Science & Technology: Industry Experts Talk About Deep-Geothermal Drilling Technology

A Deeper Understanding (Mannvit)

In the latest issue of GeoDrilling International (GDI) geothermal drill-rig manufacturers and industry experts talked about the main requirements of, and the latest trends in, deep geothermal drilling equipment and technology

When it comes to tapping into deep geothermal resources, the cost of drilling can make up around 60-70% of the total project costs, and can thus influence the overall success of a geothermal project. As a result, the industry has become more open to new technology, which might help reduce these costs.

The Drilling techniques in the geothermal field include over-balanced, hammer and under-balanced drilling, among others.“The most common method is rotary drilling by direct circulation of water-based drilling mud or water in the production part. Other frequently used methods are the aerated drilling ones. Reasons for introducing air into the drilling fluid might be highly permeable formations causing loss of circulation or to minimize formation damage to enhance possible productivity of the wells,” explain Kristinn Ingason and Thoroddur Sigurdsson from the geothermal drilling department of Mannvit, an Iceland-based engineering consulting firm.

The top sections (for surface casings) of geothermal wells may also be drilled by percussion methods, such as the air-hammer method with air and foam, especially in hard-rock formations.” The requirements of the geothermal and O&G industries are practically the same. Both industries face the same challenges and have the same end goals: drilling a well into rock to a specific depth in order to reach a reservoir."

The entire article from GDI can be found here.