Methods and aqueous acid solutions for acidizing wells containing sludging and emulsifying oil
AssigneeHalliburton Energy Services, Inc.
InventorsJuanita Cassidy, Chad Kiser, Jim Lane
Life of this patent
Estimating the term…
Abstract
Methods and aqueous acid solutions for acidizing wells containing sludging and emulsifying oil are disclosed. An aqueous acid solution of the invention comprises water, hydrochloric acid, a cationic hydrochloric acid corrosion inhibitor and a conjugate ion pair of a cationic amine oxide surfactant and an anionic surfactant that does not react with the cationic hydrochloric acid corrosion inhibitor.
Claims32
A method of acidizing a subterranean formation containing oil that forms sludge and emulsions when contacted with an aqueous hydrochloric acid solution comprising the steps of:
- preparing or providing an aqueous hydrochloric acid solution comprising water, hydrochloric acid, a cationic hydrochloric acid corrosion inhibitor and a conjugate ion pair of a cationic amine oxide surfactant and an anionic surfactant that does not react with the corrosion inhibitor and reduces the formation of sludge or emulsions resulting from the acid solution contacting the formation oil;
- and
- introducing the aqueous hydrochloric acid solution into the subterranean formation.
A method of acidizing a subterranean formation containing oil that forms sludge and emulsions when contacted with an aqueous hydrochloric acid solution at temperatures above about 250° F. comprising the steps of:
- preparing or providing an aqueous hydrochloric acid solution comprising water, hydrochloric acid, a cationic hydrochloric acid corrosion inhibitor comprising an alkylquinoline quaternary ammonium compound, or quinoline which is protonated in the acidic environment, and a conjugate ion pair of a dimethylcocoalkylamine oxide surfactant and a dodecyl sodium sulfate surfactant that does not react with the corrosion inhibitor and reduces the formation of sludge or emulsions resulting from the acid solution contacting the formation oil;
- pumping the aqueous hydrochloric acid solution into the subterranean formation;
- and
- recovering the spent aqueous hydrochloric acid solution from the subterranean formation.
An aqueous acid solution for acidizing subterranean formations containing sludging and emulsifying oil comprising water, hydrochloric acid, a cationic hydrochloric acid corrosion inhibitor and a conjugate ion pair of a cationic amine oxide surfactant and an anionic surfactant that does not react with the cationic hydrochloric acid corrosion inhibitor and reduces the formation of sludge or emulsions.
Dependencies are inferred from the claim text.