A pump jack operates at a well site leased by Devon Energy Production Company near Guthrie, Oklahoma September 15, 2015. Crude oil slid for a second session on Monday, down more than 1 percent from last week’s 2016 highs on concerns over a supply glut after the U.S rig count rose for the first time since December. U.S. energy firms last week added one oil rig after 12 weeks of cuts, according to data by industry firm Baker Hughes. The addition, coming after oil rigs had fallen by two-thirds over the past year to 2009 lows, showed the fall in crude drilling stabilizing after a 50-percent price rally since February. [RIG/U] U.S. crude CLc1 dropped 80 cents, or 2.03 percent, to $38.64 a barrel by 0747 GMT. The market on Friday climbed to $41.20 a barrel, its highest since early December, before losing ground to settle down nearly 2 […]