A growing threat of earthquakes in southeast New Mexico prompted the State to take action by upping its seismic monitoring and calling for oil and gas operators to curb the amount of produced water disposed of underground.
The byproduct water, known as produced water in industry terms, is a combination of flowback water created during hydraulic fracturing operations and water brought up from underground shale formations along with oil and natural gas.
Traditionally this water, briny and contaminated with toxic chemicals, is pumped back into the shale for disposal, but such a process was recently linked to increased seismic events in the Permian Basin shared by southeast New Mexico and West Texas.
Earlier this year, the Texas Railroad Commission announced it was establishing two seismic response areas (SRAs) in the Midland area and along the Texas-New Mexico border in Culberson and Reeves counties. It called for reductions in produced water injection volumes and advocated blocking any new permits for saltwater disposal wells (SWDs).
And on Tuesday, New Mexico’s Oil Conservation Division (OCD) announced similar actions as a string of earthquakes were reported in New Mexico throughout November.
Permits under review for SWDs in the area south of Malaga, near the Texas State Line, will require additional review, the department said.
Meanwhile, a “statewide response protocol” was put in place by the OCD that will increase reporting and monitoring measures while also reducing the volume of water injected based on further observed seismic activity.
“Category 1” of the protocol would go into effect when two quakes of magnitude (M) 2.5 or higher occur within 30 days and within a 10-mile radius of each other.
An M 2.5 earthquake is the first level where it could be lightly felt, according to the Richter Scale. Serious damage can occur at a M 3 or greater.
With 10 miles of the epicenter of such an event, operators would be required to provide to the state weekly reporting of daily injection volumes and average daily surface pressure, while digitally measuring injections volumes and pressure and providing analysis and data to the OCD when requested.
At “Category 2,” which goes into effect if one M 3 event occurs, all of Category 1 requirements would be imposed, along with requirements that operators within 3 miles reduce injection rates by 50 percent.
Within 3-6 miles, operators would be required to cut injection by 25 percent.
If a M 3.5 or higher quake is reported, operators with 3 miles must shut in their wells, and cut injection by 50 percent at 3-6 miles, and 25 percent at 6-10 miles.
OCD Director Adrienne Sandoval said most of the recent significant seismicity was reported on the Texas side of the basin, but the State was taking action to prevent the threat to New Mexico.
“The Oil Conservation Division is taking a proactive approach to managing seismic activity tied to oil and gas activity in New Mexico,” she said. “While some of the biggest events have occurred over the state line in Texas, the time is now to ensure larger events do not occur in our part of the oil field.
“Using solid data and working with our stakeholders and state partners, the plan laid out today takes a pragmatic approach to addressing this issue.”
Data shows earthquakes increased while oil boomed in the Permian Basin
Data from the U.S. Geological Survey (USGS) showed that along the Texas-New Mexico border in the Permian Basin, 422 earthquakes of M 2.5 or higher were reported in 2021, with 22 reported in November alone.
Last year, the USGS reported just 209 such quakes in that same area and only 51 in 2019.
In 2018, the USGS database showed 16 M 2.5 or greater quakes in the area and four in 2017 – the year commonly associated with the most recent boom in oil and gas credited to expanded use of hydraulic fracturing.
Most recently, on Nov. 23 a M 2.7 quake was reported about 35 miles south of Whites City, per USGS data, just over the border in Texas, along with an M 2.6 the day before in the same location.
Several more were reported throughout the month close to that area, just south of the state line.
An M 3.2 was reported Nov. 13 about 23 miles southwest of Monument, a ranching community just outside Hobbs.
About 50 M 2.5 or higher quakes were reported on the Texas side in October, per the USGS, with none in New Mexico. An M 3.3 occurred in an area about 19 miles southeast of Malaga almost directly on the border.
The previous month saw three M 2.5 or higher quakes near Jal on Sept. 1, 9 and 20. The next day, an M 3.2 quake was reported near Malaga.
How do injection wells cause earthquakes?
The injection of oil and gas wastewater was found to induce seismicity through a process called poroelasticity, the result of the interaction between fluid and solid but porous rock formations, per a May study from Virginia Tech published in the journal Science Daily.
This interaction can stress the rock and active deep or “basement” faults, the report read.
"It is quite interesting that injection above the thick, overall low-permeability shale reservoir can induce an earthquake within the deep basement, despite a minimal hydraulic connection," said Guang Zhai, a postdoctoral research scientist in the Department of Geosciences, part of the Virginia Tech College of Science.
“What we have found is that the so-called poroelastic stresses can activate basement faults, which is originated from the fluid injection causing rock deformation."
The study reported seismicity in the Permian Basin was observed to increase “significantly” since 2010 in shallow wastewater injection which led to deep seismicity.
Most of the quakes were small and largely unfelt but could point to a trend of increased magnitudes and potentially larger events, the study read.
Zhai said the problem could get worse as energy needs increase around the world, and shallow disposal injection remains the cheapest method of wastewater management.
People should use the research, Zhai said to rethink the human role in induced seismicity resulting from fossil fuel development.
"As the future energy demands increase globally, dealing with the enormous amount of coproduced wastewater remains challenging, and safe shallow injection for disposal is more cost-efficient than deep injection or water treatment," Zhai said.
"We hope the mechanism we find in this study can help people rethink the ways induced earthquakes are caused, eventually helping with better understanding them and mitigating their hazards."
Adrian Hedden can be reached at 575-618-7631, email@example.com or @AdrianHedden on Twitter.
This article originally appeared on Carlsbad Current-Argus: New Mexico taking action on oil and gas-induced earthquakes