Composite inflatable downhole packer or bridge plug

Abstract

Inflatable packer assemblies and bridge plugs that incorporate selective components made of a composite material, thereby providing improvements in weight, drillability and corrosion resistance. A through-tubing packer assembly is described having end sleeves fashioned partially from composite material of high strength fiber and polymer resin. The inflatable packer element has longitudinal ribs fashioned from composite material with a specialized cross-section having a larger cross-section of rib material in locations where additional bending resistance is required and permits additional elastomeric material to be placed about the ribs in sealing areas. An external casing packer is also described having a composite valve assembly and central mandrel formed primarily of composite material. The mandrel includes metallic fittings for threaded attachments to be made.

What is claimed is:  
     
         1 . An inflatable packer assembly comprising: 
 a central mandrel;    an inflatable bladder element surrounding the central mandrel;    a longitudinal rib member disposed adjacent the bladder element;    an end sleeve radially surrounding said central mandrel, bladder element and rib member, said end sleeve having a first portion comprised of composite material and a second metallic portion.    
     
     
         2 . The inflatable packer assembly of  claim 1  wherein the composite material of the first portion of the end sleeve comprises high strength fibers and polymer resin.  
     
     
         3 . The inflatable packer assembly of  claim 1  wherein the rib member is also comprised of composite material.  
     
     
         4 . The inflatable packer assembly of  claim 1  further comprising a support sleeve disposed between the end sleeve and the rib member, the support sleeve acting to reduce hoop stress forces appled to portions of the end sleeve during inflation of the bladder element.  
     
     
         5 . The inflatable packer assembly of  claim 4  wherein the support sleeve is formed substantially of KEVLAR®.  
     
     
         6 . The inflatable packer assembly of  claim 1  wherein the rib member includes a pair of end portions having a first thickness and a central portion having a second thickness and wherein the second thickness is less than the first thickness.  
     
     
         7 . The inflatable packer assembly of  claim 1  wherein there is a plurality of longitudinal rib members that are disposed circumferentially about the bladder element and wherein each of the rib mmbers is secured to the end sleeve by at least one fusion weld point.  
     
     
         8 . The inflatable packer assembly of  claim 1  wherein there is a plurality of longitudinal rib members that are disposed circumferentially about the bladder element and wherein each of the rib members is securely affixed to an annular load bearing ring that presents an engagement shoulder, the engagement shoulder being in load-transmitting contact with a portion of the end sleeve.  
     
     
         9 . The inflatable packer assembly of  claim 1  wherein the composite material forming the first portion of the end sleeve comprises circumferentially wrapped layers of high strength fibers in a resin matrix, the layers having been applied such that the fibers in at least one of said layers are oriented circumferentially.  
     
     
         10 . An inflatable packer assembly comprising: 
 a central mandrel having: 
 a mandrel body comprised of composite material; and  
 a metallic portion integrally formed within the mandrel body;  
 an inflatable bladder element surrounding the central mandrel;  
 a longitudinal rib member disposed adjacent the bladder element; and  
 an end sleeve radially surrounding said central mandrel, bladder element and rib member.  
   
     
     
         11 . The inflatable packer assembly of  claim 10  wherein the metallic portion comprises a metallic end piece that is secured to an axial end of the mandrel body.  
     
     
         12 . The inflatable packer assembly of  claim 10  wherein the metallic portion comprises a metallic ring having a radially external surface with threads thereupon, the metallic ring being disposed upon an outer radial surface of the mandrel body.  
     
     
         13 . The inflatable packer assembly of  claim 12  wherein the metallic ring is disposed within a recessed groove upon the mandrel body.  
     
     
         14 . The inflatable packer assembly of  claim 10  wherein the composite material of the mandrel body comprises high strength fiber within a resin matrix.  
     
     
         15 . The inflatable packer assembly of  claim 14  wherein the resin matrix comprises PEEK.  
     
     
         16 . An inflatable packer assembly comprising: 
 an inflatable bladder assembly; and    an end sleeve located at one axial end of the bladder assembly to secure the bladder assembly to a mandrel, wherein the end sleeve comprises: 
 a first portion comprised of a composite material consisting essentially of high strength fiber in a resin matrix; and  
 a second, metallic portion.  
   
     
     
         17 . The inflatable packer assembly of  claim 16  wherein the resin matrix comprises PEEK.  
     
     
         18 . The inflatable packer assembly of  claim 16  wherein the inflatable bladder assembly comprises a plurality of longitudinal rib members for reinforcement of the bladder element, at least one of said plurality of longitudinal rib members being substantially formed of composite material.  
     
     
         19 . The inflatable packer assembly of  claim 18  wherein the rib members further comprise a pair of end portions having a first thickness and a central portion having a second thickness and wherein the second thickness is less than the first thickness.  
     
     
         20 . The inflatable packer assembly of  claim 16  wherein the composite material forming the first portion of the end sleeve comprises circumferentially wrapped layers of high strength fibers in a resin matrix, the layers having been applied such that the fibers in at least one of said layers are oriented circumferentially.  
     
     
         21 . An inflatable packer assembly comprising: 
 a central mandrel having a pair of axial ends;    an inflatable bladder element surrounding the central mandrel;    a valve collar secured to one axial end of the central mandrel, the valve collar being constructed of composite material and retaining a valve assembly for selective transmission of fluid to the inflatable bladder element for inflation of the bladder element.    
     
     
         22 . The inflatable packer assembly of  claim 21  wherein the central mandrel further comprises a generally cylindrical central portion that is formed of composite material.  
     
     
         23 . The inflatable packer assembly of  claim 22  wherein the composite material of the generally cylindrical central portion further comprises a plurality of circumferentially wound fiber-reinforced layers of composite material.  
     
     
         24 . The inflatable packer assembly of  claim 22  wherein the central mandrel further comprises a threaded metallic end sleeve secured to at least one axial end.  
     
     
         25 . The inflatable packer assembly of  claim 22  wherein the central mandrel further comprises at least one threaded metallic ring secured upon an outer radial surface of the composite central portion.