Patent ID: 8180593
Filing Date: 2012-05-15
Classification: E21B,F04D,G01F,G05B,G05D

Abstract:
1. A method of determining a flow rate Q from a centrifugal pump operating at a selected pump speed Up while disposed in a wellbore for transferring fluid within the wellbore, using a controller operatively connected to the centrifugal pump, the method comprising: determining the fluid level Xc by determining a zero-flow input speed Uz of the centrifugal pump at which output flow from the centrifugal pump is substantially zero, and using the zero-flow input speed Uz to calculate a fluid level Xc in the wellbore with the controller; and calculating flow rate Q as a function of the selected speed Up and the fluid level Xc in the wellbore as calculated from the zero-flow input speed Uz using the controller.