Aqueous gels for well bore strengthening

Abstract

A process for treating an earth formation is provided, the process may include: injecting a gelling agent into the earthen formation; injecting a crosslinking agent into the earthen formation; and reacting the gelling agent and the crosslinking agent to form a gel. The gelling agent may include at least one of a lignin, a lignosulfonate, a tannin, a tannic acid, a modified lignin, a modified lignosulfonate, a modified tannin, a modified tannic acid, biopolymers, polyacrylates, polyacrylamides, polyether amines, poly vinyl amines, and combinations thereof The crosslinking agent may include at least one of ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butylene glycol diglycidyl ether, sorbitol polyglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, diglycidyl ether of neopentyl glycol, epoxidized 1,6-hexanediol, aziridine derivatives, epoxy functionalized polyalkalene glycols, an oxidized starch, and combinations thereof.

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         7 . A gel comprising:
 the reaction product of a gelling agent and a crosslinking agent;   wherein the gelling agent comprises at least one of a lignin, a lignosulfonate, a tannin, a tannic acid, a modified lignin, a modified lignosulfonate, a modified tannin, a modified tannic acid, polyacrylates, polyacrylamides, polyether amines, poly vinyl amines, and combinations thereof; and   wherein the crosslinking agent comprises at least one of ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglyleidyl ether, diglycidyl ether of neopentyl glycol, epoxidized 1,6-hexanediol, aziridine derivatives, trimethylolpropane, tris)beta-ethyleniminopropionate), eopxy functionalized polyalkalene glycols, and combinations thereof;   and   wherein the weight percent of the gelling agent relative to the total weight of the gel ranges from 11 to 25 weight percent.   
     
     
         8 . The gel of  claim 7 , wherein the reaction product is formed at a temperature between 25° C. and 350° C. 
     
     
         9 . The gel of  claim 7 , wherein the gel has a hardness of 300 gram-force or greater at a penetration depth of 20 mm. 
     
     
         10 . The gel of  claim 7 , wherein the gel has a hardness of 1000 gram-force or greater at a penetration depth of 20 mm. 
     
     
         11 . The gel of  claim 7 , wherein the gel has a hardness of 3,000 gram-force or greater at a penetration depth of 20 mm. 
     
     
         12 . The gel of  claim 7 , wherein the gel has a hardness of 5,000 gram-force or greater at a penetration depth of 25 mm. 
     
     
         13 . The gel of  claim 7 , wherein the gel has an initial viscosity in the range of approximately 500 centipoise to 20,000 centipoise measured at 20° C. using an LV2 spindle at low rotational speeds. 
     
     
         14 . The gel of  claim 7 , wherein the gel has an initial viscosity in the range of approximately 1000 centipoise to 5,000 centipoise measured at 20° C. using an LV2 spindle at low rotational speeds. 
     
     
         15 . The gel of  claim 7 , wherein the weight percent of the gelling agent relative to the total weight of the gel may range from 8 to 25 weight percent. 
     
     
         16 . The gel of  claim 7 , wherein the weight percent of the gelling agent relative to the total weight of the gel may range from 10 to 20 weight percent. 
     
     
         17 . The gel of  claim 7 , wherein the weight percent of the gelling agent relative to the total weight of the gel may range from 11 to 17 weight percent. 
     
     
         18 . Use of the gel of  claim 7  in a drilling fluid, in a loss circulation material pill, as a soil stabilizing agent, as a dust suppressant, or as a heat transfer fluid loss additive. 
     
     
         19 . A method of treating an earth formation comprising:
 injecting an aqueous gel comprising at least one gelling agent and at least one crosslinking agent in an aqueous solution and having an initial viscosity in the range of approximately 500 centipoise to 100,000 centipoise measured at 20° C. using an LV2 spindle at low rotational speeds, wherein the combined weight percent of the gelling agents and crosslinking agents relative to the total weight of water in the solution may range from 5 to 100 weight percent; and   allowing the aqueous gel to react in the earth formation,   
     
     
         20 . The method of  claim 19 , further comprising preparing the aqueous gel. 
     
     
         21 . The method of  claim 19 , wherein the combined weight percent of the gelling agents and crosslinking agents relative to the total weight of water in the solution may range from 5 to 100 weight percent. 
     
     
         22 . The method of  claim 19 , wherein the combined weight percent of the gelling agents and crosslinking agents relative to the total weight of water in the solution may range from 20 to 70 weight percent. 
     
     
         23 . The method of  claim 19 , wherein the combined weight percent of the gelling agents and crosslinking agents relative to the total weight of water in the solution may range from 25 to 65 weight percent. 
     
     
         24 . The method of  claim 19 , wherein the gelling agent comprises at least one of a lignin, a lignosulfonate, a tannin, a tannic acid, a modified lignin, a modified lignosulfonate, a modified tannin, a modified tannic acid, polyacrylates, polyacrylamides, polyether amines, poly vinyl amines, polyethylene imines, and combinations thereof. 
     
     
         25 . The method of  claim 19 , wherein the crosslinking agent comprises at least of ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, diglycidyl ether of neopentyl glycol, epoxidized 1,6-hexanediol, aziridine derivatives, trimethylolpropane tris(beta-ethyleniminopropionate), epoxy functionalized polyalkalene glycols, an and combinations thereof.