Abstract: Fluid analysis measurements may be performed during withdrawal of a downhole tool to the surface. Fluid may be collected within a fluid analysis system of the downhole tool and the collected fluid may be exposed to the wellbore pressure during withdrawal of the downhole tool. Measurements for the collected fluid, such as optical density, the gas oil ratio, fluid density, fluid viscosity, fluorescence, temperature, and pressure, among other, may be recorded continuously or at intervals as the downhole tool is brought to the surface. The measurements may be employed to determine properties of the collected fluid, such as the saturation pressure and the asphaltene onset pressure.

Abstract: The present disclosure relates to systems and methods for determining an integrity of a sample chamber. In certain embodiments, formation fluid is collected from a subterranean formation within a sample chamber disposed in a downhole tool, the downhole tool is withdrawn from a wellbore, an estimated surface pressure of the collected formation fluid is determined, the estimated surface pressure of the collected formation fluid is compared with an actual surface pressure of the sample chamber, and the integrity of the sample chamber is determined based on the comparison of the estimated surface pressure and the actual surface pressure.

Abstract: Various implementations described herein are directed to a method for assessing risks of compartmentalization. In one implementation, the method may include receiving seismic data for a formation of interest; identifying areas in the formation having a dip angle greater than about 30 degrees; performing a plurality of downhole fluid analysis (DFA) within a wellbore around the formation having the dip angle greater than about 30 degrees to identify areas experiencing mass density inversion; and determining the areas experiencing mass density inversion by DFA as having one or more risks of compartmentalization.

Abstract: The present disclosure relates to methods and apparatus for determining a viscosity-pressure profile of downhole fluid by measuring the viscosity at several different pressures during a sampling operation. According to certain embodiments, the viscosity may be measured at different times during a sampling operation and used to generate the viscosity-pressure profile. For example, the viscosity may be measured at the beginning of pumping, during filling of a sample chamber, during a pressure-build up period, and while retracting the probe. The measured viscosities may then be employed to determine a profile that represents the change in viscosity that occurs with pressure.

Abstract: A method for performing contamination monitoring through estimation wherein measured data for optical density, gas to oil ratio, mass density and composition of fluid components are used to obtain plotting data and the plotting data is extrapolated to obtain contamination levels.

Abstract: The present disclosure relates to determining hydrogen indexes of downhole fluids using fluid composition data. In certain embodiments, the type of the fluid, such as gas, water, or oil, may be determined downhole and used to select a method for determining the hydrogen index of the fluid. The selected method may then be employed while the tool is downhole to calculate the hydrogen index of the fluid.