Oklahoma is the fifth-largest producer of crude oil in the United States (Image from WikiMedia Commons).
Oklahoma operators of all oil and gas wells in the state are now forced to report all chemicals used in hydraulic fracturing either directly to FracFocus.org or to the Oklahoma Corporation Commission, which will add the information to the website’s database.
The new regulation, in effect since Wednesday, is an extension of a rule that required operators of horizontal wells in the state to disclose the makeup of their fracking fluids beginning in 2013.
NewsOK reports the former regulations only targeted horizontal wells, as that category represented most of the larger operators and about 75% of the wells drilled in Oklahoma last year.
Oklahoma is a leading US energy producer with an economy increasingly concentrated on the oil and gas industry, with 25% of all employment in the state either directly or indirectly connected to the energy industry.
In a report entitled “Earthquake Swarm Continues in Central Oklahoma,” released last October in partnership with the Oklahoma Geological Survey, the U.S. Geological Survey noted that since January 2009, more than 200 magnitude 3.0 or greater earthquakes had rattled Central Oklahoma, marking a significant rise in the frequency of these seismic events.
The report added that after analyzing recent earthquake rate changes experts concluded that they do not seem to be due to typical, random fluctuations in natural seismicity rates.
Oklahoma is not traditionally known as earthquake centre, with a yearly average of about 50 tremors, almost all of them minor. But since 2010 the state has had thousands of quakes. Last year was, in fact, the most active, with over 2,600, 87 of which were registered the first week of December.
The concern is not unique to Oklahoma. Since 2001 the average annual number of earthquakes of magnitude 3.0 or greater has jumped “significantly” across the midsection of the country, including not just Oklahoma but also Ohio, Arkansas and Texas, according to the U.S. Department of Interior.
In Arkansas, a group of homeowners who filed lawsuits against well operators alleged that their properties were damaged by a swarm of earthquakes that hit the central part of that state in 2010 and 2011. Scientists there blamed disposal wells for touching off more than 1,000 quakes in those years.