Abstract: The invention relates to a method of determining an unknown property or information of a reservoir fluid. The method includes measuring a set of responses of a measuring instrument to the fluid and measuring one or more physical or chemical properties of the fluid. The method further includes determining the unknown property or information of the fluid based on the relationship between the instrument responses and the measured properties of the fluid using equation-of-state (EOS) model.

Abstract: The present invention relates to a method of detecting synthetic mud filtrate in a downhole fluid including placing a downhole tool into a wellbore, introducing a downhole fluid sample into the downhole tool, analyzing the downhole fluid sample in the downhole tool, producing at least two filtrate markers from the analyzing of the downhole fluid sample and converting the at least two filtrate markers by vector rotation to a sufficiently orthogonal signal. The first pumped fluid sample giving initial plateau readings can be a proxy for 100% drilling fluid having an initial orthogonal signal and subsequent samples can be converted to orthogonal signals that are referenced to the first pumped fluid signal to give a calculation of percent contamination of the formation fluid.

Abstract: The present invention relates to a method of detecting synthetic mud filtrate in a downhole fluid including placing a downhole tool into a wellbore, introducing a downhole fluid sample into the downhole tool, analyzing the downhole fluid sample in the downhole tool, producing at least two filtrate markers from the analyzing of the downhole fluid sample and converting the at least two filtrate markers by vector rotation to a sufficiently orthogonal signal. The first pumped fluid sample giving initial plateau readings can be a proxy for 100% drilling fluid having an initial orthogonal signal and subsequent samples can be converted to orthogonal signals that are referenced to the first pumped fluid signal to give a calculation of percent contamination of the formation fluid.

Abstract: The invention relates to a method of determining an unknown property or information of a reservoir fluid. The method includes measuring a set of responses of a measuring instrument to the fluid and measuring one or more physical or chemical properties of the fluid. The method further includes determining the unknown property or information of the fluid based on the relationship between the instrument responses and the measured properties of the fluid using equation-of-state (EOS) model.