It depends how much money you have sitting in cash right now.
I'm holding off for a little while longer. Most of the companies that hold lots of assets in the shale plays have a lot of debt. They will find themselves in financial trouble quickly as they have to pay back debt. The property that many of them hold contains a of oil, but it is really only profitable to drill at or above around $75 a bbl.
Long story short we will not be out of the woods until prices start to come back up. They are being held down artificially now. All of the gas producing countries dislike it. I'm expecting a hard bounce within a couple months. When the oil prices bounces back so will most of the stock prices, but there are a handful of companies that could go belly up.
Look for oil companies that do not have a lot of debt.
When... Keep an eye on it.
It may be soon.