Patent ID: 8146655

Claim:
A method for downhole analysis of petroleum formation fluids comprising: (a) providing a chamber in a downhole tool suspended in a wellbore; (b) capturing in the chamber at least two immiscible fluids in a generally segregated state, the at least two fluids including petroleum fluid; (c) emulsifying the fluids in the chamber by activating a fluid mixing means for mixing the fluids; (d) allowing the emulsified fluids to segregate by deactivating the mixing means; (e) transmitting light into the fluids in the chamber and measuring light transmittance values through the fluids over time during (d); and (f) calculating the duration of a transition time period based upon the light transmittance values measured in (e), the transition time period beginning at the time of deactivation of the fluid mixing means, and the transition time period ending at a time determined by a change in the light transmittance values measured in (e).