A methodology performs downhole fluid analysis at multiple measurement stations within a wellbore traversing a reservoir to determine gradients of compositional components and other fluid properties. A model is used to predict concentrations of a plurality of high molecular weight solute part class-types at varying reservoir locations. Such predictions are compared against downhole measurements to identify the best matching solute part class-type. If the best-matching class type corresponds to at least one predetermined asphaltene component, phase stability of asphaltene in the reservoir fluid at a given depth is evaluated using equilibrium criteria involving an oil rich phase and an asphaltene rich phase of respective components of the reservoir fluid at the given depth. The result of the evaluation of asphaltene rich phase stability is used for reservoir analysis. The computational analysis that evaluates asphaltene rich phase stability can also be used in other reservoir understanding workflows and in reservoir simulation.