Application of electro-rheology in measurements of drilling fluid composition

1. A method for drilling a wellbore comprising:

circulating a drilling fluid in a wellbore;

extending the wellbore into one or more subterranean formations;

measuring one or more rheological properties of at least a portion of the drilling fluid while applying an electric field to the drilling fluid to obtain an electro-rheological profile of the portion of the drilling fluid; and

determining an estimate of a concentration of at least one additive of the drilling fluid based on the electro-rheological profile,

wherein the electro-rheological profile comprises a rate of change of at least one rheological property as a function of at least one property of the electric field.

2. The method of claim 1 , wherein the one or more rheological properties comprise at least one property selected from the group consisting of storage modulus, loss modulus, viscosity, yield stress, and combinations thereof.

3. The method of claim 1 , wherein the applying the electric field comprises applying a direct current voltage that increases or decreases as a function of time.

4. The method of claim 1 , wherein the electro-rheological profile comprises at least one of the one or more rheological properties of the drilling fluid as a function of one or properties of the electric field.

5. The method of claim 1 , wherein the determining the estimate comprises applying the rate of change to a correlation between the rate of change of at least one rheological property as a function of at least one property of the electric field for a plurality of sample drilling fluids and a concentration of the additive in the plurality of sample drilling fluids.

6. The method of claim 1 , wherein the electro-rheological profile comprises a rate of change of storage modulus as a function of voltage of the electric field.

7. The method of claim 1 , wherein the at least one additive comprises at least one electro-responsive additive selected from the group consisting of an emulsifying surfactant, a clay, and combinations thereof.

8. The method of claim 1 :

wherein the drilling fluid comprises an invert emulsion;

wherein the applying the electric field comprising applying a direct current voltage that increases as a function of time;

wherein the electro-rheological profile comprises a rate of change of storage modulus as a function of voltage of the electric field;

wherein the at least one additive comprise an emulsifying surfactant; and

wherein the determining the estimate comprises applying the rate of change to a correlation between the rate of change of the storage modulus as a function of voltage for a plurality of sample drilling fluids and a concentration of the emulsifying surfactant in the plurality of sample drilling fluids.

9. The method of claim 1 , further comprising determining a type of hydrocarbon liquid present in the drilling fluid based on the electro-rheological profile.

10. A method of using electro-rheology in determining drilling fluid properties, the method comprising:

providing a plurality of sample drilling fluids, wherein each of the sample drilling fluids comprises a hydrocarbon liquid, an aqueous liquid, and an additive, wherein a concentration of the additive varies in each of the sample drilling fluids;

measuring one or more rheological properties of the plurality of sample drilling fluids while applying an electric field to the drilling fluid to obtain an electro-rheological profile for each of the sample drilling fluids;

determining a rate of change of at least one rheological property of the electro-rheological profile as a function of at least property of the electric field for each of the sample drilling fluids;

determining a correlation between the rate of change of the at least one property and the concentration of the additive in the sample drilling fluids;

measuring one or more rheological properties of at least a portion of an additional drilling fluid while applying an electric field to the drilling fluid to obtain an electro-rheological profile of the additional drilling fluid, wherein the additional drilling fluid comprising the hydrocarbon liquid, the aqueous liquid, and the additive; and

determining a concentration of the additive in the additional drilling fluid based on the correlation.

11. The method of claim 10 , wherein the sample drilling fluids and the additional drilling fluids each individually comprise an invert emulsion.

12. The method of claim 10 , wherein the at least one rheological property comprises at least one property selected from the group consisting of storage modulus, loss modulus, viscosity, yield stress, and combinations thereof.

13. The method of claim 10 , wherein the applying the electric field in the measuring the one or more rheological properties of the plurality of sample drilling fluids and in the measuring one or more rheological properties of the additional fluids each comprise a direct current voltage that increases or decreases as a function of time.

14. The method of claim 10 , wherein the electro-rheological profile comprises a rate of change of at least one rheological property of the additional drilling fluid as a function of one or properties of the electric field.

15. The method of claim 10 , wherein the electro-rheological profile of each of the plurality of drilling fluids and the additional drilling fluid comprises a rate of change of storage modulus as a function of voltage of the electric field.

16. The method of claim 10 , wherein the at least one additive comprises at least one electro-responsive additive selected from the group consisting of an emulsifying surfactant, a clay, and combinations thereof.

17. The method of claim 10 , further comprising determining a type of hydrocarbon liquid present in the additional drilling fluid based on the electro-rheological profile.

18. A drilling system comprising:

a drill string;

a drill bit attached to a distal end of the drill string;

a fluid monitoring and handling system comprising

a mud pit operable to receive a drilling fluid from a wellbore;

a mud pump operable to circulate the drilling fluid; and

a fluid analysis system comprising a rheometer and a computer system, wherein the computer system comprises a processor and a non-transitory computer readable storage medium that when executed by the processor causes the computer system to determine an estimate of a concentration of at least one additive of the drilling fluid based on an electro-rheological profile of at least a portion of the portion of the drilling fluid,

wherein the electro-rheological profile comprises a rate of change of at least one rheological property as a function of at least one property of an electric field.

19. The drilling system of claim 18 , wherein the estimate of the concentration is determined by applying the rate of change to a correlation between the rate of change of the at least one rheological property as a function of the at least one property of the electric field for a plurality of sample drilling fluids and a concentration of the additive in the plurality of sample drilling fluids.

20. The drilling system of claim 18 , wherein the electro-rheological profile comprises a rate of change of storage modulus as a function of voltage of the electric field.