Andrew Frassetto
2013-11-19 19:58:46
"Induced/Triggered Earthquakes: Examples from Texas" will be presented
at 2 pm EST (7 pm UTC) on Wednesday, 11/20.
Register to attend: https://www2.gotomeeting.com/register/430431890
You will be emailed a confirmation containing a link for accessing the
webinar. The presentation and subsequent interactions between the
speaker, host, and audience are recorded and made available within a few
days. Access to the webinar archive, along with related materials and
more information on the series is found here:
http://www.iris.edu/hq/webinar/
Presenter: Dr. Cliff Frohlich, Associate Director & Senior Research
Scientist, Institute for Geophysics, University of Texas at Austin
Abstract: The widespread application of hydrofracturing to develop
petroleum resources has increased the need to dispose of flowback fluids
in deep injection wells. In several geographic areas this appears to
have triggered earthquakes in locations where none had been reported
historically. Texas has had a very active petroleum industry for about a
century, and at present there are more than 10,000 active disposal wells
in Texas. Thus Texas serves as a huge natural experiment where we can
explore how earthquakes are related to both fluid injection and
petroleum extraction.
The passage between 2009-2012 in Texas of EarthScope's USArray
Transportable Array seismograph stations provided an opportunity to
identify and accurately locate earthquakes with magnitudes as small as
1.5-2.5. Information about locations of wells and monthly volumes of
water, oil or gas extracted and injected are archived by the Texas
Railroad Commission and available to the public. With these data we have
been evaluating the relationship between seismic activity and fluid
injection and extraction in Texas.
For five different areas in Texas I discuss seismic sequences that
appear to have been induced or triggered by injection or extraction. In
two areas there is strong evidence that water injection has triggered
earthquakes; in two areas there is evidence that the extraction of oil
and water has triggered earthquakes; and in one area CO2 gas injection
may have triggered earthquakes.
Although these observations provide strong evidence that injection and
extraction do induce/trigger earthquakes, there are thousands of active
wells in Texas that do not trigger seismic activity. The principal
outstanding unsolved question is why earthquakes are induced/triggered
near some wells and not at others. Fluid injection for waste disposal
seems to cause earthquakes more often than fluid extraction. I am aware
of no instances in Texas where hydrofracturing itself has caused
earthquakes large enough to be felt at the surface.
Please direct any related inquiries or amusing seismology fan fiction to
Andy Frassetto (andyf<at>iris.edu).
System Requirements
PC-based attendees
Required: Windows® 7, 8, Vista, XP or 2003 Server
Macintosh®-based attendees
Required: Mac OS® X 10.5 or newer
at 2 pm EST (7 pm UTC) on Wednesday, 11/20.
Register to attend: https://www2.gotomeeting.com/register/430431890
You will be emailed a confirmation containing a link for accessing the
webinar. The presentation and subsequent interactions between the
speaker, host, and audience are recorded and made available within a few
days. Access to the webinar archive, along with related materials and
more information on the series is found here:
http://www.iris.edu/hq/webinar/
Presenter: Dr. Cliff Frohlich, Associate Director & Senior Research
Scientist, Institute for Geophysics, University of Texas at Austin
Abstract: The widespread application of hydrofracturing to develop
petroleum resources has increased the need to dispose of flowback fluids
in deep injection wells. In several geographic areas this appears to
have triggered earthquakes in locations where none had been reported
historically. Texas has had a very active petroleum industry for about a
century, and at present there are more than 10,000 active disposal wells
in Texas. Thus Texas serves as a huge natural experiment where we can
explore how earthquakes are related to both fluid injection and
petroleum extraction.
The passage between 2009-2012 in Texas of EarthScope's USArray
Transportable Array seismograph stations provided an opportunity to
identify and accurately locate earthquakes with magnitudes as small as
1.5-2.5. Information about locations of wells and monthly volumes of
water, oil or gas extracted and injected are archived by the Texas
Railroad Commission and available to the public. With these data we have
been evaluating the relationship between seismic activity and fluid
injection and extraction in Texas.
For five different areas in Texas I discuss seismic sequences that
appear to have been induced or triggered by injection or extraction. In
two areas there is strong evidence that water injection has triggered
earthquakes; in two areas there is evidence that the extraction of oil
and water has triggered earthquakes; and in one area CO2 gas injection
may have triggered earthquakes.
Although these observations provide strong evidence that injection and
extraction do induce/trigger earthquakes, there are thousands of active
wells in Texas that do not trigger seismic activity. The principal
outstanding unsolved question is why earthquakes are induced/triggered
near some wells and not at others. Fluid injection for waste disposal
seems to cause earthquakes more often than fluid extraction. I am aware
of no instances in Texas where hydrofracturing itself has caused
earthquakes large enough to be felt at the surface.
Please direct any related inquiries or amusing seismology fan fiction to
Andy Frassetto (andyf<at>iris.edu).
System Requirements
PC-based attendees
Required: Windows® 7, 8, Vista, XP or 2003 Server
Macintosh®-based attendees
Required: Mac OS® X 10.5 or newer