The consolidated service desk road map

Continuous drilling of a well bore and coring involves the use of a rotatable percussion drill having a central core barrel, the drill being operated by air circulated through a dual concentric drill pipe and a swivel at the top of the drill pipe, the air, in major part, flowing upwardly through the bore hole annulus, outside the drill pipe to remove cuttings and other material from the annulus, and a minor part of the air flows upwardly in the central core tube of the drill pipe from the center of the drill to carry uncontaminated core samples from the center of the bottom of the bore hole.