Oil engineers are using hydraulic fracturing to release oil from underground shale. This is the same method that gas well drillers have recently developed. This could yield as much as 2 million barrels of oil a day. That’s more than the output of the entire Gulf of Mexico. EOG Resources was the first company to use horizontal drilling to obtain shale oil. This info was obtained from AP Energy Writer, Jonathan Fahey, Feb. 10, 2011.