Low­Contact Drilling Technology to Enable Economical EGS Wells

Tuesday, October 06, 2009

Critical Need: Geothermal energy is a potentially vast source of clean baseload electricity in the U.S. However, it is difficult and expensive to penetrate the ultra­ hard rock formations found at many prospective geothermal sites. Conventional drill bits penetrate ultra­hard rock formations slowly and wear down quickly, which makes the drilling process time consuming and expensive. More economical drilling methods are required to enable access to next­ generation energy resources, including geothermal and natural gas.

Project Innovation + Advantages:

Foro Energy is developing a unique capability and hardware system to transmit high power lasers over long distances via fiber optic cables. This laser power is integrated with a mechanical drilling bit to enable rapid and sustained penetration of hard rock formations too costly to drill with mechanical drilling bits alone. The laser energy that is directed at the rock basically softens the rock, allowing the mechanical bit to more easily remove it. Foro Energy's laser­assisted drill bits have the potential to be up to 10 times more economical than conventional hard­rock drilling technologies, making them an effective way to access the U.S. energy resources currently locked under hard rock formations.

Potential Impact:

If successful, Foro Energy's technology would be a key enabler of economical access to the estimated over 100,000 megawatts of baseload geothermal electrical power in the U.S. by 2050.


Increased access to domestic energy sources like geothermal and natural gas would help break U.S. dependence on foreign energy sources.


Geothermal resources are a clean, renewable source of baseload electrical power.


Cost­ effective access to domestic energy resources could help spur expansion of the U.S. geothermal and natural gas industries.

Innovation Update:

(As of August 2016)

The Foro Energy team has developed a world­first hybrid laser­mechanical drill assembly technology to gain more efficient and cost­effective access to geothermal resources. Foro has received investments from a number of investors, including but not limited to North Bridge Venture Partners, Praesidio Capital, Formation 8, Chevron Technology Ventures, Energy Technology Ventures, and Conoco Phillips. The Department of Energy Geothermal Office also recently funded a project for $3.5 million with Foro to further develop its technology for geothermal borehole applications. The Foro team is also collaborating with Sandia National Laboratories in a separate Geothermal Office­funded project to validate and establish proof of concept for low­weight­on­bit drilling technology for microhole drilling. Foro has moved its focus from research to development in collaboration with the company’s target customer base for additional applications beyond drilling.

Foro’s approach combined a rotating drill bit with a new laser transmission system to project laser radiation onto the rock surface while rotating. This kind of rapid heating fractures the rock, allowing a drill bit to remove rock cuttings from the rock surface, which exposes the next rock layer to be fractured by the laser. In designing their laser­mechanical drill, Foro made significant advances in laser transmission technology, including hardened optics, low­loss rotating optical connectors and fiber optics for the harsh downhole environment. Foro demonstrated a world­first ability at surface to drill hard rock at 10 feet per hour over multiple hours of operation on test bedrock, as well as 20kW laser energy over 12,000 feet in a rig­hardened fiber optic cable. These advances combined support accessing next­generation energy resources in a more timely and cost­effective manner.
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