| 摘要 |
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, pipe-shaped exterior part (3), pipe-shaped 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, pipe-shaped support (5) in a coaxial position inside primary valve (4), an auxiliary valve (13) and (14) actuated by motor means (15). Exterior part (30) and primary valve (4) delimit 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), and outlet orifice (13) of auxiliary valve (14) can be opened and closed. The sum of the downward hydraulic forces and the gravitational forces in the drilling mud composition acting on the primary valve in its starting position when auxiliary valve (13) and (14) is open exceeds the upward hydraulic forces, and these force relations can be reversed by closing auxiliary valve (13) and (14). In the 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 without contact in the drilling mud composition (Figure 4). EASD:032/C4 |
