I'm an environmental consultant and work in mergers and acquisitions as well as help oil/gas clients manager their environmental compliance. The US is sitting on MASSIVE reserves now. There's way more oil in the country than thought just 15 years ago. New at the time technologies like fracking and deep well exploration have found all that oil.
The primary oil production issue in this country is how our refineries are designed. Decades ago, US oil refiners designed their refineries to process cheap and dirty "sour" crude from overseas. Why? Primarily because the belief was the US was running out of oil and the sour crude was cheaper to buy/process. The majority of the reserves in the US are considered "sweet" crude. It would take a massive amount of capital and time to covert the refineries to process sweet crude. It will eventually have to happen (and should have), but you know.......profits.