Corrosion inhibitors for drilling fluid brines
AssigneeCes Technology S.à R.L.
InventorsGene H. Zaid, David P. Horton, Kim Brashear
Life of this patent
Estimating the term…
Abstract
Improved corrosion inhibitors for well brines include a phosphonate or salts thereof, and a gluconic acid or salts thereof. The inhibitors are normally injected downhole into the brines. The most preferred phosphonates are amine polyphosphonates, used in combination with alkali metal salts of gluconic acid.
Claims22
A method of inhibiting corrosion of metal surfaces in petroleum well equipment when using brines during petroleum recovery, comprising the steps of:
- injecting a brine selected from the group consisting of calcium chloride and calcium nitrate, and mixtures thereof, into said well for contact with said metal surfaces;
- mixing a corrosion inhibitor with said brine, said inhibitor comprising respective amounts of a phosphonate or salts thereof, and gluconic acid or salts thereof, said phosphonate being a tertiary amine phosphonate having the general formula
- X—N—Y2 I,
- where X is selected from the group consisting of alkyl phosphonates of the formula
- alkyl alcohols of the formula
- alkoxyalcohols of the formula
- and mixtures thereof;
- and Y is selected from the group consisting of alkylphosphonates of the formula
- and alkylaminediphosphonates of the formula
- and mixtures thereof, where each respective R1 and R4 through R10 moiety is independently selected from the group consisting of C1-C6 straight or branched chain alkyl groups, and each respective R2 and R3 moiety is independently selected from the group consisting of H and C1-C6 straight or branched chain alkyl groups.
A corrosion inhibitor for brines selected from the group consisting of calcium chloride or calcium nitrate brines, or mixtures thereof, said inhibitor consisting essentially of a phosphonate or salts thereof, and gluconic acid or salts thereof, said phosphonate being a tertiary amine phosphonate having the general formula
- X—N—Y2 I,
- where X is selected from the group consisting of alkyl phosphonates of the formula
- alkyl alcohols of the formula
- alkoxyalcohols of the formula
- and mixtures thereof;
- and Y is selected from the group consisting of alkylphosphonates of the formula
- and alkylaminediphosphonates of the formula
- and mixtures thereof, where each respective R1 and R4 through R10 moiety is independently selected from the group consisting of C1-C6 straight or branched chain alkyl groups, and each respective R2 and R3 moiety is independently selected from the group consisting of H and C1-C6 straight or branched chain alkyl groups.
A well brine selected from the group consisting of calcium chloride or calcium nitrate brines, or mixtures thereof, in combination with a corrosion inhibitor comprising a phosphonate or salts thereof, and gluconic acid or salts thereof, said phosphonate being a tertiary amine phosphonate having the general formula
- X—N—Y2 I,
- where X is selected from the group consisting of alkyl phosphonates of the formula
- alkyl alcohols of the formula
- alkoxyalcohols of the formula
- and mixtures thereof;
- and Y is selected from the group consisting of alkylphosphonates of the formula
- and alkylaminediphosphonates of the formula
- and mixtures thereof, where each respective R1 and R4 through R10 moiety is independently selected from the group consisting of C1-C6 straight or branched chain alkyl groups, and each respective R2 and R3 moiety is independently selected from the group consisting of H and C1-C6 straight or branched chain alkyl groups.
A method of inhibiting corrosion of metal surfaces in petroleum well equipment when using brines during petroleum recovery, comprising the steps of:
- injecting a brine selected from the group consisting of calcium chloride and calcium nitrate, and mixtures thereof, into said well for contact with said metal surfaces;
- mixing a corrosion inhibitor with said brine, said inhibitor comprising respective amounts of a phosphonate or salts thereof, and gluconic acid or salts thereof,
- said inhibitor being present at a level of from about 10-10,000 ppm in said brine.
A well brine selected from the group consisting of calcium chloride or calcium nitrate brines, or mixtures thereof, in combination with a corrosion inhibitor comprising a phosphonate or salts thereof, and gluconic acid or salts thereof, said inhibitor being present at a level of from about 10-10,000 ppm in said brine.
A method of inhibiting corrosion of metal surfaces in petroleum well equipment when using brines during petroleum recovery, comprising the steps of:
- injecting a brine selected from the group consisting of calcium chloride and calcium nitrate, and mixtures thereof, into said well for contact with said metal surfaces;
- mixing a corrosion inhibitor with said brine, said inhibitor comprising respective amounts of a phosphonate or salts thereof, and gluconic acid or salts thereof,
- said phosphonate being an amine phosphonate.
A corrosion inhibitor for brines selected from the group consisting of calcium chloride or calcium nitrate brines, or mixtures thereof, said inhibitor consisting essentially of a phosphonate or salts thereof, and gluconic acid or salts thereof, said phosphonate being an amine phosphonate.
A well brine selected from the group consisting of calcium chloride or calcium nitrate brines, or mixtures thereof, in combination with a corrosion inhibitor comprising a phosphonate or salts thereof, and gluconic acid or salts thereof, said phosphonate being an amine phosphonate.
Dependencies are inferred from the claim text.