Method and Composition for Curing Lost Circulation

Abstract

The invention provides a composition made of fibers and a material able to exhibit reverse solubility. The invention preferably is used in a well and as a method to cure lost circulation.

1 . A composition for use in a well, comprising fibers and a material able to exhibit reverse solubility, wherein the material comprises poly(oxy)alkylene or poly-oxazoline and mixtures thereof, and wherein the material is at least 1% soluble in water at 20° C. and has a cloud point that is higher than 20° C. and lower than 60° C.,. 
     
     
         2 . The composition of  claim 1 , further comprising a second material able to stick fibers in a network when activated. 
     
     
         3 . The composition of  claim 2 , wherein the second material is embodied as a coating on a part of the fibers. 
     
     
         4 . The composition of  claim 1 , wherein the fibers comprise one or more members selected from the group consisting of metallic amorphous fiber, metallic non-amorphous fiber, glass fiber, carbon fiber and polymeric fiber. 
     
     
         5 . The composition of  claim 1 , further comprising an aqueous base fluid. 
     
     
         6 . The composition of  claim 1 , further comprising a hydraulic cement. 
     
     
         7 . The composition of  claim 1 , further comprising a non-aqueous base fluid. 
     
     
         8 . The composition of  claim 1 , wherein the material is used at a concentration of from 2 to 10 wt %. 
     
     
         9 . The composition of  claim 8 , wherein the material is used at a concentration of from 3 to 6 wt %.