Carpenter Technology Corporation
Method and Apparatus for Generating Fluid Pressure Pulses of Adjustable Amplitude

Abstract:

A pressure generating device for use in downhole drilling operations includes a rotating valve portion having a first body with at least one first flow channel, and a stationary valve portion having a second body with at least one second flow channels and at least one bypass channel. A flow restrictor is positioned within the at least one bypass channel for adjusting a total flow area of the at least one bypass channel. During rotation of the rotating valve portion relative to the stationary valve portion, a total flow area of a passage defined by the first flow channel(s), the second flow channel(s), and the at least one bypass channel varies according to a uniform closure pattern to provide uniform pressure pulses within a single revolution of the rotating valve portion. A method of generating uniform pressure pulses in downhole drilling operations is also disclosed.