North Dakota has an effect on the production increase:
"Mar Oil 11,168,656 barrels = 360,279 barrels/day
Apr Oil 10,535,492 barrels = 351,183 barrels/day (preliminary) (all time high 360,279
Mar 2011)
Mar Gas 11,063,666 MCF = 356,892 MCF/day
Apr Gas 10,758,355 MCF = 358,611 MCF/day (preliminary) (all time high)
Mar Producing Wells = 5,439
Apr Producing Wells = 5,536 (all time high) "
https://www.dmr.nd.gov/oilgas/directorscut/directorscut-2011-06-20.pdfProduction is raised from 100ths to 350ths per day from 2005 to 2010. That can be explained by the raising oil prices which makes oil drilling more profitable.
https://www.dmr.nd.gov/oilgas/stats/DailyProdPrice.pdf