Enter Flowing WHP (PSIA) and Tubing ID (inches) in the boxes on the left and then click 'Calculate'. WHP should be in range of 100 to 10,000 PSIA and the tubing I.D should be between 1 and 5 inches.
The calculated flow rate is the minimum flow rate required to continuously unload fluids without slugging. If the actual flow rate is lower then the well may be unsuitable for testing with a SPIDR well testing system.