Technology Development and Field Trials of EGS Drilling Systems at Chocolate Mountain


Polycrystalline diamond compact (PDC) bits are routinely used in the oil and gas industry for drilling medium to hard rock but have not been adopted for geothermal drilling, largely due to past reliability issues and higher purchase costs. The Sandia Geothermal Research Department has recently completed a field demonstration of the applicability of advanced synthetic diamond drill bits for production geothermal drilling. Two commercially-available PDC bits were tested in a geothermal drilling program in the Chocolate Mountains in Southern California. These bits drilled the granitic formations with significantly better Rate of Penetration (ROP) and bit life than the roller cone bit they are compared with. Drilling records and bit performance data along with associated drilling cost savings are presented herein. The drilling trials have demonstrated PDC bit drilling technology has matured for applicability and improvements to geothermal drilling. This will be especially beneficial for development of Enhanced Geothermal Systems whereby resources can be accessed anywhere within the continental US by drilling to deep, hot resources in hard, basement rock formations.

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DOE Project Name: Technology Development and Field Trials of EGS Drilling Systems
DOE Project Number: AID 20008
DOE Project Lead: Arlene Anderson
DOI: 10.15121/1225980
Last Updated: over a year ago
Data from January, 2012
Submitted Dec 13, 2012


Sandia National Laboratories


Publicly accessible License 


Steven Knudsen
Sandia National Laboratories
David Raymond
Sandia National Laboratories
Doug Blankenship
Sandia National Laboratories
Steve Bjornstad
USN Geothermal Program Office
Joel Barbour
Barbour Well Inc.
Aaron Schen
NOV Downhole


geothermal, chocolate mountains, drilling, pdc bit, roller cone, granite, chocolate mountains drilling, synthetic diamond, rate of penetration, egs, lateral vibration spectrum, California, CA, Southern California, SoCal, drilling records, performance data, drilling charts, before and after, pictures, vibration spectrum


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