Physics-based Forecasting of Injection-induced Seismicity across the U.S Mid-continent
TITLE:
Physics-based Forecasting of Injection-induced Seismicity across the U.S Mid-continent
DATE:
Friday, December 7th, 2018
TIME:
3:30 PM
LOCATION:
GMCS-314
SPEAKER:
Matthew Weingarten, Assistant Professor, Department of Geological Sciences, SDSU.
ABSTRACT:
U.S. oil fields have been producing much more water than oil for decades.
However, injection-induced seismicity has markedly increased coincident
with the recent unconventional oil revolution. A key feature of this boom
in production is that much of recent injection has occurred into non-producing
horizons. Here, I’ll discuss how reinjection of saltwater, co-produced with
oil, triggered thousands of widely felt and several damaging earthquakes in
Oklahoma and Kansas. Specifically, I’ll discuss a new methodology to forecast
the probability of damaging induced earthquakes in space and time. In our
hybrid physical-statistical model, seismicity is driven by the rate of
injection-induced pressure increases at any given location and spatial
variations in the number and stress state of preexisting basement faults
affected by the pressure increase. If current injection practices continue,
earthquake hazards are expected to decrease slowly. Approximately 190, 130
and 100 widely felt M greater than or equal to 3 earthquakes are anticipated
in 2018, 2019 and 2020, respectively, with corresponding probabilities of
potentially damaging M greater than or equal to 5 earthquakes of 32, 24 and 19%.
We identify areas where produced-water injection is more likely to cause seismicity.
Our methodology can be used to evaluate future injection scenarios intended to
mitigate seismic hazards.
HOST:
Dr. Chris Paolini
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