High density oilfield wastewater disposal causes deeper, stronger, and more persistent earthquakes
| Autor: | Hao Wu, Ryan M. Pollyea, Richard S. Jayne, Martin C. Chapman |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Science Hydrogeology General Physics and Astronomy High density Soil science Injection rate 02 engineering and technology Article General Biochemistry Genetics and Molecular Biology Sink (geography) Wastewater disposal 03 medical and health sciences lcsh:Science Injection well Seismology geography Multidisciplinary geography.geographical_feature_category Crust General Chemistry 021001 nanoscience & nanotechnology 030104 developmental biology Wastewater Environmental science lcsh:Q 0210 nano-technology Fluid pressure |
| Zdroj: | Nature Communications, Vol 10, Iss 1, Pp 1-10 (2019) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | Oilfield wastewater disposal causes fluid pressure transients that induce earthquakes. Here we show that, in addition to pressure transients related to pumping, there are pressure transients caused by density differences between the wastewater and host rock fluids. In northern Oklahoma, this effect caused earthquakes to migrate downward at ~0.5 km per year during a period of high-rate injections. Following substantial injection rate reductions, the downward earthquake migration rate slowed to ~0.1 km per year. Our model of this scenario shows that the density-driven pressure front migrates downward at comparable rates. This effect may locally increase fluid pressure below injection wells for 10+ years after substantial injection rate reductions. We also show that in north-central Oklahoma the relative proportion of high-magnitude earthquakes increases at 8+ km depth. Thus, our study implies that, following injection rate reductions, the frequency of high-magnitude earthquakes may decay more slowly than the overall earthquake rate. Oilfield wastewater is commonly discarded by pumping it into deep geologic formations, but this process is now known to cause earthquakes. Here, he authors show that high-density oilfield wastewater may sink deeper in the Earth’s crust than previously considered possible, thus increasing fluid pressure and inducing earthquakes for years after injection rates decline. |
| Databáze: | OpenAIRE |
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