Not with current prices, the keystone wouldn't have been completed for years anyway.... Plus... And I learned this while working on safety devices for transporting oil by rail.... The oil in the Bakken field is really dirty and expensive to refine... Its not getting used for gasoline refinement in volume until oil prices are already high....does shutting down a domestic pipeline with an Executive Order may have anything to do with lowering supply (at least in terms of projections) as much as having to buy overseas? Policy does have effect on economics as much as the other way around, even more so recently.
That said... Imo, if this nation needs oil we should build pipelines to avoid moving oil by trains at ALL COSTS... extremely dangerous.