Research on particle injection system in percussion drilling

Particle Injection System (PIS) in percussion drilling is a new type of particle injection system developed with the technology of percussion drilling. The particles can be injected into the high pressure drilling fluid in a designed rate, uniformly, continuously and securely. Two injection tubes were used in this system to inject particles and pressurize particles to be excluded. The two processes were completed by turns, ensuring the continuous injection of particles. Particles could be injected into the head pipe in a certain rate uniformly and stably by the screw sqeegee pump. A particle injecting principle was put forward, and the structure of the key components was designed, including particle lifting system, injection tube, screw sqeegee pump, and so on. The relationship of throttle diameter and the particle volume percentage under different pressure was obtained through experiments, which supplied the theoretical and experimental basis for field applications..