Exports of crude oil from the United States have surged since Russia invaded Ukraine last year, with Europe turning into the biggest buyer of U.S. crude. The story is pretty much the same as in gas. And so is the production side of this story. When gas prices plummeted in December amid milder-than-expected weather despite a couple of seasonal cold spells, U.S. gas companies began to curb production. Now, oil companies are doing the same, and it may have even bigger implications—because oil prices are still quite high and because,…