Inhibition of scale deposition from steam generation fluids

Claim 1

A method for treating a fluid stream passing through a conduit, which fluid stream contains liquid hot water and which water contains dissolved salts, to inhibit formation of scale in the conduit and/or to dissolve scale previously formed, comprising: (a) mixing with said fluid stream a treating agent comprising a water-soluble compound, which provides a nitrogen-containing cation capable of flashing to become a gas at high temperatures, selected from the group consisting of ammonium halides, ammonium salts of inorganic acids, ammonium salts of organic acids selected from the group consisting of mono-, di-, and tri-chloracetic acids, formic acid, acetic acid, citric acid, tartaric acid, gallic acid, glyoxylic acid, and benzoic acid, ammonium salts of alpha hydroxy organic acids, quaternary ammonium halides, quaternary ammonium salts of inorganic acids, quaternary ammonium salts of organic acids, amine hydrochlorides, amine salts of inorganic acids, amine salts of organic acids, and amides characterized by the formula: ##STR3## wherein R is hydrogen or an alkyl group containing 1 to about 8 carbon atoms, and R 1 and R 2 are the same or different alkyl groups containing 1 to about 8 carbon atoms; and (b) flashing at least a portion of the liquid hot water to steam.

Claim 2

A method for treating a fluid stream passing through a conduit, which fluid stream contains liquid hot water and which water contains dissolved salts, to inhibit formation of scale in the conduit and/or to dissolve scale previously formed, comprising: (a) mixing with said fluid stream a treating agent comprising a water-soluble compound, which provides a nitrogen-containing cation capable of flashing to become a gas at high temperatures, selected from the group consisting of ammonium halides, ammonium salts of inorganic acids, ammonium salts of organic acids selected from the group consisting of mono-, di-, and tri-chloracetic acids, formic acid, acetic acid, citric acid, tartaric acid, gallic acid, glyoxylic acid, and benzoic acid, ammonium salts of alpha hydroxy organic acids, quaternary ammonium halides, quaternary ammonium salts of inorganic acids, quaternary ammonium salts of organic acids, amine hydrochlorides, amine salts of inorganic acids, amine salts of organic acids, and amides characterized by the formula: ##STR3## wherein R is hydrogen or an alkyl group containing 1 to about 8 carbon atoms, and R 1 and R 2 are the same or different alkyl groups containing 1 to about 8 carbon atoms; and (b) flashing at least a portion of the liquid hot water to steam.

Claim 23

A method for treating a well penetrating a reservoir producing a fluid stream containing liquid hot water, which water contains dissolved salts, to inhibit formation of a scale in the reservoir in the immediate vicinity of the well, in the well itself, and in the fluid handling equipment associated with the well contacted by the fluid stream, and/or to dissolve scale previously formed, comprising: (a) mixing with the fluid stream a treating agent comprising a water-soluble compound, which provides a nitrogen-containing cation capable of flashing to become a gas at high temperatures, selected from the group consisting of ammonium halides, ammonium salts of inorganic acids, ammonium salts of organic acids selected from the group consisting of mono-, di-, and tri-chloracetic acids, formic acid, acetic acid, citric acid, tartaric acid, gallic acid, glyoxylic acid, and benzoic acid, ammonium salts of alpha hydroxy organic acids, quaternary ammonium halides, quaternary ammonium salts of inorganic acids, quaternary ammonium salts of organic acids, amine hydrochlorides, amine salts of inorganic acids, amine salts of organic acids, and amides characterized by the formula: ##STR4## wherein R is hydrogen or an alkyl group containing 1 to about 8 carbon atoms, and R 1 and R 2 are the same or different alkyl groups containing 1 to about 8 carbon atoms; and (b) producing the well under conditions at which at least a portion of the liquid hot water flashes to steam.

Claim 24

A method for treating a well penetrating a reservoir producing a fluid stream containing liquid hot water, which water contains dissolved salts, to inhibit formation of a scale in the reservoir in the immediate vicinity of the well, in the well itself, and in the fluid handling equipment associated with the well contacted by the fluid stream, and/or to dissolve scale previously formed, comprising: (a) mixing with the fluid stream a treating agent comprising a water-soluble compound, which provides a nitrogen-containing cation capable of flashing to become a gas at high temperatures, selected from the group consisting of ammonium halides, ammonium salts of inorganic acids, ammonium salts of organic acids selected from the group consisting of mono-, di-, and tri-chloracetic acids, formic acid, acetic acid, citric acid, tartaric acid, gallic acid, glyoxylic acid, and benzoic acid, ammonium salts of alpha hydroxy organic acids, quaternary ammonium halides, quaternary ammonium salts of inorganic acids, quaternary ammonium salts of organic acids, amine hydrochlorides, amine salts of inorganic acids, amine salts of organic acids, and amides characterized by the formula: ##STR4## wherein R is hydrogen or an alkyl group containing 1 to about 8 carbon atoms, and R 1 and R 2 are the same or different alkyl groups containing 1 to about 8 carbon atoms; and (b) producing the well under conditions at which at least a portion of the liquid hot water flashes to steam.