How do you spell that? precious performing loan broke Unlike in the U.S., development of potential shale resources in the U.K. has proceeded at a snail's pace. There has been no commercial shale-gas production, only a handful of exploration wells have been drilled and only one well has been fracked. As a result there is as yet no reliable estimate of how much of the U.K.'s potential shale resources can be produced at a profit.