Oil and natural gas
activities and induced seismicity
Seismic events that are caused by human activity are known as ‘induced seismicity’. Induced seismic activity is
linked to several industrial processes including above and below ground mining, geothermal energy, dam building,
construction and oil and natural gas activities including water disposal injection and hydraulic fracturing.
Seismic activity in the
3 – 4.0 magnitude range
is described to feel similar
to vibrations caused by a
heavy truck passing by.
How can oil and natural gas activities cause seismic activity?
During the hydraulic fracturing process, fluids and water are injected under high pressure
into deep geological formations where natural gas and oil are trapped in rock such as shale.
The pressurized fluid causes the rock to crack and creates tiny pathways for the natural
gas or oil to flow. Wastewater that is disposed into wells deep underground using pressure
injection can, on rare occasions, also cause seismic activity. It is the energy that is released
from high pressure injections in both instances that may induce seismic activity.
Can I feel it?
The Richter scale scientifically determines the amount of energy released underground and
measures seismic waves on a seismograph. The Mercalli Intensity Scale measures what is
felt above ground during seismic activity. Generally, the higher the intensity or magnitude
on the Richter scale the more it is felt on the surface, however this is not always the case.
Generally, seismic activity in the 3 – 4.0 magnitude range as measured on the Richter scale
is described to feel similar to vibrations caused by a heavy truck driving by.
Seismic activity from oil and natural gas activities is very seldom felt on the surface and
typically happens deep underground where the rock is being fractured.
In a 2012 and 2014 report by the B.C. Oil and Gas Commission (OGC), seismic activities were
triggered by fluid injection during hydraulic fracturing. All seismic events were low magnitude.
The reports concluded that about 0.15 per cent of these events were felt at surface.
SEISMIC EVENT FREQUENCY AND IMPACT – RICHTER SCALE
Magnitude Impact
9 – 9.9 CATASTROPHIC: can
cause irreparable
damage and immense
loss of life
Global Frequency
1 per decade
8 – 8.9 GREAT: can cause severe
damage and loss of life
1 per year
7 – 7.9 MAJOR: can cause
serious damage over
large areas
1 per month
6 – 6.9 STRONG: can be
destructive in
populated areas
2 per week
5 – 5.9 MODERATE: can cause
damage to poorly
constructed buildings
over small regions
4 per day
4 – 4.9 LIGHT: noticeable
shaking but significant
damage is unlikely
1 per hour
3 – 3.9 SMALL: often felt but
rarely causes damage
15 per hour
2 – 2.9 MINOR: easily recorded
at surface but not felt
2 per minute
<2 MICRO: not felt at
surface, causes no
damage and can only
be measured deep
underground
Continual
Source: U.S. Geological Society (USGS)
ProgressEnergy.com
The use of hydraulic fracturing for oil and natural gas activities is a highly regulated, safe and proven
production technique that has been used in Canada for more than 60 years.
In British Columbia, the OGC oversees all
aspects of oil and natural gas development
including regulations related to hydraulic
fracturing and responds to seismic events
as soon as they are detected. Regulations
require the operator to immediately suspend
hydraulic fracturing if a magnitude 4.0 or
greater event is triggered, as well as the
mandatory reporting of ‘felt’ events.
Operations can only be resumed with the
implementation of a mitigation plan approved
by the OGC.
In Alberta, the Alberta Energy Regulator
(AER) has seismic monitoring and reporting
requirements for hydraulic fracturing
operators in the Duvernay area as specified in
Alberta’s play-based regulatory pilot project.
A ‘traffic light’ system is used that requires
operators to immediately report seismic
events to the AER if they are of 2.0 magnitude
or greater and operations must cease if the
event measures 4.0 magnitude or greater.
The AER allows operations to resume once
they are satisfied with actions taken by the
operator to reduce the likelihood of seismicity.
Hydraulic fracturing has been done safely
for decades within the framework of sciencebased regulations and the use of industry
best operating practices to ensure the safety
of Canadians.
How Progress Energy manages seismic activities
The foothills of northeast British Columbia, where our asset base is primarily located, is a
naturally seismically active area with hundreds of seismic events recorded each year. More than
99 per cent of these events measure a magnitude so low that they are not felt on the surface
or pose any threat to public safety. Since 2012, Progress Energy has completed more than
3,400 hydraulic fractures with less than 0.05% linked to seismic events over 4.0 magnitude,
which is similar to a truck driving by. These rare instances did not cause injury or pose a risk
to public safety.
Given our activity levels in this area and our commitment to safe and responsible development,
Progress Energy has installed 17 localized seismograph arrays in our operating areas that
complement other monitoring stations that are part of the Canadian National Seismographic
Network (CNSN). The OGC routinely reviews data to monitor for potential occurrences of
induced seismicity. The OGC also has
access to additional seismic data collected
by industry arrays including data Progress
Energy voluntarily provides. If an anomalous
seismic event does occur, our detection
equipment allows us to more accurately
monitor seismic activity in our operating
areas. Our operations are flexible and we
can make adjustments if necessary such as
decreasing fluid volume and pressure, based
on the seismic data collected.
Earthquake facts in Canada*
• Thousands of earthquakes are recorded
each year in Canada and are usually so
small, less than 3.0 magnitude, that they
are not felt on the surface.
• Earthquakes occur across Canada.
Most are along the active plate boundaries
off the British Columbia coast, and along
the southwestern corner of the Yukon
Territory and in the Richardson Mountains
and Mackenzie Valley and arctic areas
including Nunavut and northern Quebec.
But, earthquakes also occur frequently in
the Ottawa Valley and St. Lawrence Valley,
in New Brunswick, and the offshore region
south of Newfoundland.
• The Geological Survey of Canada (GSC)
operates a Canada-wide network of
seismographs that make up the Canadian
National Seismograph Network (CNSN) and
monitor seismic activity from coast to coast.
• The largest earthquake recorded in Canada
was an 8.1 magnitude event that was off
Haida Gwaii on Canada’s west coast in 1949.
• Minor earthquakes can be triggered by
human activities such as mining, the filling
of reservoirs behind large dams, geothermal
energy and oil and natural gas activities
including water disposal injection and
hydraulic fracturing.
• Induced seismicity occurs close to the site of
the activity. There is no link between human
activities and earthquakes that occur
hundreds or thousands of kilometres away.
* Source: Earthquakes Canada
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