By Liz Hampton (Reuters) – Exxon Mobil issued a temporary “stand-down” across its U.S. shale operations last week following back-to-back worker injuries, including one fatality, according to people familiar with the matter. The incidents, one of which marked the second death this year of a contractor, comes at a turning point for oilfield service firms straining to hire workers to restart some operations. Job cuts two years ago related to the COVID-19 pandemic have led to a shortage of experienced oilfield employees. The stand-down follows two worker accidents within days at production sites r…