Production Plunger

Abstract

A production plunger that automatically reciprocates in a production string of a well to remove formation fluid from the well. The production plunger makes a sealing contact with the production string and includes a passage through which all formation fluid is caused to flow through. The passage includes a valve that operates automatically in response to pressure within the production string to open and close the passage to allow and stop formation fluid from flowing in the passage. The plunger includes a locking device to ensure the plunger does not short cycle and a fail safe mechanism ensuring the valve closes in case of plunger failure, or upon a minimal build up of pressure by shutting in the well. Further, the entire valve is enclosed in the plunger preventing damage to valve elements from impacting downhole equipment, and the plunger includes fluid ports positioned so as not to easily capture well solids.

1 . A plunger for reciprocating in a production string of a well to unload the well of formation fluid to increase well production, the plunger comprising: 
 a body for reciprocating in a production string of a well, said body having a passage extending longitudinally through said body;    a valve seat in said passage;    a valve seal positioned in said passage;    a valve rod connected to said valve seal and extending through said valve seat in said passage;    means containing air under pressure connected to said piston and urging said valve seal away from said valve seat;    resilient element urging said valve seal towards said valve seat;    locking means for releasable engagement with said valve rod to resiliently lock said valve rod in a first position where said valve seal is away from said valve seat and to resiliently lock said valve rod in a second position where said valve seal is in sealing contact with said valve seat;    seal means carried by said body for engaging the inner wall of the production string and preventing fluid in the production string from flowing through the production string between said body and the inner wall of the production string; and    said body defining a first opening on a first side of said valve seat through which formation fluid can flow into said passage, across said valve seat and out of said passage through a second opening defined by said body on a second side of said valve seat until a quantity of formation fluid is accumulated which is sufficient to compress the air contained by said means for containing air, and to release said locking means from said valve rod to position said valve seal in sealing contact with said valve seat, thereby allowing gas pressure below said seal means to move said body and the accumulated formation fluid to the surface of the well.    
   
   
       2 . The plunger of  claim 1 , further comprising: 
 first and second centralizers positioned at opposite ends of said body.    
   
   
       3 . The plunger of  claim 1 , wherein said first and second openings are defined by said body such the entrance into said first opening and the entrance into said second opening are not facing upward towards the surface of the well.  
   
   
       4 . The plunger of  claim 1 , further comprising: 
 a retrieval means attached to said body for use in retrieving said body from the production string.    
   
   
       5 . The plunger of  claim 5 , wherein said retrieval means is a fishing neck.  
   
   
       6 . The plunger of  claim 1 , wherein said means containing air under pressure is collapsible.  
   
   
       7 . The plunger of  claim 6 , wherein said means containing air under pressure includes bellows.  
   
   
       8 . The plunger of  claim 1 , wherein said locking means includes a spring loaded detent.  
   
   
       9 . The plunger of  claim 1 , wherein said locking means includes a magnet.  
   
   
       10 . The plunger of  claim 1 , wherein said resilient means is a spring.  
   
   
       11 . A plunger for reciprocating in a production string of a well to unload the well of formation fluid to increase well production, the plunger comprising: 
 a body for reciprocating in a production string of a well, said body having a passage extending longitudinally through said body;    a valve seat in said passage;    a valve seal positioned in said passage;    a valve rod connected to said valve seal and extending through said valve seat in said passage;    a piston connected to said valve rod;    means containing air under pressure connected to said piston and urging said valve seal away from said valve seat;    resilient means connected to said piston and urging said valve seal towards said valve seat;    locking means for releasable engagement with said valve rod to resiliently lock said valve rod in a first position where said valve seal is away from said valve seat and to resiliently lock said valve rod in a second position where said valve seal is in sealing contact with said valve seat;    seal means carried by said body for engaging the inner wall of the production string and preventing fluid in the production string from flowing through the production string between said body and the inner wall of the production string; and    said body defining a first opening on a first side of said valve seat through which formation fluid can flow into said passage, across said valve seat and out of said passage through a second opening defined by said body on a second side of said valve seat until a quantity of formation fluid is accumulated which is sufficient to compress the air contained by said means for containing air, and to release said locking means from said valve rod to position said valve seal in sealing contact with said valve seat, thereby allowing gas pressure below said seal means to move said body and the accumulated formation fluid to the surface of the well.    
   
   
       12 . The plunger of  claim 11 , further comprising: 
 first and second centralizers positioned at opposite ends of said body.    
   
   
       13 . The plunger of  claim 11 , wherein said first and second openings are defined by said body such the entrance into said first opening and the entrance into said second opening are not facing upward towards the surface of the well.  
   
   
       14 . The plunger of  11 , further comprising: 
 a retrieval means attached to said body for use in retrieving said body from the production string.    
   
   
       16 . The plunger of  claim 1 , wherein said means containing air under pressure is collapsible.  
   
   
       17 . The plunger of  claim 11 , wherein said resilient means is a spring.  
   
   
       18 . A plunger for reciprocating in a production string of a well to unload the well of formation fluid to increase well production, the plunger comprising: 
 a body for reciprocating in a production string of a well, said body having a passage extending longitudinally through said body;    a valve seat in said passage;    a valve seal positioned in said passage;    a valve rod connected to said valve seal and extending through said valve seat in said passage;    a piston connected to said valve rod;    a collapsible means containing air under pressure connected to said piston and urging said valve seal away from said valve seat;    resilient means connected to said piston and urging said valve seal towards said valve seat;    locking means for releasable engagement with said valve rod to resiliently lock said valve rod in a first position where said valve seal is away from said valve seat and to resiliently lock said valve rod in a second position where said valve seal is in sealing contact with said valve seat;    seal means carried by said body for engaging the inner wall of the production string and preventing fluid in the production string from flowing through the production string between said body and the inner wall of the production string;    first and second centralizers positioned at opposite ends of said body;    a retrieval means attached to said body for use in retrieving said body from the production string; and    said body defining a first opening on a first side of said valve seat through which formation fluid can flow into said passage, across said valve seat and out of said passage through a second opening defined by said body on a second side of said valve seat until a quantity of formation fluid is accumulated which is sufficient to compress the air contained by said means for containing air, and to release said locking means from said valve rod to position said valve seal in sealing contact with said valve seat, thereby allowing gas pressure below said seal means to move said body and the accumulated formation fluid to the surface of the well.    
   
   
       19 . The plunger of  claim 18 , wherein said first and second openings are defined by said body such the entrance into said first opening and the entrance into said second opening are not facing upward towards the surface of the well.  
   
   
       20 . The plunger of  claim 18 , wherein said locking means includes a spring loaded detent.