Exxon rejects fracking operations caused Texas earthquakes

A major oil and gas industry player on Wednesday joined the debate over whether Texas earthquakes were being caused by injection wells, rejecting the connection in at least in one case.

Representatives of Exxon Mobil subsidiary XTO Energy Inc claimed the earthquakes that struck the towns of Azle and Reno, northwest of Fort Worth, in 2013 and 2014 were natural events and not caused by fracking operations.

They told the Texas Railroad Commission examiners in Austin on Wednesday that the temblors were not triggered by their wastewater injection well built close to a faultline.

According to XTO officials the faults beneath Azle and Reno had been active for 600 million years.

''The earth has been moving continuously over time, and that movement is the result of natural tectonic forces far away but that express themselves right here,'' said Tim George, an attorney for XTO.

In a study published in April by researchers at Southern Methodist University, the US Geological Survey and the University of Texas the two wastewater wells, including one operated by XTO, were said to have likely triggered the events. The tremors from the  earthquakes measuring 3.6 that struck the towns were widely.

The multi-day hearing was the first time the commission was calling on a company to prove it was not to blame for earthquakes. Under recent policy changes, the commission could now require companies to conduct seismic tests before applying for permits or revoke permits if wells were linked to earthquakes.

The hearings come only weeks after governor Greg Abbott signed a law that barred cities and other municipalities from banning hydraulic fracturing, also known as fracking.

Though studies had suggested a link between small earthquakes and injection wells in parts of Texas, Oklahoma and other states, the industry had steadfastly denied any connection.

Andree Griffin, XTO's vice president of geology and geophysics, challenging the study told the commission that the quakes were naturally occurring and the Fort Worth Basin, where the gas-rich Barnett Shale was located, ''has had several episodes of movement and reactivation of faults'' over roughly 600 million years.

She added, the earthquakes were far deeper than where the wastewater was injected, challenging the SMU study's conclusion that the quakes had been caused by rumblings in the shallow formation that migrated down the fault into the deepest layer of rock.