Interference-seal plunger for an artificial lift system

Abstract

A plunger for an artificial lift system and embodiment of the plunger includes a solid body adapted to travel within a production string positioned in a wellbore. At least one sealing ring connected about the body. The at least one sealing ring having an inner surface, an outer surface, a width and a thickness. The width is sufficient such that when the body is disposed in the production string the outer surface contacts and substantially forms a seal between the body and an inner wall of the production string. The at least one sealing ring having an outside diameter greater than the inner diameter of the production tubing within which the body is adapted to travel such that when the body is disposed within the production string an interference fit causes the sealing rings to roll-form into a constricted shape and diameter that exerts the sealing contact with the production string.

1 . A plunger for an artificial lift system, the plunger comprising: 
 a body adapted to travel within a production string positioned in a wellbore; and    at least one sealing ring having an inner surface, an outer surface, a width and a thickness, the sealing ring connected about the body, wherein the width is sufficient such that when the body is disposed in the production string the outer surface contacts and substantially forms a seal between the body and an inner wall of the production string.    
   
   
       2 . The plunger of  claim 1 , wherein the production string is a tubing string.  
   
   
       3 . The plunger of  claim 1 , wherein the at least one sealing ring has a width to thickness ratio within a range from about 0.02 to about 0.2.  
   
   
       4 . The plunger of  claim 1 , wherein an outer diameter of the at least one sealing ring is between about 3% to about 6% larger than an inner diameter of the production string within which it is adapted to travel.  
   
   
       5 . The plunger of  claim 1 , wherein an outer diameter of the at least one sealing ring is about 5% larger than an inner diameter of the production string within which the body is adapted to travel.  
   
   
       6 . The plunger of  claim 1 , wherein the at least one sealing ring comprises: 
 an inner portion proximate the inner surface formed of a substantially rigid material; and    an outer portion extending from the inner portion to the outer surface formed of a material substantially flexible relative to the inner portion.    
   
   
       7 . The plunger of  claim 1 , wherein the body forms a recess and wherein the at least one sealing ring is connected to the body in the recess.  
   
   
       8 . The plunger of  claim 1 , wherein the at least one sealing ring comprises: 
 at least one sealing ring connected about the body proximate a top end of the body; and    at least one sealing ring connected about the body proximate a bottom end of the body.    
   
   
       9 . The plunger of  claim 1 , wherein when the body is disposed within the production string the at least one sealing ring assumes a shape such that the sealing ring enhances movement of the body over the drag from the sealing contact.  
   
   
       10 . The plunger of  claim 1 , wherein the at least one sealing ring has an outside diameter greater than an inner diameter of the production tubing such that when the body is disposed within the production string an interference fit causes the sealing ring to roll-form into a constricted shape and diameter that exerts the sealing contact with the inner wall of the production string.  
   
   
       11 . A plunger for an artificial lift system, the plunger comprising: 
 a solid body adapted to travel within a production string positioned in a wellbore;    at least one sealing ring having an inner surface, an outer surface, a width and a thickness, the sealing ring connected about the body, wherein the width is sufficient such that when the body is disposed in the production string the outer surface contacts and substantially forms a seal between the body and an inner wall of the production string; and    the at least one sealing ring having a width to thickness ratio within a range from about 0.02 to 0.2 wherein when the body is disposed within the production string the sealing ring assumes a shape such that the sealing ring enhances movement of the body over the drag from the sealing contact.    
   
   
       12 . The plunger of  claim 11 , wherein the outer diameter of the at least one sealing ring is between about 3% to about 6% larger than the inner diameter of the production string within which it is adapted to travel.  
   
   
       13 . The plunger of  claim 11 , wherein the at least one sealing ring comprises: 
 at least one sealing ring connected about the body proximate a top end of the body; and    at least one sealing ring connected about the body proximate a bottom end of the body.    
   
   
       14 . The plunger of  claim 11 , wherein the at least one sealing ring comprises: 
 an inner portion proximate the inner surface formed of a substantially rigid material; and    an outer portion extending from the inner portion to the outer surface formed of a material substantially flexible relative to the inner portion.    
   
   
       15 . The plunger of  claim 11 , wherein the at least one sealing ring comprises: 
 an inner portion proximate the inner surface formed of a substantially rigid material;    an outer portion extending from the inner portion to the outer surface formed of a material substantially flexible relative to the inner portion;    at least one of the at least one sealing rings being connected about the body within a recess formed proximate a top end of the body;    at least one of the at least one sealing rings being connected about the body within a recess formed proximate a bottom end of the body: and    the sealing rings having an outside diameter greater than an inner diameter of the production tubing within which the body is adapted to travel such that when the body is disposed within the production string an interference fit causes the sealing rings to roll-form into a constricted shape and diameter that exerts the sealing contact with the production string.    
   
   
       16 . A plunger for an artificial lift system, the plunger comprising: 
 a solid body adapted to travel within a production string positioned in a wellbore;    at least one sealing ring having an inner surface, an outer surface, a width and a thickness, the sealing ring connected about the body, wherein the width is sufficient such that when the body is disposed in the production string the outer surface contacts and substantially forms a seal between the body and an inner wall of the production string; and    the at least one sealing ring having an outer diameter that is between about 3% to about 6% larger than an inner diameter of the production string within which it is adapted to travel.    
   
   
       17 . The plunger of  claim 16 , wherein the at least one sealing ring has a width to thickness ratio within a range from about 0.02 to about 0.2.  
   
   
       18 . The plunger of  claim 16 , wherein the at least one sealing ring comprises: 
 an inner portion proximate the inner surface formed of a substantially rigid material; and    an outer portion extending from the inner portion to the outer surface formed of a material substantially flexible relative to the inner portion.    
   
   
       19 . The plunger of  claim 16 , wherein the at least one sealing ring comprises: 
 at least one of the at least one sealing rings being connected about the body within a recess formed proximate a top end of the body; and    at least one of the at least one sealing rings being connected about the body within a recess formed proximate a bottom end of the body.    
   
   
       20 . The plunger of  claim 16 , wherein the at least one sealing ring comprises: 
 an inner portion proximate the inner surface formed of a substantially rigid material;    an outer portion extending from the inner portion to the outer surface formed of a material substantially flexible relative to the inner portion;    at least one of the at least one sealing rings being connected about the body within a recess formed proximate a top end of the body;    at least one of the at least one sealing rings being connected about the body within a recess formed proximate a bottom end of the body: and    the sealing rings having an outside diameter greater than an inner diameter of the production tubing within which the body is adapted to travel such that wherein when the body is disposed within the production string the interference fit causes the sealing rings to roll-form into a constricted shape and diameter that exerts the sealing contact with the production string.