Composite packer cup

Abstract

A packer cup for use in a packer assembly is disclosed. The cup has an outer layer, an intermediate reinforcing layer of meshed metal plies and an inner layer. The intermediate layer acts as a continuous, but flexible reinforcement to allow expansion and contraction of the cup as it is forced into the wellbore and to resist extrusion of the elastomers under pressure. The cup outer layer is preferably abrasion resistant and the inner layer is preferably chemical resistant. The layers are vulcanized into a unitary cup capable of resisting outer wear and tear as a result of insertion into the wellbore and internal chemical deterioration as a result of the harsh downhole environment.

The embodiments of the invention is which an exclusive property or priviledge is claimed are defined as follows:  
     
         1 . An improved packer cup comprising: 
 an annular base ring for mounting to a packer assembly which is positioned in a wellbore casing to isolate a higher pressure zone from a lower pressure zone;    an annular cup extending from the annular base ring toward the higher pressure zone and having 
 an elastomeric inner layer, and  
 an elastomeric outer layer; and  
   an annularly extending flexible intermediate layer of reinforcing plies of material disposed between the inner and outer layers, and mounted at a lower end to the base ring, the inner, outer and intermediate layers being bonded together to form a unitary, flexible structure.    
     
     
         2 . The improved packer cup as described in  claim 1  wherein the inner elastomeric layer is fabricated from a chemically impervious elastomer.  
     
     
         3 . The improved packer cup as described in  claim 2  wherein the chemically impervious elastomer is Viton™.  
     
     
         4 . The packer cup as described in  claim 1  wherein the outer layer is fabricated from an abrasion resistant elastomer.  
     
     
         5 . The packer cup as described in  claim 4  wherein the abrasion resistant elastomer is Nitrile™.  
     
     
         6 . The packer cup as described in  claim 1  wherein the inner layer is fabricated from Viton™ and the outer layer is fabricated from Nitrile™.  
     
     
         7 . The packer cup as described in  claim 1  wherein the intermediate layer is formed of multiple, biased interwoven layers of reinforcing plies having upper and lower ends, the lower ends being fixed circumferentially to the annular base ring.  
     
     
         8 . The packer cup as described in  claim 7  wherein the reinforcing fibers are metal wire.  
     
     
         9 . The packer cup as described in  claim 7  wherein the reinforcing fibers are aircraft cable.  
     
     
         10 . An improved packer cup for a packer assembly, the cup isolating a higher pressure zone from a lower pressure zone in the wellbore casing wherein an inside of the cup is exposed to corrosive chemicals and hydrocarbons and an outside to mechanical abrasion, the improvement comprising: 
 an annular base ring;    an annular cup extending from the base ring and toward the zone of higher pressure and having, 
 an elastomeric chemically impervious inner layer, and  
 an elastomeric abrasion resistant outer layer; and  
 an annularly extending flexible interwoven fiber intermediate layer, disposed between the inner and outer layers, and fixed at a lower end to the base ring, the inner, outer and intermediate layers being bonded together to form a unitary, flexible structure.  
   
     
     
         11 . The packer cup as described in  claim 10  wherein the inner layer is fabricated from Viton™.  
     
     
         12 . The packer cup of  claim 10  wherein the outer layer is fabricated from Nitrile™.  
     
     
         13 . The packer cup as described in  claim 10  wherein the inner layer is fabricated from Viton™ and the outer layer is fabricated from Nitrile™.  
     
     
         14 . The packer cup as described in  claim 10  wherein the reinforcing plies are metal cables.  
     
     
         15 . The packer cup as described in  claim 13  wherein the reinforcing plies are metal cables.  
     
     
         16 . A cup-type packer assembly for positioning in a wellbore casing comprising: 
 a mandrel for positioning in the casing and forming an annulus therebetween; and    at least one packer cup, each cup having an annular base ring sealing engaged concentrically about the mandrel and an annular body for sealing against the wellbore casing for isolating a zone of higher pressure from a zone of lower pressure in the wellbore casing, the annular body comprising an elastomeric inner layer, an elastomeric outer layer; and an annularly extending flexible intermediate layer of interwoven reinforcing plies disposed between the inner and outer layers, the plies being mounted at a lower end to the base ring, the inner, outer and intermediate layers being bonded together to form a unitary, flexible structure.    
     
     
         17 . The cup-type packer assembly of  claim 13  wherein the packer is used for chemical stimulation at a zone in the wellbore casing and wherein, for each cup: 
 the inner elastomeric layer is fabricated from a chemically impervious elastomer; and  
 the outer layer is fabricated from an abrasion resistant elastomer.  
 
     
     
         18 . The cup-type packer assembly of  claim 16  further comprising: 
 one or more uphole cups mounted at an uphole end of the mandrel, each cup's annular body extending downhole from its base ring; and  
 one or more downhole cups mounted at a downhole end of the mandrel, each cup's annular body extending uphole from its base ring, the uphole and downhole cups' outer layers being resistant to abrasion during positioning of the packer in the wellbore casing and the uphole and downhole cups' inner layers being resistant to chemicals during higher pressure wellbore stimulation.  
 
     
     
         19 . The packer cup as described in  claim 16  wherein the inner layer is fabricated from Viton™.  
     
     
         20 . The packer cup of  claim 16  wherein the outer layer is fabricated from Nitrile™.  
     
     
         21 . The packer cup as described in  claim 16  wherein the inner layer is fabricated from Viton™ and the outer layer is fabricated from Nitrile™.  
     
     
         22 . The packer cup as described in  claim 16  wherein the reinforcing plies are metal cables.  
     
     
         23 . The packer cup as described in  claim 21  wherein the reinforcing plies are metal cables.