Formulations for corrosion inhibition

Abstract

An aqueous acid composition that may be used, for example, in a matrix acidizing treatment can include an acid, a polymeric acid corrosion inhibitor, and an acid corrosion inhibitor intensifier. The acid corrosion inhibitor can include iodide ions and metal ions, with the metal ions being one or more of copper, silver, bismuth, or antimony. The molar ratio of metal ions to iodide ions can be 1:X, where X is greater than or equal to 2. The polymer of the polymeric acid corrosion inhibitor can have a molecular weight less than 100,000 g/mol.

What is claimed is: 
     
         1 . An aqueous acidic formulation comprising:
 an acid;   a polymeric acid corrosion inhibitor; and   an acid corrosion inhibitor intensifier including iodide ions and metal ions, the metal ions including one or more of copper, silver, bismuth, or antimony.   
     
     
         2 . The aqueous acidic formulation of  claim 1 , the polymeric acid corrosion inhibitor including a polymer that includes including nitrogen. 
     
     
         3 . The aqueous acidic formulation of  claim 1 , the polymeric acid corrosion inhibitor including a polymer having three or more constituent repeat units. 
     
     
         4 . The aqueous acidic formulation of  claim 1 , the polymer of the polymeric acid corrosion inhibitor having a molecular weight less than 100,000 g/mol. 
     
     
         5 . The aqueous acidic formulation of  claim 1 , the polymeric acid corrosion inhibitor being present at a concentration below its critical overlap concentration. 
     
     
         6 . The aqueous acidic formulation of  claim 5 , the polymeric acid corrosion inhibitor being present at a concentration of between 0.01 wt % and 1 wt %. 
     
     
         7 . The aqueous acidic formulation of  claim 1 , the formulation including an iodide salt as a source of the iodide ions. 
     
     
         8 . The aqueous acidic formulation according to  claim 7 , the iodide salt including at least one of: an alkali metal iodide salt; an ammonium iodide salt; or a substituted (alkylated) ammonium iodide salt. 
     
     
         9 . The aqueous acidic formulation of  claim 1 , at least one of the following being a source of the metal ions:
 a metal halide;   a metal oxide; or   a metal oxy-anion salt.   
     
     
         10 . The aqueous acidic formulation of  claim 1 , the metal ions including copper ions. 
     
     
         11 . The aqueous acidic composition of  claim 1 , the molar ratio of metal ions to iodide ions being 1:X, where X is greater than or equal to two. 
     
     
         12 . The aqueous acidic formulation of  claim 11 , wherein the molar ratio of the metal ions to iodide ions is between 1:5 and 1:100. 
     
     
         13 . The aqueous acidic formulation of  claim 1 , the polymeric acid corrosion inhibitor including a polymer having a backbone including a continuous chain of carbon atoms, carbon and oxygen atoms, carbon and nitrogen atoms, or a combination thereof. 
     
     
         14 . The aqueous acidic formulation of  claim 1 , the polymeric acid corrosion inhibitor including one or more of polyallylamine; poly(vinylamine) hydrochloride; poly(l-lysine) hydrobromide; polydiallyldimethylammonium chloride; polyvinylpyridine (PVPy); polyvinylquinoline (PVQ); polyvinylpyrrolidone (PVP); polyvinylcaprolactam (PVC); chitosan; aminated cellulose; aminated starch; polyethylenimine (PEI); or polypropylenimine (PPI). 
     
     
         15 . The aqueous acidic formulation of  claim 1 , the acid corrosion inhibitor intensifier including silver oxide and a reducing agent to reduce the silver oxide to provide the metal ions. 
     
     
         16 . The aqueous acidic formulation of  claim 1 , the polymeric acid corrosion inhibitor including a polymer modified with one or more of: alkyl groups; aromatic groups; alkyl-aromatic groups; alkyl amino groups; pyrrolidone groups; or acetylenic alcohol groups. 
     
     
         17 . The aqueous acidic formulation of  claim 1 , the polymeric acid corrosion inhibitor including a polymer modified with one or more of: pyridyl; quinolyl; hydrogenated pyridyl; or hydrogenated quinolyl groups. 
     
     
         18 . The aqueous acidic formulation of  claim 1 , the composition of the aqueous acid formulation being configured to, when contacting a treating surface, provide an open circuit potential (OCP) that drops to within ±15% of the baseline-OCP for the treating surface in contact with uninhibited acid. 
     
     
         19 . A method of treating a subterranean formation penetrated by a wellbore comprising:
 flowing an aqueous acidic formulation through a wellbore into the subterranean formation, wherein the aqueous acidic formulation comprises:
 an acid; and 
 a polymeric acid corrosion inhibitor having a molecular weight less than 100,000 g/mol, and present at a concentration below its critical overlap concentration. 
   
     
     
         20 . A formulation for reducing corrosion of a metal surface that is contacted with an acidic fluid, the formulation comprising:
 a polymeric acid corrosion inhibitor; and   an acid corrosion inhibitor intensifier including iodide ions and metal ions, the molar ratio of metal ions to iodide ions being 1:X, where X is greater than or equal to 2.