Method and system for determining asphaltene onset pressure using a wavelength dependent signal

Abstract

Methods and systems for determining asphaltene onset pressure of a formation fluid are disclosed herein. The method includes positioning a wellbore tool within a wellbore and drawing a formation fluid sample into the wellbore tool. The method further includes transmitting light through the sample and detecting light that is transmitted through the sample. The light is transmitted within the sample along a short path length of less than 2 mm. While the light is being transmitted, the pressure of the sample is varied. A wavelength dependent signal is determined using (i) the intensity of the transmitted light at a first wavelength and (ii) the intensity of the transmitted light at a second wavelength. The asphaltene onset pressure of the sample is determined by identifying a change in the wavelength dependent signal at a particular pressure.

Dependencies are inferred from the claim text.