The Texas Railroad Commissioner, Ryan Sitton, has told media that his agency will study the link between "oil and gas injection activities" and the increased risk of earthquakes. According to Sitton, there is scientific evidence that shows such a link exists: between wastewater injection into underground reservoirs and consequent increased seismic activity.
The decision comes as neighboring Oklahoma reports ever-growing numbers of so-called seismic events. In the last seven days, the state registered as many as 20 quakes, and has been shaken almost daily since the start of 2015.
Oklahoma has been dubbed by media as the new earthquake capital of the country, because prior to 2009, the state had fairly negligible seismic activity. Then the shale boom started quickening its pace, and today, the state is shaken by an average of two quakes a day.
In Texas, quakes have not risen to that frequency, but an increase in seismic activity has been noted there as well. In late October, a 2.9 quake was registered in central Texas, followed by another one with a magnitude of 3 on the Richter scale in the southwestern part of the state. As UPI notes, both regions are in rich in unconventional oil and gas.
According to the USGS, most conventional wastewater injection wells do not tend to cause earthquakes. The factors that increase this risk seem to have to do with the amount of wastewater injected into the ground and the rate of injection. Given that fracked wells use up a lot more water than conventional ones, it has been suggested that there is a direct link between unconventional oil and gas extraction and increased seismic activities.
In Oklahoma, measures employed include the Oklahoma Commission telling oil-well operators in the area to reduce the amount of wastewater they pump into the ground, or stop it temporarily altogether.
Texas is home to most of the Permian shale formation, which is currently the focus of the most intensive drilling activity across the U.S. shale patch.
By Irina Slav for Oilprice.com
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Comments
As to the "earthquake capital of the country," it is worth noting that a single magnitude 7.1 earthquake in January in Alaska released more seismic energy than all the earthquakes in Oklahoma in 2015 combined. California likewise experienced about ten times as much seismic energy released, thanks to the three magnitude 5+ earthquakes there in 2015.
It is also true that, after reaching a peak of 4.5 magnitude 3+ earthquakes per day in mid-2015, the rate has declined to about 2.3 in late 2016. This decline, which reflects a decline in injection by more than 1 million barrels per day, is a vital part of the argument that injection caused the earthquakes. It is also apparently not exciting enough for reporters to include in their stories very often. Before drawing conclusions about Oklahoma, it might be wise to talk to someone in the state.