Showing papers on "Variable-frequency drive published in 1982"
TL;DR: In this article, a three-phase induction motor is used as a sensing instrument to determine downhole pressure, both static and flowing, and a new electronic device, installed at the surface, is developed and tested to monitor the actual revolutions per minute (r/min) of the downhole pump and motor.
Abstract: The production of a submersible pump can be optimized with the use of a microcomputer-controlled variable frequency drive. A new approach to monitoring the pump and motor performance is presented. Instead of downhole sensors, pressure bomb, or acoustical wave method, the three-phase induction motor is used as a sensing instrument to determine downhole pressure, both static and flowing. A new electronic device, installed at the surface, has been developed and tested to monitor the actual revolutions per minute (r/min) of the downhole pump and motor. Using the basic induction motor equivalent circuit, the motor terminal voltage can be determined and thus controlled to meet the motor manufacturer's design criteria. The detailed analysis then permits calculation of the liquid level which can be used as the governing parameter for oil production. Also a method is discussed to prevent cavitation, determine specific gravity, and calculate downhole temperature.
2 citations
01 Jan 1982
TL;DR: In this paper, a three-phase induction motor is used as a sensing instrument to determine downhole pressure, both static and fluid, and a new electronic device is developed and tested to monitor the actual revolutions perminute(r/min) of the downhole pump and motor.
Abstract: The production ofasubmersible pumpcanbeoptimized withtheuseofamicrocomputer-controlled variable frequency drive. A newapproach tomonitoring thepumpandmotorperformance is presented. Instead ofdownhole sensors, pressure bomb,oracoustical wavemethod, thethree-phase induction motorisusedasasensing instrument todetermine downhole pressure, bothstatic andflowing. A newelectronic device, installed atthesurface, hasbeendeveloped andtested tomonitor theactual revolutions perminute(r/min) ofthe downholepump and motor.Usingthebasicinduction motor equivalent circuit, themotorterminal voltage canbedetermined and thuscontrolled tomeetthemotormanufacturer's design criteria. The detailed analysis thenpermits calculation oftheliquid level whichcan beusedasthegoverning parameter foroilproduction. Alsoamethod isdiscussed toprevent cavitation, determine specific gravity, and calculate downhole temperature.