Deposits of valuable liquid hydrocarbons or fossil fuels. Distributions are geologic maps, models, and observations that indicate location, volume, and geochemical composition of underground deposits. Assessments evaluate locations, methods, and profitability of oil extraction and transportation; environmental impacts; and interactions with other uses. Predictions are the results of models or projections of future oil reserves based on extraction or natural processes, or they are predicted changes in profitability and risk due to economic, regulatory, technological, and environmental changes.