The Dhi Qar Oil Company (DQOC) on Saturday shut down the Nassiriya oil field as job-seekers crowded around the state-run company’s headquarters and its flagship asset — the latest instance of nationwide protests affecting Iraq’s oil sector . Industry and security officials said there were not enough security forces on hand at the field to handle protests staged by recent graduates and local residents who were seeking jobs. The demonstrations impeded shift changes, which caused the field to shut down.