Patent Number: 7,762,339

Title: Apparatus and method for controlling the speed of a pump in a well

Abstract: A controller for controlling the pump unit of an oil well includes a sensor having a first and second probe for placement in the flow of oil from the well bore. Each of the probes contains a heater. A constant power source is selectively connected to one of the heaters. Each of the probes also includes a linear RTD at each of their tips respectively for generating a signal indicative of the temperature measured at each of the first and second probes. A control unit receives signals from the RTD's and determines a flow rate therefrom. A pump control signal is generated in response to the flow rate, wherein the pump control signal continuously varies a predetermined parameter for controlling the flow rate of a pumping unit during operation of the pumping unit.

Inventors: Bevan; Stuart F. (Glencoe, Ontario, CA), Lownie; Timothy (London, Ontario, CA)


International Classification: E21B 43/12 (20060101); F04B 47/00 (20060101); F04B 49/00 (20060101)

Expiration Date: 7/27/12018