Originally Posted: March 20, 2018
Analysis indicates decades of oil production activity have destabilized localities in an area of about 4,000 square miles populated by small towns, roadways and a vast network of oil and gas pipelines and storage tanks
Two giant sinkholes near Wink, Texas, may just be the tip of the iceberg, according to a new study that found alarming rates of new ground movement extending far beyond the infamous sinkholes.
That’s the finding of a geophysical team from Southern Methodist University, Dallas that previously reported the rapid rate at which the sinkholes are expanding and new ones forming.
Now the team has discovered that various locations in large portions of four Texas counties are also sinking and uplifting.
Radar satellite images show significant movement of the ground across localities in a 4000-square-mile area — in one place as much as 40 inches over the past two-and-a-half years, say the geophysicists.
“The ground movement we’re seeing is not normal. The ground doesn’t typically do this without some cause,” said geophysicist Zhong Lu, a professor in the Roy M. Huffington Department of Earth Sciences at SMU and a global expert in satellite radar imagery analysis.
“These hazards represent a danger to residents, roads, railroads, levees, dams, and oil and gas pipelines, as well as potential pollution of ground water,” Lu said. “Proactive, continuous detailed monitoring from space is critical to secure the safety of people and property.”
The scientists made the discovery with analysis of medium-resolution (15 feet to 65 feet) radar imagery taken between November 2014 and April 2017. The images cover portions of four oil-patch counties where there’s heavy production of hydrocarbons from the oil-rich West Texas Permian Basin.
The imagery, coupled with oil-well production data from the Railroad Commission of Texas, suggests the area’s unstable ground is associated with decades of oil activity and its effect on rocks below the surface of the earth.
The SMU researchers caution that ground movement may extend beyond what radar observed in the four-county area. The entire region is highly vulnerable to human activity due to its geology — water-soluble salt and limestone formations, and shale formations.
“Our analysis looked at just this 4000-square-mile area,” said study co-author and research scientist Jin-Woo Kim, a research scientist in the SMU Department of Earth Sciences.
“We’re fairly certain that when we look further, and we are, that we’ll find there’s ground movement even beyond that,” Kim said. “This region of Texas has been punctured like a pin cushion with oil wells and injection wells since the 1940s and our findings associate that activity with ground movement.”
Lu, Shuler-Foscue Chair at SMU, and Kim reported their findings in the Nature publication Scientific Reports, in the article “Association between localized geohazards in West Texas and human activities, recognized by Sentinel-1A/B satellite radar imagery.”
The study is among the first of its kind to identify small-scale deformation signals over a vast region by drawing from big data sets spanning a number of years and then adding supplementary information.