Sealing assembly

Abstract

A downhole sealing assembly ( 10 ) includes a sleeve ( 12 ) comprising a swellable medium ( 22 ). The sleeve ( 12 ) is mounted on a base pipe ( 14 ) and defines a flow path ( 18 ) between the sleeve ( 12 ) and the base pipe ( 14 ).

1 . A downhole sealing assembly including a sleeve comprising a swellable medium wherein the sleeve is adapted to be mounted on an outer surface of a base pipe to define a flow path between the sleeve and the base pipe. 
     
     
         2 . The assembly of  claim 1 , wherein the swellable medium is adapted to swell to provide a seal within an annulus formed between the sleeve and a surrounding bore wall. 
     
     
         3 . The assembly of  claim 2 , adapted to maintain the flow path following formation of said seal. 
     
     
         4 . The assembly of  claim 1 , wherein the swellable medium is adapted to swell during deployment into a bore. 
     
     
         5 . The assembly of  claim 1 , wherein the flow path is adapted to permit resident or ambient wellbore fluids to be displaced therethrough as the sealing assembly is run in-hole. 
     
     
         6 . The assembly of  claim 1 , wherein the flow path is adapted to permit cement to cure therein, such that the cement provides a seal across the sealing assembly. 
     
     
         7 . The assembly of  claim 1 , adapted to be utilised adjacent, in combination with or part of a cement shoe. 
     
     
         8 . The assembly of  claim 1 , comprising a base pipe. 
     
     
         9 . The assembly of  claim 8 , wherein the base pipe comprises a downhole tubular comprising at least one of: a casing tubular, liner tubular, drilling tubular, drilling collar, cement shoe and coiled tubing. 
     
     
         10 . The assembly of  claim 8 , wherein the base pipe is adapted to define or be coupled to and form part of a tubing string to be run downhole into a bore. 
     
     
         11 . The assembly of  claim 1 , wherein the swellable medium is adapted to swell at least in part by volumetric expansion thereof. 
     
     
         12 . The assembly of  claim 1 , wherein the swellable medium is adapted to swell upon exposure to an activator. 
     
     
         13 . The assembly of  claim 1 , wherein the swellable medium comprises an elastomer. 
     
     
         14 . The assembly of  claim 1 , comprising a support assembly adapted to mount the sleeve on the base pipe. 
     
     
         15 . The assembly of  claim 14 , wherein the support assembly is adapted for retrofitting the sleeve to an existing base pipe. 
     
     
         16 . The assembly of  claim 14 , wherein the support assembly is adapted for mounting the sleeve on the base pipe without penetrating the base pipe. 
     
     
         17 . The assembly of  claim 14 , wherein a support assembly is provided at each axial end of the sleeve. 
     
     
         18 . The assembly of  claim 14 , wherein a support assembly is provided intermediate the axial ends of the sleeve. 
     
     
         19 . The assembly of  claim 1 , wherein the sleeve is adapted to be axially fixed relative to the base pipe. 
     
     
         20 . The assembly of  claim 1 , wherein the sleeve is adapted to be axially movable relative to the base pipe. 
     
     
         21 . The assembly of  claim 20 , wherein the axial movement of the sleeve relative to the base pipe is limited by at least one stop. 
     
     
         22 . The assembly of  claim 1 , wherein the sleeve is adapted to be rotationally fixed relative to the base pipe. 
     
     
         23 . The assembly of  claim 1 , wherein the sleeve is adapted to be rotationally movable relative to the base pipe. 
     
     
         24 . The assembly of  claim 1 , comprising a band of swellable medium disposed on the sleeve. 
     
     
         25 . The assembly of  claim 24 , comprising a plurality of bands of swellable medium disposed axially along the sleeve. 
     
     
         26 . The assembly of  claim 25 , wherein the bands are spaced apart. 
     
     
         27 . The assembly of  claim 25 , wherein the bands comprise the same swellable material. 
     
     
         28 . The assembly of  claim 25 , wherein the bands comprise different swellable materials. 
     
     
         29 . The assembly of  claim 28 , wherein at least one band comprises a swellable material adapted to be activated by water, and at least one band comprises a swellable material adapted to be activated by hydrocarbons. 
     
     
         30 . The assembly of  claim 1 , comprising a swellable medium disposed outside the sleeve. 
     
     
         31 . The assembly of  claim 1 , comprising a swellable medium disposed inside the sleeve. 
     
     
         32 . The assembly of  claim 31 , wherein the swellable medium disposed inside the sleeve is adapted to establish a seal in the flow path. 
     
     
         33 . The assembly of  claim 30 , wherein swellable media disposed outside and inside the sleeve have different swelling characteristics. 
     
     
         34 . The assembly of  claim 33 , wherein the swellable medium disposed inside the sleeve is adapted to swell at a slower rate that the swellable medium disposed outside the sleeve. 
     
     
         35 . The assembly of  claim 1 , wherein the assembly is adapted to provide downhole mechanical support for at least the base pipe. 
     
     
         36 . The assembly of  claim 35 , wherein the assembly is adapted to function as a tubing hanger. 
     
     
         37 . (canceled) 
     
     
         38 . A method of establishing a downhole seal, said method comprising the steps of:
 providing a base pipe;   mounting a sleeve on an outer surface the base pipe to define a flow path therebetween, wherein the sleeve comprises a swellable medium; running the base pipe into a wellbore; and   causing the swellable medium to swell to establish a seal.   
     
     
         39 . The method of  claim 38 , wherein the swellable medium establish a seal against a wall of the wellbore. 
     
     
         40 . The method of  claim 38 , wherein the swellable medium is caused to swell by exposure to an activator. 
     
     
         41 . The method of  claim 38 , further comprising flowing cement into a wellbore and permitting the cement to flow through the flow path defined between the sleeve and the base pipe. 
     
     
         42 . The method of  claim 41 , comprising permitting the cement to cure in and seal the flow path. 
     
     
         43 . A method of completing a wellbore, said method comprising the steps of:
 providing a tubing string;   mounting at least one sleeve on an outer surface of the tubing string to define a flow path therebetween, wherein the sleeve comprises a swellable medium;   running the tubing string into a wellbore;   causing the swellable medium to swell; and   flowing cement into the annulus formed between the tubing string and a wall of the wellbore, wherein cement flows through the flow path.   
     
     
         44 . A cement shoe comprising:
 a tubular body adapted to be mounted on a lower end of a tubing string;   a sleeve including a swellable medium mounted on an outer surface of the tubular body; and   a flow path defined between the tubular body and the sleeve.   
     
     
         45 . A downhole support assembly including a sleeve comprising a swellable medium and adapted to be mounted on an outer surface of a base pipe and define a flow path therebetween. 
     
     
         46 . A method of supporting a tubular body within a bore, said method comprising the steps of:
 mounting a sleeve comprising a swellable medium on an outer surface of the tubular body to define a flow path between the sleeve and the body;   running the tubular body into a bore; and   activating the swellable medium to engage a wall of the bore.