Method For Determining The Formation Of A Winsor III Microemulsion System

1 . A dynamic method for determining the formation of a Winsor III microemulsion system, the method comprising the steps of:

providing a mixture of an aqueous medium and a hydrocarbon medium in a chamber;

continuously altering the concentration of at least one component in the mixture, while the ratio of the aqueous medium to the hydrocarbon medium remains constant and while stirring the mixture; and

continuously measuring at least one physicochemical property of the mixture.

2 . The method according to claim 1 , wherein the concentration of only one component in the mixture is altered, while the concentration of the other components of the mixture remains constant.

3 . The method according to claim 1 , wherein the aqueous medium is or derives from produced water, fresh water, aquifer water, formation water, sea water or combinations thereof and/or wherein the aqueous medium has an initial salinity from 0 to 300 g/L.

4 . The method according to claim 1 , wherein the hydrocarbon medium is a hydrocarbon fluid recovered from a subterranean formation.

5 . The method according to claim 1 , wherein the mixture is initially a water-in-oil emulsion or an oil-in-water emulsion.

6 . (canceled)

7 . The method according to claim 1 , wherein the ratio of the aqueous medium to the hydrocarbon medium is from 0.2 to 5.

8 . The method according to claim 1 , wherein the mixture comprises a surfactant and wherein the surfactant has an initial concentration in the mixture from 0.001 to 30%.

9 - 10 . (canceled)

11 . The method according to claim 1 , wherein the mixture comprises a co-solvent and wherein the co-solvent has an initial concentration in the mixture from 0.001 to 30%.

12 . (canceled)

13 . The method according to claim 1 , wherein the at least one component is an inorganic salt, and/or a surfactant, and/or a co-solvent and wherein the surfactant is chosen from a surfactant of formula (VI):

R 14 —O—(CH 2 —CH(CH 3 )—O) k —(CH 2 CH 2 O) p —H  (VI)

wherein:

R 14 is a linear or branched alkyl group having from 1 to 24 carbon atoms;

p is a rational number from 1 to 30;

k is a rational number from 0 to 30;

and a surfactant of formula (VII):

R 14 —O—(CH 2 —CH(CH 3 )—O) x —(CH 2 —CH 2 —O) y —(CH 2 ) w —X − M +   (VII)

wherein:

R 14 is a linear or branched alkyl group having from 1 to 24 carbon atoms;

x is a number from 2 to 24; and

y is a number from 0 to 24;

w is a number from 0 to 2;

X − is an anionic group selected from the group of —OSO 3 —, —R 15 —SO 3 —, —SO 3 —, or —R 15 —COO—; and

M + is a hydrogen atom or a cation;

as well as their mixtures.

14 . (canceled)

15 . The method according to claim 1 , which comprises continuously adding an aqueous solution and additional hydrocarbon medium to the mixture in the chamber and/or continuously withdrawing part of the mixture from the chamber.

16 . (canceled)

17 . The method according to claim 1 , wherein altering the concentration of the at least one component is performed by increasing said concentration in the mixture and/or decreasing its concentration in the mixture.

18 . The method according to claim 15 , wherein the aqueous solution and/or the additional hydrocarbon medium comprises the component the concentration of which is altered, in a higher concentration than in the mixture.

19 - 22 . (canceled)

23 . The method according to claim 15 , wherein the aqueous solution and/or the additional hydrocarbon medium does not comprise the component the concentration of which is altered, or comprises the component the concentration of which is altered in a lower concentration than in the mixture.

24 - 26 . (canceled)

27 . The method according to claim 1 , being carried out at a constant temperature and/or at constant pressure, wherein the temperature is from 25° C. to 140° C. and/or wherein the pressure is from 1 to 5 bars.

28 - 29 . (canceled)

30 . The method according to claim 1 , wherein the physicochemical property of the mixture is chosen from conductivity, viscosity and light backscattering.

31 . The method according to claim 30 , wherein the physicochemical property is conductivity and wherein the method further comprises a step of determining the concentration of the component at which the conductivity suddenly decreases from a value higher than 0 to substantially 0 and/or at which the conductivity suddenly increases from a value of substantially 0 to a value higher than 0.

32 . (canceled)

33 . A device for determining the formation of a Winsor III microemulsion system, the device comprising:

a chamber ( 1 ) configured to receive a fluid sample;

at least two feed lines ( 2 a ) for continuously feeding two respective fluids to the chamber ( 1 );

at least one discharge line ( 3 a ) for continuously withdrawing fluid from the chamber ( 1 );

at least one sensor for measuring at least one physicochemical property of the fluid sample in the chamber ( 1 ); and

a stirring system ( 4 ) for stirring fluid in the chamber ( 1 ).

34 . The device according to claim 33 , wherein the physicochemical property of the mixture is chosen from conductivity, viscosity and light backscattering and/or wherein the sensor is a conductivity sensor ( 5 ).

35 . (canceled)

36 . The device according to claim 33 , further comprising a sensor for measuring the temperature of the fluid sample in the chamber ( 1 ) and/or a system for regulating the temperature of the chamber ( 1 ) and/or a cap ( 8 ) for sealing the chamber ( 1 ).

37 - 42 . (canceled)

43 . The device according to claim 33 , wherein the fluid sample is a mixture of a first fluid and a second fluid, and wherein the first fluid of the mixture is an aqueous medium and the second fluid of the mixture is a hydrocarbon medium, and wherein two different fluids are injected into the chamber ( 1 ), each fluid being injected through a different feed line ( 2 a ).

44 - 45 . (canceled)