Table of Contents
Fiber lasers and geothermal drilling efficiency
The high-powered fiber laser system demonstrates high efficiency during field testing to make hard rock weaker, improve the cost of geothermal drilling, and a laser beam process applied to achieve geothermal heat that is considered to be a clean and stable source of energy.
Problems of traditional drilling
The drilling process deep into the earth’s crust leads to an increase in the drill bit temperature; in this case, the drill bit wears faster and its penetration rate reduces. The cost of drilling without fiber laser application is extremely high, and this problem deters investors from being involved with deep geothermal projects.
New fiber laser technology for hard rock drilling
Nevertheless, a team of researchers from Germany has developed a fiber laser technology for laser beam drilling of hard rock that potentially allows both enhancing the penetration rate of geothermal drilling and saving the cutting edge of the bit by loosening and destroying the rock immediately before the drilling begins.
Operating principle of the developed system
The operating principle of the system developed is based on the installation of a ytterbium fiber laser (with an output power of up to 30 kilowatts) on a test rig. The fiber laser system has already been tested on such materials as sandstone, granite, and quartzite, all of which are regarded as hard rocks with a strength of more than 150 megapascals.
Role of water-jet and laser optics protection
The researchers apply a water-jet to direct the laser beam to the rock face, like an optical fiber directs the laser beam. This fiber laser technology protects from contamination and damage to the sensitive laser optics and simplifies the removal of the rock debris by the drilling device. Then the team employs “the laser system on the drilling rig in a specially developed drill string and tests the new tool under realistic conditions in field trials, which also proved to be a success.”
Future improvements of fiber laser drilling
Additionally, the researchers plan to further increase the distribution of the laser beam power and add several sensors to the hybrid device to receive feedback from the drilling process by the fiber laser system, resulting in the opportunity to respond to changes in material along the drilling path.
Adjustable laser power for drilling processes
It is possible to quickly adjust the output power of the fiber laser, making it particularly helpful in drilling processes. This type of drilling system, based on fiber laser technology, allows decreasing the cost of deep geothermal drilling in the future and expanding the application of geothermal energy as an inexhaustible source of energy, replacing other renewable sources, for example, sunlight, wind, and water.