"Petroleum geologists know where the oil is." As a research geologist in petroleum exploration for most of my professional career, I can tell you that there is little chance of a big oil play in the continental U. S. except for the oil shale formations (expensive); research still in progress on the most economic and effective means of extracting the oil. Whatever methods are used (and they will be multiple because the deposits are not uniform), it will be expensive.
Starting some 50 years ago, the Alberta Research Council, university partners, and oil company research groups worked in the laboratory and in field experiments on how to extract the bitumens locked in Alberta and Saskatchewan (and Dakotas) sediments. Many methods were proposed and tried, including in situ burning and flushing. It took a long time to pick the most viable means just for the sands. As it is, only the most accessible and rich oil sand deposits are being produced today. Engineering of equipment was a headache which is still being researched.
The United States Geological Survey and several research institutions in the states have carried out similar research.
No one seems to have any idea of the amount of research and engineering that has to go into making a new type of oil play viable. Then one must deal with the infrastructure, the people on the land and provide for reasonable environmental care.

There is talk of the offshore oil plays on the U. S. continental shelf. A few scattered test wells have hinted at possible commercial oil deposits, but all predictions are guesstimates. Much drilling from platforms, plus more than just run-of-the-mill amounts are needed to prove whether the reserves are accessible and exploitation is economic. The costs will be high.
Prudhoe Bay was an important field, but current production has dropped to 25% of peak production as the reserves are used up. It will not be viable much longer. Prospects are there on the Arctic Coast, but not proven of commercial size. Towards the Canadian shelf, thermal effects reduce the prospects of liquid oil. The cost to the environment may be great.

World demand and increasing costs of exploration insure that prices will remain high.
My personal opinion is that alternative sources of energy, most likely nuclear, and emission controls for coal-fired plants, should be selected, designed and built now to take care of industrial needs. We have large coal reserves, as does China.