Energy Technologies: How They Work and Their Induced Seismicity Potential - Induced Seismicity Potential in Energy Technologies - page 68

Saltwater disposal well
FIGURE 3.12 Map of oil and gas wells (red dots) and saltwater disposal wells (green boxes) in Tarrant
and surrounding counties in Texas. The approximate location of the Dallas-Fort Worth (DFW) airport is
marked with box (as labeled), along with the injection wells near the airport. SOURCE: Modified from
Frohlich et al. (2010).
researchers are investigating whether a recent increase in the rate of M > 3.0 earthquakes in the
state of Oklahoma (see Figure 3.13) might be attributed to wastewater injection (Ellsworth
et al., 2012). One of the best-documented cases of induced seismicity from fluid injection is
in the Paradox Basin, Colorado, where brine from a natural seep has been reinjected in one
disposal well at 14,000 to 15,000 feet (4,300 to 4,600 m) depth since 1996 to prevent brine
flow into the Colorado River (Appendix K). To date over 4,600 induced seismic events ( M 0.5
to M 4.3) as far away as 16 km (9.9 miles) from the injection well have been documented in
the Paradox Basin (Block, 2011). Although the number of felt induced seismic events relative