The slow, but steady, gain in oil production expected from the U.S. waters of the Gulf of Mexico shows the region is more stable than shale, a rig analyst said.  The bulk of total U.S. oil production comes from inland shale basins. Total U.S. output is expected to reach 9.9 million barrels per day next year, the highest level ever if forecasts are accurate. The U.S. Energy Information Administration estimates about 20 percent of total U.S. oil production comes from the Gulf of Mexico.  Oilfield service company Baker Hughes reported 21 rigs in the Gulf of Mexico for the week ending July 7, unchanged from the previous week and up 16 percent from the same week in 2016. Energy price agency S&P Global Platts offered a more fluid picture for the week, but added the region as a whole was stable.