TABLE OF CONTENTS A new two-piece plunger (MGM Well Service, Corpus Christi, TX; Figure 7-16) is designed to trip to bottom while the well is producing at considerable rate. In some wells, the plunger falls to the bottom while the well is producing at 1000 Mscf/D or more. Both pieces of the two-piece plunger have considerable bypass area when they are falling independently in the well, allowing the well to produce around the bottom piece (the ball) and through the top piece (the piston). They join at the bottom and are held together by the flow from the zones below as it pushes the plunger (now one unit) and any liquid in the tubing to the surface as would a conventional plunger system. The surfacing plunger strikes a shifting rod and a gas-powered catch cylinder. The shifting rod separates the two pieces, and the piston is held at the surface by the catch cylinder or in some cases by just the flow around the cylinder. The ball falls back to the bottom to await the arrival of the piston. When released from the surface, the piston arrives at the bottom of the well and joins with the ball, beginning the process again. The cylinder can be released by a short shut-in time so that pressure and fluid drag will cease holding the plunger at the surface. If the arrangement is not such that pressure and drag are holding the plunger cylinder at the surface, then a mechanical catch system...
