Degradable Metal Barrier For Downhole Screens

Abstract

A method and system for temporarily preventing fluid flow through a screen assembly installed in a wellbore can include a screen assembly interconnected in a tubing string. Components of the screen assembly can include a base pipe, one or more filter layers, an optional drainage layer(s), with flow paths through each of the components. A degradable metal barrier can be applied to at least one of the components, which thereby temporarily prevents fluid flow through the flow paths, and temporarily provides pressure isolation radially between an interior and an exterior of the screen assembly. Degradation of the metal barrier can allow fluid and pressure communication radially between the interior and the exterior of the screen assembly.

1 . A system for temporarily preventing fluid flow through a screen assembly installed in a wellbore, the system comprising:
 a screen assembly configured to interconnect in a tubing string, with components of the screen assembly comprising:
 a base pipe, and 
 at least one filter layer, with flow paths through each of the base pipe and the filter layer; and 
   a degradable metal barrier that is applied to at least one of the components, which thereby temporarily prevents fluid flow through the flow paths, and temporarily provides pressure isolation between an interior and an exterior of the screen assembly, wherein degradation of the metal barrier allows fluid and pressure communication between the interior and the exterior of the screen assembly.   
     
     
         2 . The system according to  claim 1 , wherein the degradation is a result of a period of time the degradable metal barrier is exposed to a downhole environment. 
     
     
         3 . The system according to  claim 1 , wherein the degradation is a result of a degrading agent placed in contact with the degradable metal barrier. 
     
     
         4 . The system according to  claim 1 , wherein the degradation is a result of at least one selected from a group consisting of corrosion, erosion, dispersion, dissolution, hydrolytic degradation, chemical reactions, thermal reactions, and reactions induced by radiation. 
     
     
         5 . The system according to  claim 1 , wherein the components of the screen assembly further comprise at least one drainage layer. 
     
     
         6 . The system according to  claim 1 , further comprising a surface coating applied to the degradable metal barrier, thereby either increasing or decreasing a rate of degradation of the degradable metal barrier. 
     
     
         7 . The system according to  claim 6 , wherein the surface coating is selected from the group consisting of a metal, a polymer, a polyurethane, a plastic, a TEFLON® material, a wax, a drying oil, an epoxy, a crosslinked partially hydrolyzed polyacrylic, a silicate material, a glass, an inorganic durable material, polylactic acid, polyvinyl alcohol, polyvinylidene chloride, a hydrophobic material, paint, and any combinations thereof. 
     
     
         8 . The system according to  claim 1 , wherein the degradable metal barrier comprises a degradable metal material that is applied to the at least one component by one of the group consisting of the material sprayed on the at least one component, the material painted on the at least one component, and the at least one component dipped in the material. 
     
     
         9 . The system according to  claim 1 , wherein the degradable metal barrier comprises a thin sheet of degradable metal material, and wherein the thin sheet is applied to the at least one component by being wrapped around the at least one component such that the thin sheet blocks flow passages through the at least one component. 
     
     
         10 . The system according to  claim 9 , wherein the at least one component is selected from a group consisting of the base pipe, a drainage layer, the filter layer, and a shroud. 
     
     
         11 . A method of temporarily preventing fluid flow through a screen assembly installed in a wellbore, the method comprising:
 interconnecting the screen assembly in a tubing string, wherein components of the screen assembly comprise:
 a base pipe, and 
 at least one filter layer, with flow paths through each of the base pipe and the filter layer; and 
   applying a degradable metal barrier to at least one of the components;   temporarily preventing fluid flow through the flow paths, thereby temporarily preventing fluid and pressure communication between an interior and an exterior of the screen assembly;   installing the screen assembly in the wellbore;   degrading the degradable metal barrier in the wellbore; and   allowing fluid and pressure communication between the interior and the exterior of the screen assembly in response to the degrading.   
     
     
         12 . The method according to  claim 11 , wherein the degrading is a result of a period of time the degradable metal barrier is exposed to a downhole environment. 
     
     
         13 . The method according to  claim 11 , wherein the degrading is a result of a degrading agent placed in contact with the degradable metal barrier. 
     
     
         14 . The method according to  claim 11 , wherein the degrading is a result of at least one selected from a group consisting of corrosion, erosion, dispersion, dissolution, hydrolytic degradation, chemical reactions, thermal reactions, and reactions induced by radiation. 
     
     
         15 . The method according to  claim 11 , wherein the components of the screen assembly further comprise at least one drainage layer. 
     
     
         16 . The method according to  claim 11 , further comprising applying a surface coating to the degradable metal barrier, thereby either increasing or decreasing a rate of degradation of the degradable metal barrier. 
     
     
         17 . The method according to  claim 16 , wherein the surface coating is selected from the group consisting of a metal, a polymer, a polyurethane, a plastic, a TEFLON® material, a wax, a drying oil, an epoxy, a crosslinked partially hydrolyzed polyacrylic, a silicate material, a glass, an inorganic durable material, polylactic acid, polyvinyl alcohol, polyvinylidene chloride, a hydrophobic material, paint, and any combinations thereof. 
     
     
         18 . The method according to  claim 11 , further comprising forming the degradable metal barrier by applying a degradable metal material to the at least one component by one of the group consisting of spraying the material on the at least one component, painting the material on the at least one component, and dipping the at least one component in the material. 
     
     
         19 . The method according to  claim 11 , further comprising forming the degradable metal barrier by applying a thin sheet of degradable metal material to the at least one component by wrapping the thin sheet around the at least one component such that the thin sheet blocks flow paths through the at least one component. 
     
     
         20 . The method according to  claim 19 , wherein the at least one component is selected from a group consisting of the base pipe, a drainage layer, the filter layer, and a shroud.