Catastrophic hit indicator for catcher in plunger gas/fluid lift system for well operations

Abstract

A catastrophic or heavy-hit indicator subassembly is included in a plunger lift system lubricator which includes a coil spring above a striker block, a piston above the striker block, the piston sealed but moveable within the bore of the subassembly, above the piston another spring or set of spring washers, a space, and above the space a thin membrane or wall in a top nut or seal at the top of the lubricator. If the plunger reaches the lubricator with sufficient force, it will compress the coil spring and move the striker block to push the piston upward within the bore of the lubricator, the piston will compress the second spring or set of spring washers, and the top end of the piston, which is preferably pointed, will pierce the membrane or wall in the top of the lubricator.

What is claimed is: 
     
         1 . A lubricator subassembly for a plunger gas lift system for a well, the subassembly comprising:
 a. a striker block   b. a coil spring resting on the upper end of the striker block   c. a housing resting within the upper end of the coil spring   d. a piston extending in a cylinder deposed through the housing   e. the piston with a feature midway its length upon which a spring assembly sits   f. an indicator cap above the housing capable of being pierced by the piston's upper end   g. the subassembly being sealed within a chamber in the upper end of the lubricator   h. the lubricator with a viewing port or window through which an observer can observe whether the indicator cap has been pierced.   
     
     
         2 . A method of providing an observable indication that a force above a certain magnitude has been applied to the lubricator and associated top-hole equipment and to the plunger by installing the subassembly of  claim 1  with springs configured to permit the piston to pierce the indicator cap when that force has been applied by the system's plunger. 
     
     
         3 . The subassembly where the indicator cap is brass. 
     
     
         4 . The subassembly where the spring assembly is a series of Belleville spring washers or discs. 
     
     
         5 . The piston and cylinder housing where the piston is sealed to the cylinder by an o-ring deployed between them at the bottom of the cylinder where the piston extends out from the bottom of the cylinder. 
     
     
         6 . The subassembly where the housing is sealed to the lubricator by a compression seal or o-ring between the top of the housing and the indicator cap and another between the indicator cap and the top of the lubricator cavity within which the subassembly resides when installed.