Well, there are some misconceptions and misstatements in that commentary on the Bakken to set straight. Here goes...
We have been drilling the Bakken for roughly 50 years, usually on the way to another producing formation (a layer of rock which can be mapped) deeper within the Williston Basin (a geological basin which covers parts of North Dakota, Montana, Saskatchewan, and smaller parts of Alberta, South Dakota, and Manitoba).
There are over a dozen different rock formations (mappable layers) which may produce oil in the Williston Basin, among dozens more formations which do not produce oil, forming a stratagraphic stack (think pancakes in a bowl) some 15,000 feet thick at the deepest part of the Basin.
The Bakken Formation is one of the layers about two thirds of the way down from the top of that stack, and it is a smaller 'pancake', in that it is only found in the subsurface, it does not outcrop along the edges.
The oil which formed from the organics trapped in the crust of that pancake, the shales, is now mostly in the porous layer in the middle, or has escaped along faults or fractures to other rock layers.
Since the 1980s, the ability to drill horizontal wells has become refined to the point where the Middle portion of the Bakken Formation (the porous layer) can be more widely economically produced using this technology. An increase in prices makes this economically feasible while the technology makes it technically possible.
In a few areas the Bakken already had produced oil from vertical wellbores, but it is a formation which is difficult to test in open hole (before running casing), and few would gamble on the expense to run pipe through it in a vertical well unless they were anticipating producing enough oil from a deeper formation to make a profit on the well. Often, the Bakken would not be produced as the deeper zones took precedence and the oils from formations of different geological ages are not comingled during production as a matter of practice (and by law).
With horizontal drilling, though, instead of producing from a few feet of wellbore running vertically through the formation, you can put a few thousand feet of wellbore through the zone horizontally, which allows for far more rapid and efficient recovery of the oil there, often the deciding factor in whether a well will pay for itself (not just how much oil you can get out of the well, but how fast you can get it).
No oil company ever gives up on finding a big play, not unless the auction was yesterday...
'Big oil', (the major companies whose reach is international in scope), commonly looks for very large plays where very large investments have very large returns.
If they can find fields which will produce on the order of tens to hundreds of thousands of barrels of oil per day, it is much more cost-effective than hundreds of small fields which produce a few hundred to a few thousand barrels of oil per day, and that also justifies the sort of infrastructure investments which convert that crude, ultimately, to fuel and so much more.
Enter an alien concept to the American press: 'Small' oil. The 'little' oil companies out there looking for wells and fields which will make the sort of R.O.I. which will give them an opportunity to grow, and whose size makes such smaller plays a winner.
These are the companies often on the cutting edge, quietly investigating new ideas and rolling profits back into investment in acreage (leases) and more drilling to capture a larger share of their new finds as they grow before the word gets out, and they are always looking for new finds.
In the meantime, new technologies are often developed by service companies working with the 'Big' oil companies on major projects (often offshore) where the expense can be justified because of the scale of the returns if the effort is successful.
However, the real Bakken development (ongoing) did not take place at 16 dollars a barrel, it really did not get rolling until after oil hit $30-40, and then took off when oil got past $80. Keep in mind, too, that rig costs have gone up, as have fuel prices, and prices for services as well, so I'd say the sixteen dollar figure is off by a factor of 4 or more.
Keep in mind the Bakken oil is not 'shale oil', even though there is at least one shale layer associated with (probably the source of) the oil, but oil found in a tight conventional porus rock reservoir layer in the Bakken Formation.
Oil Shale, like the Mahogany Beds of the Green River Formation (CO, UT, WY) is another thing, and the extraction of that oil is more subject to environmentalists' objections because it is not so readily extracted from the relatively impermeable shale as is oil in conventional porous reservoirs, and most of the area is under Federal Land.
Work was done on the oil shales back in the last 'oil boom' in the late '70s and early '80s, and it is fairly safe to say that even with a green light from all concerned it would cost more than $16/bbl to extract as well, otherwise the Unocal project at Parachute, CO might have remained viable.
No arguments from me with the concept that we need to develop our own resources, but short of a deflationaly cycle, it will not be as cheap as it was, though changes in policy can help make it cheaper.
Even at a few dollars more, we are not funding our enemies while shelling out the expense in money, personnel, and materiel to maintain some semblance of order in a region halfway around the globe. Which is not to say we should not seek to stop terrorism, but that our dependence on foreign energy sources means we also pay an additional hidden premium on 'cheaper' foreign oil in tax dollars for their national security as part of our own.