Drilling system incorporating inverse mud circulation - comprises raising debris-laden mud to surface by depression created in upper part of train of rods by air injection

摘要

A device for operating a drilling process, in which the drilling mud is raised to the surface inside the train or rods by means of a depression created in the upper part of the train or rods by injection of air into the mud, incorporates a head at the upper part of the train of rods, formed by an inner pipe for the passage of drilling mud loaded with debris and an annular part into which the air is injected. The lower part of the head is connected to a double tubing provided with an air diffuser. Communication of the annular space of the double tubing with the inner tube is effected by means of clack valves disposed on a pipe of the diffuser connected to the inner tube and giving passage to the air when the press. of injected air is greater than the press. of the mud in the diffuser pipe. The diffuser pipe is connected to the train of rods, to the lower end of which the drilling tool is fixed.