Acidizing Fluids Comprising a Salt Block Inhibitor and Methods for Use Thereof

Abstract

Treatment fluids comprising hydrofluoric acid, a hydrofluoric acid-generating compound, or any combination thereof can be used in conjunction with acidizing a subterranean formation that contains a siliceous material. Inclusion of a salt block inhibitor in the treatment fluids may eliminate or reduce the formation of insoluble fluorosilicates and aluminosilicates that can occur when an acidizing operation is conducted. Methods for treating a subterranean formation can comprise: providing a treatment fluid that comprises a salt block inhibitor comprising a fructan, and hydrofluoric acid, a hydrofluoric acid-generating compound, or any combination thereof; and introducing the treatment fluid into a subterranean formation.

The invention claimed is: 
     
         1 . A method comprising:
 providing a treatment fluid that comprises:
 a salt block inhibitor comprising a fructan; and 
 hydrofluoric acid, a hydrofluoric acid-generating compound, or any combination thereof; and 
   introducing the treatment fluid into a subterranean formation.   
     
     
         2 . The method of  claim 1 , further comprising:
 allowing the fructan to interact with an alkali metal ion.   
     
     
         3 . The method of  claim 2 , wherein the interaction between the fructan and the alkali metal ion reduces or eliminates the formation of insoluble fluorosilicates or aluminosilicates in the subterranean formation, relative to a like treatment fluid lacking the fructan. 
     
     
         4 . The method of  claim 1 , wherein the fructan comprises an inulin, a levan, a graminin, any salt thereof, any derivative thereof, or any combination thereof. 
     
     
         5 . The method of  claim 4 , wherein the fructan comprises carboxymethylinulin, carboxyethylinulin, any salt thereof, or any combination thereof. 
     
     
         6 . The method of  claim 1 , wherein the treatment fluid further comprises a carrier fluid comprising alkali metal ions. 
     
     
         7 . The method of  claim 1 , wherein the treatment fluid further comprises a chelating agent, an alkali metal salt of a chelating agent, a non-alkali metal salt of a chelating agent, or any combination thereof. 
     
     
         8 . The method of  claim 1 , wherein the treatment fluid has a pH of about 8 or less. 
     
     
         9 . The method of  claim 1 , wherein the treatment fluid has a pH ranging between about 0 and about 8. 
     
     
         10 . A method comprising:
 providing a treatment fluid having a pH ranging between about 0 and about 8 that comprises:
 a salt block inhibitor comprising a fructan; and 
 hydrofluoric acid, a hydrofluoric acid-generating compound, or any combination thereof; 
   introducing the treatment fluid into a subterranean formation; and   performing an acidizing operation in the subterranean formation.   
     
     
         11 . The method of  claim 10 , wherein performing an acidizing operation in the subterranean formation comprises at least partially dissolving a silicate or an aluminosilicate in the subterranean formation. 
     
     
         12 . The method of  claim 10 , wherein the treatment fluid further comprises a carrier fluid comprising alkali metal ions. 
     
     
         13 . The method of  claim 10 , wherein the treatment fluid further comprises another acid, an acid-generating compound, or any combination thereof. 
     
     
         14 . The method of  claim 10 , wherein the acidizing operation is performed in the absence of an NH 4   +  salt. 
     
     
         15 . The method of  claim 10 , wherein the treatment fluid performs the acidizing operation. 
     
     
         16 . The method of  claim 10 , wherein the fructan interacts with an alkali metal ion in the subterranean formation so as to reduce or eliminate the formation of insoluble fluorosilicates or aluminosilicates, relative to a like treatment fluid lacking the fructan;
 wherein the insoluble fluorosilicates or aluminosilicates are generated during the acidizing operation.   
     
     
         17 . The method of  claim 10 , wherein the treatment fluid further comprises a chelating agent, an alkali metal salt of a chelating agent, a non-alkali metal salt of a chelating agent, or any combination thereof. 
     
     
         18 . The method of  claim 10 , wherein the fructan comprises an inulin, a levan, a graminan, any salt thereof, any derivative thereof, or any combination thereof. 
     
     
         19 . The method of  claim 18 , wherein the fructan comprises carboxymethylinulin, carboxyethylinulin, or any combination thereof. 
     
     
         20 . A method comprising:
 providing a treatment fluid that comprises:
 a carrier fluid comprising alkali metal ions; 
 a salt block inhibitor comprising a fructan; and 
 hydrofluoric acid, a hydrofluoric acid-generating compound, or any combination thereof; 
   introducing the treatment fluid into a subterranean formation having a siliceous material present therein; and   allowing the hydrofluoric acid, hydrofluoric acid-generating compound, or any combination thereof to at least partially dissolve the siliceous material in the subterranean formation.   
     
     
         21 . The method of  claim 20 , wherein the treatment fluid further comprises a chelating agent, an alkali metal salt of a chelating agent, a non-alkali metal salt of a chelating agent, or any combination thereof. 
     
     
         22 . The method of  claim 20 , wherein the fructan comprises an inulin, a levan, a graminan, any salt thereof, any derivative thereof, or any combination thereof.