Here is the paper from the Manhattan Institute.
"At present, break-even costs across U.S. shale fields range from $10 per barrel–$55 per barrel.50 Delivering North Dakota oil to Gulf Coast refineries and ports by rail can add another $15 per barrel. Using analytics to double output, thus cutting oil costs in half, means that shale break-even costs would drop to $5 per barrel–$25 per barrel. America’s shale fields would then be competitive in volume and in price with Saudi Arabia’s vaunted ultralow-cost oil fields."