Received a 1099 misc for working interest in oil well. Do I enter this information on a Schedule C? Also all expenses deductible? Net profit is a loss.

Yes, Schedule C. Gross revenue is income. Gross production tax and LOE are expenses. Tangibles are equipment and get 7 year life for both regular tax and AMT. IDCs can be amortized, because excess IDCs (90% of your guy's IDC is almost certainly excess IDC) are an AMT adjustment, or they can be expensed, assuming your guy has never ever ever had any IDCs before. If your guy has ever had IDCs and not deducted them, he's made an irrevocable election to capitalize them into LHC forever. If your guy has never had IDCs, you should be careful to currently expense at least a dollar, to avoid having made the irrevocable election to capitalize them into LHC forever. If there was production, you should calculate cost depletion (1 percent of net LHC per month of production is a common rule of thumb, if you don't have reserve data), because with a loss, you won't get percentage depletion.

If the interest is owned through a liability-limiting entity, this activity doesn't qualify for the "all working interests are by definition active, not passive" rule. 

If you have no idea what I just said, please refer this client to someone who does a lot of oil & gas, because it's kind of a specialized thing.