TABLE OF CONTENTS Two methods are mentioned here using plunger lift for weak wells. One is the use of the casing plunger and the other is the use of a side string for gas injection.
The casing plunger travels in the casing only, and there is no tubing in the well. The plunger senses when a head of liquid appears above the plunger, the internal bypass valve then closes, and the well gas production lifts the plunger and slug of liquid to the surface. Then at the surface, the plunger internal valve will open and the plunger will drop. The casing plunger rises and falls slowly. It has rubber cups that fit the casing. The cups will not last long enough for satisfactory service if the casing is very rough. Figure 7-17 shows a casing plunger.
Figures 7-18, 7-19, 7-20, and Table 7-2 are introduced to allow the sample calculation that follows to size cycle gas requirements for using a casing plunger. The calculations are from FBI (Tyler, TX) who no longer supply casing plungers. MULTI (Millersburg, OH) has been a supplier of casing plungers.
