High power lasers from Foro Energy can increase the speed and efficiency of drilling through hard rock by two to four times. Being able to more quickly, cheaply and efficiently dig holes is very useful for oil and gas, geothermal, telecommunications, transportation and other applications.
ARPA-E – Foro Energy is developing a unique capability and hardware system to transmit high power lasers over long distances via fiber optic cables.potential to be up to 10 times more economical than conventional hard-rock drilling technologies, making them an effective way to access the U.S. energy resources currently locked under hard rock formations.
A high-power laser beam leaving Foro Energy’s drill bit and striking a hard rock formation.
Conventional mechanical drill bits cut softer rocks with stresses created by rotating a cutting surface with high weight-on-bit (WOB). Unfortunately, ultra-hard (i.e. high compressive strength) rocks inherently do not yield efficiently to even the most advanced mechanical cutters. The resulting slow drilling and short bit lifetimes result in poor performance and high expense.
Foro Energy developed a process that uses the laser to destroy rock and conventional mechanical bit components to remove the rock. This laser-mechanical drilling process enables
* Step change in drilling rate (2-4x)
* Extremely low WOB (less than 1000 lbs)
* Extremely low torque (less than 300 ft-lbs)
* Longer bit life
* Lower drilling cost per foot
Conventional workover & completion techniques use brute force consumables such as mechanical steel grinding, explosive charges, and harsh chemicals.
Foro Energy uses high power lasers to rapidly and precisely cut away steel and formation to enable:
* Rapid cutting rates (2-4X+)
* Ability to perform any job in single downhole pass without multiple trips or consumables
* Higher precision cutting without crush zones
* No explosives or harsh chemicals
* Ability to handle exotic metals
Still quite a bit of work to make this work under tough real world conditions
Foro’s intense laser beam heats hard rock surfaces so fast that thermal shock fractures the upper few millimetres, leaving a crumbled layer that a mechanical drill can scrape away quickly and with little wear.
A flashy prototype is far from proof that the rig will hold up in the brutal environment found in the bottom of a borehole, which is filled with rock chips and churning water that lubricates the drill bit. The optics must deliver the beam directly to the rock, says Jared Potter of Potter Drilling in Redwood City, California, who is developing a drilling process that shatters rock with extremely hot water. If the beam hits fluid, it will heat the liquid instead of the rock face. “It’s amazing how much energy it takes to boil water,” Potter says, and even a powerful laser couldn’t hope to zap both water and rock at once. He thinks Foro “has a long way to go to have a tool they can deploy in a geothermal or oil well”.
Still, the cost of drilling has been a roadblock to expanding the adoption of geothermal energy. If Foro can prove its technology is ready for the grunt work of punching hundreds of holes through the hard igneous rocks, it would change the mathematics of low-carbon energy. In the meantime, Potter says Foro’s lasers could be used instead of explosives to make holes in the steel casings of oil and gas wells, which are needed to drain fluid from the surrounding rock.