Abstract: Halite scales in an oilfield brine that has a potential for halite scaling can have halite scale formation inhibited or prevented by adding an effective amount of an additive, where the additive contains at least one non-water-soluble quaternary ammonium compound and at least one organic solvent. The quaternary ammonium compound may be benzyl-alkyldimethyl ammonium chloride, where the alkyl group has from 2 to 30 carbon atoms. The organic solvent may be one or more alcohol or glycol.

Abstract: Halite scales in an oilfield brine that has a potential for halite scaling can have halite scale formation inhibited or prevented by adding an effective amount of an additive, where the additive contains at least one non-water-soluble quaternary ammonium compound and at least one organic solvent. The quaternary ammonium compound may be benzyl-alkyldimethyl ammonium chloride, where the alkyl group has from 2 to 30 carbon atoms. The organic solvent may be one or more alcohol or glycol.

Abstract: Methods of treating a petroleum hydrocarbon fluid are described wherein the petroleum hydrocarbon fluid is contacted with an asphaltene inhibitor composition having an ionic liquid and an asphaltene inhibitor. The ionic liquid has a cation of R1R2R3R4N+ or R1R2R3N+R8N+R5R6R7 and an anion, wherein R1, R2, R3, R4, R5, R6 and R7 are independently selected from hydrogen, a straight or branched C1-30 alkyl group, benzyl, a C7-30 alkylbenzyl group, a C7-30 arylalkyl group, a straight or branched C3-30 alkenyl group, a C1-30 hydroxyalkyl group, a C7-30 hydroxyalkylbenzyl group, an oxyalkylene or a polyoxyalkylene group or a zwitterion; R8 is a straight or branched C1-30 alkylene, an alkylene oxyalkylene or an alkylene polyoxyalkylene; and the anion includes halides, hydroxyl, bicarbonate, carbonate, alkyl carbonates, alkoxides, carboxylates, hydroxycarboxylates or a combination thereof.

Abstract: A method of stabilizing asphaltenes in a petroleum hydrocarbon fluid comprises contacting the petroleum hydrocarbon fluid with a mixed phenol aldehyde derived from an aldehyde and two or more unsubstituted or alkyl-substituted monophenols, the two or more unsubstituted or alkyl-substituted monophenols comprising a first phenol which is a C1-20 linear or branched alkyl monophenol; and a second phenol which is unsubstituted or a C1-20 linear or branched alkyl monophenol different from the first phenol, wherein the molar ratio of the first phenol relative to the second phenol is about 4:1 to about 1:4.

Abstract: Methods of treating a petroleum hydrocarbon fluid are described wherein the petroleum hydrocarbon fluid is contacted with an asphaltene inhibitor composition having an ionic liquid and an asphaltene inhibitor. The ionic liquid has a cation of R1R2R3R4N+ or R1R2R3N+R8N+R5R6R7 and an anion, wherein R1, R2, R3, R4, R5, R6 and R7 are independently selected from hydrogen, a straight or branched C1-30 alkyl group, benzyl, a C7-30 alkylbenzyl group, a C7-30 arylalkyl group, a straight or branched C3-30 alkenyl group, a C1-30 hydroxyalkyl group, a C7-30 hydroxyalkylbenzyl group, an oxyalkylene or a polyoxyalkylene group or a zwitterion; R8 is a straight or branched C1-30 alkylene, an alkylene oxyalkylene or an alkylene polyoxyalkylene; and the anion includes halides, hydroxyl, bicarbonate, carbonate, alkyl carbonates, alkoxides, carboxylates, hydroxycarboxylates or a combination thereof.

Abstract: A method of stabilizing asphaltenes in a petroleum hydrocarbon fluid comprises contacting the petroleum hydrocarbon fluid with a mixed phenol aldehyde derived from an aldehyde and two or more unsubstituted or alkyl-substituted monophenols, the two or more unsubstituted or alkyl-substituted monophenols comprising a first phenol which is a C1-20 linear or branched alkyl monophenol; and a second phenol which is unsubstituted or a C1-20 linear or branched alkyl monophenol different from the first phenol, wherein the molar ratio of the first phenol relative to the second phenol is about 4:1 to about 1:4.