Defining the Characteristics and Performance of Gas Lift Plungers

A Laboratory investigation was conducted to provide data necessary to better predict the behavior of gas Lift plungers. The Laboratory phase of the study was necessary since no data was available on full size commercially available plungers. A test well was instrumented to provide pressure, velocity, and volumetric information during the fall and rise cycle of a variety of commercially available plungers. A data bank representing 132 individual runs has been compiled and behavior of 13 different plunger configurations has been characterized by gas slippage, Liquid fallback, and fall velocity. Performance characteristics of the individual plungers has been incorporated in a modified Foss and Gaul* mathematical model which provides predicted minimum casing pressure in close agreement with actual Laboratory tests. The Laboratory data should provide a basis for improved plunger selection and design. As a second part of the evaluation program, actual field data was collected and the correlations developed for the Laboratory tests were finally adjusted to fit field data. The field data was collected from four field Locations with a variety of operating conditions. The final correlations and equations describing plunger Lift operations have been included in a computer program that can be used for design and analysis of plunger Lift operation.