Arresting and supplying apparatus for increasing pellet impact drilling speed per run

Abstract

The paper describes pellet impact drilling which might be used to increase the drilling rate and the penetration rate of hard and tough rock drilling. Pellet impact drilling implies rock destruction by metal pellets having high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are recirculated in the bottom of the bore hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The arresting and supplying apparatus is supposed to increase speed per run in pellet impact drilling, as it not only replenishes the pellets but also supplies and then picks up the pellets from the bottom hole. The paper presents the design of the pellet-supplying component which ensures a portion of pellets supply to the bottom hole.