Seals for Geothermal Roller Drill Bits

A significant factor contributing to short bit life and attendant high costs for geothermal drilling is the lack of seals for elevated temperatures. To assist development of a high-temperature seal, a test facility was constructed to simulate the seal environment in a roller bit during geothermal drilling. Although none of the tested elastomers appear suitable for compression seals above 200°C, extensive testing was performed to determine their exact limits. Several new heterogeneous seal designs were found usable to higher temperatures.