Once again, not quite right. Fracking techniques and drilling rigs have greatly improved. Fracking is cheaper and more productive. In petroleum basin geology you have to understand the stratigraphy. Where the rock strata are layered as cyclothems, meaning repeating depositional cycles, the top strata are generally exploited first. In the case of the Williston basin the Bakken formation is the topmost shale stratum and it isn't close to depleted. Below that are several more, likely identical. This basin will produce for the rest of this century at least. There are similar basins in Russia, Europe, and elsewhere. The current glut will continue.

Once again, you are wrong. There is no depletion, simply a slowing of new drilling because the glut has depressed prices. This is also true of "gas fields". Natural gas is dirt cheap. Until the US can get its LNG terminals up and running for export, there is little incentive to drill. The petroleum is there, the profit aren't.