At present, whether in domestic construction or overseas contracting of water well projects, roller cone drilling technology is generally used, especially for deep water wells and geothermal wells. Judging from the field of roller bit use in recent years, it has been extended to pile foundation construction, trenchless engineering construction, and coal mine gas drainage well construction. The scope of application is continuously expanding, and the social and economic benefits produced are very significant. Engineering practice has proved that the use of roller bit drilling technology has no special requirements on the formation and groundwater conditions, and has the characteristics of good adaptability and wide application range. It should be promoted and applied.
The drilling technology of roller cone bits is 1 to several times higher than the efficiency of general barrel core drilling. The life of the drill bit is also long. A tri-cone drill bit is drilled in 5-6 medium-hard rocks. Tens of meters to 100 meters are generally not a problem, the cost is low, and the one-time investment is not large. During the drilling process, the pure drilling time is increased and the auxiliary time is shortened (sometimes the drilling is only raised once in a few shifts). The wall of the well is smooth, complete, and high in verticality, which is also the special advantage of the positive circulation drilling process.
