From the Energy Information Administration FAQs:
"According to the U.S. Energy Information Administration’s (EIA) International Energy Outlook 2017 (IEO2017), the global supply of crude oil, other liquid hydrocarbons, and biofuels is expected to be adequate to meet the world's demand for liquid fuels through 2050. There is substantial uncertainty about the levels of future liquid fuels supply and demand. EIA reflects some of this uncertainty by developing a Reference case, High and Low Economic Growth cases, and High and Low Oil Price cases in its projections. The oil resources currently in the earth's crust, in combination with expected production of other liquid fuels, are estimated to be sufficient to meet total world demand for liquid fuels in all cases of the IEO2017.
An often cited, but misleading, measurement of future resource availability is the reserves-to-production ratio, which is calculated by dividing the volume of total proved reserves by the volume of current annual consumption. Proved reserves are an accounting concept that is based on known projects, and it is not an appropriate measure for judging total resource availability in the long term. Over time, global reserves will likely increase as new technologies increase production at existing fields and as new projects are developed."
- Long-Term Global Oil Scenarios: Looking Beyond 2030 (PDF), Energy Information Administration
A technical presentation with an analysis of world oil supply under various supply and demand scenarios.
- International Energy Outlook (Report), Energy Information Administration
Includes EIA's most recent forecast for world oil supply.
- Crude Oil Proved Reserves (Website), Energy Information Administration
Time-series data for the last five years showing proved reserves of crude oil by country. Also provides information on production, consumption, imports, exports, stocks, and more, for oil, coal, and natural gas, plus information on renewable energy.