Method of inhibiting acid corrosion of ferrous metals

Abstract

A method for inhibiting acid corrosion of metal well equipment which comprises introducing into an aqueous acid solution an inhibiting amount of a quaternary compound prepared by reacting a tertiary aromatic heterocyclic amine with a (halo-substituted-aryl) alkyl halide, and contacting the well equipment with the inhibited aqueous acid solution.

What is claimed is: 
     
       1. A method of inhibiting corrosion of ferrous metals which comprises treating a system wherein metals are susceptible to corrosion with a corrosion inhibiting amount of a quaternary compound prepared by reacting a tertiary aromatic heterocyclic amine with a (halo-substituted-aryl) alkyl halide wherein the halogen substitution on the aromatic ring of the (halo-substituted -aryl) alkyl halide does not enter into the reaction and remains intact on said aromatic ring, and the alkyl group contains from 1 to 3 carbon atoms. 
     
     
       2. The method of claim 1 wherein the heterocyclic amine is selected from the group consisting of quinoline, isoquinoline, quinaldine, pyridine, acridine, phenanthridine, and coal tar bases, with or without substituents, and mixtures of the foregoing. 
     
     
       3. The method of claim 1, wherein the quaternary compound has the formula of: ##STR5## wherein ARYL is a heterocyclic ring or rings; N +  is a positively charged nitrogen atom and is part of ARYL; ARYL' is an aromatic ring or rings; R is an alkyl group containing from 1 to 3 carbon atoms and connects N +  to ARYL'; X is a halogen; Y is a halogen substituted on ARYL'; and Z is a halogen or hydrogen substituted on ARYL'. 
     
     
       4. The method of claim 1 wherein the quaternary compound has a formula selected from the group consisting of ##STR6## wherein R is an alkyl group containing from 1 to 3 carbon atoms; X and Y are halogens; and Z is a halogen or hydrogen. 
     
     
       5. The method of claim 1 wherein the (halo-substituted-aryl) alkyl halide is halobenzyl halide. 
     
     
       6. A method of acidizing a subterranean formation penetrated by a well having pipe extending from the surface to said formation, which comprises injecting through the pipe and into said formation an aqueous acid solution having dissolved or dispersed therein an acid inhibiting amount of a quaternary compound prepared by the reaction of a tertiary heterocyclic amine with a halogen substituted benzyl halide wherein the substituted halogen is on the aromatic ring and the halide on the benzyl methylene carbon reacts with the amine to form the quaternary compound. 
     
     
       7. The method of claim 6 wherein the halogen substituted benzyl halide is selected from the group consisting of a chlorobenzyl chloride, a fluorobenzyl chloride, bromobenzyl chloride, an iodobenzyl chloride, a chlorotoluene, and a chloromethyl chloronaphthalene. 
     
     
       8. The method of claim 6 wherein the aqueous acid is selected from the group consisting of hydrochloric acid, hydrofluoric acid, acetic acid, formic acid, and mixture of these. 
     
     
       9. The method of claim 8, wherein the quaternary compound comprises from 0.01 to 10.0 vol % of the aqueous acid solution. 
     
     
       10. The method of claim 7 wherein the quaternary compound comprises from 0.05 to 3.0 vol % of the aqueous acid solution. 
     
     
       11. The method of claim 6 wherein the heterocyclic amine is selected from the group consisting of coal tar bases, quinoline, quinaldine, isoquinoline, pyridine, acridene, phenanthradine, and mixtures and substitutions thereof. 
     
     
       12. An inhibited acid comprising (a) an aqueous solution of a well treating acid selected from the group consisting of hydrochloric acid, hydrofluoric acid, acetic acid, formic acid, and mixtures thereof; and   (b) from about 0.01 to 10.0 vol % of the treating acid of a quaternary compound prepared by reacting a tertiary aromatic heterocyclic amine with a (halo-substituted-aryl) alkyl halide wherein the halogen substitution is on the aromatic ring and the alkyl halide does not enter into the reaction and remains intact on the aromatic ring and the alkyl group contains from 1 to 3 carbon atoms.   
     
     
       13. The inhibited acid of claim 12 wherein the quaternary compound has the formula consisting of ##STR7## wherein ARYL is a heterocyclic ring or rings; N +  is a positively charged nitrogen atom and is part of ARYL; ARYL' is an aromatic ring or rings; R is an alkyl group containing from 1 to 3 carbon atoms and connects N +  to ARYL'; X is a halogen; Y is a halogen substituted on ARYL'; and Z is a halogen or hydrogen substituted on ARYL'. 
     
     
       14. The inhibited acid of claim 12 and further comprising a water soluble surfactant. 
     
     
       15. The inhibited acid of claim 12, further comprising an effective amount of acetylenic alcohol. 
     
     
       16. The inhibited acid of 12, and further comprising formic acid or formamide. 
     
     
       17. The inhibited acid of claim 12, and further comprising potassium iodide or aqueous iodide. 
     
     
       18. The inhibited acid of claim 12 and further comprising a hydrocarbon liquid. 
     
     
       19. The inhibited acid of claim 12 and further comprising acetylenic alcohol, a hydrocarbon liquid, a water wetting surfactant, and formic acid or formamide. 
     
     
       20. A formulation for inhibiting aqueous acid solutions selected from the group consisting of hydrochloric acid, hydrofluoric acid, acetic acid, formic acid and mixtures thereof which comprises (a) a quaternary compound having the formula ##STR8##  wherein ARYL is a heterocyclic ring or rings; N +  is a positively charged nitrogen atom and is part of ARYL; ARYL' is an aromatic ring or rings; R is an alkyl group containing from 1 to 3 carbon atoms and connects N +  to ARYL'; X is a halogen; Y is a halogen substituted on ARYL'; and Z is a halogen or hydrogen substituted on ARYL'; and   (b) an additive selected from the group consisting of acetylenic alcohol, hydrocarbon liquid, water wetting surfactant, formic acid, formamides, and mixtures thereof.   
     
     
       21. A corrosion inhibitor formulation comprising (a) from 5 to 50 wt % of the corrosion inhibitor having the formula of ##STR9##  wherein ARYL is a heterocyclic ring or rings; N +  is a positively charged nitrogen atom and is part of ARYL; ARYL' is an aromatic ring or rings; R is an alkyl group containing from 1 to 3 carbon atoms and connects N +  to ARYL'; X is a halogen; Y is a halogen substituted on ARYL'; and Z is a halogen or hydrogen substituted on ARYL'.   (b) from 5 to 25 wt % of acetylenic alcohol;   (c) from 5 to 20 wt % of a hydrocarbon liquid selected from the group consisting of mineral oil, pine oil, aromatic naptha, and C 14  to C 20  fatty acids;   (d) from 1 to 10 wt % of a surfactant capable of dispersing the corrosion inhibitor; and   (e) from 10 to 50 wt % of formic acid or formamide.