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Low dosage naphthenate inhibitors, such as a surfactant or hydrotrope, delivered into production fluids for contact with mixtures of oil and water, such as in a hydrocarbon producing formation, production equipment, or processing systems. Inhibitor compounds such as monophosphate esters and diphosph

Low dosage naphthenate inhibitors, such as a surfactant or hydrotrope, delivered into production fluids for contact with mixtures of oil and water, such as in a hydrocarbon producing formation, production equipment, or processing systems. Inhibitor compounds such as monophosphate esters and diphosphate esters exhibit surface-active properties that cause the inhibitors to self-associate at oil-water interfaces and inhibit interactions between organic acids in the oil with cations or cation complexes in the water. These compounds also inhibit aggregation of organic acid carboxylate salts that form when pH and pressure conditions are amenable to organic acid ionization. Preferred inhibitors do not form emulsions due to the formation of unstable mixed interface structures that result in coalescence of dispersed droplets. Naphthenate inhibitor compound dosages of less than 100 ppm can effectively inhibit naphthenate salts or other organic acid salts that can form precipitates or emulsions during crude oil production or processing.

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What is claimed is: 1. A method comprising: supplying at least one surface active compound into a mixture of divalent cation-containing water and organic acid-containing oil at a dosage rate that is effective to self-associate at interfaces between the water and oil and inhibit formation of divalen

What is claimed is: 1. A method comprising: supplying at least one surface active compound into a mixture of divalent cation-containing water and organic acid-containing oil at a dosage rate that is effective to self-associate at interfaces between the water and oil and inhibit formation of divalent cation salts of the organic acid, wherein the compound is added before a choke, manifold, turret, or a combination thereof; and after supplying the compound into the mixture, reducing the pressure to release carbon dioxide gas from the oil. 2. The method of claim 1, wherein the organic acid includes naphthenic acid. 3. The method of claim 2, wherein the compound inhibits formation of naphthenate salts. 4. The method of claim 1, wherein the dosage rate of the at least one surface active compound is between 10 and 1000 ppm. 5. The method of claim 1, wherein the dosage rate of the at least one surface active compound is between 10 and 100 ppm. 6. The method of claim 1, wherein the dosage rate of the at least one surface active compound is between 10 and 60 ppm. 7. The method of claim 1, wherein the dosage rate of the at least one surface active compound is between 25 and 50 ppm. 8. The method of claim 1, wherein the divalent cation salts of the organic acid are capable of forming deposits, stabilizing emulsions, or a combination thereof. 9. The method of claim 1, wherein the mixture of water and oil includes an emulsion. 10. The method of claim 1, wherein the pH of the oil and water mixture is greater than 5.2 following the addition of the compound. 11. The method of claim 1, wherein the pH of the oil and water mixture is greater than 6 following the addition of the compound. 12. The method of claim 1, wherein the pH of the oil and water mixture is greater than 6.5 following the addition of the compound. 13. The method of claim 12, wherein the organic acid includes naphthenic acid. 14. The method of claim 13, wherein the compound inhibits formation of naphthenate salts. 15. The method of claim 1, wherein the compound inhibits formation of organic soap deposits or organic soap emulsions by inhibiting cations in the water from interacting with organic acid in the oil. 16. The method of claim 1, wherein the compound inhibits the cations and organic acid from interacting along the interface between the water and oil. 17. The method of claim 1, wherein the water has a cation concentration of greater than 100 ppm. 18. The method of claim 1, wherein the divalent cations are selected from calcium, magnesium, and combinations thereof. 19. The method of claim 1, wherein the organic-acid-containing oil has a total acid number greater than 0.5. 20. The method of claim 1, wherein the oil contains naphthenic acid. 21. The method of claim 1, wherein the oil contains napthenic acid at a concentration greater than 100 ppm. 22. The method of claim 1, further comprising: producing the mixture of water and oil from a subterranean formation. 23. The method of claim 22, further comprising: releasing carbon dioxide gas from the mixture. 24. The method of claim 22, further comprising: breaking an emulsion of the water and oil. 25. The method of claim 24, further comprising: adding an emulsion breaker composition into the produced mixture. 26. The method of claim 24, further comprising: physically breaking the emulsion. 27. The method of claim 1, wherein the compound has a hydrophilic portion and an oleophilic portion. 28. The method of claim 27, wherein the compound is a surfactant. 29. The method of claim 28, wherein the surfactant is selected from anionic surfactants, amphoteric surfactants, and combinations thereof. 30. The method of claim 28, wherein the surfactant is selected from phosphates, sulfates, sulfonates, sulfosuccinates, polysulfosuccinates, phenols, betaines, thiocarbamates, xanthates and combinations thereof. 31. The method of claim 27, wherein the compound concentrates along the oil-water interface. 32. The method of claim 31, wherein the at least one surface active compound includes at least one hydrotrope. 33. The method of claim 32, wherein the hydrotope is in an acid form, a salt form, or a combination thereof. 34. The method of claim 32, wherein the at least one hydrotrope includes a monophosphate ester compound, a diphosphate ester compound, or a combination thereof. 35. The method of claim 1, wherein the compound includes the product formed by a reaction between phosphorus pentoxide and an alcohol. 36. The method of claim 1, wherein the compound includes a phosphate ester having an organic side chain comprising the product formed by a reaction between a fatty acid and 1 to 9 moles of ethylene oxide, propylene oxide, butylene oxide, or combinations thereof. 37. The method of claim 36, wherein the butylene oxide is 1,2 butylene oxide. 38. The method of claim 1, wherein the water is connate water or formation water. 39. The method of claim 1, wherein the compound is added at a concentration of less than 500 ppm in the mixture of oil and water. 40. The method of claim 1, wherein the compound is added at a concentration of less than 250 ppm in the mixture of oil and water. 41. The method of claim 1, wherein the compound is added at a concentration of less than 120 ppm in the mixture of oil and water. 42. The method of claim 1, wherein the compound is added at a concentration of less than 100 ppm in the mixture of oil and water. 43. The method of claim 1, wherein the compound is added at a concentration of less than 50 ppm in the mixture of oil and water. 44. The method of claim 41, wherein the compound further comprises acetic acid. 45. The method of claim 43, wherein the compound further comprises less than 200 ppm acetic acid. 46. The method of claim 41, wherein the compound is provided in the absence of acetic acid. 47. The method of claim 1, wherein the water is selected from connate water, seawater, and combinations thereof. 48. The method of claim 1, wherein the step of adding the compound includes injecting the compound downhole. 49. The method of claim 1, wherein the step of adding the compound includes dosing the compound to an oil-water separator. 50. The method of claim 1, further comprising: adding the compound as the oil and water mixture is being produced from a formation. 51. The method of claim 1, wherein the oil has a TAN greater than 0.05. 52. The method of claim 1, wherein the amount of the compound added to the oil and water mixture is effective to protonate naphthenate salts formed prior to the addition of the compound. 53. The method of claim 1, wherein the compound is an acid. 54. The method of claim 1, wherein the compound forms a mixed interface with surfactants or organic acid metal ion salts. 55. The method of claim 1, wherein the compound modifies the crystal habit of the divalent cation salts of the organic acid. 56. A method comprising: supplying a compound into a conduit comprising a flowing mixture of cation-containing water and an organic-acid-containing oil, wherein the compound is added before or after a choke, manifold, turret or combination thereof, wherein the compound self-associates at an interface between the water and oil to inhibit the formation of organic soap and salt deposits or precipitates, and wherein the pressure on the flowing mixture is reduced after the choke, manifold, turret or combination thereof to release carbon dioxide gas from the oil. 57. The method of claim 56, wherein the compound is supplied by injection into the conduit. 58. The method of claim 56, wherein the conduit is selected from a drill string, casing, offshore riser, transport pipeline, processing pipe, and combinations thereof. 59. The method of claim 56, wherein the compound is supplied into the conduit by injection into an oil-containing formation that is in fluid communication with the conduit. 60. The method of claim 56, wherein the compound is a surfactant. 61. The method of claim 60, wherein the surfactant is selected from phosphates, sulfates, sulfonates, sulfosuccinates, polysulfosuccinates, phenols, betaines, thiocarbamates, xanthates and combinations thereof. 62. The method of claim 56, wherein the at least one surface active compound includes at least one hydrotrope. 63. The method of claim 62, wherein the at least one hydrotrope includes a monophosphate ester compound, a diphosphate ester compound, or a combination thereof. 64. The method of claim 56, wherein the compound includes a phosphate ester having an organic side chain comprising the product formed by a reaction between a fatty acid and 1 to 9 moles of ethylene-oxide, propylene-oxide, butylene-oxide, or combinations thereof. 65. The method of claim 56, wherein the water is connate water or formation water. 66. The method of claim 56, wherein the compound is added at a concentration of less than 100 ppm in the mixture of oil and water. 67. A method comprising: injecting at least one surface active compound into a mixture of water and oil, wherein the at least one surface active compound includes at least hydrotrope selected from the group consisting of monophosphate ester compounds, diphosphate ester compounds, and combinations thereof, and wherein the compound self-associates at interfaces between the water and oil to inhibit the formation of organic soaps and organic soap deposits or precipitates. 68. The method of claim 67, wherein the compound includes a phosphate ester having an organic side chain comprising the product formed by a reaction between a fatty acid and 1 to 9 moles of ethylene-oxide, propylene-oxide, butylene-oxide, or combinations thereof. 69. The method of claim 67, wherein the water is connate water or formation water. 70. The method of claim 67, wherein the compound is added at a concentration of less than 100 ppm in the mixture of oil and water. 71. A method comprising: injecting at least one surface active compound into a mixture of water and oil, wherein the at least one surface active compound includes at least hydrotrope selected from the group consisting of monophosphate ester compounds, diphosphate ester compounds, and combinations thereof, and wherein the compound self-associates at an interface between the water and oil to inhibit a component in the water from interacting with a component of the oil. 72. The method of claim 71, wherein the mixture of water and oil is an oil production fluid. 73. The method of claim 71, wherein the compound includes a phosphate ester having an organic side chain comprising the product formed by a reaction between a fatty acid and 1 to 9 moles of ethylene-oxide, propylene-oxide, butylene-oxide, or combinations thereof. 74. The method of claim 71, wherein the water is connate water or formation water. 75. The method of claim 71, wherein the compound is added at a concentration of less than 100 ppm in the mixture of oil and water. 76. In a method for reducing the tendency of organic-acid in oil to form divalent metal salt complexes when mixed with water containing divalent metal cations, the improvement comprising: supplying at least one surface active compound into the mixture of oil and water at a dosage rate that is effective to inhibit formation of divalent cation salts of the organic acid without raising the pH above 6.5, wherein the compound is added before or after a choke, manifold, turret or combination thereof, and wherein the pressure on the flowing mixture is reduced after the choke, manifold, turret or combination thereof to release carbon dioxide gas from the oil. 77. The method of claim 76, wherein the at least one surface active compound includes a surfactant selected from phosphates, sulfates, sulfonates, sulfosuccinates, polysulfosuccinates, phenols, betaines, thiocarbamates, xanthates and combinations thereof. 78. The method of claim 76, wherein the at least one surface active compound includes at least one hydrotrope. 79. The method of claim 78, wherein the at least one hydrotrope includes a monophosphate ester compound, a diphosphate ester compound, or a combination thereof. 80. The method of claim 76, wherein the water is connate water or formation water. 81. The method of claim 76, wherein the compound is added at a concentration of less than 100 ppm in the mixture of oil and water. 82. A method comprising: reducing the pressure on a mixture of divalent cation-containing water and organic acid-containing oil to release carbon dioxide gas from the mixture; and then supplying at least one surface active compound into the mixture at a dosage rate that is effective to self-associate at interfaces between the water and oil and inhibit formation of divalent cation salts of the organic acid, wherein the compound is supplied after a choke, manifold, turret, or a combination thereof.