Research ArticleSeismology

Oklahoma’s recent earthquakes and saltwater disposal

See allHide authors and affiliations

Science Advances  18 Jun 2015:
Vol. 1, no. 5, e1500195
DOI: 10.1126/sciadv.1500195
  • Fig. 1 Earthquakes and injection wells in Oklahoma.

    The map shows the locations of recent earthquakes (2009–2014 as red dots), historical earthquakes (1974–2008 as yellow dots), and EOR wells (black x’s) and SWD injection wells (blue x’s) that injected more than 30,000 barrels (~4800 m3) in any month in the most recent 3 years of data. Eight study areas are outlined, each named for a nearby town, and are presented in Figs. 3 to 5.

  • Fig. 2 Statewide injection and earthquakes.

    (Top) Cumulative number of M2.5 or greater earthquakes in Oklahoma since 1997. (Bottom) The left axis shows the total combined injection rate of all UIC wells in Oklahoma by type (see the text). The right axis shows all earthquakes in the state by magnitude through time in the state. Earthquake data are complete through 2014. The injection data are only available through 2013.

  • Fig. 3 Injection and earthquakes in three study areas.

    Monthly injection rates from EOR, SWD, and unknown wells within the Cherokee, Perry, and Jones study areas, as well as the times and magnitudes of earthquakes in each area. Detailed maps of each study area are also shown. The symbols for earthquakes and injection wells on the maps are the same as in Fig. 1. Note that the vertical scale is the same for each study area in this figure. Each study area is 5000 km2.

  • Fig. 4 Injection and earthquakes in three additional study areas with fewer earthquakes and less SWD.

    In contrast to those in Fig. 3, here are three comparable areas with comparatively few earthquakes. The vertical scales in the Enid and Oklahoma City study areas are the same as in Fig. 3. The Ardmore area has a different vertical axis because of the very large volumes of EOR injection.

  • Fig. 5 Injection and earthquakes in two areas within the Prague and Jones study areas.

    These show monthly injection rates and locations of EOR, SWD, and unknown wells as well as earthquakes. The symbols for earthquakes and injection wells are the same as in the maps in Fig. 3. Note that the vertical scale is different for each area, as are the sizes of the study areas.

  • Fig. 6 SWD in the three seismically active areas shown in Fig. 3.

    Volumes injected into EOR wells and SWD wells in the Cherokee, Perry, and Jones study areas are shown between 2009 and 2013. Also shown is an upper bound estimate of the volume of hydraulic fracturing flow-back water that was disposed of in each area in any given year. It is clear that most of the saltwater disposed of in SWD is produced water and not flow-back water from hydraulic fracturing.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/1/5/e1500195/DC1

    Fig. S1. Relocations of certain events in parts of the Jones box (22).

    Fig. S2. Cumulative injection in the seismically active study areas as a function of the average injection rate of individual wells.

  • Supplementary Materials

    This PDF file includes:

    • Fig. S1. Relocations of certain events in parts of the Jones box (22).
    • Fig. S2. Cumulative injection in the seismically active study areas as a function of the average injection rate of individual wells.

    Download PDF

    Files in this Data Supplement:

Navigate This Article