System and method of mixing a formation fluid sample in a downhole sampling chamber with a magnetic mixing element

1. A method of mixing a formation fluid sample in a downhole sampling chamber having a longitudinal axis and a generally cylindrical inner surface, the method comprising:

running the downhole sampling chamber into a wellbore;

obtaining the formation fluid sample in the downhole sampling chamber;

retrieving the downhole sampling chamber containing the formation fluid sample from the wellbore;

positioning the downhole sampling chamber in a support stand;

imposing a magnetic field on a mixing element disposed within the downhole sampling chamber and having a close fitting relationship with the generally cylindrical inner surface of the downhole sampling chamber;

longitudinally moving the mixing element back and forth through the downhole sampling chamber responsive to the magnetic field; and

mixing the formation fluid sample.

2. The method as recited in claim 1 further comprising rotating the mixing element in the formation fluid sample.

3. The method as recited in claim 2 wherein rotating the mixing element in the formation fluid sample further comprises rotating the mixing element in the formation fluid sample responsive to the magnetic field.

4. The method as recited in claim 2 wherein rotating the mixing element in the formation fluid sample further comprises rotating the mixing element in the formation fluid sample responsive to interaction with the formation fluid sample.

5. The method as recited in claim 1 further comprising heating the formation fluid sample.

6. A method of mixing a formation fluid sample in a downhole sampling chamber having a longitudinal axis and a generally cylindrical inner surface, the method comprising:

running the downhole sampling chamber into a wellbore;

obtaining the formation fluid sample in the downhole sampling chamber;

retrieving the downhole sampling chamber containing the formation fluid sample from the wellbore;

positioning the downhole sampling chamber in a support stand;

imposing a magnetic field on a mixing element disposed within the downhole sampling chamber and having a close fitting relationship with the generally cylindrical inner surface of the downhole sampling chamber;

longitudinally moving the mixing element back and forth through the downhole sampling chamber responsive to the magnetic field;

rotating the mixing element in the formation fluid sample; and

mixing the formation fluid sample.

7. The method as recited in claim 6 wherein rotating the mixing element in the formation fluid sample further comprises rotating the mixing element in the formation fluid sample responsive to the magnetic field.

8. The method as recited in claim 6 wherein rotating the mixing element in the formation fluid sample further comprises rotating the mixing element in the formation fluid sample responsive to interaction with the formation fluid sample.

9. The method as recited in claim 6 further comprising heating the formation fluid sample.

10. A system for mixing a formation fluid sample in a downhole sampling chamber having a longitudinal axis and a generally cylindrical inner surface, the system comprising:

a mixing element disposed in the downhole sampling chamber, the mixing element having a close fitting relationship with the generally cylindrical inner surface of the downhole sampling chamber;

a support stand operable to receive the downhole sampling chamber; and

a magnetic field generator operably associated with the downhole sampling chamber such that when the magnetic field generator generates a magnetic field, the mixing element moves longitudinally back and forth through the downhole sampling chamber responsive to the magnetic field, thereby mixing the formation fluid sample.

11. The system as recited in claim 10 further comprising a heating element operably associated with the downhole sampling chamber operable to heat the formation fluid sample.

12. The system as recited in claim 10 wherein the mixing element further comprises a spherical mixing element.

13. The system as recited in claim 10 wherein the mixing element further comprises a substantially cylindrical mixing element.

14. The system as recited in claim 10 wherein the mixing element further comprises a fluted external surface.

15. The system as recited in claim 10 wherein the mixing element further comprises an internal fluid passageway.

16. The system as recited in claim 15 wherein the internal fluid passageway further comprises a fluted internal surface.

17. The system as recited in claim 10 wherein the mixing element further comprises a plurality of blades.