Systematic slim-tube displacement tests and coreflooding tests were performed to determine displacement mechanisms and the minimum miscibility pressure (MMP) for nitrogen with light oils. Emphasis of the study was on the injection of a slug of solution gas before. The effect of slug size and composition on the MMP was also studied. Candidate oils from Alaskan reservoirs (26/degree/ and 48/degree/ API) were also tested for the applicability of nitrogen miscible displacement and the slug injection technique. A series of nitrogen displacement experiments was performed on one of Alaskan oils at varying gas-oil-ratios (GOR) to determine the effect of the intermediate components (C/sub 2/-C/sub 5/) of the oil on the MMP. A correlation for the MMP has also been developed from literature data on pure nitrogen displacement and data obtained from this work. The proposed correlation shows good agreement with the prediction of the MMP of 14 oils tested. More realistic tests for the nitrogen miscible displacement method were performed in a 2-in. diameter, 2-ft long Berea sandstone core to investigate the effects of gravity segregation and mobility ratio on the recovery efficiency. Secondary and tertiary nitrogen injection tests as well as an initial evaluation of foam flooding as an improvement to nitrogen displacement were also performed. 10 refs., 7 figs., 3 tabs.