Study Suggests Relationship Between Fluid Extraction and Seismic Activity in the Eagle Ford Shale

The Earth and Planetary Science Letters published a study by Cliff Frohlich and Michael Brunt that suggests a connection between oil and water extraction and seismic activity in the Eagle Ford Shale region in Texas.  While the authors concluded that the data suggested "a relationship between seismic activity and extraction of fluids (oil + water)," they found that the "increases in fluid extraction, rather than injection, occurred prior to the majority of [the seismic] events."  The study investigated 64 potential earthquakes centered at 14 sites in the Eagle Ford Shale region. The authors found that only 2 of the 14 sites had increased fluid injection in the area before the seismic activity occurred, while 8 of the sites had increased oil and water extraction before the potential earthquakes.  The study did note that 4 sites were not situated near either fluid injection or gas extraction and that the data was only collected for a period of two years, which is an insufficient amount of time to provide "unequivocal statistical evidence" of causation.  Further, the authors noted that fluid injection is prevalent in the Eagle Ford region and that it is possible that earthquakes of natural origin may incidentally occur near active wells.

The study may be found at:

http://www.sciencedirect.com/science/article/pii/S0012821X13004007

Tom Panighetti
August 28, 2013