A method for determining a parameter of interest of a formation fluid, comprises moving a tool attached to a tubular member along a borehole in a subterranean formation. The tool is used to determine a formation fluid pressure and a formation fluid temperature at predetermined locations along the borehole and calculating a formation fluid density along the borehole therefrom. A density of a reference fluid is determined along the borehole and is related to the formation fluid pressure and the formation fluid temperature. The parameter of interest of the formation fluid is determined at a predetermined location from a comparison of the corresponding formation fluid density and the reference fluid density at the predetermined location.