is that increases in fluid pressure do not induce fault slippage. Rather, fluid pressure bears part of the weight of the rock (lithostatic load) which allows the fault zone to slip
And the notion of fluids “lubricating” the fault zone is silly unless the fluids could be shown to alter clay mineralogy
I am willing to be corrected if my memory is faulty Heh-heh)
That’s more or less how I remember it. But… Structural and engineering geology classes are 40+ year old memories… But I still have the textbooks. I think I even still have the Wolf (or Schmitt) Net we made with thumbtacks and manila folders.
Ah, yes, the “good old days” when we explored geologic structure by hand with stereonets and mechanical drawing (map views, sections, down-plunge views, etc.) No wonder we learned it so well.
I have fond memories of mapping out an ore deposit with plane-table, rod, and alidade
I hate to admit this… But a couple of years ago, I needed to solve a Three-Point Problem, so I pulled out my field geology textbook (Compton), looked it up, got a headache… And then Googled to see if there was an Excel spreadsheet that would do the math for me. There was… And the depth of the target formation came in right where the Three-Point solution predicted. I had three points of well control, the most up-dip having an oil show and a good HCI. The problem was that the seismic reflector appeared to dip down under the trapping fault, often caused by velocity issues. The “old school” solution worked, even though I cheated by using Excel… 😉
David, you’re sliding into Geological Engineering. You already have pronounced Geophysical Tendencies, and this continuation into Geological Engineering will end badly. I hope you get treatment before it is too late.
Engineering Geology was one of my favorite classes… And I spend more time working 3d seismic data than sliding well logs… But I still prefer camping…
Does not “lubricate,” but an increase in pore pressure moves the proverbial mohr circle to the left until failure. These are not earthquakes. They are small induced seismic events with magnitudes between 2 and 3. The faults that slip would slip eventually anyway (geologically speaking.) Having said that companies are getting really good at identifying “critically stressed” faults and avoid completing stages on azimuth with them.
+42 x 1042
Can the faults be mapped on seismic reflection data?
Most, but not all the faults can be mapped with 3D seismic. Included in our completion applications to the BCOGC are now hazard assessments.
Agreed, GeologyJim!
As David notes in his article above, the researchers that claim fracking fluids “lubricate” and “trigger” faults base their claims upon their “model”…
Another model that happens to predict based upon a programmers assumptions, not hard evidence experiments.
Global WarmingClimate changeClimate disruptionClimate disastersClimate weirdingClimate whatever has based their long history of absurd predictions upon a programmer’s gross assumptions without proof.• Warming means drought.
• Warming means more powerful storms.
• Warming means more frequent storms.
• Warming means heavier rain.
• Warming means more floods.
etc. etc. etc
Basically, the predictions are always based upon their assumptions not proven causes and resulting effects. Which is odd, since actual weather forecasting is all about causes and effects.
Geology, including tectonics, faults and earthquakes are all about cause and effect. Not assumed causes and possible effects.
Increases in fluid pressure would cause the fluid to bear more of the lithostatic load. One of the primary means by which a lubricant works is by separating contact faces, i.e., bearing the lithostatic load in this case.
Very nice analysis David!
I love this thread!
Clearly, many of us “old school” geologists and engineers ACTUALLY PAID ATTENTION in college and learned through experience what approaches are really useful and instructive.
Take that, kids!
“All models are wrong, but some are also useful”
AMEN
Bingo. One big quake is a lot worse than a bunch of little ones. If we could trigger an earthquake every week, that would prevent damaging ones.
Thus, if fracking does cause earthquakes, that’s a good thing.
And, if the pressure is down there and possibly increasing, there is not reason to expect that it would be stable forever. Little quakes only upset the scientists and not the people.
David, Shirley there is an ability to detect and differentiate between P-waves and S-waves. P-waves are the compressional waves that radiate perpendicular to the fault surface and S-waves propagate basically in all directions in a sine form. Hydrocarbon reserves are found in the total variety of stress-strain environments, so any of the fault types are possible. Any small movement (negative values?) induced by basin subsidence/inflation due to fluid extraction or reinjection is not of any consequence.
If Fracking does trigger an Earthquake, surely the appropriate response is “thank you”?
If Fracking does cause Earthquakes, then fracking is a bit like back burning to prevent bushfires, it would reduce stresses which are already present before they have a chance to cause a serious Earthquake.
Speaking only of western Canada (excepting the Pacific coastal region and the orogenic mountain areas), it’s a unlikely scenario. We’re probably one of the most tectonically-stable areas of the world…certainly of North America.
And the only real danger to groundwater is if the well casing/cement fails at an “appropriate” depth. Wells completed in the Montney are completed over 1000m below the fresh-water table. That’s a lot of overburden to defeat, quite a lot of which is entirely impermeable to fluid flow.
In the “release valve” mechanism postulated by Eaton & Schultz, hydrocarbon formation created the overpressure. As pressure builds up, faults become critically pressured and eventually slip, releasing some pressure. Then the pressure builds back up again, creating a cycle. Frac’ing simply triggers quakes that we’re about to happen anyway. These aren’t the sort of faults that would build up stress to the point of triggering large earthquakes.
If their model is correct, production will eventually depressurize the reservoir, effectively subduing the cycle.
With total respect to Mr Middleton for whom I have respect for his knowledge. Fracking may well not contribute to Earth Quakes however possible contamination or pollution of groundwater has been indicated in other countries.”There is no evidence whatsoever that frac’ing has ever polluted groundwater” is possibly not correct. It may be the case in USA and Canada. I would like to point to a case in South Africa which has demonstrated this did occur during exploration for oil. http://www.un-earthed.com/fracking-fears-run-deep-karoo/. The risk in this case is of great concern as water is very scarce in this region and that this may well cause untold problems for the people living in this very arid region. I am sure as he is a geologist he would be interested in this story.
The 1960’s incident in South Africa had nothing to do with frac’ing.
Now that I’ve actually read the full “article”… It’s not even an article, it’s a crackhead conspiracy theory blog post.
How can you tell the difference?
Glancing at the article, it looked like a standard Josh Fox Gasland-ignorant article. After reading it and skimming through the website, it was obvious that it was more of an Alex Jones crackhead conspiracy theory blog, centered on frac’ing. More of a distinction rather than a difference.
When rock fractures there will be some kind of acoustic/mechanical energy released. Is there any information on what that looks like? Could it be described as micro tremors?
cB,
“Acoustic emission (AE) is a spontaneously radiated elastic wave resulting from brittle rupture of materials under external compressions. The AE technique has been widely used to investigate fracture behavior and damage evolution of brittle rocks from many aspects, such as cumulative events
(Diederichs et al.May 31, 2019
https://academic.oup.com › article
Crack-induced acoustic emission and anisotropy variation of brittle rocks …”
https://www.google.com/search?client=ms-android-huawei&sxsrf=ACYBGNQI014nRBuGHZmvS4_4MwiHH7njKw%3A1575353430866&ei=VvzlXYe8NMOImwX1n63ADw&q=rock+fracture+acoustic+emission&oq=rock+fracture+acou&gs_l=mobile-gws-wiz-serp.
All fracking in the UK has now been temporarily stopped by the UK government until further notice because of minor earth tremors occurring during one or two fracking operations. There is a ridiculously low Richter Scale 0.5 limit set by the government on all sites that requires operators to immediately shut down their work when such tremors occur.
This is the text of an email I sent to my MP setting out some basic technical facts. Typically I’ve had no reply!
Fracking Induced Earthquake Scaremongering!
Professionally and personally, I am appalled by the Report issued and broadcast today concerning the stoppage of fracking in the UK due to certain problems, including earthquakes and claimed reduced public support. Is it no wonder that the public are frightened, given the scaremongering in this document regarding the risk of earthquakes; as reported by the BBC and as vociferously preached by the anti-fracking brigade. This rumour needs to be scotched immediately. The Richter Scale limit of 0.5 during fracking operations needs to be significantly increased, well above 0.5 as is and has been set out in other countries. You need to campaign vigorously within the HOC and Government for this seismic limit to be so raised. We need a level playing field for the UK’s fracking industry, otherwise there will be unacceptable massive increases in energy costs all round which, in turn, will increase all our other costs and decrease our competitiveness. The resultant economic cost to the UK, and the resultant further decline in the UK’s strategic manufacturing industries and their numbers of skilled jobs, would be totally unacceptable. We need to resurrect such strategic industries.
The following details can be quickly confirmed via Google and specialist internet sites! Firstly, the word “earthquake” should never be used during any debate about fracking. Even the highest Richter Scale intensity recorded in the UK following fracking is simply categorised in science as an earth tremor! A recent natural “earthquake” in the UK was of magnitude 3.9 on the Richter Scale and, elsewhere, the highest magnitude of natural quake occurring last year in the UK was Richter Scale 4.6. In contrast the recent fracking “earthquake” in Lancashire which stopped the exploratory fracking works was only Richter Scale 2.3 or so and, as noted above, was not even an earthquake but an earth tremor! I have personally experienced an earthquake overseas, and have seen the consequences of others, and I have also been employed to manage the design and building of necessary major seismic resistant structures!
The Richter scale is logarithmic, that means each whole number increase in Richter scale magnitude represents a tenfold increase in measured amplitude of quake! In terms of energy release, each whole number increase corresponds to an increase of about 32 times the amount of energy released, and each increase of 0.2 corresponds to a doubling of the energy released. The energy released is a direct measure of the risk of injuries and deaths, and of damage caused to buildings, services and other infrastructure works. This means that the above-mentioned recent natural UK tremor of Richter 3.9 released 2^((3.9 – 2.3)/0.2) = approximately 250 times more energy than the recent “fracking quake” and the largest natural UK quake last year of Richter 4.6 released 2^((4.6-2.3)/0.2) = roughly 2900 times more. Yet these natural “quakes” caused no injuries, let alone deaths and no recorded damage to buildings! Such natural tremors/quakes are frequent within the UK!
Any fracking induced earth tremor generated in the UK, can provide no greater risks or greater intensity of quake than naturally induced earth tremors as they simply provide an artificial release of the same locked in geological stresses across fault lines which are frequently naturally released. Any geologist will tell you that fracking itself only inputs a very, very miniscule proportion of the energy needed to generate even an earth tremor.
It is ridiculous that a tremor of Richter 0.5 should require an immediate shutdown of fracking operations when the above mentioned massively higher intensity earth tremors and minor earthquakes very frequently occur naturally in the UK and which, as recorded, cause no injuries, let alone deaths and no damage to buildings and structures. Structures within the UK are also not required to be designed to accommodate seismic loadings. Given the imposition of such a low limit of Richter Scale intensity earth tremor during fracking, it follows that we should immediately require all new building and structural works to be designed to resist seismic loadings. This would be a massively disruptive, expensive but totally unnecessary imposition! Even much higher intensity of seismic activity which occurs naturally and very frequently within the UK is considered to be no significant risk.
What’s an acceptable risk for naturally occurring seismic events should be good enough for similar fracking induced seismic events!
Great post Peter,
The only problem is that, universally, the large majority of government bureaucrats and politicians are mathematically illiterate.
The mere sight of the word “logarithm” induces a cold sweat and has been known to cause arrhythmia and brain seizures, there is no chance that they could ever understand what a base 10 logarithmic function is.
They are the ones that claimed the dog ate their math homework, and they are barely capable of reading their bank statements, which is what they seem to spend their time doing.
Brain seizures? That pre-supposes a great deal!
To say nothing of the large areas of the UK that have been subjected to multiple “earthquakes” in the past as a result of settlement following the extraction of another valuable fuel, coal. This subsidence was accepted as a consequence of the prosperity brought by the coal mining industry.
Thanks, David, for another fact-filled and entertaining post. Well done.
Regards,
Bob
I love writing these sorts of posts… because I learn about plays I have never worked. Up until a few days ago, I had no idea how prolific the Montney was… I hadn’t even heard of it. I spend my work days in the Pleistocene, Pliocene and Miocene conventional plays in the Gulf of Mexico.
I spent many an enjoyable weekend in the Galveston portion of the Gulf, many decades ago, back when I lived in Houston. Great body of water. Sad to say, I’m not fixin’ to go back.
Regards,
Bob
If we accept the premise that fracking can trigger earthquakes in areas prone to earthquakes would it not be preferable to artificially trigger numerous smaller earthquakes rather than allowing naturally caused earthquakes to build up to damaging levels?
If there were a Marcellus in the UK, we’d need our own President Trump to enable us to exploit it.
This article is patrolled by watermelons. https://en.wikipedia.org/wiki/Marcellus_natural_gas_trend
I only wish we had such a politician – someone who would tell it like it is instead of fawning over these deluded, drug-addled oxygen wasters!
It doesn’t take much observation to realize that humans almost always worry about the wrong things. For a recent example I would point out the halftime sit-in by Students at the annual Harvard/Yale football game. They were protesting the lack of action to address the “climate emergency”. I would suggest to them that what they should have been protesting was the ridiculous price of tuition at their schools. Assuming they are matriculating via student loans, the next decade of their lives will be far more affected by student loan repayments than any damaging changes to the climate. But perhaps these were all students from wealthy families that don’t have to borrow money to pay the ridiculous tuitions being charged these days.
Marc, their parents should certainly be demanding a refund, as clearly the college is failing to teach those snowflakes anything useful for all that money they’re being charged.
James
The implication of ‘thinking’ moving from the amygdala to the prefrontal cortex is that liberals suffer from arrested maturation.
Had to do a quick re-read of your last line there Clyde – my first skim registered “arrested MASTURBATION”.
Then when I re-read your whole comment, I decided it was entirely valid to accept my first interpretation. 🙂
Reminds me of that quote
“Any man who is not a socialist at age 20 has no heart. Any man who is still a socialist at age 40 has no head.”
Good read, David.
If you’re interested, I can get you most of the well data you’d need to correlate directly to the completion operations (possibly all, except for confidential wells).
I’m always interested… But I work the Gulf of Mexico and already have a more-than full time job. To make a meaningful correlation of frac’ing operations to earthquakes, you would have to have pre-2005 earthquake records comparable to those collected since 2013.
David
There really wasn’t much horizontal drilling or hydraulic fracturing done in the Montney until around 2011. Thanks for posting this.
True. It literally exploded out of nothing in just a few years. Thanks for being persistent. I always like learning about oil & gas plays that I will likely never work.
I wonder if Monty Python knows about this Montney guy?
Even if a few tiny tremors were to result from fracking activity–and this seems plausible–then so effing what? There is no damage; groundwater reservoirs are unaffected; few individuals would even notice. Call me when there is a real problem.
This is purely perceptual. The media are using the scare word “earthquake” to describe minor earth movements, not realizing that these happen all the time. And of course, energy corporations are all run by mustache-twirling villains.
Fracking is a game changer, a boon, a gift to humanity, which needs lots of energy to maintain its advanced ways. Benefit/risk is very large, and what problems there are relatively minor and manageable.
No break eggs, no have omelets.
“They have a model and they have a statistical correlation… Sound familiar?”
Just like oil and gas exploration—seismic modeling.
In seismic modeling we usually have 1) well logs and 2) seismic data. We have both geological and geophysical data. While non-uniqueness is still pervasive, the objective is usually along the lines of trying to determine if a seismic anomaly is consistent with a hydrocarbon accumulation. This is a simple matter of fluid replacement. Gas, oil and brine filled sandstones exhibit different seismic velocities and densities. These sort of models are generally very constrained. That said, I’ve seen more than a few dry holes drilled on seismic anomalies that modeled as oil and/or gas. Mother nature has a wicked sense of humor.
David
But, you test your model predictions by drilling, and admit when the model is wrong. Where is the vetting and admission of failure in climate models? As I recollect, you and I pointed out problems with Mann’s 1989 prediction of temperatures. Yet, the alarmist zealots still claim that Mann did a good job of predicting because the slopes of the predictions and measurements both had the same sign (+), albeit the slopes had significantly different numerical values.
I think you mean Hansen… And… Yep. If our drilling results matched our prognoses the way temperature data matches the models, we’d be out of business.
Yep, Hansen it is. Hard to tell them apart. If you’ve seen one quacking duck, you’ve seen them all.
just models and statistical correlations
Hypotheses and pattern matching. Modern “science”.
Sometimes that’s all you have.
It may be sufficient to start, but necessarily to conclude. Thus the expectation there will be moderation based on other criteria (e.g. economic viability, social stability, cultural integrity, utilitarian applications). Case in point: [catastrophic] [anthropogenic] climate change.
OK, I was wrong about negative magnitude earthquakes. I thought a zero magnitude earthquake had zero energy in it.
David: From my personal history:
I was in Iran, doing a high rate acid matrix treatment (>20 bbls/minute). The completion was open hole below the liner casing.
Apparently there was an earthquake. I did not feel it, as I was in the data van. Guys on the ground reported it. So a mild event.
Oil production on this treatment fell to zero, and NIOC (the National Iranian oil company) blamed us. When wireline went in to evaluate, it hung up well above the production interval. Apparently the seismic event sheared the wellbore, as the earth shifted across the open hole.
Did we cause it? Likely.
It’s hard to see how that could have triggered fault displacement sufficient to shear casing, with a barely noticed quake. Although, in the Gulf of Mexico, I’ve seen several examples of faults shearing casing around salt domes. In many, maybe most, cases, the salt is still moving.
Correlation does not prove causation.
This thread has probably run its course, but having been involved in the type of job you describe, is it possible that you had a bad cement job, and collapsed your casing?
It was an open hole completion. There was no casing across the interval being treated.
OK Les,
(Knowing absolutely nothing about the job you were on, and what down hole tools were in the hole) I still have to ask. You had to have a packer to inject through to stimulate the open hole, no? I was thinking maybe casing collapsed above the packer. Never mind, just interested. I’ve had it happen to me a few times stimulating through well testing tools.
Probably not applicable to your event.
No. It was an open hole completion.
Most of the acid work we did in Iran was open ended. Often there was not even tubing, and the treatment was done through casing, and produced through casing. (We would displace with reformate, which was enough to bring the well on production). The only barrier was the wellhead, which is totally unacceptable in most of the rest of the world.
Les
Gotcha. Thanks, I was just curious. Interesting.
Induced Seismicity is occurring in the Montney in N.E. B.C. There are natural faults oriented near parallel to maximum principle stress. The critically stressed faults will move if there is an increase in pore pressure (fracture treatment.) The result is a tiny tremor around 2-3 moment magnitude. Nothing dangerous, and nothing that would not slip given enough time, but induced by fracturing nonetheless. No public property damage has been caused. The risk is all on the oil and gas company to maintain the integrity of the subsurface casings. Nobody wants to junk a well.
Plate tectonics causes earthquakes. Is there any scientific evidence to the contrary?
Mining, quarrying, fluid injection operations can all trigger non-tectonic earthquakes. Some intraplate earthquakes are also considered to be non-tectonic.
David
Also, apparently, the filling of large surface reservoirs can cause non-tectonic earthquakes.
Melting glaciers causes earthquakes—New England Is still having glacial rebound quakes. If we don’t stop burning hydrocarbons “worse than expected” quakes will emanate from Greenland, and we will all perish.
I was thinking Dawson Creek could use some excitement.
There was some snarkiness in your last posting, and for my part I would like to apologize.
There were two points I was trying to make in your previous posting. One was that if earthquakes were occurring, then the casing in the horizontal section would be damaged during the fracing process. As far as I know and as far as your present posting details, that is not happening.
My second point had to do with the amount of energy entering the formation during a frac. I used gallons of diesel rather than joules to keep the numbers manageable. Most of the energy entering the formation during a frac is returned to the wellbore or dissipated to the matrix relatively quickly. Can this small amount of energy be the trigger for an earthquake? For me, the only seismic event is the creation of the fracture; a parting of a few mils. What you might describe as a negative event.
When it comes to wastewater disposal, the OGCC’s will not allow the pressure on disposal wells to exceed the frac gradient. In the case of the Oklahoma disposal well I seem to remember that the experts were saying that the seismic event was not occurring in the disposal formation but that the waste water was somehow leaking into a deeper formation where slippage could occur. I found this a bit hard to take seriously. It sounded more like an environmental witch hunt looking for a witch, and any witch would do.
I never apologize for snarkiness, I usually strive for it… 😎
At any rate the one mag 5 in the pre fracking time comparison more then makes up for the extra 4s in the post fracking.