While the true number of recoverable barrels under the Eagle Ford is unknown, the U.S. Geological Survey estimates the field holds between 7 billion to 10 billion barrels of oil. If these figures are accurate, the field would be the largest on-shore oil reserve ever discovered in the continental U.S.2) The Eagle Ford is the fastest growing play in the world. Keep in mind that when PetroHawk-now owned by BHP Billiton Limited (ADR) (NYSE:BHP) - drilled its first well in the Eagle Ford back in 2008, production was only 358 bpd. During that same year, the Texas Railroad Commission issued 26 well drilling permits. By 2012, the commission issued 4,141 permits representing a 160 fold increase within four years. In May, Eagle Ford output hit a record 580,000 bpd-up 58% year-over-year. According to estimates by Bentek Energy, that figure could hit 1.6 million bpd by 2016. 3) The Eagle Ford is producing some of the most valuable crude in the world There're two reasons why Eagle Ford crude is particularly prized buy refiners. First, it's exceptionally light and sweet making it cheap to refine. Second, the field is located just 100 miles from major refining hubs in Houston and Corpus Christi making it especially inexpensive to transport. And unlike other formations, investors shouldn't have to worry about pipeline capacity issues popping up in the future. Platts estimates that new capacity from pipeline construction will outpace upstream production growth over the next four years. This is definitely not the case in other plays like the Bakken or Marcellus. 4) Drilling costs in the Eagle Ford are falling rapidly. While production growth steals all the headlines, the more important development is the falling cost of doing business in the Eagle Ford. At EOG Resources, average well costs have fallen to $5.8 million per completed well in 2013 -- a big difference from the $9.1 million spent per well in 2009. Management thinks it can shave another $300,000 from the figure by year-end. Last month, Forest Oil Corporation (NYSE:FST) reported average well completion costs fell 14% year-over-year to $6 million during the quarter. This adds up to substantial savings for investors. For Forest Oil, who expects to completed 30 this year, could save a pretty substantial $30 million. Given that the company had a $470 million funding gap last year, every bit of saving count. What's driving this trend? Much of these cost savings can be attributed to improved drilling techniques, the falling price for hydraulic fracturing services, and experience operating in the play.