Eastman Christensen Company

Johann Biehl

Alfred Ostertag

Dagobert Feld

The apparatus for the generation of pressure pulses in a drilling mud composition which flows downward in a drill string (1) is composed of a valve (V) inside the drill string (1), with a stationary, braced, tubular exterior housing (3), tubular primary valve (4) which can be translated from a lower starting position against the flow direction (2) of the drilling mud composition into an upper operational end position, a stationary, tubular support (5) in a coaxial position inside primary valve (4), and a pilot valve (13), (14) actuated by motor means (15). Exterior housing (3) and primary valve (4) define a constricted segment (29) whose flow cross section can be modified by the position of primary valve (4), and primary valve (4) and the support (5) surround an interior flow channel (21), (12) and (10), which can be opened and closed by outlet orifice (13) of pilot valve (13), (14). The sum of the downward fluid forces and the gravitational forces in the drilling mud composition acting on the primary valve in its starting position when pilot valve (13), (14) is open exceeds the upward fluid forces, and these force relations can be reversed by closing auxiliary valve (13), (14). In the fluid operational end position of primary valve (4), the sum of all forces acting on primary valve (4) is equal to zero, and primary valve (4) is suspended in the drilling mud composition without contacting stop (34) thereabove.

Apparatus for the generation of pressure pulses in drilling mud

A core drilling tool with direct drive consisting of an outer pipe that can be connected to a drilling shaft, a core drilling appliance reciprocally mountable in the outer pipe which in turn includes a core barrel that carries a drill bit and an inner pipe mounted in rotatable relation therewith and for reciprocal movement therewith, and a drilling mud driven motor that is integrally coupled to the core drilling appliance and is secured against rotation in the outer pipe and having reaction faces that are put under pressure to produce a downward axial feed force acting on both the core drilling appliance and the motor, plus a capture device for pulling up the motor together with the core drilling appliance. In order to produce a sufficiently great axial feed force of an adjustable size that is essentially independent of the exposure of the core drilling appliance, the motor is connected to the core drilling appliance to form a common movable unit and devices are provided for adjusting the axial feed force.

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Kirchheim/Teck, Germany

Johann Biehl