Gas Interference Detection and Control of Long-Stroke Pumping Unit Speed for Gas Interference Mitigation

Abstract

Managing gas interference in a downhole pump, such as for liquid hydrocarbon well production, is accomplished by monitoring pump operational data indicating liquid pump fillage values, determining from indicative patterns in the monitored data, possibly observed over a number of pump strokes, whether a gas interference condition exists, and in response to determining that the gas interference condition exists, increasing a normal pump speed to a higher speed. In response to determining that the gas interference condition does not exist, a normal pump speed may be resumed.

What is claimed is: 
     
         1 . A method for managing a gas interference condition in a downhole pump, comprising:
 monitoring, by a controller of the downhole pump, data indicating liquid pump fillage values for the downhole pump;   determining, by the controller, one or more patterns in the monitored data indicating that the gas interference condition exists; and   in response to determining that the gas interference condition exists, increasing, by the controller, a normal pump operation speed of the downhole pump to a higher speed.   
     
     
         2 . The method of  claim 1 , further comprising:
 determining, by the controller, that the gas interference condition is no longer present in the downhole pump; and   in response to determining that the gas interference condition is no longer present, resuming the normal pump operation speed for the downhole pump.   
     
     
         3 . The method of  claim 1 , wherein the downhole pump comprises a long-stroke pumping unit configured for liquid hydrocarbon production. 
     
     
         4 . The method of  claim 1 , wherein the monitored data further comprises dynamometer data indicating pump force values versus pump displacement values. 
     
     
         5 . The method of  claim 1 , wherein the determining further comprises:
 identifying an increase in a variance of the liquid pump fillage values;   identifying an increase in the liquid pump fillage values followed by a decrease in the liquid pump fillage values followed by another increase in the liquid pump fillage values;   evaluating the monitored data during a number of pump operating cycles; or a combination thereof.   
     
     
         6 . The method of  claim 1 , wherein the determined patterns correspond to gas compression and gas expansion in the downhole pump. 
     
     
         7 . The method of  claim 1 , wherein the normal pump operation speed further comprises a rate of performing upstrokes and downstrokes that maximizes the liquid pump fillage values in an absence of the gas interference condition. 
     
     
         8 . The method of  claim 1 , wherein the increasing further comprises increasing a speed of a variable-frequency-drive electric motor that drives the downhole pump. 
     
     
         9 . An apparatus for managing a gas interference condition in a downhole pump, comprising:
 a controller that performs operations comprising:
 monitoring data indicating liquid pump fillage values for the downhole pump; 
 determining one or more patterns in the monitored data indicating that the gas interference condition exists; and 
 in response to determining that the gas interference condition exists, increasing a normal pump operation speed of the downhole pump to a higher speed. 
   
     
     
         10 . The apparatus of  claim 9 , wherein the controller further:
 determines that the gas interference condition is no longer present in the downhole pump; and   in response to determining that the gas interference condition is no longer present, resumes the normal pump operation speed for the downhole pump.   
     
     
         11 . The apparatus of  claim 9 , further comprising:
 the downhole pump;   a pump motor that actuates the downhole pump; and   a sensor that generates the data.   
     
     
         12 . The apparatus of  claim 9 , wherein the downhole pump comprises a long-stroke pumping unit. 
     
     
         13 . The apparatus of  claim 9 , wherein the monitored data further comprises dynamometer data indicating pump force values versus pump displacement values. 
     
     
         14 . The apparatus of  claim 9 , wherein the determining further comprises:
 identifying an increase in a variance of the liquid pump fillage values;   identifying an increase in the liquid pump fillage values followed by a decrease in the liquid pump fillage values followed by another increase in the liquid pump fillage values;   evaluating the monitored data during a number of pump operating cycles; or a combination thereof.   
     
     
         15 . The apparatus of  claim 9 , wherein the determined patterns correspond to gas compression and gas expansion in the downhole pump. 
     
     
         16 . The apparatus of  claim 9 , wherein the normal pump operation speed further comprises a rate of performing upstrokes and downstrokes that maximizes the liquid pump fillage values in an absence of the gas interference condition. 
     
     
         17 . The apparatus of  claim 9 , wherein the increasing further comprises increasing a speed of a variable-frequency-drive electric motor that drives the downhole pump. 
     
     
         18 . A non-transitory computer-readable storage medium having embedded therein a set of instructions which, when executed by one or more processors of a computer, causes the computer to execute operations for managing a gas interference condition in a downhole pump, the operations comprising:
 monitoring data indicating liquid pump fillage values for the downhole pump;   determining one or more patterns in the monitored data indicating that the gas interference condition exists; and   in response to determining that the gas interference condition exists, increasing a normal pump operation speed of the downhole pump to a higher speed.   
     
     
         19 . The non-transitory computer-readable storage medium of  claim 18 , wherein the operations further comprise:
 determining that the gas interference condition is no longer present in the downhole pump; and in response to determining that the gas interference condition is no longer present, resuming the normal pump operation speed for the downhole pump.   
     
     
         20 . The non-transitory computer-readable storage medium of  claim 18 , wherein the operations further comprise:
 determining further comprises identifying an increase in a variance of the liquid pump fillage values;   identifying an increase in the liquid pump fillage values followed by a decrease in the liquid pump fillage values followed by another increase in the liquid pump fillage values;   evaluating the monitored data during a number of pump operating cycles; or a combination thereof.