The oil industry is in the midst of one of the steepest downturns in years as the oil price is off its peak by 45%. As is typical during a downturn, investors haven't acted rationally, and some oil stocks have been severely beaten down. In fact, several oil stocks are now so cheap that an investor can buy the oil these companies control for less than $20 per barrel, and get all their natural gas reserves for free.

Using data from S&P Capital IQ, I've uncovered the 10 oil stocks that have the lowest enterprise value-to-proved oil reserves. That list is detailed in the slideshow below.

Matt DiLallo owns shares of ConocoPhillips and Denbury Resources. The Motley Fool owns shares of Denbury Resources. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.