The U.S. shale-oil industry has made another enemy: Europe’s largest crude explorers. Standard & Poor’s Ratings Services revised its outlook to negative for Royal Dutch Shell Plc (RDSA) , Total SA (FP) and BP Plc (BP/) as the oil-market rout driven by weakening demand and a flood of supply from American shale fields threatens cash flow into 2016. The credit-rating company also cast a dim eye on Houston-based ConocoPhillips, saying it’s facing similar cash flow pressure, and said it may cut the ratings on Eni SpA (ENI) and BG Group Plc’s BG Energy Holdings. S&P cited “the dramatic deterioration in the oil price outlook” and the 50 percent increase in debt loads for the biggest European oil producers since the end of 2008. BP, down 7.3 percent in the past month in London , pared losses today with a 0.5 percent gain to 415.65 pence by 8:55 a.m. local […]