METHOD OF ANALYZING THE KINETICS OF GAS HYDRATE FORMATION IN FLUIDS

• US 20090103586A1
• Filed: 05/24/2006
• Published: 04/23/2009
• Est. Priority Date: 06/02/2005
• Status: Active Grant

• Current Assignee: Institut Francais Du Petrole
• Original Assignee: Institut Francais Du Petrole
• Inventors: Dalmazzone, Christine, Rousseau, Lionel, Herzhaft, Benjamin
• Granted Patent: US 8,038,342 B2
• Time in Patent Office: Days
• US Class Current: 374/31
• CPC Class Codes: C09K 2208/22 Hydrates inhibition by using well treatment fluids containing inhibitors of hydrate formers
• CPC Class Codes: C09K 8/52 Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning
• CPC Class Codes: C10L 3/108 Production of gas hydrates
• CPC Class Codes: G01N 25/14 by using distillation, extraction, sublimation, condensation, freezing, or crystallisation G01N25/02 takes precedence

Abstract

The present invention relates to a method for determining the kinetics of gas hydrate formation in a fluid comprising water, wherein the following stages are carried out:

• • a sample of the fluid is provided in form of a water-in-oil stable emulsion,
  • DSC measurements are performed on the sample to obtain at least one peak corresponding to the gas hydrate conversion energy in the water drops of said emulsion,
  • kinetic characteristics of the formation of hydrates in said fluid are deduced from the peak.

Claims

1. ) A method for determining the kinetics of gas hydrate formation in a fluid comprising water, wherein the following stages are carried out:

a sample of said fluid is provided in form of a water-in-oil stable emulsion,

DSC measurements are performed on said sample to obtain at least one peak corresponding to the gas hydrate conversion energy in the water drops of said emulsion,

kinetic characteristics of the formation of hydrates in said fluid are deduced from the peak.

2. ) A method as claimed in claim 1, wherein said fluid is of aqueous continuous phase type, said emulsion being formed with addition of an organic liquid.

3. ) A method as claimed in claim 1, wherein said fluid is of oil continuous phase type in water-in-oil emulsion.

4. ) A method as claimed in claim 1, wherein the stability of said emulsion is controlled prior to DSC measurements.

5. ) A method as claimed in claim 1, wherein the DSC measurements are performed with said gas under pressure.

6. ) A method as claimed in claim 1, wherein a hydrate crystallization peak and a hydrate dissociation peak are determined.

7. ) A method as claimed in claim 1, wherein a hydrate crystallization peak is determined by carrying out at least one isotherm cycle at a predetermined temperature lower than the dissociation temperature.

8. ) A method as claimed in claim 1, wherein:

—

isotherms are performed at a lower temperature than the dissociation temperature, said isotherms being of different durations, —

hydrates formed after each isotherm of different duration are heated to obtain a dissociation peak.

9. ) A method as claimed in claim 6, wherein a crystallization temperature T1 and a dissociation temperature T1diss are deduced from said peaks, and at least one kinetic parameter of the formation of hydrates is deduced from the undercooling degree Δ

T=T1diss−

T1.

10. ) A method as claimed in claim 7, wherein at least one kinetic parameter of the formation of hydrates can be deduced from time t1 when the peak appears and from time t′

1 at the vertex of the peak.