Paper: Two Piece Plunger Test Results

The two piece plunger (a steel ball below and a hollow cylinder above) lifts liquids when the pieces are together and on reaching the surface the ball falls and the cylinder falls when a short shut-in period occurs. There are many instances where using this plunger results in production increases. However in some cases, it appears to have a lesser effect. Results of testing show that above certain rates, the components will not fall in the well. Test results, and the result of drag models to fit the test data are extended to show the potential user what the maximum allowable rates are from the well, before the individual components are predicted to be unable to fall in the well, thereby making application impossible without a temporary reduction in the flow rate. The results should allow the user to be able to better use the two piece plunger in a wider range of application conditions.