PLUNGER LIFT ASSEMBLY WITH AN IMPROVED FREE PISTON ASSEMBLY

摘要

An improved free piston assembly for use in combination with a plunger lift assembly is provided. The improved free piston assembly includes a sleeve member, a flow restriction member, and retention means. In some embodiments of the invention the sleeve member has an inner surface that is contoured to provide a seat for the flow restriction member during lifting operations. The flow restriction member can be a ball held in the interior of the sleeve by retention means capable of overcoming the force of gravity but at the same time designed to release the flow restriction member when a rod of the plunger lift assembly contacts the flow restriction member. In one embodiment of the invention the retention means is a plurality of inwardly biased spring loaded held in place by a retention ring that is fittably received by a groove in the exterior surface of the sleeve. In other embodiments of the invention the retention means are in the form of a raised lip or a retention sleeve.

主权项

1. An improved free piston assembly for use in combination with a plunger lift assembly for a well producing hydrocarbon fluids through apertures in a production string, said apertures communicating with a hydrocarbon containing formation, said free piston assembly comprising:
(a) a sleeve member having an inner surface providing a seat for a flow restriction member; (b) a flow restriction member that is not mechanically latched to said sleeve member but is configured to seat in said sleeve member to seal off the flow of fluids through said sleeve member while seated; and (c) retention means for retaining said flow restriction member in said sleeve member if said flow restriction member is unseated during lifting operations, said retention means being physically spaced apart from said flow restriction member when said flow restriction member is seated in said sleeve member.