Paper: PLUNGER LIFT OPEN CRITERIA

To unload liquid from a conventional plunger lift well requires that sufficient pressure builds during the shut-in time period as the plunger falls through gas, liquid and then rests at bottom on the bumper spring. Industry rule-of-thumb criteria to determine when the well should be opened to unload the liquid include building casing pressure, CP, to 1 _ times the line pressure, LP, or also using the tubing pressure, TP, in the Load Factor (CP-TP)/(CP-LP) calculation to be less than one-half(_). The best technique to predict the maximum casing build pressure may be to use the Foss and Gaul1 model to predict the rise velocity within a range of 500-1000 fpm, more optimally at 750 fpm that will unload plunger and liquid to the surface. These criteria are compared to one another and several well examples are analyzed using all three methods. Analysis of the results allow an operator to determine the shut-in casing pressure a plunger lift well should be allowed to build to before opening the valve to unload the liquid.