Why is oil and gas activity causing earthquakes? And can we reduce the risk?

The Conversation

Originally Posted: May 11, 2015

If you’ve been following the news lately, chances are you’ve heard
image-20150507-1212-1qgtj56about – or even felt – earthquakes in the central United States. During the past five years, there has been an unprecedented increase in earthquakes in the North American mid-continent, a region previously considered one of the most stable on Earth.

According to a recent report by the Oklahoma Geological Survey, Oklahoma alone has seen seismicity rates increase 600 times compared to historic levels.

The state has gone from experiencing fewer than two magnitude-three earthquakes per year to greater than two per day, the report found. Similarly, my home state of Texas has experienced a near 10-fold increase in magnitude-three earthquakes or greater in the past five years.

The recent uptick in earthquakes in Texas, Oklahoma and several other central US states raises an obvious question: What is causing all of this seismicity? READ MORE

James Brooks receives 2015 AAPG Presidential Award for Exemplary Service

JEBrooks-219x300

James Brooks, provost emeritus and professor emeritus in SMU’s Roy M. Huffington Department of Earth Sciences, has received the 2015 AAPG Presidential Award for Exemplary Service, one of the highest honors of the American Association of Petroleum Geologists (AAPG).

AAPG President Randi Martinsen bestowed the honor upon Brooks “for a lifetime of inspired and dedicated service to his profession and community, and for the education of hundreds of students for whom he has served as an outstanding teacher, wise mentor and genuine friend.”

AAPG is the premier organization for U.S. petroleum geologists. It is one of the world’s largest professional geological societies with more than 36,000 members. READ MORE

Heather DeShon and Matthew Hornbach, seismology research links fluid injections/removal to earthquakes

Oil and Gas Daily

Originally Posted: April 30, 2015

Combination of gas field fluid injection and removal cause of earthquakes

Several natural and man-made factors can influence the subsurface stress regime resulting in earthquakes. Natural ones include intraplate stress changes related to plate tectonics and natural water table or lake level variations caused by changing weather patterns or water drainage patterns over time, or advance or retreat of glaciers. Man-made include human-generated changes to the water table, including dam construction, and industrial activities involving the injection or removal of fluids from the subsurface.
A seismology team led by Southern Methodist University (SMU), Dallas, finds that high volumes of wastewater injection combined with saltwater (brine) extraction from natural gas wells is the most likely cause of earthquakes occurring near Azle, Texas, from late 2013 through spring 2014.

In an area where the seismology team identified two intersecting faults, they developed a sophisticated 3D model to assess the changing fluid pressure within a rock formation in the affected area. They used the model to estimate stress changes induced in the area by two wastewater injection wells and the more than 70 production wells that remove both natural gas and significant volumes of salty water known as brine.

Conclusions from the modeling study integrate a broad-range of estimates for uncertain subsurface conditions. Ultimately, better information on fluid volumes, flow parameters, and subsurface pressures in the region will provide more accurate estimates of the fluid pressure along this fault.

“The model shows that a pressure differential develops along one of the faults as a combined result of high fluid injection rates to the west and high water removal rates to the east,” said Matthew Hornbach, SMU associate professor of geophysics. “When we ran the model over a 10-year period through a wide range of parameters, it predicted pressure changes significant enough to trigger earthquakes on faults that are already stressed.” READ MORE

State lawmakers quiz scientists on earthquake study

Fort Worth Star-Telegram

Originally Posted: May 4, 2015

By Max Baker

On a day that small earthquakes continued to shake North Texas, Southern Methodist University researchers testified before a House committee on Monday about their study linking a swarm of previous temblors near Azle and Reno to oil and gas operations.

While no one linked earthquakes recorded near Irving and Dallas in recent days to drilling, lawmakers at the state Capitol were definitely interested in getting a better understanding of what is making the ground shake with more regularity in the Metroplex. . .

SMU professors Brian Stump and Matthew Hornbach testified before the committee, along with Jon Olson from the University of Texas at Austin, about the study published late last month in the scientific journal Nature Communications regarding 27 earthquakes that occurred northwest of Fort Worth from November 2013 to January 2014.

After analyzing 3D modeling and reviewing historical data on earthquake activity in the area, the researchers concluded that the tremors were not caused by natural phenomenon, such as drought conditions or a natural shift of the Earth’s plates, but by oil and gas activity. READ MORE

 

Emergency officials study Dallas-Fort Worth area’s growing quake risk

Dallas Morning News

April 24, 2015

The U.S. Geological Survey reported Thursday that North Texas’ risk of damaging earthquakes has more than tripled since 2008, the year the region first began experiencing more frequent ground-shaking.

The Dallas-Fort Worth area’s earthquake risk is now on par with parts of Oklahoma and California, Mark Petersen, chief of the agency’s National Seismic Hazard Project in Golden, Colo., said in an interview.

Dallas’ Office of Emergency Management said it would continue to strengthen the city’s preparedness for earthquakes. READ MORE

Matthew Hornbach and Heather DeShon, both associate professors of geophysics featured in KERA article on earthquake findings

Associated Press and KERA News
Originally Posted: April 21, 2015

SMU Study Links Azle Earthquake Swarm To Natural Gas Drilling

What’s causing the Azle earthquakes? SMU researchers say that wastewater injection and saltwater extraction from natural gas wells is the most likely cause.

A study published Tuesday in the journal Nature Communications says researchers from Southern Methodist University and the U.S. Geological Survey monitored the shaking from nearly 30 small quakes west of Fort Worth from November 2013 to January 2014. The area hadn’t had any recorded quakes in 150 years.

The scientists say the shaking decreased when the volume of injections did. They have concluded that removing saltwater from the wells and injecting that wastewater back underground is “the most likely cause” for the swarm of quakes.

Other studies have made a connection between wastewater injections and a spike in earthquakes in Oklahoma and southern Kansas.

The state’s official seismologist has no plans for immediate action following the report. Craig Pearson said at a news conference Tuesday that he wouldn’t recommend that the Railroad Commission, the state’s oil and gas regulator, suspend activity at two wells the report’s authors identify as the source of the temblors in Azle. READ MORE

 

SMU-led seismology team reveals Azle findings

Combination of gas field fluid injection and removal is most likely cause of 2013-14 earthquakes

azle-earthquake-report-graphic-01

An SMU-led seismology team finds that high volumes of wastewater injection combined with saltwater (brine) extraction from natural gas wells is the most likely cause of earthquakes occurring near Azle, Texas, from late 2013 through spring 2014.

In an area where the seismology team identified two intersecting faults, they developed a sophisticated 3D model to assess the changing fluid pressure within a rock formation in the affected area. They used the model to estimate stress changes induced in the area by two wastewater injection wells and the more than 70 production wells that remove both natural gas and significant volumes of salty water known as brine.

Conclusions from the modeling study integrate a broad-range of estimates for uncertain subsurface conditions. Ultimately, better information on fluid volumes, flow parameters, and subsurface pressures in the region will provide more accurate estimates of the fluid pressure along this fault.

“The model shows that a pressure differential develops along one of the faults as a combined result of high fluid injection rates to the west and high water removal rates to the east,” said Matthew Hornbach, SMU associate professor of geophysics. “When we ran the model over a 10-year period through a wide range of parameters, it predicted pressure changes significant enough to trigger earthquakes on faults that are already stressed.” Model-predicted stress changes on the fault were typically tens to thousands of times larger than stress changes associated with water level fluctuations caused by the recent Texas drought. READ MORE

Tim Brys Dinosaur Fossil Dates Back to 100 Million Years Ago

NewsMax

Posted: April 10, 2015

Tim Brys and his son made a discovery of their lifetimes on a hill behind a Texas grocery store when they found a dinosaur fossil that paleontologists believe dates back 100 million years.

Brys, who is employed at the Dallas Zoo, and 4-year-old Wylie received help from a team of scientists from Dallas’ Southern Methodist University this week in excavating the fossil they originally found last fall in the Fort Worth suburb of Mansfield, reported the Dallas Morning News.

“We commonly go collect fossils as something we can do together to be outside. Wiley enjoys coming with me on my trips,” Brys told KXAS-TV about his walks with his son.

“We were finding some fish vertebrae in the hillside, and then Wiley walked a little ways ahead of me and came back with a piece of bone. And I paused and was like, ‘OK, where did you find this?'”

Even though the Brys found the bones in September, this week was one of the earliest days SMU researchers could start digging because they needed permits to get on the land and excavate. READ MORE

100 million year old dinosaur bones discovered in Mansfield, headed to SMU

NBC 5

Originally Posted: April 7, 2015

Dinosaur bones estimated to be 100 million years old recently discovered in Mansfield by a 4-year-old boy are now on their way to Southern Methodist University in Dallas for further study.

The dinosaur bones were first discovered in September next to a Mansfield retail center that was under construction.

Since the discovery, experts have been digging and excavating near the Sprouts grocery store on Matlock Road and Debbie Lane.

When all of that earth and dirt was dug up to make way for the shopping center, a Dallas zookeeper who lives nearby thought he’d be able to find fish fossils.

The whole area was covered in water millions of years ago, said the Dallas Zoo.

Zookeeper Tim Brys thought his son Wiley, 4, would enjoy going on a fossil hunt.

“We commonly go collect fossils as something we can do together to be outside. Wiley enjoys coming with me on my trips,” Brys explained. READ MORE

Many in North Texas feel latest quake

Star Telegram

Originally Posted: April 2, 2015

SMU quake monitor
Brian Stump, professor of earth sciences at SMU, points to seismographs at a news conference in January about earthquakes in North Texas. KYE R. LEE STAR-TELEGRAM ARCHIVES

 

Three earthquakes rattled the Irving area Thursday, the second one with a magnitude of 3.3, the U.S. Geological Survey confirmed.

It wasn’t the area’s strongest quake to date — that was a 3.6-magnitude quake, also near Irving, in January — but its effect seemed widespread, as people across North Texas reported feeling the earth shake at 5:36 p.m. The epicenter of the afternoon quake was two miles northeast of Irving, the USGS reported.

“I’m in Irving and it was insane! The entire apartment shook,” one man tweeted.

A woman wrote, “A 3.3 earthquake, Texas? That’s cute. –Californian.”

A Star-Telegram reporter said she felt the quake at her Keller residence.

The first earthquake of the day was a 2.7 magnitude at 5:38 a.m. four miles northeast of Irving, the USGS reported. READ MORE