Most drilling rigs utilize an appendage pulsation dampener installed on the strainer block over the flow line. These pulsation dampeners are great options as they are light and have a small footprint. A drawback of an appendage pulsation dampener is its inability to reduce energy in the drilling fluid that passes underneath the pulsation dampener. In general terms, low frequency or mechanical pulsation energy is slow enough to be dampened by the pulsation dampener. On the other hand, the high frequency or the acoustic signature in the drilling fluid is high-speed, and very little of this energy is affected by the pulsation dampener.

These high-frequency acoustics don’t manifest themselves in the same way as the low-frequency energy waves do. Whereas the failure to dampen or mitigate low-frequency waves results in numerous physical and even visual manifestations, the high-frequency energy present doesn’t generally display itself. This is often why the system acoustics are referred to as the silent killer. These high-frequency waves are responsible for premature component failure and significant disturbances with downhole tools.

Many times, rig personnel will attempt to diagnose system failures based on low-frequency issues. Once they have exhausted their known quick-fixes, they are often left scratching their heads. These system failures can range from failed seals and gaskets to ruptured pulsation dampener bladders and even premature Kelly hose failure. These failures are quite expensive and require several hours of downtime. Acoustic resonance in your pumping system will quietly fatigue your system. This resonance can manifest itself as slight vibrations, much like a tuning fork. As the pumping system is absorbing this energy, it’s slowly weakening the structural integrity.

Not only is the structural integrity being compromised, but downhole tools also have a difficult time functioning correctly as well. The high-frequency energy will disrupt the MWD signal and make syncing challenging to accomplish. Acoustic telemetry is extremely vulnerable to high-frequency acoustic resonance in the drill string.