From "Massive July Jump in Bakken Oil Production" 

North Dakota produced a record 9.7 billion cubic feet of natural gas per day in July, nearly a quarter of that was flared. Part of the problem was that Oneok (NYSE: OKS  ) ran into some mechanical problems at one of its natural gas processing plants. However, the overarching issue is that there still isn't enough processing capacity or pipelines to get the gas to market.