Sealing of an annular space proximate to a sand screen

Abstract

An apparatus for sealing an annular space proximate to an end of a sand screen on a downhole tubular may include a flexible seal configured to encircle the tubular. The flexible seal may include a first state in which an outer diameter of the flexible seal is less than a diameter of a wellbore, and a second state in which the outer diameter of the flexible seal is the same as the diameter of the wellbore. The apparatus may further include a deployment mechanism configured to cause the flexible seal to transition from the first state to the second state.

1 . An apparatus for sealing an annular space proximate to an end of a sand screen on a tubular in a wellbore, the apparatus comprising:
 a flexible seal configured to encircle the tubular, wherein the flexible seal comprises a first state in which an outer diameter of the flexible seal is less than a diameter of the wellbore, and a second state in which the outer diameter of the flexible seal is the same as the diameter of the wellbore; and   a spring configured to cause the flexible seal to transition from the first state to the second state.   
     
     
         2 . The apparatus of  claim 1 , wherein the spring comprises a coil spring configured to encircle the tubular, wherein the coil spring is part of a deployment mechanism comprising a coupling configured to releasably fix the flexible seal to the sand screen, wherein the coil spring is configured to bias the flexible seal towards the sand screen, and wherein the coupling is configured to release the flexible seal in response to expansion of the sand screen. 
     
     
         3 . The apparatus of  claim 2 , wherein
 the deployment mechanism further comprises a base configured to encircle the tubular and a slip configured to be affixed to the tubular,   the flexible seal is mounted to the base,   the coupling extends from the base or the flexible seal, and   the coil spring extends from the slip to the base.   
     
     
         4 . The apparatus of  claim 1 , wherein further comprising a deployment mechanism comprising a base, wherein the flexible seal extends from the base towards the sand screen, and wherein the base is configured to be activated in response to hydrostatic pressure in the wellbore exceeding a threshold. 
     
     
         5 . The apparatus of  claim 4 , wherein the base comprises:
 a first portion having a first inner diameter corresponding to a first outer diameter of the tubular;   a second portion having a second inner diameter corresponding to a second outer diameter of the tubular; and   a port extending radially inward from an outer surface of the base into a chamber formed between the base and the tubular,   wherein the deployment mechanism comprises a shearable retaining element configured to releasably fix the base to the tubular.   
     
     
         6 . The apparatus of  claim 1 , further comprising a deployment mechanism comprising a dissolvable sleeve configured to constrain the flexible seal in the first state. 
     
     
         7 . The apparatus of  claim 6 , wherein in the first state, the flexible seal is disposed between the dissolvable sleeve and the tubular. 
     
     
         8 . The apparatus of  claim 1 , further comprising a deployment mechanism comprising a fracturable sleeve configured to constrain the flexible seal in the first state. 
     
     
         9 . The apparatus of  claim 8 , wherein in the first state, the flexible seal is disposed between the fracturable sleeve and the tubular. 
     
     
         10 . A method of installing a sand screen in a well, the method comprising:
 expanding the sand screen radially outward, wherein the sand screen is disposed between a tubular of the well and an interior surface of a wellbore; and   activating an apparatus, by a spring, to cause a flexible seal to transition from a first state to a second state,   wherein in the first state, there is a gap between the flexible seal and the interior surface of the wellbore, and   wherein in the second state, the flexible seal spans from the tubular to the interior surface of the wellbore to seal an area proximate to the sand screen and between the tubular and the interior surface of the wellbore.   
     
     
         11 . The method of  claim 10 , wherein the spring is part of a deployment mechanism of the apparatus. 
     
     
         12 . The method of  claim 10 , wherein the expanding of the sand screen comprises activating an activation chamber of the sand screen. 
     
     
         13 . The method of  claim 11 , wherein the activating of the deployment mechanism occurs in response to the expanding of the sand screen. 
     
     
         14 . The method of  claim 10 , wherein the transitioning to the second state comprises extending the flexible seal over the sand screen. 
     
     
         15 . The method of  claim 10 , wherein the flexible seal is releasably constrained in the first position by a sleeve. 
     
     
         16 . A system for filtering sand from formation fluid in a well, the system comprising:
 a tubular disposed inside a wellbore;   one or more sand screens fixed to the tubular and configured to radially expand upon activation; and   one or more apparatuses each disposed proximate to at least one of the one or more sand screens, each of the one or more apparatuses comprising:
 a flexible seal configured to encircle the tubular, wherein the flexible seal comprises a first state in which an outer diameter of the flexible seal is less than a diameter of the wellbore, and a second state in which the outer diameter of the flexible seal is the same as the diameter of the wellbore; and 
 a spring configured to cause the flexible seal to transition from the first state to the second state. 
   
     
     
         17 . The system of  claim 16 , wherein the spring is part of a deployment mechanism comprising a coupling configured to releasably fix the flexible seal to the sand screen, and a biasing member configured to bias the flexible seal towards the sand screen, wherein the coupling is configured to release the flexible seal in response to expansion of the sand screen. 
     
     
         18 . The system of  claim 16 , wherein further comprising a deployment mechanism comprising a base, wherein the flexible seal extends from the base towards the sand screen, wherein the base is configured to be activated in response to hydrostatic pressure in the wellbore exceeding a threshold, wherein the base comprises a first portion having a first inner diameter corresponding to a first outer diameter of the tubular, a second portion having a second inner diameter corresponding to a second outer diameter of the tubular, and a port extending radially inward from an outer surface of the base into a chamber formed between the base and the tubular, and wherein the deployment mechanism comprises a shearable retaining element configured to releasably fix the base to the tubular. 
     
     
         19 . The system of  claim 16 , wherein further comprising a deployment mechanism comprising a dissolvable sleeve configured to constrain the flexible seal in the first state, and wherein in the first state, the flexible seal is disposed between the dissolvable sleeve and the tubular. 
     
     
         20 . The system of  claim 16 , wherein further comprising a deployment mechanism comprising a fracturable sleeve configured to constrain the flexible seal in the first state, and wherein in the first state, the flexible seal is disposed between the fracturable sleeve and the tubular.