This satellite image shows salt formations in Winkler county that have dissolved and created subsidence. (Photo Courtesy Southern Methodist University).
New research from geo-physicists at Southern Methodist University says areas in West Texas are becoming unstable and sinking. Part of the reason why: decades of oil and gas activity.
The study used satellite technology to measure ground change over the course of roughly 3 years in West Texas.
In some cases researchers Zhong Lu and Jin-woo Kim found areas where the ground was sinking up to 4 inches a year. And in one place, the report found an area with up to 40 inches of “significant movement” in the last 2-and-half years.
“The ground movement we’re seeing is not normal,”said Lu in a press release. “The ground doesn’t typically do this without some cause,”
Lu and Kim were part of the team that previously studied the so-called “Wink Sinks” — two sinkhole formations in Wink, Texas. Lu says this new research shows similar subsidence, like the two sinkholes, may be spreading throughout West Texas. “We found out, about a mile east to the Wink sinkhole, we see very enormous subsidence is taking place at about 50-half meters per year,” says Lu.
The region this study looked at — an area of 4,000 acres, crossing 6 Permian Basin counties — dates back millions of years, when it was covered by shallow water. The geology that remains today is limestone, shale and salt formations. Lu says water leaking into the ground — like from wells not properly plugged — are dissolving salt layers, which is causing the subsidence. “This area is heavily populated with oil and gas production equipment and installations, hazardous liquid pipelines, as well as two communities,” says Kim, one of the geologists from SMU in a press release. “The intrusion of freshwater to underground can dissolve the interbedded salt layers and accelerate the sinkhole collapse.”
The team of researchers also noticed uplift which is caused by underground pressure.
Lu says the research isn’t meant to “point fingers” at industry, or place blame. He says he wants the research to inform and guide any future development in the area.