When it comes to fossil fuels, there's no such thing as 'energy independence' because fossil fuels are traded on a global market. In addition, not all oil is the same. So you have to trade it because what you can extract may not be what is useful to you, but useful to someone else.

In short, the US cannot functionally be independent on fossil fuels even if we extracted every drop of oil within our borders--because we literally cannot use all of it, and most of it would be wasted just sitting around.