Trykkpulsdemper

A downhole in-line tubular accumulator for the attenuation of pressure pulses generated by operation of a downhole vibratory apparatus in an oil or gas well. An inner tube is positioned within a hollow housing, with the inner tube being attached to the housing at their upper ends. The lower end of the inner tube is unattached within the housing, thereby establishing an annular upper cavity between the inner tube and the housing, and an open lower cavity in the housing below the unattached lower end of the inner tube. The attenuator is run into the well on a work string. Pressure pulses traveling through the fluid column in the work string are attenuated by entrapped air in the annular upper cavity in the housing.