Texas and three other natural gas-producing states are banding together to combat the mounting risks of earthquakes tied to the disposal of wastewater from hydraulic fracturing for natural gas.
A representative from the Texas Railroad Commission and regulators from Kansas, Oklahoma and Ohio met for the first time this month in Oklahoma City to exchange information on the man-made earthquakes and help states toughen their standards.
The nation’s mid-continent area recorded a sixfold jump in quakes 2001 to 2011. The trend has continued with a swarm of more than 30 small quakes in the Azle area since November and 341 quakes in central Oklahoma in the past year.
“It was a very productive meeting, No. 1, because it gave the states the opportunity to get together and talk collectively about the public interest and the science,” said Gerry Baker, who attended as associate executive director of the Interstate Oil and Gas Compact Commission, a group that represents energy-producing states. “It was a good start in coordinating efforts.”
The Texas Railroad Commission, which regulates the oil and gas industry in the state, was represented by its chief geologist, Leslie Savage, said agency spokeswoman Ramona Nye. Nye said the agency would not comment on the meeting, deferring to Baker as the group’s designated spokesman.
U.S. oil and gas production surged to a two-decade high last year as technological advances such as hydraulic fracturing, or fracking, let drillers coax liquids from rock formations. The process, in which a mix of water, sand and chemicals is shot into shale to free gas and oil, also generates huge volumes of wastewater.
As fracking expanded to more fields, reports tied quakes to underground disposal wells from Texas to Ohio.
The goal of the regulators is to develop a set of common procedures to monitor for earthquakes, investigate their cause and draft rules and regulations to prevent them, said Scott Anderson, senior policy adviser for the Environmental Defense Fund in Austin, who has been in communication with state regulators on the issue.
Researchers this month installed five monitors in a production field near the Kansas-Oklahoma border after an increase in seismic activity, said Art McGarr, a geophysicist with the U.S. Geological Survey in Menlo Park, Calif. Quakes began as drillers switched to fracking from conventional drilling, he said.
Southern Methodist University this year installed 12 seismic monitors in the Azle area in northern Parker County following its quakes. There have been no quakes recorded by the USGS around Azle since Jan. 28.
There are 11 wastewater disposal wells around Azle, according to the Railroad Commission. It says it inspected those wells earlier this year and found all in compliance with permitted volume and pressure limits, although one had been shut down as its operator dealt with another issue.
More than 800 people attended a Jan. 2 town hall meeting in Azle to complain that the state wasn’t doing enough in response to dozens of recent earthquakes. The Texas Railroad Commission on Jan. 7 said it would hire a staff seismologist to help study the problem.
Nye said Thursday that the agency has not yet hired a seismologist.
The Railroad Commission has avoided attributing the quakes around Azle to the wells, saying more research is needed. Quakes at Dallas/Fort Worth Airport in 2009 and in Johnson County in 2010 ended after operators voluntary shut down injection wells near the quakes.
McGarr said that besides Azle, in the past year earthquakes thought to be tied to wastewater disposal wells were recorded in Jones, Okla., and in northeastern Ohio. Researchers also have linked wells to earthquakes at Youngstown, Ohio, and Guy, Ark.
“There’s close to 150,000 injections wells and the number where there’s even been a connection suggested is just a handful,” said Dan Whitten, a spokesman for America’s Natural Gas Alliance, an industry group in Washington. “It’s appropriate that this be addressed at the state level.”
Arkansas, Illinois, Ohio and Oklahoma are among states that proposed or adopted rules targeting the man-made earthquakes. Others may follow.
Since 2009, earthquake reports in Oklahoma are almost 40 times higher than in the previous three decades, according to the Oklahoma Geological Survey. Most occur in the Arbuckle formation where wastewater is pumped 6,000 feet to 10,000 feet underground, said Austin Holland, a research seismologist with the Oklahoma Geological Survey.
“Disposal wells have been operating in the state for decades, and so the question becomes why now,” Holland said. “If we start shutting down disposal wells indiscriminately, it’s going to have a major impact on the state’s economy.”
Scientists linked Oklahoma’s biggest recorded earthquake to wastewater wells. The 5.7-magnitude temblor near Prague, Okla., on Nov. 6, 2011, may be the biggest tied to drilling wastewater, according to researchers from the University of Oklahoma, Columbia University and the U.S. Geological Survey.
The state’s geological office disagreed, saying the link was inconclusive. Prague is about 50 miles east of Oklahoma City and 65 miles southwest of Tulsa.
The Oklahoma Corporation Commission this month said well operators will have to record injection well pressure daily instead of monthly. The rule needs approval from the state legislature and the signature of Gov. Mary Fallin.
Oklahoma would be the first state to require a daily test, said Kristy Hartman, energy and policy specialist at the National Conference of State Legislatures.
In Texas, operators must report how much they injected at a well each month, but only have to file that report once a year. In the Barnett Shale, those reports are due each November and cover the previous 12 months ending in September, Nye said.
In 2011, Arkansas regulators permanently shut four disposal wells in the Fayetteville shale formation after an outbreak of earthquakes near the town of Guy, including a 4.7-magnitude temblor.
Rules that took effect in Ohio last year ban injection wells in certain formations and let the state require seismic monitoring, said Mark Bruce, a spokesman for the Ohio Department of Natural Resources.