For this study, enhanced oil recovery (EOR) is considered in a narrow sense and is defined as: the additional recovery of oil from a petroleum reservoir over that which can be economically recovered by conventional primary and secondary methods. The study is based primarily on a review of the applicability of EOR processes to a data base of 245 known reservoirs in California, Texas, and Louisiana. From this data base, extrapolations were made for all reservoirs in the three states and for the U.S. as a whole. The report does not consider the impact on future supply of oil fields discovered after Dec. 31, 1975, nor the application of EOR processes to those fields. The report presents estimates of what could happen under certain technical and economic circumstances and is not intended to represent a forecast of what will occur. Other recent studies on enhanced recovery were used as references when appropriate and their results are compared with the results of this study. The possible environmental impacts of enhanced oil recovery operations are considered; Chapter Four includes a general discussion on environmental protection, and specific details on the possible effects of each process are contained in the appendixes. This report does not address the broader issues of energy policy such as energy conservation, import dependency, alternate energy forms, etc. It focuses on only one of the several possibilities to increase the supply of domestically produced petroleum. The Council feels that, despite its technical uncertainties and expected high costs, the pursuit of enhanced recovery is in the Nation's best interest. However, the degree to which enhanced recovery should be pursued as an instrument of U.S. energy policy must be addressed in the broader context of an overall policy. The Council is currently conducting a study on Future Energy Prospects, which will address these broader issues; this report is expected to be completed in the spring of 1977.