Storing carbon dioxide in the same shale formations that produce natural gas may be an effective way to sequester carbon dioxide produced by fossil fuel-burning power plants, according to a U.S. study. Computer models by researchers at the University of Virginia suggest the Marcellus Shale, a 600-square-mile formation in the northeastern U.S. that is a center of hydrofracturing natural gas, is capable of storing half the CO2 emitted by U.S. coal plants from now to 2030.
Fracked shale wells are good candidates for carbon storage because CO2 can be injected in much the same way that natural gas was extracted, the researchers say. Fracking involves injecting pressurized fluids in wells to fracture the shale rock, which creates cracks that let gas seep out. The authors of this study suggest those networks of cracks could be filled with CO2 before sealing the natural gas wells.
One advantage of using fracked shale formations for carbon storage is that it would not require building new infrastructure to sequester the CO2. A question that needs to be answered is whether the stored carbon, injected in the wells in liquid form, would migrate back toward the surface in fracked shale formations.
Article appearing courtesy Yale Environment 360.