Biodegradable Bag and Method of Use Thereof

Abstract

A method for protection of underwater structures and earthen surfaces. A biodegradable bag is filled with particulate material, such as a cement mixture, and placed underwater so as to protect an underwater structure from damage. The bag has a multi-layer wall, with an outer layer of a biodegradable fabric such as burlap, and an inner layer of a biodegradable material which is permeable to water yet which will not permit very fine solids to pass through the material. A suitable inner layer material is heavy kraft paper. After placement underwater, water penetrates the wall layers and hydrates the cement, eventually forming a firm mass. Another embodiment of the bag comprises a filler tube formed from the bag wall material, which extends into the interior of the bag sufficiently far that escape of the particulate material is minimized during the filling of the bag.

1 . A method of protecting underwater structures, comprising the steps of:
 providing a biodegradable bag, comprising a wall comprising a first layer of biodegradable fabric bonded to a second layer of biodegradable paper, said paper being permeable to water but not permitting passage of solid particles therethrough;   inserting a desired amount of particulate material into said bag; and   placing one or more of said bags in a desired position relative to said underwater structure for protection of same.   
     
     
         2 . The method of  claim 1 , wherein said first layer of biodegradable fabric comprises an open weave burlap on the exterior of said bag, and said second layer of biodegradable paper comprises a kraft paper on the interior of said bag. 
     
     
         3 . The method of  claim 2 , wherein said particulate material comprises cement. 
     
     
         4 . The method of  claim 3 , wherein said particulate material further comprises sand mixed with said cement. 
     
     
         5 . A method of protecting an underwater earthen surface, comprising the steps of:
 providing a biodegradable bag, comprising a wall comprising a first layer of biodegradable fabric bonded to a second layer of biodegradable paper, said paper being permeable to water but not permitting passage of solid particles therethrough;   inserting a desired amount of particulate material into said bag; and   placing one or more of said bags in a desired position on said underwater earthen surface, for protection of said underwater earthen surface from erosion.   
     
     
         6 . A multi-layer bag for containment of particulate material, comprising:
 a wall material comprising a first layer of biodegradable fabric and a second layer of biodegradable paper;   an elongated filler tube attached to said bag and providing a conduit therein, said filler tube protruding beyond an outer border of said bag and extending into the interior of said bag a sufficient distance to prevent particulate material from escaping said interior of said bag while said bag is being filled, wherein said filler tube is formed from a piece of said wall material.   
     
     
         7 . The multi-layer bag of  claim 6 , wherein said first layer of biodegradable fabric is on the outside of said wall material, and said second layer of biodegradable paper is on the inside of said wall material. 
     
     
         8 . The multi-layer bag of  claim 7 , wherein said filler tube protrudes outside of said bag approximately one inch, and said filler tube protrudes into said interior of said bag approximately six inches. 
     
     
         9 . The multi-layer bag of  claim 6 , wherein said filler tube protrudes outside of said bag approximately one inch, and said filler tube protrudes into said interior of said bag approximately six inches. 
     
     
         10 . A method of protecting underwater structures, comprising the steps of:
 providing a multi-layer bag suitable for containment of particulate material, said multi-layer bag comprising:
 a wall formed from a wall material comprising a a first layer of biodegradable fabric and a second layer of biodegradable paper; 
 an elongated filler tube attached to said bag and providing a conduit therein, said filler tube protruding beyond an outer border of said bag and extending into the interior of said bag a sufficient distance to prevent particulate material from escaping said interior of said bag while said bag is being filled, wherein said filler tube is formed from a piece of said wall material; 
   inserting a desired amount of particulate material into said bag; and   placing one or more of said bags in a desired position relative to said underwater structure for protection of same.   
     
     
         11 . The method of  claim 10 , wherein said particulate material comprises cement. 
     
     
         12 . The method of  claim 11 , wherein said underwater structure comprises a pipeline. 
     
     
         13 . The method of  claim 11 , wherein said underwater structure comprises a valve assembly. 
     
     
         14 . The method of  claim 11 , wherein said underwater structure comprises a wellhead. 
     
     
         15 . A method of protecting an underwater earthen surface subject to erosion by water action, comprising the steps of:
 providing a multi-layer bag suitable for containment of particulate material, said multi-layer bag comprising:
 a wall formed from a wall material comprising a a first layer of biodegradable fabric and a second layer of biodegradable paper; 
 an elongated filler tube attached to said bag and providing a conduit therein, said filler tube protruding beyond an outer border of said bag and extending into the interior of said bag a sufficient distance to prevent particulate material from escaping said interior of said bag while said bag is being filled, wherein said filler tube is formed from a piece of said wall material; 
   inserting a desired amount of particulate material into said bag; and   placing one or more of said bags in a desired position on said underwater earthen surface, for protection of said underwater earthen surface from erosion.