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Title: Seal/lubricant systems for geothermal drilling equipment

Technical Report ·
DOI:https://doi.org/10.2172/5231616· OSTI ID:5231616

The development and testing of seals and lubricants for journal-type roller-cone rock bits for drilling into geothermal reservoirs at temperatures over 260/sup 0/C (500/sup 0/F) are described. The conditions experienced by seals and lubricants subjected to geothermal drilling are reviewed along with the basic design requirements for roller-cone bit seals and journal bearing lubricants. Two unique test facilities are described: a seal test machine which simulates pressures, temperatures, and mechanical eccentricities, and a lubricant tester capable of evaluating load-bearing ability at temperature and pressure. Three candidate elastomeric compounds demonstrated 288/sup 0/C (550/sup 0/F) capability and several others demonstrated 260/sup 0/C (500/sup 0/F) or greater capability. Successful elastomeric seal candidates were proprietary compounds based on EPDM, Kalrez, and/or Viton polymers. Three mechanical seals for reservoir temperatures over 288/sup 0/C (550/sup 0/F) are presented. Lubricant screening tests on more than 50 products are summarized, and several newly developed lubricants which meet both the compatibility and lubrication requirements are described. Several seal/lubricant systems are recommended for laboratory or field geothermal drilling tests in roller-cone drill bits. The future availability of drill bits for geothermal use is discussed, as well as the potential spinoffs of the program findings for nongeothermal roller-cone bits.

Research Organization:
Terra Tek, Inc., Salt Lake City, UT (USA)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
5231616
Report Number(s):
SAND-80-7101
Country of Publication:
United States
Language:
English