Real Time Pump Monitoring

Abstract

A system and method for monitoring operation of a pump are disclosed herein. The methods and systems make use of acoustic sensors to collect and analyze data in order to detect cavitation. The disclosed methods and systems may also be used to detect valve damage. The pump may be a positive displacement pump that is employed in a wellbore servicing operation such as pumping a wellbore servicing fluid into a wellbore.

1 . A method of servicing a wellbore, comprising:
 establishing baseline acoustic data for a pump;   pumping a wellbore servicing fluid into the wellbore with the pump;   gathering service acoustic data for the pump while pumping the wellbore servicing fluid;   comparing the baseline acoustic data to the service acoustic data; and   determining a presence or absence of an abnormal operating condition of the pump.   
     
     
         2 . The method of  claim 1  wherein the baseline acoustic data and the service acoustic data are provided by a knock sensor coupled to the pump. 
     
     
         3 . The method of  claim 1  wherein the baseline acoustic data, the service acoustic data, or both are time domain data. 
     
     
         4 . The method of  claim 1  further comprising converting the time domain data to frequency domain data. 
     
     
         5 . The method of  claim 4  wherein the baseline acoustic data and the service acoustic data are compared at a frequency range of from greater than about 0 to about 5000 Hz. 
     
     
         6 . The method of  claim 5  wherein the comparing further comprises comparing the magnitude of the service acoustic data to the baseline acoustic data and determining the presence of an abnormal operating condition of the pump when the service acoustic data is at least 50% greater than the service data. 
     
     
         7 . The method of  claim 6  wherein the service acoustic data and the baseline acoustic data are measures in g's, are compared at a first sub-frequency range of from about 2,000 to about 3,000 Hz, and the abnormal operating condition is identified as cavitation. 
     
     
         8 . The method of  claim 7  wherein the service acoustic data and the baseline acoustic compared at a second sub-frequency range of from about 3,500 to about 4,500 Hz, and the abnormal operating condition is identified as cavitation. 
     
     
         9 . The method of  claim 6  wherein the service acoustic data and the baseline acoustic data are measures in g's, are compared at a first sub-frequency range of from about 4,500 to about 5,000 Hz, and the abnormal operating condition is identified as valve leakage. 
     
     
         10 . The method of  claim 9  wherein the service acoustic data and the baseline acoustic compared at a second sub-frequency range of from about 1,750 to about 2,250 Hz, and the abnormal operating condition is identified as valve leakage. 
     
     
         11 . The method of  claim 3  wherein the comparing further comprises comparing the service acoustic data to the baseline acoustic data and determining the presence of an abnormal operating condition of the pump when valve bounce is detected upon closing of a suction valve of the pump. 
     
     
         12 . The method of  claim 11  wherein the abnormal operating condition is cavitation. 
     
     
         13 . The method of  claim 3  wherein the comparing further comprises comparing the service acoustic data to the baseline acoustic data and determining as present an abnormal operating condition of the pump when lag is detected in closure of a valve of the pump. 
     
     
         14 . The method of  claim 13  wherein the lag is detected in comparison to an expected valve closure time based upon position of a plunger in the pump. 
     
     
         15 . The method of  claim 13  wherein the abnormal operating condition is cavitation. 
     
     
         16 . The method of  claim 1  wherein the pump is a positive displacement pump. 
     
     
         17 . The method of  claim 2  wherein the pump is a positive displacement pump fluid end and the knock sensor is mounted adjacent the fluid end. 
     
     
         18 . The method of  claim 17  wherein the pump is operated at from about 100 to about 500 rpm. 
     
     
         19 . The method of  claim 1  further comprising sounding an alarm upon determining the presence of an abnormal operating condition. 
     
     
         20 . The method of  claim 1  further comprising adjusting one or more pump system parameters upon determining the presence of an abnormal operating condition.