The West Sak reservoir located on the North Slope of Alaska is estimated to contain up to 25 billion barrels of heavy oil in place and represents the largest known heavy oil accumulation in the United States. The research pertains to study of thermal and miscible processes for the recovery of West Sak crude. This report provides a description of the West Sak reservoir along with the petrophysical properties of various sand members based on the analysis of well log data; experimentally measured fluid properties (PVT) of West Sak crude and phase behavior of CO{sub 2}-West Sak crude mixtures; slim tube experiments, asphaltene precipitation tests and equation of state predictions (in presence and absence of aqueous phase) conducted to study applicability of miscible flooding with enriched hydrocarbon gas solvents and carbon dioxide. Studies on thermal recovery include: prediction of steamflood performance with a simplified steamflood model, experimental one dimensional corefloods conducted to study effect of addition of gases such as carbon dioxide, nitrogen and methane to steam on the recovery of West Sak crude and development of analytical heat transfer model to simulate injection of steam/hot water in a one dimensional linear reservoir. 107 refs., 166 figs., 44 tabs.