Stronger Proof: Oil Recovery Triggered Texas Tremors
|November 16, 2013||Posted by Staff under Environmental|
This 2013 excerpt of Nature, Nov 4, is by Jeff Tollefson.
First came reports of earthquakes caused by hydraulic fracturing and the reinjection of water during oil and gas operations. Now US scientists are reporting tremors may have been caused by the injection of carbon dioxide during oil production. Since 2006, a series of tremors has rattled Snyder, Texas, which lies in the oil-rich Permian Basin.
The evidence centres on a sudden burst of seismic activity around an old oil field in the Permian Basin in northwest Texas. From 2006 to 2011, after more than two decades without any earthquakes, seismometers in the region registered 38 tremors, including 18 larger quakes ranging from magnitude 3 to 4.4. The tremors began just two years after injections of significant volumes of CO2 began at the site, in an effort to boost oil production.
The earthquakes have rattled residents in the nearby town of Snyder and spurred questions about the link to oil and gas activity in the region.
Any time you are putting material into the ground, particularly under pressure, you are going to have the potential to break rock.
The data suggest that there is a previously unidentified fault running through the area, and that the CO2 injections effectively lubricate that fault, enabling slippage. (Scientists documented a series of earthquakes in the area from 1975 through 1982, but those tremors were linked to water injections, also intended to boost oil production.)