MIT is researching new technology that can ‘drill’ by using radio-frequency wave generators to melt or vaporise hard rock.
Paul Woskov, a senior research engineer at MIT’s Plasma Science and Fusion Centre (PSFC) is using gyrotrons, specialised radio frequency (RF) wave generators used in fusion research, as an alternative to traditional drilling, according to MIT News.
Millimetre RF waves can reportedly cut holes in rock by melting or vaporising them completely, and Woskov believes this method could increase penetration rates by more than ten times at significantly lower costs compared to mechanical rotary drilling systems, and allow miners to drill deeper.
Current drilling systems utilise mud, which is used to maintain hole pressure and remove excess cuttings, however it can only withstand pressures up to depths of nine kilometres.
“What if you could drill beyond this limit? What if you could drill over ten kilometers into the Earth’s crust?” Woskov asked, stating he believes gyrotron technology makes this theoretically possible.
“With a gyrotron, high-temperature physics will replace the mechanical functions of low-temperature mud, allowing drillers to extract rock matter through vaporisation or displace the melt through pressurisation,” MIT reports.
“Similarly, the high temperature melted rock will seal the walls of the borehole, and the high pressure from the increased temperature will prevent collapse. In principle, because an increase in temperature in a confined volume will always result in an increase in pressure over local pressure, drillers could maintain the stability of a borehole to greater depths than possible with drilling muds.”
Woskov went on to state that holes can be ‘drilled’ in different shapes in order to fit local conditions.
“Our beams don’t need to be round. Forces underground are anisotropic — not symmetrical, that is one reason holes collapse; but we can shape our beam to respond to local pressures.
“You can create an elliptical hole with the major axis corresponding to the anisotropy of the forces, essentially recovering the strength of a round hole in a symmetrical force field.”
Woskov’s research is also looking into how the technology can replace crushing and rock breaking on the surface, its applications in tunnelling, as well as its potential use in fracking as a replacement for pressurised water systems.