Check out the convenient table of the stocks highlighted in the article. Clearly, further research is needed to understand any of these well enough to invest. Each company has its own unique mix of oil & gas proven reserves and risks.
The article does highlight several as being attractively valued. Not surprisingly, the cheapest are some of the integrated (ie. those that search for, produce, and refine) oil businesses. Among the pure exploration companies Apache sells for the lowest multiple at 11.5x earnings.
Whether actually cheap or not obviously depends on assumptions on what happens to the price of oil going forward. I have no opinion.
The one stock that jumps out as being clearly expensive is Anadarko. I'm sure there is a good story here but with a 35 multiple seems an outlier among this group.
Have long positions in COP and CVX established at much lower than recent market prices