DENVER and HOUSTON, July 25, 2014 /PRNewswire/ -- Oil production from shale formations in North Dakota and Texas increased by more than 33% in June, according to Bentek Energy, an analytics and forecasting unit of Platts, a leading global provider of energy, petrochemicals, metals and agriculture information. The production increase is most likely attributable to the rise in returns producers are realizing in these basins, according to Jack Weixel, Bentek Energy director of energy analysis. "Bentek estimates that internal rates of return on drilling and carrying costs exceed 65% in the Eagle Ford and 50% in the Bakken*," Weixel said. "To the average producer that means for every $1 million they sink into drilling a well, they can expect to recover at least $1.5 million in crude oil, liquids and natural gas over the course of a year." Crude oil production in the North Dakota section of the Bakken shale formation of the Williston Basin averaged 1.1 million barrels per day (b/d) in June, according to Bentek. This is up 28.9% from the monthly average seen in June 2013. In another of the nation's predominant oil shale plays, the Eagle Ford in Texas, production averaged 1.4 million b/d last month, a 37.6% increase from June 2013, Bentek data showed. "Prices of Bakken shale oil have been largely range-bound this year, while prices of Eagle Ford shale oil have been on an upward trajectory since the beginning of 2014," said Richard Capuchino, Platts managing editor of Americas crude. The Platts Eagle Ford Marker, a daily price assessment launched in October 2012and reflecting the value of oil out of the Eagle Ford Shale formation in South Texas, is up 7.5% since January 1, with an average price year to date of $104.43 per barrel (/b). The marker has fluctuated between $98.29/b and $110.71/b year to date. The price of oil out of the Bakken formation at Williston, North Dakota, has ranged between $89.46/b and $96.59/b since January, according to the Platts Bakken assessment. It reached a high of $96.59/b in mid-June before leveling off and trading closer to the $92.78/b average for the year. The Platts Bakken, introduced earlier this year , is a daily assessment of price for oil closest to the wellhead prior to determination of transportation by rail or pipe. The assessment reflects a sulfur content of 0.2% or less and an American Petroleum Institute (API)** gravity of 42 or less, similar to the nature of North Dakota Light Sweet crude. The Platts Eagle Ford Marker reflects the value of a median 47-API Eagle Ford crude barrel, based on the crude's product yields and Platts product price assessments, adjusted for U.S. Gulf Coast logistics. Platts introduced the world's first independent daily price reference valuing crude oil produced from a shale formation in May 2010 when it began assessing Bakken Blend shale oil injected into pipelines at Clearbrook, Minnesota, and Guernsey, Wyoming. Platts began publishing its Platts Bakken assessment on April 22. For more information on Platts price assessments methodology visit these links: Details of Platts Bakken and Platts Eagle Ford Marker. Bentek Energy's shale oil production figures are derived from proprietary data models using publicly available data. For more information on data models, reports or Bentek's methodology, please contact email@example.com. Platts will publish monthly updates via press release on Bakken and Eagle Ford shale oil production and price data.