Rob Port's SayAnythingBlog.com notes that 90% of the Bakken oil is untapped. 

He added:

Keep in mind that, just a few short years ago, there were “peak oil” theories which indicated that we would run out of oil. Back in the 1970′s and 1980′s, some were predicting that we would run out of oil in our lifetimes.

But, like the agriculture Malthusians before them, they were wrong. Because they didn’t take into account the ingenuity and inventiveness of mankind. We are constantly inventing new and better ways of doing things. That’s what fracking was for oil and gas production. A new and better way of tapping into our natural resources.

KFYR-TV has the story:

Hydraulic fracturing and horizontal drilling have opened the flood gates to extract oil from the Bakken. Yet companies are still only recovering six to eight percent of the oil in the ground.

So now the goal is to become more efficient and test new technologies that would allow the other 92 percent of the oil in the Bakken to be used.

This energy industry animation illustrates what happens 10,000 feet below the surface.