Method for identifying naphthenates in a hydrocarbon containing liquid

1. A method for quantifying the presence of naphthenic acids in a hydrocarbon-comprising liquid, the method comprising:

contacting a hydrocarbon-comprising liquid with gaseous ammonia to produce a reaction product;

aging the reaction product of said contacting step by cooling said hydrocarbon-comprising liquid to a temperature of 10° C. or less for a period sufficient to form the reaction product as a precipitate, an emulsion, or both;

isolating the reaction product produced by said aging step;

analyzing said reaction product for the presence of naphthenates using a mass spectrometry technique.

2. The method of claim 1 , wherein said hydrocarbon-comprising liquid comprises crude oil.

3. The method of claim 1 , wherein a duration of said contacting step is sufficient to cause the reaction product to comprise an ammonium naphthenate salt if said hydrocarbon-comprising liquid comprises a naphthenic acid.

4. The method of claim 3 , wherein said duration is at least thirty minutes.

5. The method of claim 1 , wherein said mass spectrometry technique comprises a Fourier transform ion cyclotron resonance mass spectrometer, an ion trap mass spectrometer, a quadrupole mass spectrometer, an orbitrap mass spectrometer, a time-of-flight mass spectrometer or a magnetic sector mass spectrometer.

6. The method of claim 1 , wherein said mass spectroscopy technique comprises an ionization technique selected from the group consisting of electrospray ionization, photoionization, chemical ionization, electron ionization, fast atom bombardment ionization, field ionization, field desorption/ionization, or a combination thereof.

7. The method of claim 1 , wherein said analyzing step comprises comparing mass spectrometry results of said reaction product to standards for naphthenic acids known to form commercial naphthenate deposits.

8. The method of claim 7 , wherein said naphthenic acids known to form commercial naphthenate deposits comprise (i) ions of tetraprotic carboxylic acids having molecular weights ranging from 1225 to 1270 Daltons, (ii) n-alkyl or branched carboxylic acids having molecular weights ranging from 250 to 650 Daltons, or (iii) both.

9. The method of claim 7 , wherein said naphthenic acids known to form commercial naphthenate deposits comprise tetraprotic carboxylic acids of Formula I:

C n H 2(n+1-DBE) O 8

wherein: n=77-85, and DBE (double bond equivalent)=8-12.

10. The method of claim 1 , wherein said reaction product is a precipitate, an emulsion, or both.

11. A method for determining whether a crude oil composition will produce commercial naphthenate deposits during crude oil processing, comprising:

contacting a crude oil composition with gaseous ammonia to produce a reaction product;

aging the reaction product of said contacting step by cooling the crude oil composition to a temperature of 10° C. or less for a period sufficient to form the reaction product as a precipitate, an emulsion, or both;

isolating the reaction product produced by said aging step;

analyzing said reaction product for the presence of naphthenic acid salts with a mass spectrometry technique, said analyzing step comprising:

comparing mass spectrometry results of said reaction product to standards for naphthenic acids known to form commercial naphthenate deposits.

12. The method of claim 11 , wherein said naphthenic acids known to form commercial naphthenate deposits comprise (i) ions of tetraprotic carboxylic acids having a molecular weight ranging from 1225 to 1270 Daltons, (ii) n-alkyl or branched carboxylic acids having molecular weights ranging from 250 to 650 Daltons, or (iii) both.

13. The method of claim 11 , wherein a duration of said contacting step is sufficient to produce a reaction product comprising an ammonium naphthenate salt in said hydrocarbon-comprising liquid comprises a naphthenic acid.

14. The method of claim 11 , wherein said mass spectrometry technique comprises a Fourier transform ion cyclotron resonance mass spectrometer, an ion trap mass spectrometer, a quadrupole mass spectrometer, an orbitrap mass spectrometer, a time-of-flight mass spectrometer or a magnetic sector mass spectrometer.

15. The method of claim 11 , wherein said mass spectroscopy technique comprises an ionization technique selected from the group consisting of electrospray ionization, photoionization, chemical ionization, electron ionization, fast atom bombardment ionization, field ionization, field desorption/ionization, or a combination thereof.

16. A method of operating a crude oil operation to avoid the formation of naphthenate deposits, comprising:

contacting a crude oil mixture used in a crude oil operation with gaseous ammonia to produce a reaction product;

aging the reaction product of said contacting step by cooling the crude oil mixture to a temperature of 10° C. or less for a period sufficient to form the reaction product as a precipitate, an emulsion, or both;

isolating the reaction product produced by said aging step;

analyzing said reaction product for the presence of naphthenic acid ions present in commercial naphthenate deposits with a mass spectrometry technique;

comparing mass spectrometry results from said analyzing step to mass spectrometry standards for naphthenic acid ions present in commercial naphthenate deposits; and

adjusting the composition of the crude oil mixture to reduce the formation of commercial naphthenate deposits if said comparing step indicates said reaction product comprises a naphthenic acid ion present in commercial naphthenate deposits.

17. The method of claim 16 , wherein said crude oil mixture comprises production water and said treating step comprises, (i) modifying a pH of said production water, (ii) reducing in said production water a concentration of one or more ions selected from the group consisting of HCO 3− , Ca 2+ , Fe 2+ , Mg 2+ , Na + and K + , or (iii) both.

18. The method of claim 16 , wherein said naphthenic acid ions present in commercial naphthenate deposits comprise (i) ions of tetraprotic carboxylic acids having molecular weights ranging from 1225 to 1270 Daltons, (ii) n-alkyl or branched carboxylic acids having molecular weights ranging from 250 to 650 Daltons, or (iii) both.