A report out a few weeks back made it clear that, for a plethora of reasons, fracking represents a clear and present threat to millions of Americans. Now, a new study published in Scientific Reports reminds us that the dangers posed by the oil industry in general aren't always immediately obvious.
West Texas sits on top of a large reserve of oil and associated natural gas, which is being plundered like it’s going out of fashion. As a direct consequence of this rearrangement of the geology here, it’s increasing the risk that sudden sinkholes will emerge, swallowing up whatever happens to be on the surface.
Ground deformation around oil and gas extraction sites aren’t a new phenomenon, and the science behind their formation is well understood. Wastewater from oil, gas and fracking operations is injected into the ground, often creating uplift. After a while, the fluids move on, triggering decay and collapse in these injection wells.
Texas is no stranger to its ground rising and falling. Back in 2008, a stadium-sized sinkhole appeared in south Texas’ oil county; it appeared right next to an oil-field wastewater disposal facility, which was soon found to have been injecting twice as much wastewater into the ground as was legally permitted.
A 2016 blog post and study by the new paper’s geophysicists makes their ubiquity unnervingly clear.
“Residents of Wink and neighboring Kermit have grown accustomed to the two giant sinkholes that sit between their small West Texas towns,” it notes, nonchalantly. The authors then add that these sinkholes are expanding, and the ground nearby to them is becoming increasingly unstable.
A pair of geophysicists from Southern Methodist University used newly launched radar satellites Sentinel-1A/B to measure topographical changes over time, in order to probe the various causes of the local subsidence, uplift, and micro-earthquakes.
Examining four massive swaths of West Texas, they concluded that hydrocarbon extraction, the dissolution of salt in abandoned oil facilities, and the injection of fluids into the ground are having “negative impacts on the ground surface and infrastructures, including possible induced seismicity.”
The study points out that the uplift, subsidence, and sinkholes hazards in the region are plentiful. Radar imagery, modeling and strong correlations with hydrocarbon-based activities over time suggest that “most [of them] were induced by, or at least influenced by, human activities.”
The authors explain that this part of the Gulf Coast is vulnerable to subsidence for natural reasons, due to both sediment loading and long-term changes in response to the disappearance of regional glaciers. Human-induced topographical changes, however, is happening 10-100 times faster – sometimes on an order of tens of centimeters per year – and is occurring over a smaller area.
Worryingly, although the major sinkholes are clearly making headlines, the authors note that most of West Texas’ geohazards “have not been noticed and reported yet,” suggesting that local authorities are woefully unprepared for the dangers to come.
The study concludes by stressing that their monitoring efforts are “essential to securing the safety of humanity, preserving property, and sustaining the growth of the hydrocarbon production industry.”
So, can anything be done?
"For the subsidence over the abandon wells, it is best to reseal the wells. For the subsidence near the Wink sinkhole area, it is recommended to re-check the borehole management," co-lead author Prof. Zhong Lu of SMU, told IFLScience.
"Of course, if production wells are shut down, the subsidence will be mostly gone."
A recent estimate by the United States Geological Survey (USGS) suggests there's around 20 billion barrels of oil in West Texas’ Wolfcamp Shale Formation alone – “the largest estimate of continuous oil than the USGS has ever assessed in the United States.” It’s part of the overall Permian Basin geological province, and it’s all technically recoverable.
Based on the pro-fossil fuel inclinations of the Trump administration, then, we’d expect that it’ll most certainly be made available for continued extraction, regardless of the detrimental economic, environmental, and public health-related effects it’ll have.
