scholarly journals Quantification of potential macroseismic effects of the induced seismicity that might result from hydraulic fracturing for shale gas exploitation in the UK

2014 ◽  
Vol 47 (4) ◽  
pp. 333-350 ◽  
Author(s):  
Rob Westaway ◽  
Paul L. Younger
Keyword(s):  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Induced Seismicity ◽  
Macroseismic Effects ◽  
The Uk

scholarly journals Fracking bad language – hydraulic fracturing and earthquake risks

2021 ◽  
Vol 4 (2) ◽  
pp. 303-327
Author(s):  
Jennifer J. Roberts ◽  
Clare E. Bond ◽  
Zoe K. Shipton
Keyword(s):  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Perceived Risk ◽  
Induced Seismicity ◽  
Earthquake Risk ◽  
Public Concern ◽  
Public Events ◽  
Risk Magnitude ◽  
The Uk ◽  
Survey Responses

Abstract. Hydraulic fracturing, or fracking, is a borehole stimulation technique used to enhance permeability in geological resource management, including the extraction of shale gas. The process of hydraulic fracturing can induce seismicity. The potential to induce seismicity is a topic of widespread interest and public concern, particularly in the UK where seismicity induced by hydraulic fracturing has halted shale gas operations and triggered moratoria. Prior to 2018, there seemed to be a disconnect between the conclusions of expert groups about the risk of adverse impacts from hydraulic-fracturing-induced seismicity and the reported level of public concern about hydraulic fracturing induced seismicity. Furthermore, a range of terminology was used to describe the induced seismicity (including tremors, earthquakes, seismic events, and micro-earthquakes) which could indicate the level of perceived risk. Using the UK as a case study, we examine the conclusions of expert-led public-facing reports on the risk (likelihood and impact) of seismicity induced by hydraulic fracturing for shale gas published between 2012 and 2018 and the terminology used in these reports. We compare these to results from studies conducted in the same time period that explored views of the UK public on hydraulic fracturing and seismicity. Furthermore, we surveyed participants at professional and public events on shale gas held throughout 2014 asking the same question that was used in a series of surveys of the UK public in the period 2012–2016, i.e. “do you associate shale gas with earthquakes?”. We asked our participants to provide the reasoning for the answer they gave. By examining the rationale provided for their answers, we find that an apparent polarisation of views amongst experts was actually the result of different interpretations of the language used to describe seismicity. Responses are confounded by the ambiguity of the language around earthquake risk, magnitude, and scale. We find that different terms are used in the survey responses to describe earthquakes, often in an attempt to express the risk (magnitude, shaking, and potential for adverse impact) presented by the earthquake, but that these terms are poorly defined and ambiguous and do not translate into everyday language usage. Such “bad language” around fracking has led to challenges in understanding, perceiving, and communicating risks around hydraulic-fracturing-induced seismicity. We call for multi-method approaches to understand the perceived risks around geoenergy resources and suggest that developing and adopting a shared language framework to describe earthquakes would alleviate miscommunication and misperceptions. Our findings are relevant to any applications that present – or are perceived to present – the risk of induced seismicity. More broadly, our work is relevant to any topics of public interest where language ambiguities muddle risk communication.

The Potential Water Quality Impacts of Shale Gas Exploitation

2020 ◽  
Author(s):  
Hsiao-Yuan Tammy Hsu ◽  
Fred Worrall ◽  
Andy Aplin
Keyword(s):  
Chemical Composition ◽  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Fluid Composition ◽  
Potential Contribution ◽  
Sources Of Information ◽  
Geothermal Waters ◽  
Rock Interaction ◽  
The Uk

<p>     The potential development of shale gas has brought with it several concerns about environmental impacts, these include: induced seismicity, air pollution, and groundwater contamination. During hydraulic fracturing for shale gas, large volumes of oxic and acidic water are injected into the gas-bearing formations. The injected fluids contain a range of additives and will mix and react with the in-situ groundwater and shale rock with the potential to drive water-rock interactions; release metal contaminants; alter the permeability of the bedrock; with each of these affecting the transport and recovery of water, hydrocarbons, and contamination. The purpose of this study is to understand the geochemical processes and inorganic metals release during hydraulic fracturing to assess the potential contribution of fluid-rock interaction for the composition of produced waters and alteration of shale mechanical properties.<br>     The study has: <br>i) Statistically analysed the chemical composition of hydraulic fracturing in USGS dataset to create prior distributions for the prediction of the salinity and chemical composition of flowback fluids in the UK. <br>ii) Statistically analysed the composition and controls on geothermal waters in the UK. Deep geothermal waters are an analogue for the in-situ groundwater composition with which injected fracking fluids will react and mix.<br>iii) Both sources of information have assisted in the design of the high pressure, high temperature experiments that will simulate the fracking fluid processes<br>iv) Undertaken sequential extraction of target shales to understand the data from existing batch experiments undertaker</p><p>     Future work will include isotope proxy and mineralogical texture studies to predict flowback fluid composition and the post-frack condition of the shale.</p>

scholarly journals Real‐Time Imaging, Forecasting, and Management of Human‐Induced Seismicity at Preston New Road, Lancashire, England

2019 ◽  
Author(s):  
Huw Clarke ◽  
James P. Verdon ◽  
Tom Kettlety ◽  
Alan F. Baird ◽  
J‐Michael Kendall
Keyword(s):  
Hydraulic Fracturing ◽  
Real Time ◽  
Shale Gas ◽  
Statistical Models ◽  
Induced Seismicity ◽  
Red Light ◽  
Fracture Network ◽  
Fluid Injection ◽  
Traffic Light ◽  
Subsurface Fluid

ABSTRACTEarthquakes induced by subsurface fluid injection pose a significant issue across a range of industries. Debate continues as to the most effective methods to mitigate the resulting seismic hazard. Observations of induced seismicity indicate that the rate of seismicity scales with the injection volume and that events follow the Gutenberg–Richter distribution. These two inferences permit us to populate statistical models of the seismicity and extrapolate them to make forecasts of the expected event magnitudes as injection continues. Here, we describe a shale gas site where this approach was used in real time to make operational decisions during hydraulic fracturing operations.Microseismic observations revealed the intersection between hydraulic fracturing and a pre‐existing fault or fracture network that became seismically active. Although “red light” events, requiring a pause to the injection program, occurred on several occasions, the observed event magnitudes fell within expected levels based on the extrapolated statistical models, and the levels of seismicity remained within acceptable limits as defined by the regulator. To date, induced seismicity has typically been regulated using retroactive traffic light schemes. This study shows that the use of high‐quality microseismic observations to populate statistical models that forecast expected event magnitudes can provide a more effective approach.

scholarly journals Green, yellow, red, or out of the blue? An assessment of Traffic Light Schemes to mitigate the impact of hydraulic fracturing-induced seismicity

2020 ◽  
Author(s):  
James P. Verdon ◽  
Julian J. Bommer
Keyword(s):  
Hydraulic Fracturing ◽  
Induced Seismicity ◽  
Risk Mitigation ◽  
Red Light ◽  
Fundamental Parameter ◽  
Traffic Light ◽  
The Usa ◽  
The Uk ◽  
The Impact ◽  
Magnitude Increase

Abstract Mitigating hydraulic fracturing-induced seismicity (HF-IS) poses a challenge for shale gas companies and regulators alike. The use of Traffic Light Schemes (TLSs) is the most common way by which the hazards associated with HF-IS are mitigated. In this study, we discuss the implicit risk mitigation objectives of TLSs and explain the advantages of magnitude as the fundamental parameter to characterise induced seismic hazard. We go on to investigate some of the key assumptions on which TLSs are based, namely that magnitudes evolve relatively gradually from green to yellow to red thresholds (as opposed to larger events occurring “out-of-the-blue”), and that trailing event magnitudes do not increase substantially after injection stops. We compile HF-IS datasets from around the world, including the USA, Canada, the UK, and China, and track the temporal evolution of magnitudes in order to evaluate the extent to which magnitude jumps (i.e. sharp increases in magnitude from preceding events within a sequence) and trailing events occur. We find in the majority of cases magnitude jumps are less than 2 units. One quarter of cases experienced a post-injection magnitude increase, with the largest being 1.6. Trailing event increases generally occurred soon after injection, with most cases showing no increase in magnitude more than a few days after then end of injection. Hence, the effective operation of TLSs may require red-light thresholds to be set as much as two magnitude units below the threshold that the scheme is intended to avoid.

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