Aqueous dispersion of an oil soluble demulsifier for breaking crude oil emulsions
AssigneeNalco/Exxon Energy Chemicals, L.P.
InventorsRadhakrishnan Selvarajan, Ananthasubramanian Sivakumar, Robert A. Marble
Life of this patent
Estimating the term…
Abstract
Demulsification of a water-in-oil, especially a water-in-crude oil, emulsion is effected by contacting it with an aqueous composition having at least one oil-soluble demulsifier and at least one water-soluble surfactant. These aqueous formulations are advantageous over conventional organic formulations of demulsifiers, as the need for toxic and/or flammable/combustible organic solvents is eliminated.
Claims2
A stable aqueous formulation of a water-insoluble organic demulsifier consisting essentially of:
- a) a water-insoluble oil-soluble organic demulsifier;
- b) a water soluble surfactant;
- and
- c) balance water,
- wherein the water-insoluble oil-soluble organic demulsifer is a combination of a dicarbamate and a polyoxyalkylated alkylphenol resin, wherein the dicarbamate is the reaction product of from about 1% to about 15% by weight of toluene diisocyanate and from about 85% to about 99% by weight of an oxyalkylated polyol of formula:
- H(OCH2CH2)x(OR1)yOR2
- where y is an integer from 2 to 70;
- R1 is a radical selected from the group consisting of
- R2 is a radical selected from the group consisting of —H and —CH(CH2CH2OH)2;
- and x is an integer from 0 to 40;
- the polyoxyalkylated alkylphenol resin is an ethoxylated/propoxylated nonylphenol-formaldehyde condensate;
- and the water-soluble surfactant is a combination of sulfated nonylphenol ethoxylate and octylphenol ethoxylate in a ratio of surfactants of from about 0.2:1 to about 1.2:1.
A method for separating water from a crude oil emulsion of water and oil, comprising the steps of:
- a) treating said crude oil emulsion with an effective demulsifying amount of an aqueous composition consisting essentially of:
- i. at least one water-insoluble oil-soluble organic demulsifier;
- ii. at least one water-soluble surfactant;
- iii. and the balance water;
- wherein the water-insoluble oil-soluble organic demulsifer is a combination of a dicarbamate and a polyoxyalkylated alkylphenol resin, wherein the dicarbamate is the reaction product of from about 1% to about 15% by weight of toluene diisocyanate and from about 85% to about 99% by weight of ethylene oxide/propylene oxide block copolymer, the polyoxyalkylated alkylphenol resin is an ethoxylated/propoxylated nonylphenol-formaldehyde condensate and the water-soluble surfactant is a combination of sulfated nonylphenol ethoxylate and octylphenol ethoxylate in a ratio of surfactants of from about 0.2:1 to about 1.2:1.
- b) coalescing water droplets from said emulsion;
- and,
- c) removing coalesced water.
Dependencies are inferred from the claim text.