Performance Evaluation of a New Rock Bit Bearing Seal

Abstract

Abstract Reliability functions derived from field performance data are used to measure the effectiveness of a new rock bit bearing seal. The new seal is a metal face seal and its performance is compared to the standard O-ring seal. The results show a significant increase in bit life measured in cone revolutions under typical operating conditions. This increase in cone revolutions may be utilized to increase rotating time, rotary speed or both. An example comparing various alternatives is provided. Data are also provided which show a much improved tolerance to high bottom hole temperatures.